Title of Invention

ELECTRONIC CONTROLLED ELECTRIC POWER METER

Abstract

An electronic controlled electric power meter capable of detecting an abnormality when there is an illegal use is formed by a voltage detection unit configured to detect a voltage of a measurement target system, a current detection unit configured to detect a current of the measurement target system, an electric power calculation unit configured to obtain an amount of consumed electric power of the measurement target system by multiplying a detection signal of the voltage detection unit and a detection signal of the current detection unit, and an abnormality judgement unit configured to judge that there is abnormality when the current detection unit detects the current while the voltage detection unit does not detect the voltage.

Full Text

ELECTRONIC CONTROLLED ELECTRIC POWER METER BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to an electronic controlled electric power meter for measuring an amount of comsumed electric power of a measurement target system. DESCRIPTION OF THE RELATED ART Conventionally, the electronic controlled electric power meter for measuring electric power data such as an amount of comsumed electric power at home, factory or office has been becoming popular. This electronic controlled electric power meter has an electric power calculation unit for measuring and calculating an electric power of a measurement target system, a control unit for editing the calculation result calculated by the electric power calculation unit into an electric power data such as an amount of comsumed electric power or a maximum consumed electric power, and a display unit for displaying the electric power data edited by the control unit. Also, the known method for storing the measurement data includes a meter inspection system for providing an RF tag outside a measurement device and manually inputting necessary data such as the measurement data into the RF tag through a handy terminal or the like (see Japanese Patent Application Laid Open No. 2003-323686, for example), and a measurement device and a measurement system for storing necessary data such as the measurement data into an RF tag provided inside or outside the measurement device (see Japanese Patent Application Laid Open No. 2001-147144, for example. Also, the known electric power meter for preventing the illegal use by disconnecting the voltage side input includes an electric power meter characterized by providing a terminal block with a voltage shortening piece that is difficult to remove (see Japanese Patent Application Laid Open No. 2001-74780, for example). However, in the conventional electronic controlled electric power meter, there is no method for detecting the case of illegal use by the consumer. The electronic controlled electric power meter calculates the electric power amount by detecting a voltage and a current, so that the electric power calculation result from a viewpoint of the electronic controlled electric power meter can be reduced or nullified by not supplying a voltage. Since it is possible to reduce or nullify the measured amount by the electronic controlled electric power meter without blocking the electric power supply-to the consumer, there are many incidents of illegal use by breaking the voltage applied to a voltage detection unit of the electronic controlled electric power meter in recent years. Consequently, there has been needs to prevent or detect the illegal use because the electric power meter is to be used for the transaction of the electric power fee of the electric power consumer. BRIEF SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electronic controlled electric power meter capable of detecting the illegal use of electric power as noted above. According to one aspect of the present invention there is provided an electronic controlled electric power meter, comprising: a voltage detection unit configured to detect a voltage of a measurement target system; a current detection unit configured to detect a current of the measurement target system; an electric power calculation unit configured to obtain an amount of consumed electric power of the measurement target system by multiplying a detection signal of the voltage detection unit and a detection signal of the current detection unit; and an abnormality judgement unit configured to judge that there is abnormality when the current detection unit detects the current while the voltage detection unit does not detect the voltage. Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an internal configuration of an electronic controlled electric power meter according to the first embodiment of the present invention. Fig. 2 is a block diagram showing an internal configuration of a radio transmission/reception memory device used in the electronic controlled electric power meter of Fig. 1. Fig. 3 is a block diagram showing an internal configuration of an electronic controlled electric power meter according to the second embodiment of the present invention. Fig. 4 is a block diagram showing an internal configuration of a memory device used in the electronic controlled electric power meter of Fig. 3. DETAILED DESCRIPTION OF THE INVENTION Referring now to Fig. 1 and Fig. 2, the first embodiment of the electronic controlled electric power meter according to the present invention will be described in detail. Fig. 1 shows an internal configuration of the electronic controlled electric power meter according to this embodiment. In the electronic controlled electric power meter of Fig. 1, a terminal block 1 is provided to connect a main body of the electronic controlled electric power meter with electric power line, and has terminals IS, 2S and 3S on a power source side, and terminals 1L. 2L and 3L on a load side. Note that, in this embodiment, the electronic controlled electric power meter is adapted to be a single phase 3 line type. An electric power calculation unit 2 calculates an amount of consumed electric power, and has a current detection unit 2a for detecting a current between IS and 1L (1-side current), a current detection unit 2b for detecting a current between 3S and 3L (3-side current), a voltage detection unit 2c for detecting a voltage between IS and 2S (1-side voltage) and a voltage between 3S and 2S (3-side voltage), and an electric power multiplying unit 2d for multiplying the 1-side current with the 1-side voltage, and 3-side current with the 3-side voltage. A control unit 3 is formed by a micro-computer or the like, for editing the calculation results of the electric power calculation unit 2 into the electric power data, and controls storing and displaying of the electric power data. Note that the electric power data here refer to data regarding the consumed electric power of the consumer such as an amount of consumed electric power of a measurement target system, a maximum consumed electric power, etc. A breaker 4 breaks the current in a case that is judged as abnormal by the control unit 3 such as a case of the illegal use, and has first breaker 4a for breaking between IS and 1L (1-side current) and a second breaker 4b for breaking between 3S and 3L (3-side current). The breaking operation of the breaker 4 is controlled by the control unit 3. A display device 5 is formed by a liquid crystal display or the like, for displaying an abnormality information in a case that is judged as abnormal by the control unit 3 such as a case of the illegal use, or the electric power data calculated by the control unit 3. A communication unit 6 is formed by an interface circuit such as a current loop, and connected to a telephone line through an external transmission control device or to a network, for transmitting” the abnormality information in a case that is judged as abnormal such as a case of the illegal use or the electric power data obtained by the control unit 3, to the external. A radio transmission unit 7 is provided for transmitting the abnormality information in a case that is judged as abnormal such as a case of the illegal use or the electric power data obtained by the control unit 3, in a form of radio signals, to a radio transmission/reception type memory device 8 to be attached to an external of the electronic controlled electric power meter of this embodiment. The transmission operation of the radio transmission unit 7 is controlled by the control unit 3. The radio transmission/reception type memory device 8 is formed by a non-volatile semiconductor memory that can be read or written by using radio signals, such as the so called RF tag or IC tag, for storing the abnormality information or the electric power data transmitted from the radio transmission unit 7. This radio transmission/reception type memory device 8 is pasted to a casing surface of an electric power measurement unit 10A which is the main body of the electronic controlled electric power meter. Here, the radio transmission/reception type memory device 8 can have an internal configuration as shown in Fig. 2, for example, which has an antenna 201 for transmitting or receiving radio signals, a transmission/reception unit 202 for transmitting or receiving radio signals through the antenna 201, and a memory unit 203 formed by a non-volatile memory such as a ferroelectric memory (F-RAM), which has functions for storing the abnormality information or the electric power data received by the transmission/reception unit 202 along with data such as a previous data acquisition date and a consumer ID number, and reading out the stored data such as the abnormality information or the electric power data to be transmitted by the transmission/reception unit 202. Next, the operation of the electronic controlled electric power meter of this embodiment will be described. The electric power calculation unit 2 calculates an amount of electric power consumed by the consumer, and notifies the calculation result to the control unit 3. The control unit 3 converts the calculation result into the electric power data such as the amount of consumed electric power, stores that data, and displays that data on the display device 5. Here, if the measured amount of the electric power meter could be reduced or nullified by the consumer, it would be possible to reduce the electric power fee. For this reason, in recent years, there are many incidents of illegal use by disconnecting signal lines connected to the voltage detection unit 2c from the IS terminal and the 3S terminal, at either the IS side or the 3S side or both. In such a case, the current line between IS and 1L and the current line between 3S and 3L remain connected, so that it is still possible to conduct electricity to the load side but the measured amount of the electric power meter would be reduced or nullified. For example, in the case of disconnecting the voltage only at the IS side or at the 3S side, the measured amount will becomes approximately one half, and in the case of disconnecting the voltage at both IS and 3S sides, the measured amount will be nullified. However, in the electronic controlled electric power meter of this embodiment, even in the case of such an illegal act, the illegal act is detected as follows. Namely, when the current detection units 2a and 2b respectively detect the 1-side current and the 3-side current as a result of using loads and the voltage detection unit 2c detects the voltages at the IS terminal side and the 3S terminal side to be zero, it implies that there is the illegal use. For this reason, the control unit 3 judges that there is an illegal act when the current detection unit 2a detects the current while the IS side voltage is effectively zero, or when the current detection unit 2b detects the current while the 3S side voltage is effectively zero. The control unit 3 which judged that there is an illegal act then stores the abnormality information indicating that there is an illegal act into the radio transmission/reception type memory device 8 through the radio transmission unit 7. In addition, the control unit 3 also stores the measurement data of the electronic controlled electric power meter into the radio transmission/reception type memory device 8 through the radio transmission unit 7. In this way, when the measured value is collected by a meter inspector once in every one month, for example, the meter inspector peels off the radio transmission/reception type memory device 8 in a form of the RF tag and take it to the office, and reads out the measured value and checks whether there is any illegal act or not at the office, such that it becomes possible to prevent the transaction of the illegal fee. Note that it becomes possible to acquire the measured value and the abnormality information at the next meter inspection occasion by pasting an RF tag with no data written therein at the same time as the RF tag is peeled off. Also, the control unit 3 which judged that there is an illegal act also displays the abnormality information indicating that there is an illegal act on the display device 5. It is also possible for the control unit 3 which judged that there is an illegal act to transmit the abnormality information indicating that there is an illegal act to a center device located at the office by using the telephone line and the e-mail, for example, through the communication unit 6. In addition, it is also possible for the control unit 3 which judged that there is an illegal act to issue the breaking command to the breakers 4a and 4b such that the breakers 4a and 4b breaks the current lines to stop the electricity conduction to the loads, so as to prevent the illegal act. As described, according to this embodiment, it is possible to provide the electronic controlled electric power meter which is capable of detecting the abnormality, storing, transmitting or displaying this fact as the abnormality information, and stopping the electricity conduction to the loads, when there is an illegal use. Referring now to Fig. 3 and Fig. 4, the second embodiment of the electronic controlled electric power meter according to the present invention will be described in detail. Fig. 3 shows an internal configuration of the electronic controlled electric power meter according to this embodiment. The electronic controlled electric power meter of Fig. 3 differs from that of the first embodiment in that, unlike the first embodiment in which the abnormality information and the electric power data are stored into the externally attached radio transmission/reception type memory device 8 through the radio transmission unit 7, a memory device 9 is provided inside an electric power measurement unit 10B which is the main body of the electronic controlled electric power meter, and these data are stored into this memory device 9. The memory device 9 has a radio transmission function and an internal configuration as shown in Fig. 4. The memory device 9 is formed by a non-volatile semiconductor memory that can be read or written by using radio signals, such as the so called RF tag or IC tag, whose storing and reading operations are controlled by electrically connected control unit 3, but data can also be read by using radio signals entered from an external of the electronic controlled electric power meter. The memory device 9 has an internal configuration as shown in Fig. 4, which has an antenna 401 for transmitting or receiving radio signals from an external device such as a handy terminal having radio signal generation function, for example, and a transmission/reception unit 402 for storing data such as a previous data acquisition date and a consumer ID number received by the antenna 401 into a memory unit 403, and transmitting the electric power data such as an amount of consumed electric power, a maximum consumed electric power, etc. stored in the memory unit 403, in a form of radio signals. The memory unit 403 is formed by a non-volatile memory such as a ferroelectric memory (F-RAM), which has functions for storing data such as a previous data acquisition date and a consumer ID number that are set by using radio signals through the antenna 401 and the transmission/reception unit 402, and data such as the electric power data entered from the control unit 3 of the electronic controlled electric power meter main body through a control circuit 404. The control circuit 404 controls electric transmission and reception with respect to the external, for writing or reading data by being electrically connected to the control unit 3 via a bus or the like. The control unit 3 which judged that there is an illegal act stores the abnormality information and the electric power data into the memory device 9- By reading out the abnormality information and the electric power data stored in the memory device 9 by a handy terminal having a radio transmission and reception function or the like and checking whether there is any illegal act or not, it becomes possible to prevent the transaction of the illegal fee. On the other hand, in the usual case of carrying out radio transmission and reception, a large electric power is required for the radio transmission and reception. However, in the case where the illegal act of disconnecting the voltage line is committed, it cannot expect the electronic controlled electric power meter to be operated by using the external power source, so that the electronic controlled electric power meter have to be operated by using an internal back-up battery or the like as a power supply source. In the usual case of carrying out radio transmission and reception, the back-up battery or the like of a large capacity is necessary because of the large power consumption required, but the memory device 9 of this embodiment can be operated by using the radio signals from the external as the power source and does not require the back-up battery or the like, so that it suffices to provide a compact power source to the electronic controlled electric power meter. As described, according to this embodiment, it is possible to provide the electronic controlled electric power meter with a compact power source, which is capable of detecting the abnormality, storing, transmitting or displaying this fact as the abnormality information, and stopping the electricity conduction to the loads, when there is an illegal use. Thus, according to the present invention, it becomes possible to detect the illegal use at the electronic controlled electric power meter, so that it becomes possible to prevent the transaction of the illegal fee. It is to be noted that, besides those already mentioned above, many modifications and variations of the above embodiments may be made without departing from the novel and advantageous features of the present invention. Accordingly, all such modifications and variations are intended to be included within the scope of the appended claims. WHAT IS CLAIMED IS: 1. An electronic controlled electric power meter, comprising: a voltage detection unit configured to detect a voltage of a measurement target system; a current detection unit configured to detect a current of the measurement target system; an electric power calculation unit configured to obtain an amount of consumed electric power of the measurement target system by multiplying a detection signal of the voltage detection unit and a detection signal of the current detection unit; and an abnormality judgement unit configured to judge that there is abnormality when the current detection unit detects the current while the voltage detection unit does not detect the voltage. 2. The electronic controlled electric power meter of claim 1, further comprising: a radio transmission unit configured to transmit an abnormality information indicating that there is abnormality as judged by the abnormality judgement unit in a form of radio signals; and a memory device provided at an external of an electric power measurement unit containing the voltage detection unit, the current detection unit, the electric power calculation unit, the abnormality judgement unit and the radio transmission unit, and configured to store the abnormality information transmitted from the radio transmission unit in a form of radio signals. 3. The electronic controlled electric power meter of claim 1, further comprising: a memory device configured to store an abnormality information indicating that there is abnormality as judged by the abnormality judgement unit, from which the abnormality information can be read by using radio signals from an external device. 4. The electronic controlled electric power meter of claim 1, further comprising: a display unit configured to display an abnormality information indicating that there is abnormality as judged by the abnormality judgement unit. 5. The electronic controlled electric power meter of claim 1, further comprising: a communication unit configured to notify an abnormality information indicating that there is abnormality as judged by the abnormality judgement unit, to an external. 6. The electronic controlled electric power meter of claim 1, further comprising: a terminal block having a power source side terminal and a load side terminal; and a breaker connected between the power source side terminal and the load side terminal of the terminal block, configured to carry out a breaking operation when the abnormality judgement unit judges that there is abnormality.

Documents:

0571-che-2006 correspondence po.pdf

0571-che-2006 form-18.pdf

0571-che-2006 power of attorney.pdf

0571-che-2006 abstract.pdf

0571-che-2006 form-2.pdf

0571-che-2006 others.pdf

571-che-2006-claims.pdf

571-che-2006-correspondnece-others.pdf

571-che-2006-description(complete).pdf

571-che-2006-drawings.pdf

571-che-2006-form 1.pdf

571-che-2006-form 3.pdf

571-che-2006-form 5.pdf