Title of Invention	A PREPAID WATT-HOUR METER SYSTEM
Abstract	The invention relates to a prepaid watthour meter system, said system comprising a power-selling computer(1) for selling power to a user by a database managing window thereon, and transmitting user power-purchasing data to a concentrator through an up channel a concentrator (3), provided at low voltage side of user end transformer, for receiving the user power-purchasing data from the power-selling computer, and forwarding the received user power-purchasing data to a user watthour meter by power line carrier through a down channel; and at least one user watthour meter, said user watthour meter comprising a user watthour meter carrier module (4), and said user watthour meter carrier module comprising a power-purchasing data storage section, said user watthour meter carrier module receiving the user power-purchasing data forwarded by the concentrator, and storing the power-purchasing data to the power-purchasing data storage section in a specified format; the user watthour meter carrier module is further configured to: send back received power-purchasing data as acknowledgement information to the concentrator by power line carrier, after storing the power-purchasing data to the power-purchasing data storage section; and the concentrator is further configured to: upon receipt of the user power-purchasing data as acknowledgement information, send back the user power-purchasing data as acknowledgement information to the power-selling computer through the up channel, so as to verify that data is correctly transmitted.

Title of Invention

A PREPAID WATT-HOUR METER SYSTEM

Abstract

The invention relates to a prepaid watthour meter system, said system comprising a power-selling computer(1) for selling power to a user by a database managing window thereon, and transmitting user power-purchasing data to a concentrator through an up channel a concentrator (3), provided at low voltage side of user end transformer, for receiving the user power-purchasing data from the power-selling computer, and forwarding the received user power-purchasing data to a user watthour meter by power line carrier through a down channel; and at least one user watthour meter, said user watthour meter comprising a user watthour meter carrier module (4), and said user watthour meter carrier module comprising a power-purchasing data storage section, said user watthour meter carrier module receiving the user power-purchasing data forwarded by the concentrator, and storing the power-purchasing data to the power-purchasing data storage section in a specified format; the user watthour meter carrier module is further configured to: send back received power-purchasing data as acknowledgement information to the concentrator by power line carrier, after storing the power-purchasing data to the power-purchasing data storage section; and the concentrator is further configured to: upon receipt of the user power-purchasing data as acknowledgement information, send back the user power-purchasing data as acknowledgement information to the power-selling computer through the up channel, so as to verify that data is correctly transmitted.

Full Text	Carrier Type Data Security Protection Method And Reading System For Prepaid Watthour Meter Technical Field The present invention relates to electric power measuring, control and charging management, and more particularly, to a distributed control management system, which implements concentrated watthour meter-reading and charging using power lines carrier as information channel, and achieves prepaid function on each user watthour meter, so as to protect the security on data information and make it avoid malicious attack from outside. Background Art With regard to measuring and charging of electric power, at present, it is common that a dedicated watthour meter-reading person periodically door-to-door reads watthour meters mounted at each user's power supply entry, then, the user pays for the consumed electric power at a charging office. This not only takes both time and efforts, but also may make mistakes due to various reasons. As the lacking of effective measures to urge the collection of electric: power charge, the users in debt for electric power charge are increasing for many power supply enterprises or house-keeping companies. The power supply enterprises or house-keeping companies are forced to even cut off the power supply in order to urge the user to pay for the electric power charge, which directly disturbs people's life and social security. To address the problem in collecting electric power charge for watthour meter, Chinese Patent ZL 01261220.0 "Single phase IC card watthour meter" and Chinese Patent ZL 02223241.9 "digital type prepaid watthour meter" proposed a solution on watthour meter aiming to not only solve the problem of collecting electric power charge, but also improve on security. Both the solutions of the two patents encrypt user power-purchasing information through a single chip processor in the IC card or the keyboard, and then read them through a single chip processor mounted in the watthour meter, so as to achieve the object of improving the security on user's power-purchasing information. Because there is still a data entry window to the user, such as IC card or keyboard in the two solutions, it only improves security to some extent, but fails to essentially avoid malicious attack from outside. In addition, there is no information feedback channel which enables the watthour meter-reacing and power-selling computer to check the user watthour meter-reading and the power-purchasing data from time to time. Thus, there is a big security loophole in user power-purchasing charging data information and user watthour meter-reading data information. Summary of the Invention An object of the prevent invention is to provide a technology for electric power watthour meter-reading and charging and control management, and a data security protection method, which not only can solve the problem of the charging for automatic remote electric power watthour meter-reading, but also can protect the data information security of the charging for power-purchasing, so as to essentially avcid the attack from outside. Another object of the prevent invention is to provide a watthour meter-reading system for the charging of electric power watthoir meter-reading and distribution control management. The method proposed by the present invention is that: providing a database for watthour meter-reading, controlling and charge managing in a watthour meter-reading and power-selling computer; providirg a carrier watthour meter-reading concentrator at low voltage side of a user end transformer; providing a carrier module integrated with the user watthour meter at the user entry of the power lines, and said carrier module comprising a power-purchasing data storage circuit. The process for user power-purchasing charging management and control is as follows: a. when the user purchases electric power, an operator logs into a selling management window in the watthour meter-reading and power-selling computer after authenticating password, collects money for the user and prints receipt; b. the power-purchasing data information is sent to the carrier watthour meter-reading concentrator by the watthour meter-reading and power-selling computer through the up channel, and upon receipt of the user power-purchasing data by the watthour meter-reading concentrator, the watthour meter-reading concentrator forwards the data to the user watthour meter by carrier through the power lines; c. after the user watthour meter carrier module receives this power-purchasing data information, a single chip computer within the user watthour meter carrier module makes a judgment immediately, then stores the power-purchasing data to a power-purchasing date storage circuit in a specified format, and in the meantime, sends back the acknowledgement information on receipt of the power-purchasing data to the watthour meter-reading concentrator by carrier through the power lines; the watthour meter-reading concentrator then sends the acknowledgement information back to the watthour meter-reading ard power-selling computer through the up channel; d. each user wattliour meter carrier module collects the increment information on user's electric power consumption in real time, and compares it with the power-purchasing data every time the consumption adds by lKWh, and calculates balance; when the balance of the power-purchasing data is reduced to below the setting value, the carrier module produces an acousto/optic alarm, and prompts the balance of the power-purchasing data; e. when the balance of the power-purchasing data is reduced to zero, the carrier module operates the relay to cut the power off; f. the above process is repeat when the user pays money to purchase power a gain, and when the user watthour meter carrier module detects that the balance of the power-purchasing data is more than zero, it operates the relay to turn the power on. When the user watthour meter carrier module receives the user power-purchasing data, the user watthour meter carrier module sends back the user power-purchasing data to the watthour meter-reading and power-selling computer for acknowledgement, in addition to performing at least one of code verification, parity verification and frame data sum verification. Since the power-purchasing data transmitted to the user watthour meter carrier module by the watthour meter-reading and power-selling computer is the total amount of the ever-purchased power, the value stored in the power-purchasing data storage circuit in the carrier module should be consistent with the value sent by the watthour meter-reading and power-selling computer. After the watthour meter-reading and power-selling computer has sent the user power-purchasing data, if no returned information is received or the returned data received is inconsistent with the transmitted value, this communication is deemed as failure, and then automatic re-transmission is performed. If there is still failure with repeated re-transmissions for many times, it indicates that the communication channel cannot be used temporarily, and this transmitted value is then stored temporarily in the hard disk of the computer, the operator may transmit again after one or two hours until transmission succeeds. In general, the user power-purchasing data information can be sent successfully within 24 hours through the carrier communication channel in the case of the power supply line ON, which guarantees that the user power-purchasing data may not be left unsent or wrongly sent. The watthour meter-reading system for watthour meter-reading, charging and distribution control management includes: a database created for watthour meter-reading, controlling and charge managing in a watthour meter-ieading and power-selling computer; a carrier watthour meter-reading concentrator provided at low voltage side of user end transformer; a carrier module for data collecting, carrier communication and controlling output provided at respective user watthour meter; the carrier module for user watthour meter including a power-purchasing data storage circuit which is comprised of a nonvolatile RAM (EEPROM, FRAM) device, and mounted together with the user watthour meter; the watthour meter-reading and power-selling computer being coupled to an up channel by a modem, the up channel being comprised of a public telephone network; the watthour meter-reading concentrator is coupled to the up channel by a modem, the up channel being comprised of the public telephone network or the like, and on the other hand, the watthour meter-reading concentrator being ronnected to the down channel comprised of the low voltage power supply line through carrier communication modules; the user watthour meter carrier module connected at one end to the down channel comprised of the low voltage power supply line through coupling capacitors, and connected at the other end to e pulse output terminal for user watthour meter, where a control relay receives ON/OFF control signal from a single chip computer, and a power output contact is connected in serial to output terminal for the pnase line of the watthour meter. The up channel may be a mobile communication network, or a specific communication network which is composed of fiber, microwave, data transmission station, coaxial cable or twisted-pair or the like. The method and system according to the present invention have the following advantage, as compared with the prior art: 1. The prepaid watthour meter can prevent the user from being in debt for the charge, control the carrier type watthour meter's bad analysis on a household basis, and monitor the running state in real time. The two major problems of difficulties in watthour meter-reading and payment charging can be solved. 2. The information on the user power-purchasing data is transmitted by full-sealed and secure power lines carrier channel, which eliminates the open window for IC card type prepaid watthour meter and protects security of power-purchasing information, and avoids it from any malicious attacks. 3. The information on the user power-purchasing data is stored in the watthour meter, the watthour meter-reading concentrator, and the watthour meter-reading and power-selling computer simultaneously, and the user power-purchasing data can be restored 100 percent when any one of the devices is corrupted, which avoids user's disputes that occurs frequently on IC cards type prepaid watthour meter, and can collect evidences when needed. 4. When the power price and other power-consumption polices need to be adjusted, they can be regulated correspondingly by the watthour meter-reading computer according to new power price polices (such as peak to valley power price, bottommost power price) and so on. It can response quickly and securely, without causing the problems of social security. 5. When using IC card type prepaid watthour meter, the pcwer management department is unable to know the actual power-consumption amount, thus unable to work out the power charge taken back from the users for the present month. If large "line-loss" rate due to abnormal power-using (such as power-stealing, power-leaking) appears, it may lead to a long term accumulation for a huge amount of "line-loss" power charge. Since the method according to the present invention can calculates accurately "line-loss" for the present month in time, so it can find the problems in time and take measures against a huge amount of irremediable losses. 6. The method according to the present invent not only solves :he problem of difficulty in charging in term of the known "the power lines carrier watthour meter", but also stops the information security loopholes of being vulnerable to be attacked and power-stealing from the known " IC card type prepaid watthour meter". This will put the distribution, use, measurement and charging of electric power uncer computer monitor and control, allow the power supply enterprises or the house-keeping company to get rid of the heavy burden on the user's long term money-owing and a huge amount of money-owing, and this provides effective technical means for the electric power system to take back a large amount of investments. The cost for carrying out the present invention is almost equals to the "the power lines carrier watthour meter", "the IC card type prepaid watthour meter" of prior art. The performance and function double, but the price keeps unchanged. Thus, its performance/cost ratio is high, using risk is low and comprehensive benefit is good. The method and system according to the present invent economizes the manpower and resources. One person which sits at office may know the power-using and the electric power charging of each user in a entire working unit or residential area, thereby prevents the action of the power-stealing and protects the legal right of the power supply enterprises. The present invention can be widely used to work units or residential areas, It has good comprehensive benefits on the society and economy, Brief Description of the Accompanying Drawings Fig. 1 is a schematic diagram of method and schematic structure diagram of system according to the present invention; Fig. 2 is a schematic structure diagram of a watthour meter-reading concentrator in Fig. 1; Fig. 3 is a schematic structure diagram of a carrier module in Fig 1; Fig. 4 is a schematic circuit diagram of a signal coupling circui:, a signal receiving c rcuit and a signal transmitting circuit in the carrier module in Fig. 3; Fig. 5 is a schematic circuit diagram of a carrier signal demodulation circuit in Fig. 3; Fig. 6 is a schematic diagram of the pulse input circuit between a data storage circuit and a single chip computer system, and a sample measuring module and the single chip computer system in Fig. 3; Fig. 7 is a schematic diagram of the data storage circuit comprised of a ferroelectric memory; Fig. 8 is a schematic diagram of the data storage circuit comprised of serial communication interface of the single chip computer system and a ferroelectric memory; Fig. 9 is a schematic diagram of the data storage circuit comprised of the I2C bus interface of the single chip computer system and a ferroelectric memory; Fig. 10 is a schematic diagram of an alarm state display circuit and a latch buffer control circuit; Fig. 11 is a schematic diagram of a carrier signal modulation circuit; Fig. 12 is a schematic diagram of the carrier signal modulation- demodulation circuit according to another embodiment; Fig. 13 is a schematic diagram of the carrier signal modulation- demodulation circuit according to one embodiment; Fig. 14 is a schematic diagram of the carrier signal modulation- demodulation circuit according to further embodiment. Mode Detailed Description of the Embodiments The embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to Fig. 1, the watthour meter-reading system is constituted in follcwing manners: a. creates a database for watthour meter-reading, controlling and charge managing in a watthour meter-reading and power-selling computer 1; b. provides a carrier watthour meter-reading concentrator 3 at low voltage side of user end transformer; c. provides a carrier moduls 4 for data collecting, carrier communication and controlling output at respective user watthour metter; d. the carrier module 4 for user watthour meter includes a power-purchasing; data storage circuit which is comprised cf a nonvolatile RAM (EEPROM, FRAM) device, and is mounted together with the user watthour meter; e. the watthour meter-reading and power-selling computer 1 is coupled to a public telephone network by a modem, which public telephone network may be a mobile communication network, or coupled to a up channel comprised of a specific communication network, which specific communication network uses fiber, microwave, data transmission station, coaxial cable or twisted-pair or the like; f. the watthour meter-reading concentrator 3 is coupled to the up channel 2 by a modem when the up channel 2 is comprised of the public telephone network, and on the other hand, the watthour meter-reading concentrator 3 is connected to the down channel 6 comprised of the low voltage power supply line through three carrier communication modules 11; g. the user watthour meter carrier module is connected at one end to the down channel 6 comprised of the low voltage power supply line through coupling capacitors, and is connected at the other end tc a pulse output terminal for user watthour meter 5, where a control relay receives ON/OFF control signal from a single chip computer, and a power output contact is connected in serial to output terminal for the phase line of the watthour meter. The process for user power-purchasing charging management and control is as follows: a. when the user purchases electric power, an operator logs into a selling management window in the watthour meter-reading and power-selling computer 1 after authenticating password, collects money for the user and prints receipt; b. the power-purchasing data information is sent to the carrier watthour meter-reading concentrator 3 by the watthour meter-reading and power-selling coriputer 1 through the up channel 2, and upon receipt of the user power-purchasing data by the watthour meter-reading concentrator 3, the watthour meter-reading concentrator 3 forwards the data to the user watthour meter 5 by carrier through the power lines 6; c. after the user watthour meter carrier module 4 receives this power-purchasing data information, a single chip computer within the user watthour meter carrier module 4 makes a judgment immediately, then stores the power-purchasing data to a power-purchasing date storage circuit in a specified format, and in the meantime, sends back the acknowledgement information on receipt of the power-purchasing data to the watthour meter-reading concentrator 3 by carrier through the power lines 6; the watthour meter-reading concentrator 3 then sends the acknowledgement information back to the watthour meter-reading and power-selling computer 1 through the up channel 2; d. each user watthour meter carrier module 4 collects the increment information on user's electric power consumption in real time, and compares it with the power-purchasing data every time the consumption adds by 1K Wh, and calculates balance; when the balance of the power-purchasing data is reduced to below the setting value, the carrier module 4 produces an acousto/optic alarm, and prompts the balance of the power-purchasing data; e. when the balance of the power-purchasing data is reduced to zero, the carrier module 4 operates the relay to cut the power off; f. the above process is repeat when the user pays money to purchase power again, and when the user watthour meter carrier module detects that the balance of the power-purchasing data is more than zero, it operates the relay to turn the power on. After the watthour meter-reading and power-selling computer 1 sends the user power-purchasing data, if the returned information is not received or the returned data received is inconsistent with the transmitted value, this communication is deemed as failure and then automatic re-transmission is performed. If there is still failure with repeated re-transmissions for many times, it indicates that the communication channel cannot be used temporarily, and this transmitted value is then stored temporarily in the hard disk of the watthour meter-reading and power-selling computer 1, the operator will transmit again after one or two hours until transmission succeeds. Fig. 2 shows a schematic structure diagram of the carrier watthour meter-reading concentrator 3 according to one embodiment of he invention. In the carrier watthour meter-reading concentrator 3, a power module 7 provides required power to the concentrator 3. Information such as settings, watthour meter-reading commands or user power-purchasing data etc. from the watthour meter-reading database in the watthour meter- reading and power-selling computer 1 is transmitted to a modem 8 by the telephone line 12, and the modem 8 then performs demodulation and transmits the demodulated above information to an operation control circuit 9 via the RS-232 interface. The operation control circuit 9 serves to transmit the user power-purchasing data or the watthour meter-reading data, which is transmitted from the watthour meter-reading database or carrier communication modules 11, to a data storage circuit 10. The data storage circuit 10 is composed of a nonvolatile RAM (EEPROM, FRAM) device, which will not lose any data information even if power-off or the like occurs. Three carrier communication modules 11 are coupled to triphase power lines A, B, C through capacitois, respectively. The carrier communication modules 11 serves to transmit the watthour meter-reading control command or the user power-purchasing data to the user watthour meter carrier module 4, on the other hand, the carrier communication modules 11 also serves to receive the reading data or the watthour meter-reading data acknowledgement information transmitted from the carrier module 4, and then forwards it to the operation control circuit 9. After the operation control circuit 9 receives the watthour meter-reading control command, the operation control circuit 9 transmits the watthour meter-reading cata stored in the data storage circuit 10 to the modem 8 via the RS-232 interface, or the operation control circuit 9 may transmits the user power-purchasing data stored in the data storage circuit 10 to the modern 8 via the RS-232 interface. The modem 8 forwards the modulated watthour meter-reading data or the power-purchasing data to the watthour meter-reading and power-selling computer 1 through the up channel 12 composed of for example telephone line. The operation control circuit 9 may comprises a single chip computer which is used as main component, and above-mentioned data operation process and communication cortrol program are resided in the program storage of the single chip computer. Each of three carrier communication modules 11 is also composed of a single chip computer as main component together with specially designed carrier communication specific integrated circuit or modulation-demodulation integrated circuit. The modem 8 may be modified from a finished product MODEM, or composed of the specially designed MODEM chip. Fig. 3 shows a schematic structure diagram of the carrier module 4 for user watthour meter according to one embodiment of the invention. L, N denote a phase line and a zero line of the power lines respectively, reference number 13 denotes a carrier signal coupling circuit, reference number 14 denotes a carrier signal receiving circuit, reference number 15 denotes a carrier signal demodulation circuit, reference number 16 denotes a single chip computer system, reference number 17 denotes a watthour meter pulse input circuit, reference number 18 denotes an operation alarming state display circuit, reference number 19 denotes a latch buffer control circuit, reference number 20 denotes a data storage circuit, reference number 21 denotes a carrier signal modulation circuit, 22 denotes a carrier signal transmission circuit. The carrier signal on the power lines L, N is entered into the signal receiving circuit 14 through the coupling circuit 13. The carrier signal is pre-processed by the signal receiving circuit 14, and the pre-processed signal is entered nto the carrier signal demodulation circuit 15. The pre-processed signal is demodulated by the carrier signal demodulat; on circuit 15, and the demodulated digital signal are sent to the single chip computer system 16 to perform the identification operational process. If it is identified that the information is power-purchasing data information transmitted from the main station, then the power-purchasing data information is stared in the data storage circuit 20, and the acknowledgement data information to be returned is transmitted to tie carrier signal modulation circuit 21. The acknowledgement data information is transmitted to the carrier signal transmission circuit 22 after it is modulated according to frequency spreading or FSK by the carrier signal modulation circuit 21, then, is transmitted to the power lines L, N by the carrier signal coupling circuit 13. If it is identifiec that the information is watthour meter-reading command transmitted from the concentrator 3, the user power-purchasing data or the watthour meter-reading data in real time that is stored in the data storage circuit 20 is packaged, and is transmitted to the power lines L, N according to the above mentioned path and procedure likewise. If it is identified that the information is ON/OFF control command transmitted from the concentrator, corresponding operation action is output to control relay KJ via the latch buffer control circuit 19. The real-time measuring pulse MC from the watthour meter 5 is entered into the single chip computer system 16 to perform counting and operation by the watthour meter pulse input circuit 17, and the operation result is stored in the data storage circuit 20. Every time the operation result is added by lKWh, the single chip computer system 16 compares a power counting value with the user power-pu -chasing data in the data storage circuit 20 to calcu ate the balance for the user power-purchasing data. If the balance for the user power-purch ising data reaches zero, a power-off command is output to the latch buffer control circuit 19, and in the meantime a power-off state dir.play signal is output to the operation alarming state display circuit 18. If the balance for the user power-purchasing date is smaller than a setting value (for example, l0Kwh) and larger than zero, an acousto-optic a arming signal is output from the operation alarming state display circuit 18. If the balance for the user power-purchasing data is larger than or equal to the setting value (for example, 10Kwh), the original operation status is maintained. The processing program for the above-mentioned communication operation control and the like are all resided in program memory of the single chip computer system 16. The single chip computer system 16 can also be comprised of a digital signal processor DSP. The data storage circuit 20 can be comprised of EEPROM or ferroelectric memory FRAM. Fig. 4 shows a schematic circuit ciagram of the signal coupling circuit 13, the sgnal receiving circuit 14, and the signal transmitting circuit 22 in the user watthour meter carrier module 4 according to one embodiment of the invention. The carrier signal input by the power ines L, N enters into a impedance converter T and D1 through the coupling capacitor C1, then is coupled to IN through a resistor R1, capacitors C3 and C2, an induciance L1, diodes D2 and D3. The output signal entered through OUT is amplified by a power amplifier comprised of triodes Q1, Q2, Q3 and Q4, capacitors C5 and C6, resistors R2 and R3, and diodes D4, D5, D6 and D7, then coupled to the impedance converter T through a inductance L2 and a capacitor C4, and then is coupled, through capacitor C1, to the power lines L, N for output. Fig. 5 shows a schematic circuit diagram of the FSK carrier signal demodulation circuit 15 according to one embodiment of the invention. The signal from the signal receiving circuit 14 enters through IN, and the entered signal is subject to frequency mixing, frequency discrimination and demodulation by U1 (MC3361), capacitors C11, C12, C13, C14, C15, C16, C17 and C18, resistors R9 and R10, CR1, CR2, BF1 and U2 (LM258), capacito-s C7, C8, C9 and C10, resistors R4, R5, R6, R7, R8, R11, then input into the single chip computer system 16 through IN1 and P1.x. Fig. 6 shows a schematic diagram of the pulse input circuits between the data storage circuit 20 and the single chip computer system 16, and between the sample measuring module 17 and the single chip computer system 16 according to one embodiment of the invention. The single chip computer system 16 may be comprised of MCS-51 series or PIC series, or also any type of single chip computer, together with crystal X1 and capacitors C19 and C20. The pulse input, circuit between the sample measuring module 17 and the single chip computer system 16 is comprised of photoelectric coupler U3 and a resistor R12, and the measuring pulse s input through CFO and CF1. The data storage ciruit 20 is comprised of the U4 (X25045) and a resistor R13. Fig. 7 shows a schematic diagram of the data storage circuit 20 comprised of ferroelectric memory U5 (FM25040) and a resistor R14 according to another embodiment of the invention. Fig. 8 shows a schematic diagram of the data storage circuit 20 comprised of ser al communication interfaces RXD and TXD of the single chip computer system and ferroelectric memory U6 (FM25040) according to further embodiment of the invention. Fig. 9 shows a schematic diagram of the data storage circuit 20 comprised of I2C bus interface of the single chip computer system, ferroelectric memory U7 (FM24C04) and resistors R15, R16 according to further embodiment of the invention. Fig. 10 shows a schematic circuit diagram of the operation alarming state display circuit 18 and the latch buffer control circuit 19 accord ng to one embodiment of the invention. The control signal output by P3.x. is decoded and latched through U8 (BH3024) and resistors R20, R21 and R22, and then drives the relay KJ to work. Resistors R17, R18, R19 and a light emitting diode D8 constitute a three state (light, flickering, dark) display 18. Fig. 11 shows a schematic diagram of the FSK carrier signal modulation circuit 21 which is comprised of two 4001s, capacitors C23, C24, C25 and C26, resistors R23, R24 and R25 and R26, CR3 and CR4, and one 4013 according to one embodiment of the invention. The modulated signal is amplified by a triode Q5, a resistor R27 and a capacitor C27, then output through OUT. Fig. 12 shows a schematic diagram of the carrier signal demodulation circuit 15 and the carrier signal modulation circuit 21 according to another embodiment of the invention. The carrier signal which is input by the signal coupling circuit via IN is subject to frequency-mixing by U1 (MC3361), resistors R28 and R32, capaci:ors C29 and C31, and BF1, then, is coupled to a triode Q6, resistors F29, R30 and R31 thrcugh a capacitor C28 to be high-frequency amplif. ed. The amplified signal is then coupled into specific frequency spreading communication integrated circuit U12 (PL2000A) to be demodulated, and the demodulated digital signal is sent to single chip computer MCU to perform identification operational process. The user power-purchasing data or the real-time watthour meter-reading data to be sent by the single chip computer MCU is also output into the specific frequency spreading communication integrated circuit U12 to be modulated, and then, sent to signal coupling section through OUT In Fig. 12, capacitors C32, X3, C33 and C34, resistors R34, R35, R36 and R33, capacitois C35, C36, C37, C38, C39 and C40, and crystal X4 are peripheral circuit components of U12. Fig. 13 shows a schematic diagram of the carrier sigral demodulation circuit 15 and the carrier signal modulation circuit 21 according to ancther embodiment of the invention. The carrier signal which is input by the signal coupling circuit via IN is high-frequ;ncy amplified by a riode Q7, resistors R37, R38, R39 and R40 and a capacitor C41, then, is coupled, through a capacitor C42, to specific frequency spreading communication integrated circuit U13 (PL2000B) to be demodulated, the demodulated digital signals are sent into single chip computer MCU to perform identification operation process. The user power-purchasing data or the real-time watthour meter-reading data to be transmitted by the single chip computer MCU is also output to specific frequency spreading communication integrated circuit U13 to be modulated, and then, sent to the signal coupling circuit through OUT. In Fig. 13, BF2, resistors R44, R41, R42, R43 and R45, and capacitors C43, C45, C46 and C47 are peripheral circuit components of U13. A crystal X5 and a capacitor C44 are peripheral circuit components for the clock circuit of the MCU, Fig. 14 shows a schematic diagram of the carrier signal demodulation circuit 15 and the carrier signal modulation circuit 21 according to further embodiment of the invention. The carrier signal which is input by the signal coupling circuit via IN is high-frequency amplified by a triode Q8, resistors R46, R47, R48 and R49 and a capacitor C48, then, is coupled, through a capacitor C49, to specific frequency spreading communication integrated circuit U14 (PL2101) to be demodulated. The demodulated digital signal is sent into single chip computer MCU to perform identification operation process. The user power-purchasing data or the real-time watthour meter-reading data to be transmitted by the single chip computer MCU is also output to specific frequency spreading communication integrated circuit U14 to be modulated, and then, sent to the signal coupling circuit through OUT. In Fig. 14, resistors R53, R50, R51, R52 and R54, crystal X6, capacitors C50, C51, C52, C58, C59 and C60, and BF3 are peripheral circuit components of U14. A crystal X7, capacitors C56 and C57, and a battery BAT are peripheral circuit components for the real-time clock circuit of U14, so as to achieve the design of complex-rate prepaid watthour meter. As above described, one of the specific watthour meter chips from AD7755, BL0932, BL0955 and CS5460 and the like is selected as nam device to constitutes the user watthour meter 5. The digital signal processor DSP or any one of the single chip computers such as MCS-51 series, PIC series and so on is selected to constitute the single chip computer system 16 according to Fig. 6, and the process programs for communication operation or control and so on are solidified in the program storage of the MCU. One of the solutions from Fig. 6, Fig. 7, Fig. 8 or Fig. 9 is selected to constitute the data storage circuit 20; One of the solutions from Fig. 12, Fig. 13, Fig. 14 or Fig. 5 in connect on with Fig. 11 is selected to constitute the carrier signal demodulation circuit 15 and the carrier signal modulation circuit 21 in the carrier module 4. The signal coupling circuit 13, the signal receiving circuit 14 and the signal transmission circuit 22 are constituted with the circuits in Fig. 4. The operation alarming state display circuit 18 and the latch buffer control circuit 19 are constituted with me circuit in Fig. 10. The respective circuit above-mentioned is combined to constitute the carrier module 4 with reference to the schematic diagram in Fig. 3, and the carrier module 4 may be integrated with the u:;er watthour meter in a single meter housing. The watthour meter-reading concentrator is constituted referring to the schematic diagram in Fig. 2, and the carrier :ommunication and operation process programs are solidified in the program storage of the MCU of the watthour meter-reading concentrator. As shown ir. Fig. 1, the integrated user watthour meter 5 and the carrier module 4 are placed at respective user who consumes electric power. The concentrator 3 is mounted at the low voltage side of the power supply transformer or mounted at the power entry of a power load center, and an entry line of telephone is connected to the concentrator 3. After the main station computer has installed the software tor watthour meter-reading and power-selling, each of the user watthour meter information is input into the watthour meter-reading and power-selting database, and an entry line of telephone is connected to the main station computer via a medem, then it may work. WE CLAIM 1. A prepaid watthour meter system, said system comprising: a power-selling computer(l) for selling power to a user by a database managing window thereon, and transmitting user power-purchasing data to a concentrator through an up channel; a concentrator (3), provided at low voltage side of user end transformer, for receiving the user power-purchasing data from the power-selling computer, and forwarding the received user power- purchasing data to a user watthour meter by power line carrier through a down channel; and at least one user watthour meter, said user watthour meter comprising a user watthour meter carrier module (4), and said user watthour meter carrier module comprising a power-purchasing data storage section, said user watthour meter carrier module receiving the user power-purchasing data forwarded by the concentrator, and storing the power-purchasing data to the power- purchasing data storage section in a specified format; the user watthour meter carrier module is further configured to: send back received power- purchasing data as acknowledgement information to the concentrator by power line carrier, after storing the power-purchasing data to the power-purchasing data storage section; and the concentrator is further configured to: upon receipt of the user power-purchasing data as acknowledgement information, send back the user power-purchasing data as acknowledgement information to the power-selling computer through the up channel, so as to verify that data is correctly transmitted. 2. The prepaid watthour meter system as claimed in claim 1, wherein the user power-purchasing data transmitted to the user watthour meter carrier module by the power-selling computer is the total amount of the ever-purchased power. 3. The prepaid watthour meter system as claimed in claim 1, wherein the concentrator is configured to store the user power-purchasing data transmitted from the power-selling computer therein, and both the data stored in the concentrator and the data stored in the power-purchasing data storage section of the user watthour meter carrier module are dentical with the data transmitted by the power-selling computer, so that the user power-purchasing data can be restored without loss in the case that any one of the power-selling computer, the concentrator and the user watthour meter carrier module corrupts or error in data transmission occurs. 4. The prepaid watthour meter system as claimed in claim 1, wherein the user watthour meter carrier module is further configured to: collect increment information on user's electric power consumption in real time, and compare it with the power-purchasing data every time the consumption adds by a predetermined value, and calculate balance; produce an alarm when the balance of the power-purchasing data is reduced to below a setting value, and promote the balance of the power-purchasing data; operate a relay to cut the power off when the balance of the power-purchasing, data is reduced to zero; and operate the relay to turn the power on when the user purchases power again, and the user watthour meter carrier module detects that the balance of the power-purchasing data is more than zero. 5. The prepaid watthour meter system as claimed in claim 1, wherein the up channel is constituted by a specific communication network, said specific communication network is comprised of at least one of a public telephone network fiber, microwave, data transmission station, coaxial cable and twisted-pair. 6. The prepaid watthour meter system as claimed in claim 1, wherein the down channel is comprised of low voltage power supply lines. 7. The prepaid watthour meter system as claimed in claim 1, wherein the power-purchasing data storage section is comprised of a nonvolatile memory device. 8. The prepaid watthour meter system as claimed in claim 1, wherein the concentrator is comprised of a modem (8), an operation control circuit (9) coupled with the modem, and three carrier communication modules (11) coupled with the operation control circuit respectively, and wherein the modem (8) serves to demodulate the user power-purchasing data transmitted by the power- selling computer and transmit the demodulated user power-purchasing data to the operation control circuit, and the modem also serves to modulate the same user power-purchasing data transmitted as acknowledge information from the operation control circuit, and send the modulated user power-purchasing data to tie power-selling computer; the operation control circuit (9) serves to receive the demodulated user power-purchasing data from the modem, and send said demodulated user power-purchasing data to the user watthour meter carrier module through the three carrier communication modules, and the operation control circuit (9) also serves to receive the same user power-purchasing data transmitted as acknowledge information from said three carrier communication modules, and send the received user power- purchasing data as acknowledge information to the modem so that the received user power- purchasing data is modulated by the modem and then sent to the power-selling computer; said three carrier communication modules (11) are coupled with triphase power lines A, B and C through coupling capacitors, respectively, servers to send the user power-purchasing data transmitted from the operation control circuit to the user watthour meter carrier module, and said three carrier communication modules also serves to receive the same user power-purchasing data transmitted as acknowledge information from the user watthour meter carrier module, and forward it to the operation control circuit, so as to be sent to the power-selling computer by the modem. 9. The prepaid watthour meter system as claimed in claim 1, wherein the user watthour meter carrier module (4) comprises: a carrier signal coupling circuit (13) , a carrier signal receiving circuit (14), a carrier signal demodulation circuit (15), a single chip computer system (16), a data storage section (20), a carrier signal modulation circuit (21) and a carrier signal transmission circuit (22), wherein one end of the carrier signal coupling circuit (13) is connected to the carrier signal receiving circuit (14), the carrier signal receiving circuit (14) is connected to the carrier signal demodulation circuit (15), the carrier signal demodulation circuit (15) is connected to the single chip computer system (16), the single chip computer system (16) is further connected to the data storage circuit (20) and the carrier signal modulation circuit (21), the carrier signal modulation circuit (21) is connected to the carrier signal transmission circuit (22), and the carrier signal transmission circuit (22) is connected to one end of the carrier signal coupling circuit (13). 10. The prepaid watthour meter system as claimed in claim 9, wherein the data storage circuit (20) is comprised of a ferroelectric memory device. 11. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier module (4) comprises: a control relay (KJ), and a latch buffer control circuit (19) connected to the control relay (KJ), wherein when the single chip computer system (16) identifies that ON/OFF control command is forwarded from the concentrator, corresponding operation action is output to control the relay KJ via the latch buffer control circuit. 12. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier module (4) comprises: a watthour meter pulse input circuit (17) connected to the single chip computer system (16), and real-time measuring pulse (MC) connected with the watthour meter pulse input circuit (17), wherein the real-time measuring pulse (MC) from the watthour meter is entered into the single chip computer system to perform counting and operation by the watthour meter pulse input circuit, and the operation result is stored in the data storage circuit, and every time the operation result is added by a predetermined value, the single chip computer system compares power counting value with the user power-purchasing data stored in the data storage circuit to calculate the balance for the user power-purchasing data. 13. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier module (4) comprises: an operation alarming state display circuit (18) connected to the single chip computer system (16), wherein when the balance for the user power-purchasing data is smaller than a setting value and larger than zero, the operation alarming state display circuit output an alarming signal. 14. The prepaid watthour meter system as claimed in claim 9, wherein the operation alarming state display circuit (18) is a three status display comprised of one LED indicator light and three resistors, and the anode of the indicator light is connected respectively to +5V and two resistors, the other ends of the two resistors are connected respectively to two control output terminals of the single chip computer, and cathode of the (LED) indicator light is connected to another resistor, the other end of this resistor is connected to one of the two control output terminals. 15. The prepaid watthour meter system as claimed in claim 9, wherein said single chip computer system is comprised of DSP. 16. The prepaid watthour meter system as claimed in claim 8, wherein the concentrator comprises: a power module (7) for providing power supply for the components in the concentrator; and a data storage circuit (10) coupled with the operation control circuit (9), for storing the user power- purchasing data sent from the power-selling computer. ABSTRACT TITLE: A PREPAID WATT-HOUR METER SYSTEM The invention relates to a prepaid watthour meter system, said system comprising a power-selling computer(1) for selling power to a user by a database managing window thereon, and transmitting user power-purchasing data to a concentrator through an up channel a concentrator (3), provided at low voltage side of user end transformer, for receiving the user power-purchasing data from the power-selling computer, and forwarding the received user power-purchasing data to a user watthour meter by power line carrier through a down channel; and at least one user watthour meter, said user watthour meter comprising a user watthour meter carrier module (4), and said user watthour meter carrier module comprising a power-purchasing data storage section, said user watthour meter carrier module receiving the user power-purchasing data forwarded by the concentrator, and storing the power-purchasing data to the power-purchasing data storage section in a specified format; the user watthour meter carrier module is further configured to: send back received power-purchasing data as acknowledgement information to the concentrator by power line carrier, after storing the power-purchasing data to the power-purchasing data storage section; and the concentrator is further configured to: upon receipt of the user power-purchasing data as acknowledgement information, send back the user power-purchasing data as acknowledgement information to the power-selling computer through the up channel, so as to verify that data is correctly transmitted.

Full Text

Carrier Type Data Security Protection Method And
Reading System For Prepaid Watthour Meter
Technical Field
The present invention relates to electric power measuring, control
and charging management, and more particularly, to a distributed control
management system, which implements concentrated watthour
meter-reading and charging using power lines carrier as information
channel, and achieves prepaid function on each user watthour meter, so
as to protect the security on data information and make it avoid
malicious attack from outside.
Background Art
With regard to measuring and charging of electric power, at present,
it is common that a dedicated watthour meter-reading person
periodically door-to-door reads watthour meters mounted at each user's
power supply entry, then, the user pays for the consumed electric power
at a charging office. This not only takes both time and efforts, but also
may make mistakes due to various reasons. As the lacking of effective
measures to urge the collection of electric: power charge, the users in
debt for electric power charge are increasing for many power supply
enterprises or house-keeping companies. The power supply enterprises
or house-keeping companies are forced to even cut off the power supply
in order to urge the user to pay for the electric power charge, which
directly disturbs people's life and social security.
To address the problem in collecting electric power charge for
watthour meter, Chinese Patent ZL 01261220.0 "Single phase IC card

watthour meter" and Chinese Patent ZL 02223241.9 "digital type
prepaid watthour meter" proposed a solution on watthour meter aiming
to not only solve the problem of collecting electric power charge, but
also improve on security. Both the solutions of the two patents encrypt
user power-purchasing information through a single chip processor in
the IC card or the keyboard, and then read them through a single chip
processor mounted in the watthour meter, so as to achieve the object of
improving the security on user's power-purchasing information. Because
there is still a data entry window to the user, such as IC card or keyboard
in the two solutions, it only improves security to some extent, but fails to
essentially avoid malicious attack from outside. In addition, there is no
information feedback channel which enables the watthour meter-reacing
and power-selling computer to check the user watthour meter-reading
and the power-purchasing data from time to time. Thus, there is a big
security loophole in user power-purchasing charging data information
and user watthour meter-reading data information.
Summary of the Invention
An object of the prevent invention is to provide a technology for
electric power watthour meter-reading and charging and control
management, and a data security protection method, which not only can
solve the problem of the charging for automatic remote electric power
watthour meter-reading, but also can protect the data information
security of the charging for power-purchasing, so as to essentially avcid
the attack from outside.
Another object of the prevent invention is to provide a watthour
meter-reading system for the charging of electric power watthoir

meter-reading and distribution control management.
The method proposed by the present invention is that: providing a
database for watthour meter-reading, controlling and charge managing in
a watthour meter-reading and power-selling computer; providirg a
carrier watthour meter-reading concentrator at low voltage side of a user
end transformer; providing a carrier module integrated with the user
watthour meter at the user entry of the power lines, and said carrier
module comprising a power-purchasing data storage circuit. The process
for user power-purchasing charging management and control is as
follows: a. when the user purchases electric power, an operator logs into
a selling management window in the watthour meter-reading and
power-selling computer after authenticating password, collects money
for the user and prints receipt; b. the power-purchasing data information
is sent to the carrier watthour meter-reading concentrator by the
watthour meter-reading and power-selling computer through the up
channel, and upon receipt of the user power-purchasing data by the
watthour meter-reading concentrator, the watthour meter-reading
concentrator forwards the data to the user watthour meter by carrier
through the power lines; c. after the user watthour meter carrier module
receives this power-purchasing data information, a single chip computer
within the user watthour meter carrier module makes a judgment
immediately, then stores the power-purchasing data to a
power-purchasing date storage circuit in a specified format, and in the
meantime, sends back the acknowledgement information on receipt of
the power-purchasing data to the watthour meter-reading concentrator by
carrier through the power lines; the watthour meter-reading concentrator
then sends the acknowledgement information back to the watthour

meter-reading ard power-selling computer through the up channel; d.
each user wattliour meter carrier module collects the increment
information on user's electric power consumption in real time, and
compares it with the power-purchasing data every time the consumption
adds by lKWh, and calculates balance; when the balance of the
power-purchasing data is reduced to below the setting value, the carrier
module produces an acousto/optic alarm, and prompts the balance of the
power-purchasing data; e. when the balance of the power-purchasing
data is reduced to zero, the carrier module operates the relay to cut the
power off; f. the above process is repeat when the user pays money to
purchase power a gain, and when the user watthour meter carrier module
detects that the balance of the power-purchasing data is more than zero,
it operates the relay to turn the power on.
When the user watthour meter carrier module receives the user
power-purchasing data, the user watthour meter carrier module sends
back the user power-purchasing data to the watthour meter-reading and
power-selling computer for acknowledgement, in addition to performing
at least one of code verification, parity verification and frame data sum
verification. Since the power-purchasing data transmitted to the user
watthour meter carrier module by the watthour meter-reading and
power-selling computer is the total amount of the ever-purchased power,
the value stored in the power-purchasing data storage circuit in the
carrier module should be consistent with the value sent by the watthour
meter-reading and power-selling computer. After the watthour
meter-reading and power-selling computer has sent the user
power-purchasing data, if no returned information is received or the
returned data received is inconsistent with the transmitted value, this

communication is deemed as failure, and then automatic re-transmission
is performed. If there is still failure with repeated re-transmissions for
many times, it indicates that the communication channel cannot be used
temporarily, and this transmitted value is then stored temporarily in the
hard disk of the computer, the operator may transmit again after one or
two hours until transmission succeeds. In general, the user
power-purchasing data information can be sent successfully within 24
hours through the carrier communication channel in the case of the
power supply line ON, which guarantees that the user power-purchasing
data may not be left unsent or wrongly sent.
The watthour meter-reading system for watthour meter-reading,
charging and distribution control management includes: a database
created for watthour meter-reading, controlling and charge managing in
a watthour meter-ieading and power-selling computer; a carrier watthour
meter-reading concentrator provided at low voltage side of user end
transformer; a carrier module for data collecting, carrier communication
and controlling output provided at respective user watthour meter; the
carrier module for user watthour meter including a power-purchasing
data storage circuit which is comprised of a nonvolatile RAM
(EEPROM, FRAM) device, and mounted together with the user
watthour meter; the watthour meter-reading and power-selling computer
being coupled to an up channel by a modem, the up channel being
comprised of a public telephone network; the watthour meter-reading
concentrator is coupled to the up channel by a modem, the up channel
being comprised of the public telephone network or the like, and on the
other hand, the watthour meter-reading concentrator being ronnected to
the down channel comprised of the low voltage power supply line

through carrier communication modules; the user watthour meter carrier
module connected at one end to the down channel comprised of the low
voltage power supply line through coupling capacitors, and connected at
the other end to e pulse output terminal for user watthour meter, where a
control relay receives ON/OFF control signal from a single chip
computer, and a power output contact is connected in serial to output
terminal for the pnase line of the watthour meter.
The up channel may be a mobile communication network, or a
specific communication network which is composed of fiber, microwave,
data transmission station, coaxial cable or twisted-pair or the like.
The method and system according to the present invention have the
following advantage, as compared with the prior art:
1. The prepaid watthour meter can prevent the user from being in
debt for the charge, control the carrier type watthour meter's bad
analysis on a household basis, and monitor the running state in real time.
The two major problems of difficulties in watthour meter-reading and
payment charging can be solved.
2. The information on the user power-purchasing data is transmitted
by full-sealed and secure power lines carrier channel, which eliminates
the open window for IC card type prepaid watthour meter and protects
security of power-purchasing information, and avoids it from any
malicious attacks.
3. The information on the user power-purchasing data is stored in
the watthour meter, the watthour meter-reading concentrator, and the
watthour meter-reading and power-selling computer simultaneously, and
the user power-purchasing data can be restored 100 percent when any
one of the devices is corrupted, which avoids user's disputes that occurs

frequently on IC cards type prepaid watthour meter, and can collect
evidences when needed.
4. When the power price and other power-consumption polices need
to be adjusted, they can be regulated correspondingly by the watthour
meter-reading computer according to new power price polices (such as
peak to valley power price, bottommost power price) and so on. It can
response quickly and securely, without causing the problems of social
security.
5. When using IC card type prepaid watthour meter, the pcwer
management department is unable to know the actual
power-consumption amount, thus unable to work out the power charge
taken back from the users for the present month. If large "line-loss" rate
due to abnormal power-using (such as power-stealing, power-leaking)
appears, it may lead to a long term accumulation for a huge amount of
"line-loss" power charge. Since the method according to the present
invention can calculates accurately "line-loss" for the present month in
time, so it can find the problems in time and take measures against a
huge amount of irremediable losses.
6. The method according to the present invent not only solves :he
problem of difficulty in charging in term of the known "the power lines
carrier watthour meter", but also stops the information security
loopholes of being vulnerable to be attacked and power-stealing from the
known " IC card type prepaid watthour meter". This will put the
distribution, use, measurement and charging of electric power uncer
computer monitor and control, allow the power supply enterprises or the
house-keeping company to get rid of the heavy burden on the user's long
term money-owing and a huge amount of money-owing, and this

provides effective technical means for the electric power system to take
back a large amount of investments. The cost for carrying out the present
invention is almost equals to the "the power lines carrier watthour
meter", "the IC card type prepaid watthour meter" of prior art. The
performance and function double, but the price keeps unchanged. Thus,
its performance/cost ratio is high, using risk is low and comprehensive
benefit is good.
The method and system according to the present invent economizes
the manpower and resources. One person which sits at office may know
the power-using and the electric power charging of each user in a entire
working unit or residential area, thereby prevents the action of the
power-stealing and protects the legal right of the power supply
enterprises. The present invention can be widely used to work units or
residential areas, It has good comprehensive benefits on the society and
economy,

Brief Description of the Accompanying Drawings
Fig. 1 is a schematic diagram of method and schematic structure
diagram of system according to the present invention;
Fig. 2 is a schematic structure diagram of a watthour meter-reading
concentrator in Fig. 1;
Fig. 3 is a schematic structure diagram of a carrier module in Fig 1;
Fig. 4 is a schematic circuit diagram of a signal coupling circui:, a
signal receiving c rcuit and a signal transmitting circuit in the carrier
module in Fig. 3;
Fig. 5 is a schematic circuit diagram of a carrier signal
demodulation circuit in Fig. 3;

Fig. 6 is a schematic diagram of the pulse input circuit between a
data storage circuit and a single chip computer system, and a sample
measuring module and the single chip computer system in Fig. 3;
Fig. 7 is a schematic diagram of the data storage circuit comprised
of a ferroelectric memory;
Fig. 8 is a schematic diagram of the data storage circuit comprised
of serial communication interface of the single chip computer system
and a ferroelectric memory;
Fig. 9 is a schematic diagram of the data storage circuit comprised
of the I2C bus interface of the single chip computer system and a
ferroelectric memory;
Fig. 10 is a schematic diagram of an alarm state display circuit and
a latch buffer control circuit;
Fig. 11 is a schematic diagram of a carrier signal modulation
circuit;
Fig. 12 is a schematic diagram of the carrier signal modulation-
demodulation circuit according to another embodiment;
Fig. 13 is a schematic diagram of the carrier signal modulation-
demodulation circuit according to one embodiment;
Fig. 14 is a schematic diagram of the carrier signal modulation-
demodulation circuit according to further embodiment.
Mode Detailed Description of the Embodiments
The embodiments of the present invention will be described below
with reference to the accompanying drawings.
Referring to Fig. 1, the watthour meter-reading system is
constituted in follcwing manners: a. creates a database for watthour

meter-reading, controlling and charge managing in a watthour
meter-reading and power-selling computer 1; b. provides a carrier
watthour meter-reading concentrator 3 at low voltage side of user end
transformer; c. provides a carrier moduls 4 for data collecting, carrier
communication and controlling output at respective user watthour metter;
d. the carrier module 4 for user watthour meter includes a
power-purchasing; data storage circuit which is comprised cf a
nonvolatile RAM (EEPROM, FRAM) device, and is mounted together
with the user watthour meter; e. the watthour meter-reading and
power-selling computer 1 is coupled to a public telephone network by a
modem, which public telephone network may be a mobile
communication network, or coupled to a up channel comprised of a
specific communication network, which specific communication
network uses fiber, microwave, data transmission station, coaxial cable
or twisted-pair or the like; f. the watthour meter-reading concentrator 3
is coupled to the up channel 2 by a modem when the up channel 2 is
comprised of the public telephone network, and on the other hand, the
watthour meter-reading concentrator 3 is connected to the down channel
6 comprised of the low voltage power supply line through three carrier
communication modules 11; g. the user watthour meter carrier module is
connected at one end to the down channel 6 comprised of the low
voltage power supply line through coupling capacitors, and is connected
at the other end tc a pulse output terminal for user watthour meter 5,
where a control relay receives ON/OFF control signal from a single chip
computer, and a power output contact is connected in serial to output
terminal for the phase line of the watthour meter.
The process for user power-purchasing charging management and

control is as follows: a. when the user purchases electric power, an
operator logs into a selling management window in the watthour
meter-reading and power-selling computer 1 after authenticating
password, collects money for the user and prints receipt; b. the
power-purchasing data information is sent to the carrier watthour
meter-reading concentrator 3 by the watthour meter-reading and
power-selling coriputer 1 through the up channel 2, and upon receipt of
the user power-purchasing data by the watthour meter-reading
concentrator 3, the watthour meter-reading concentrator 3 forwards the
data to the user watthour meter 5 by carrier through the power lines 6; c.
after the user watthour meter carrier module 4 receives this
power-purchasing data information, a single chip computer within the
user watthour meter carrier module 4 makes a judgment immediately,
then stores the power-purchasing data to a power-purchasing date
storage circuit in a specified format, and in the meantime, sends back the
acknowledgement information on receipt of the power-purchasing data
to the watthour meter-reading concentrator 3 by carrier through the
power lines 6; the watthour meter-reading concentrator 3 then sends the
acknowledgement information back to the watthour meter-reading and
power-selling computer 1 through the up channel 2; d. each user
watthour meter carrier module 4 collects the increment information on
user's electric power consumption in real time, and compares it with the
power-purchasing data every time the consumption adds by 1K Wh, and
calculates balance; when the balance of the power-purchasing data is
reduced to below the setting value, the carrier module 4 produces an
acousto/optic alarm, and prompts the balance of the power-purchasing
data; e. when the balance of the power-purchasing data is reduced to

zero, the carrier module 4 operates the relay to cut the power off; f. the
above process is repeat when the user pays money to purchase power
again, and when the user watthour meter carrier module detects that the
balance of the power-purchasing data is more than zero, it operates the
relay to turn the power on.
After the watthour meter-reading and power-selling computer 1
sends the user power-purchasing data, if the returned information is not
received or the returned data received is inconsistent with the transmitted
value, this communication is deemed as failure and then automatic
re-transmission is performed. If there is still failure with repeated
re-transmissions for many times, it indicates that the communication
channel cannot be used temporarily, and this transmitted value is then
stored temporarily in the hard disk of the watthour meter-reading and
power-selling computer 1, the operator will transmit again after one or
two hours until transmission succeeds.
Fig. 2 shows a schematic structure diagram of the carrier watthour
meter-reading concentrator 3 according to one embodiment of he
invention. In the carrier watthour meter-reading concentrator 3, a power
module 7 provides required power to the concentrator 3. Information
such as settings, watthour meter-reading commands or user
power-purchasing data etc. from the watthour meter-reading database in
the watthour meter- reading and power-selling computer 1 is transmitted
to a modem 8 by the telephone line 12, and the modem 8 then performs
demodulation and transmits the demodulated above information to an
operation control circuit 9 via the RS-232 interface. The operation
control circuit 9 serves to transmit the user power-purchasing data or the
watthour meter-reading data, which is transmitted from the watthour

meter-reading database or carrier communication modules 11, to a data
storage circuit 10. The data storage circuit 10 is composed of a
nonvolatile RAM (EEPROM, FRAM) device, which will not lose any
data information even if power-off or the like occurs. Three carrier
communication modules 11 are coupled to triphase power lines A, B, C
through capacitois, respectively. The carrier communication modules 11
serves to transmit the watthour meter-reading control command or the
user power-purchasing data to the user watthour meter carrier module 4,
on the other hand, the carrier communication modules 11 also serves to
receive the reading data or the watthour meter-reading data
acknowledgement information transmitted from the carrier module 4,
and then forwards it to the operation control circuit 9. After the operation
control circuit 9 receives the watthour meter-reading control command,
the operation control circuit 9 transmits the watthour meter-reading cata
stored in the data storage circuit 10 to the modem 8 via the RS-232
interface, or the operation control circuit 9 may transmits the user
power-purchasing data stored in the data storage circuit 10 to the modern
8 via the RS-232 interface. The modem 8 forwards the modulated
watthour meter-reading data or the power-purchasing data to the
watthour meter-reading and power-selling computer 1 through the up
channel 12 composed of for example telephone line. The operation
control circuit 9 may comprises a single chip computer which is used as
main component, and above-mentioned data operation process and
communication cortrol program are resided in the program storage of
the single chip computer. Each of three carrier communication modules
11 is also composed of a single chip computer as main component
together with specially designed carrier communication specific

integrated circuit or modulation-demodulation integrated circuit. The
modem 8 may be modified from a finished product MODEM, or
composed of the specially designed MODEM chip.
Fig. 3 shows a schematic structure diagram of the carrier module 4
for user watthour meter according to one embodiment of the invention. L,
N denote a phase line and a zero line of the power lines respectively,
reference number 13 denotes a carrier signal coupling circuit, reference
number 14 denotes a carrier signal receiving circuit, reference number
15 denotes a carrier signal demodulation circuit, reference number 16
denotes a single chip computer system, reference number 17 denotes a
watthour meter pulse input circuit, reference number 18 denotes an
operation alarming state display circuit, reference number 19 denotes a
latch buffer control circuit, reference number 20 denotes a data storage
circuit, reference number 21 denotes a carrier signal modulation circuit,
22 denotes a carrier signal transmission circuit.
The carrier signal on the power lines L, N is entered into the signal
receiving circuit 14 through the coupling circuit 13. The carrier signal is
pre-processed by the signal receiving circuit 14, and the pre-processed
signal is entered nto the carrier signal demodulation circuit 15. The
pre-processed signal is demodulated by the carrier signal demodulat; on
circuit 15, and the demodulated digital signal are sent to the single chip
computer system 16 to perform the identification operational process. If
it is identified that the information is power-purchasing data information
transmitted from the main station, then the power-purchasing data
information is stared in the data storage circuit 20, and the
acknowledgement data information to be returned is transmitted to tie
carrier signal modulation circuit 21. The acknowledgement data

information is transmitted to the carrier signal transmission circuit 22
after it is modulated according to frequency spreading or FSK by the
carrier signal modulation circuit 21, then, is transmitted to the power
lines L, N by the carrier signal coupling circuit 13. If it is identifiec that
the information is watthour meter-reading command transmitted from
the concentrator 3, the user power-purchasing data or the watthour
meter-reading data in real time that is stored in the data storage circuit 20
is packaged, and is transmitted to the power lines L, N according to the
above mentioned path and procedure likewise. If it is identified that the
information is ON/OFF control command transmitted from the
concentrator, corresponding operation action is output to control relay
KJ via the latch buffer control circuit 19. The real-time measuring pulse
MC from the watthour meter 5 is entered into the single chip computer
system 16 to perform counting and operation by the watthour meter
pulse input circuit 17, and the operation result is stored in the data
storage circuit 20. Every time the operation result is added by lKWh, the
single chip computer system 16 compares a power counting value with
the user power-pu -chasing data in the data storage circuit 20 to calcu ate
the balance for the user power-purchasing data. If the balance for the
user power-purch ising data reaches zero, a power-off command is
output to the latch buffer control circuit 19, and in the meantime a
power-off state dir.play signal is output to the operation alarming state
display circuit 18. If the balance for the user power-purchasing date is
smaller than a setting value (for example, l0Kwh) and larger than zero,
an acousto-optic a arming signal is output from the operation alarming
state display circuit 18. If the balance for the user power-purchasing data
is larger than or equal to the setting value (for example, 10Kwh), the

original operation status is maintained. The processing program for the
above-mentioned communication operation control and the like are all
resided in program memory of the single chip computer system 16. The
single chip computer system 16 can also be comprised of a digital signal
processor DSP. The data storage circuit 20 can be comprised of
EEPROM or ferroelectric memory FRAM.
Fig. 4 shows a schematic circuit ciagram of the signal coupling
circuit 13, the sgnal receiving circuit 14, and the signal transmitting
circuit 22 in the user watthour meter carrier module 4 according to one
embodiment of the invention. The carrier signal input by the power ines
L, N enters into a impedance converter T and D1 through the coupling
capacitor C1, then is coupled to IN through a resistor R1, capacitors C3
and C2, an induciance L1, diodes D2 and D3. The output signal entered
through OUT is amplified by a power amplifier comprised of triodes Q1,
Q2, Q3 and Q4, capacitors C5 and C6, resistors R2 and R3, and diodes
D4, D5, D6 and D7, then coupled to the impedance converter T through
a inductance L2 and a capacitor C4, and then is coupled, through
capacitor C1, to the power lines L, N for output.
Fig. 5 shows a schematic circuit diagram of the FSK carrier signal
demodulation circuit 15 according to one embodiment of the invention.
The signal from the signal receiving circuit 14 enters through IN, and the
entered signal is subject to frequency mixing, frequency discrimination
and demodulation by U1 (MC3361), capacitors C11, C12, C13, C14,
C15, C16, C17 and C18, resistors R9 and R10, CR1, CR2, BF1 and U2
(LM258), capacito-s C7, C8, C9 and C10, resistors R4, R5, R6, R7, R8,
R11, then input into the single chip computer system 16 through IN1 and
P1.x.

Fig. 6 shows a schematic diagram of the pulse input circuits
between the data storage circuit 20 and the single chip computer system
16, and between the sample measuring module 17 and the single chip
computer system 16 according to one embodiment of the invention. The
single chip computer system 16 may be comprised of MCS-51 series or
PIC series, or also any type of single chip computer, together with
crystal X1 and capacitors C19 and C20. The pulse input, circuit between
the sample measuring module 17 and the single chip computer system
16 is comprised of photoelectric coupler U3 and a resistor R12, and the
measuring pulse s input through CFO and CF1. The data storage ciruit
20 is comprised of the U4 (X25045) and a resistor R13.
Fig. 7 shows a schematic diagram of the data storage circuit 20
comprised of ferroelectric memory U5 (FM25040) and a resistor R14
according to another embodiment of the invention.
Fig. 8 shows a schematic diagram of the data storage circuit 20
comprised of ser al communication interfaces RXD and TXD of the
single chip computer system and ferroelectric memory U6 (FM25040)
according to further embodiment of the invention.
Fig. 9 shows a schematic diagram of the data storage circuit 20
comprised of I2C bus interface of the single chip computer system,
ferroelectric memory U7 (FM24C04) and resistors R15, R16 according
to further embodiment of the invention.
Fig. 10 shows a schematic circuit diagram of the operation alarming
state display circuit 18 and the latch buffer control circuit 19 accord ng
to one embodiment of the invention. The control signal output by P3.x. is
decoded and latched through U8 (BH3024) and resistors R20, R21 and
R22, and then drives the relay KJ to work. Resistors R17, R18, R19 and

a light emitting diode D8 constitute a three state (light, flickering, dark)
display 18.
Fig. 11 shows a schematic diagram of the FSK carrier signal
modulation circuit 21 which is comprised of two 4001s, capacitors C23,
C24, C25 and C26, resistors R23, R24 and R25 and R26, CR3 and
CR4, and one 4013 according to one embodiment of the invention. The
modulated signal is amplified by a triode Q5, a resistor R27 and a
capacitor C27, then output through OUT.
Fig. 12 shows a schematic diagram of the carrier signal
demodulation circuit 15 and the carrier signal modulation circuit 21
according to another embodiment of the invention. The carrier signal
which is input by the signal coupling circuit via IN is subject to
frequency-mixing by U1 (MC3361), resistors R28 and R32, capaci:ors
C29 and C31, and BF1, then, is coupled to a triode Q6, resistors F29,
R30 and R31 thrcugh a capacitor C28 to be high-frequency amplif. ed.
The amplified signal is then coupled into specific frequency spreading
communication integrated circuit U12 (PL2000A) to be demodulated,
and the demodulated digital signal is sent to single chip computer MCU
to perform identification operational process. The user power-purchasing
data or the real-time watthour meter-reading data to be sent by the single
chip computer MCU is also output into the specific frequency spreading
communication integrated circuit U12 to be modulated, and then, sent to
signal coupling section through OUT In Fig. 12, capacitors C32, X3,
C33 and C34, resistors R34, R35, R36 and R33, capacitois C35, C36,
C37, C38, C39 and C40, and crystal X4 are peripheral circuit
components of U12.
Fig. 13 shows a schematic diagram of the carrier sigral

demodulation circuit 15 and the carrier signal modulation circuit 21
according to ancther embodiment of the invention. The carrier signal
which is input by the signal coupling circuit via IN is high-frequ;ncy
amplified by a riode Q7, resistors R37, R38, R39 and R40 and a
capacitor C41, then, is coupled, through a capacitor C42, to specific
frequency spreading communication integrated circuit U13 (PL2000B)
to be demodulated, the demodulated digital signals are sent into single
chip computer MCU to perform identification operation process. The
user power-purchasing data or the real-time watthour meter-reading data
to be transmitted by the single chip computer MCU is also output to
specific frequency spreading communication integrated circuit U13 to be
modulated, and then, sent to the signal coupling circuit through OUT. In
Fig. 13, BF2, resistors R44, R41, R42, R43 and R45, and capacitors C43,
C45, C46 and C47 are peripheral circuit components of U13. A crystal
X5 and a capacitor C44 are peripheral circuit components for the clock
circuit of the MCU,
Fig. 14 shows a schematic diagram of the carrier signal
demodulation circuit 15 and the carrier signal modulation circuit 21
according to further embodiment of the invention. The carrier signal
which is input by the signal coupling circuit via IN is high-frequency
amplified by a triode Q8, resistors R46, R47, R48 and R49 and a
capacitor C48, then, is coupled, through a capacitor C49, to specific
frequency spreading communication integrated circuit U14 (PL2101) to
be demodulated. The demodulated digital signal is sent into single chip
computer MCU to perform identification operation process. The user
power-purchasing data or the real-time watthour meter-reading data to
be transmitted by the single chip computer MCU is also output to

specific frequency spreading communication integrated circuit U14 to be
modulated, and then, sent to the signal coupling circuit through OUT. In
Fig. 14, resistors R53, R50, R51, R52 and R54, crystal X6, capacitors
C50, C51, C52, C58, C59 and C60, and BF3 are peripheral circuit
components of U14. A crystal X7, capacitors C56 and C57, and a battery
BAT are peripheral circuit components for the real-time clock circuit of
U14, so as to achieve the design of complex-rate prepaid watthour meter.
As above described, one of the specific watthour meter chips from
AD7755, BL0932, BL0955 and CS5460 and the like is selected as nam
device to constitutes the user watthour meter 5.
The digital signal processor DSP or any one of the single chip
computers such as MCS-51 series, PIC series and so on is selected to
constitute the single chip computer system 16 according to Fig. 6, and
the process programs for communication operation or control and so on
are solidified in the program storage of the MCU. One of the solutions
from Fig. 6, Fig. 7, Fig. 8 or Fig. 9 is selected to constitute the data
storage circuit 20; One of the solutions from Fig. 12, Fig. 13, Fig. 14 or
Fig. 5 in connect on with Fig. 11 is selected to constitute the carrier
signal demodulation circuit 15 and the carrier signal modulation circuit
21 in the carrier module 4. The signal coupling circuit 13, the signal
receiving circuit 14 and the signal transmission circuit 22 are constituted
with the circuits in Fig. 4. The operation alarming state display circuit 18
and the latch buffer control circuit 19 are constituted with me circuit in
Fig. 10. The respective circuit above-mentioned is combined to
constitute the carrier module 4 with reference to the schematic diagram
in Fig. 3, and the carrier module 4 may be integrated with the u:;er
watthour meter in a single meter housing. The watthour meter-reading

concentrator is constituted referring to the schematic diagram in Fig. 2,
and the carrier :ommunication and operation process programs are
solidified in the program storage of the MCU of the watthour
meter-reading concentrator.
As shown ir. Fig. 1, the integrated user watthour meter 5 and the
carrier module 4 are placed at respective user who consumes electric
power. The concentrator 3 is mounted at the low voltage side of the
power supply transformer or mounted at the power entry of a power load
center, and an entry line of telephone is connected to the concentrator 3.
After the main station computer has installed the software tor watthour
meter-reading and power-selling, each of the user watthour meter
information is input into the watthour meter-reading and power-selting
database, and an entry line of telephone is connected to the main station
computer via a medem, then it may work.

WE CLAIM
1. A prepaid watthour meter system, said system comprising:
a power-selling computer(l) for selling power to a user by a database managing window thereon,
and transmitting user power-purchasing data to a concentrator through an up channel;
a concentrator (3), provided at low voltage side of user end transformer, for receiving the user
power-purchasing data from the power-selling computer, and forwarding the received user power-
purchasing data to a user watthour meter by power line carrier through a down channel; and
at least one user watthour meter, said user watthour meter comprising a user watthour meter
carrier module (4), and said user watthour meter carrier module comprising a power-purchasing
data storage section, said user watthour meter carrier module receiving the user power-purchasing
data forwarded by the concentrator, and storing the power-purchasing data to the power-
purchasing data storage section in a specified format;
the user watthour meter carrier module is further configured to: send back received power-
purchasing data as acknowledgement information to the concentrator by power line carrier, after
storing the power-purchasing data to the power-purchasing data storage section; and the
concentrator is further configured to: upon receipt of the user power-purchasing data as
acknowledgement information, send back the user power-purchasing data as acknowledgement
information to the power-selling computer through the up channel, so as to verify that data is
correctly transmitted.

2. The prepaid watthour meter system as claimed in claim 1, wherein the user power-purchasing data
transmitted to the user watthour meter carrier module by the power-selling computer is the total
amount of the ever-purchased power.
3. The prepaid watthour meter system as claimed in claim 1, wherein the concentrator is configured
to store the user power-purchasing data transmitted from the power-selling computer therein, and
both the data stored in the concentrator and the data stored in the power-purchasing data storage
section of the user watthour meter carrier module are dentical with the data transmitted by the
power-selling computer, so that the user power-purchasing data can be restored without loss in the
case that any one of the power-selling computer, the concentrator and the user watthour meter
carrier module corrupts or error in data transmission occurs.
4. The prepaid watthour meter system as claimed in claim 1, wherein the user watthour meter carrier
module is further configured to:
collect increment information on user's electric power consumption in real time, and compare it
with the power-purchasing data every time the consumption adds by a predetermined value, and
calculate balance;
produce an alarm when the balance of the power-purchasing data is reduced to below a setting
value, and promote the balance of the power-purchasing data;
operate a relay to cut the power off when the balance of the power-purchasing, data is reduced to
zero; and
operate the relay to turn the power on when the user purchases power again, and the user
watthour meter carrier module detects that the balance of the power-purchasing data is more than
zero.

5. The prepaid watthour meter system as claimed in claim 1, wherein the up channel is constituted by
a specific communication network, said specific communication network is comprised of at least one
of a public telephone network fiber, microwave, data transmission station, coaxial cable and
twisted-pair.
6. The prepaid watthour meter system as claimed in claim 1, wherein the down channel is comprised
of low voltage power supply lines.
7. The prepaid watthour meter system as claimed in claim 1, wherein the power-purchasing data
storage section is comprised of a nonvolatile memory device.
8. The prepaid watthour meter system as claimed in claim 1, wherein the concentrator is comprised of
a modem (8), an operation control circuit (9) coupled with the modem, and three carrier
communication modules (11) coupled with the operation control circuit respectively, and wherein
the modem (8) serves to demodulate the user power-purchasing data transmitted by the power-
selling computer and transmit the demodulated user power-purchasing data to the operation
control circuit, and the modem also serves to modulate the same user power-purchasing data
transmitted as acknowledge information from the operation control circuit, and send the modulated
user power-purchasing data to tie power-selling computer;

the operation control circuit (9) serves to receive the demodulated user power-purchasing data
from the modem, and send said demodulated user power-purchasing data to the user watthour
meter carrier module through the three carrier communication modules, and the operation control
circuit (9) also serves to receive the same user power-purchasing data transmitted as acknowledge
information from said three carrier communication modules, and send the received user power-
purchasing data as acknowledge information to the modem so that the received user power-
purchasing data is modulated by the modem and then sent to the power-selling computer;
said three carrier communication modules (11) are coupled with triphase power lines A, B and C
through coupling capacitors, respectively, servers to send the user power-purchasing data
transmitted from the operation control circuit to the user watthour meter carrier module, and said
three carrier communication modules also serves to receive the same user power-purchasing data
transmitted as acknowledge information from the user watthour meter carrier module, and forward
it to the operation control circuit, so as to be sent to the power-selling computer by the modem.
9. The prepaid watthour meter system as claimed in claim 1, wherein the user watthour meter carrier
module (4) comprises:
a carrier signal coupling circuit (13) , a carrier signal receiving circuit (14), a carrier signal
demodulation circuit (15), a single chip computer system (16), a data storage section (20), a carrier
signal modulation circuit (21) and a carrier signal transmission circuit (22), wherein one end of the
carrier signal coupling circuit (13) is connected to the carrier signal receiving circuit (14), the carrier
signal receiving circuit (14) is connected to the carrier signal demodulation circuit (15), the carrier

signal demodulation circuit (15) is connected to the single chip computer system (16), the single
chip computer system (16) is further connected to the data storage circuit (20) and the carrier
signal modulation circuit (21), the carrier signal modulation circuit (21) is connected to the carrier
signal transmission circuit (22), and the carrier signal transmission circuit (22) is connected to one
end of the carrier signal coupling circuit (13).
10. The prepaid watthour meter system as claimed in claim 9, wherein the data storage circuit (20) is
comprised of a ferroelectric memory device.
11. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier
module (4) comprises:
a control relay (KJ), and a latch buffer control circuit (19) connected to the control relay (KJ),
wherein when the single chip computer system (16) identifies that ON/OFF control command is
forwarded from the concentrator, corresponding operation action is output to control the relay KJ
via the latch buffer control circuit.
12. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier
module (4) comprises:
a watthour meter pulse input circuit (17) connected to the single chip computer system (16), and
real-time measuring pulse (MC) connected with the watthour meter pulse input circuit (17),
wherein the real-time measuring pulse (MC) from the watthour meter is entered into the single chip
computer system to perform counting and operation by the watthour meter pulse input circuit, and

the operation result is stored in the data storage circuit, and every time the operation result is
added by a predetermined value, the single chip computer system compares power counting value
with the user power-purchasing data stored in the data storage circuit to calculate the balance for
the user power-purchasing data.
13. The prepaid watthour meter system as claimed in claim 9, wherein the user watthour meter carrier
module (4) comprises:
an operation alarming state display circuit (18) connected to the single chip computer system (16),
wherein when the balance for the user power-purchasing data is smaller than a setting value and
larger than zero, the operation alarming state display circuit output an alarming signal.
14. The prepaid watthour meter system as claimed in claim 9, wherein the operation alarming state
display circuit (18) is a three status display comprised of one LED indicator light and three resistors,
and the anode of the indicator light is connected respectively to +5V and two resistors, the other
ends of the two resistors are connected respectively to two control output terminals of the single
chip computer, and cathode of the (LED) indicator light is connected to another resistor, the other
end of this resistor is connected to one of the two control output terminals.
15. The prepaid watthour meter system as claimed in claim 9, wherein said single chip computer
system is comprised of DSP.

16. The prepaid watthour meter system as claimed in claim 8, wherein the concentrator comprises:
a power module (7) for providing power supply for the components in the concentrator; and
a data storage circuit (10) coupled with the operation control circuit (9), for storing the user power-
purchasing data sent from the power-selling computer.

ABSTRACT

TITLE: A PREPAID WATT-HOUR METER SYSTEM
The invention relates to a prepaid watthour meter system, said system comprising a power-selling
computer(1) for selling power to a user by a database managing window thereon, and transmitting user
power-purchasing data to a concentrator through an up channel a concentrator (3), provided at low
voltage side of user end transformer, for receiving the user power-purchasing data from the power-selling
computer, and forwarding the received user power-purchasing data to a user watthour meter by power
line carrier through a down channel; and at least one user watthour meter, said user watthour meter
comprising a user watthour meter carrier module (4), and said user watthour meter carrier module
comprising a power-purchasing data storage section, said user watthour meter carrier module receiving
the user power-purchasing data forwarded by the concentrator, and storing the power-purchasing data to
the power-purchasing data storage section in a specified format; the user watthour meter carrier module is
further configured to: send back received power-purchasing data as acknowledgement information to the
concentrator by power line carrier, after storing the power-purchasing data to the power-purchasing data
storage section; and the concentrator is further configured to: upon receipt of the user power-purchasing
data as acknowledgement information, send back the user power-purchasing data as acknowledgement
information to the power-selling computer through the up channel, so as to verify that data is correctly
transmitted.

Documents:

02853-kolnp-2006-abstrct.pdf

02853-kolnp-2006-assignment.pdf

02853-kolnp-2006-claims.pdf

02853-kolnp-2006-correspondence 1.2.pdf

02853-kolnp-2006-correspondence others-1.1.pdf

02853-kolnp-2006-crrespondence others.pdf

02853-kolnp-2006-description (complete).pdf

02853-kolnp-2006-drawings.pdf

02853-kolnp-2006-form 6.pdf

02853-kolnp-2006-form-26.pdf

02853-kolnp-2006-form1.pdf

02853-kolnp-2006-form2.pdf

02853-kolnp-2006-form3.pdf

02853-kolnp-2006-form5.pdf

02853-kolnp-2006-international publication.pdf

02853-kolnp-2006-international search authority report.pdf

02853-kolnp-2006-pct form.pdf

02853-kolnp-2006-pct other.pdf

02853-kolnp-2006-priority document.pdf

2853-KOLNP-2006-(14-08-2012)-CORRESPONDENCE.pdf

2853-KOLNP-2006-(21-01-2013)-ABSTRACT.pdf

2853-KOLNP-2006-(21-01-2013)-CLAIMS.pdf

2853-KOLNP-2006-(21-01-2013)-CORRESPONDENCE.pdf

2853-KOLNP-2006-(21-01-2013)-FORM 1.pdf

2853-KOLNP-2006-(21-01-2013)-FORM 2.pdf

2853-KOLNP-2006-ASSIGNMENT.pdf

2853-KOLNP-2006-CORRESPONDENCE 1.3.pdf

2853-KOLNP-2006-CORRESPONDENCE 1.5.pdf

2853-KOLNP-2006-EXAMINATION REPORT.pdf

2853-KOLNP-2006-FORM 18.pdf

2853-KOLNP-2006-FORM 26.pdf

2853-KOLNP-2006-FORM 6.pdf

2853-KOLNP-2006-GRANTED-ABSTRACT.pdf

2853-KOLNP-2006-GRANTED-CLAIMS.pdf

2853-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

2853-KOLNP-2006-GRANTED-DRAWINGS.pdf

2853-KOLNP-2006-GRANTED-FORM 1.pdf

2853-KOLNP-2006-GRANTED-FORM 2.pdf

2853-KOLNP-2006-GRANTED-FORM 3.pdf

2853-KOLNP-2006-GRANTED-FORM 5.pdf

2853-KOLNP-2006-GRANTED-SPECIFICATION-COMPLETE.pdf

2853-KOLNP-2006-OTHER PATENT DOCUMENT.pdf

2853-KOLNP-2006-PETITION UNDER RULE 137.pdf

2853-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

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Patent Number

255671

Indian Patent Application Number

2853/KOLNP/2006

PG Journal Number

11/2013

Publication Date

15-Mar-2013

Grant Date

13-Mar-2013

Date of Filing

03-Oct-2006

Name of Patentee

QI, CHANGYUAN

Applicant Address

ELECTRONICS SCIENCE DEPARTMENT OF NORTHWEST UNIVERSITY, NO. 229 TAIBAI BEILU, XI'AN CITY, SHAANXI 710069 CHINA

Inventors:

#	Inventor's Name	Inventor's Address
1	QI, CHANGYUAN	ELECTRONICS SCIENCE DEPARTMENT OF NORTHWEST UNIVERSITY, NO 229 TAIBAI BEILU, XI'AN CITY, SHAANXI 710069 CHINA

PCT International Classification Number

G01R11/00; G01R11/56

PCT International Application Number

PCT/CN2005/000252

PCT International Filing date

2005-03-01

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	200410025895.0	2004-03-01	China