|Title of Invention||
POWER LINE COUPLING SYSTEM FOR HIGH SPEED COMMUNICATION
|Abstract||This present invention relates to the art of carring out high speed communication on powerline of different voltages. In this invention, we have designed a new coupler which improves the speed of communication on powerline and can be used at various voltage levels. This invention will provide an amicable system and method to get developed for streaming data, speech etc on powerline with good through put.|
|Full Text||FORM 2
THE PATENTS ACT, 1970
[39 of 1970]
(See Section 10)
Power line Coupling system for High Speed Communication
Matrix Energy Solutions Pvt Ltd
C/o M/s V.R.MOMAYA and Associates
Army Navy building
148, M.G Road
The following specification particularly describes the manner of the invention and the manner in which it has to be performed.
The following Specification describes the nature of the invention
FIELD OF TECHNOLOGY
The field of technology is related to power line carrier communication. Coupler is a device that injects a communication signal into the power line and it receives a signal from power line and forwards it to the power line modem. Coupler is in a way a band pass filter for power line.
DESCRIPTION OF RELATED ART
Power line carrier communication is a way old technology. PLC phone are in use in Power distribution companies. These technologies are based on FSK technology and the components that are used in communication in PLC are modem (FSK based), Line trap and Coupler. These PLC systems are working for ultra high voltage power line ranging from 110KV to 440KV AC system. The modem is connected to communication system to Coupler on the one side and same equipment is connected to the other side to create a Channel. Line Trap is tuned in parallel connected L and C . Line trap is the device that is used for tuning the line impedances so that good signal strength is insured. Power trap is tuned series connected L and C. Power trap is the device that blocks the power frequency to flow in the circuit, this is tuned so that signal can easily flow through the power trap. Signal trap which is also sometime referred as line trap is LC parallel connected. As the name suggests it is the device that blocks the signal from flowing in the circuit. Usually it is called signal trap as the signal is tapped out of this point and is feed in coupling transformer (CT) or to coupling system.
Limitations of the existing art
Following are the limitation of the existing coupling devices.
1. The main limitation of existing coupler is that the coupler devices are available either for very high voltages or for very low voltage lines. Because of this it has restricted its viability as other mode of communication. For example 11KV, 22KV, 33KV couplers are not available which can provide communication link on respective line voltages.
2. The existing couplers, need to be tuned in the existing technology for getting signal strength, there by remaining highly susceptible to the line condition.
3. Couplers that are being currently used have their limitation in terms of communicating it to smaller distance and does not offer scalability in terms to communicating to different distance levels.
4. Coupler on 11 KV.22, 33kV are not having the test mechanisms as well that can be used in the field at time of deployment.
5. Most important of all, existing technology of power-line coupling is based on trapping power frequency using inductor capacitor series and trapping signal around tuned parallel inductor and capacitor. The draw back of this is, wide band signal will find it difficult to work with and hence high speed communication and wide band communication was difficult to achieve.
OBJECTS OF THE INVENTION
The primary object of invention is to invent power line coupler for 11KV, 22KV
Another object of invention is to invent a method where in invented power line
coupling system can be used with a wide variety of two-way communicating
modems in the specified band of communication.
It is another object of invention to invent a power line coupler, that is, scalable in
sense of communicating for different distances.
It is another object of invention to invent power line coupling that can do
communication with high speed and for broadband.
SUMMARY OF THE INVENTION:
1. Figure -1 show the normal PLC network along with its components like Power line, Power line coupler, Power line modem and system interface to modem. It can be seen that the communication emanating from one system goes to the modem. And from the modulated output is feed into a power line coupler. Coupler injects the modulated signal into the power line and at the other end where it has to get received, power line coupler receives modulated signal and does not allow power frequency to enter the modem. Modem receives only the modulated signal and passes the appropriate signal into the system. Figure-2 shows the various components of the coupler for power line of the existing technology. The precised value and specification of its components are shown in the figure-2. It can be seen in the figure that Capacitor (d) blocks the power frequency and Inductor (L1) makes high impedance for signal frequency. Capacitor (C2) and Inductor (L2) in parallel forms a resonant circuit for the signal frequency and the signal is trapped at. The design of this parallel LC network is crucial to the implementation of communication on existing coupler. Modern broad band signal communication requirement puts lots of constrains on this LC circuit design. In this art we propose to come up with a design that can avoid usage of this LC network which has acted as bottleneck to the high speed, wide band communication requirements. Figure-3 shows the block diagram representation of existing art of figure-2. Figure-4 shows the block diagram of the invented coupler for 11KV, 22Kv and 33KV and table-1 specification of components. Modulated signal in the stipulated band enters from one of the sides through Tx point on the coupler and is received modulated through coupler through its Rx point. Capacitor provides an isolation of power and power frequency to the modem. Figure - 5 shows the circuit diagram of the invented coupler for11kV, 22KV and 33KV.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: Existing PLC system with its component.
Figure 2: Existing Coupling circuit and its components.
Figure 3: Block diagram representation of existing coupling system.
Figure 4: Block diagram of the invented coupling.
Figure 5 : Circuit diagram of the invented coupling.
Table 1: Bill of material and specification of components for invented coupling.
DETAILED DESCRIPTION OF THE INVENTION
If power-line is used as communication medium implies power-line is carrying signal and power frequency on same medium simultaneously. This implies that power frequency and signal frequencies are way apart from each other. Usually power frequency is at 50Hz and signal frequency as specified by CELENEC-C is 200KHz. Hence power frequency and modulated signal frequency can coexist on power line as medium of communication if there exists some device that can distinguish the power frequency and signal frequency. This is what the invented power line coupler does. It traps the power frequency and passes the signal frequency. In the present art of coupler design this was the fundamental use, line coupler (LC) are tuned to pass the signal. Hence the existing technology of coupler can pass signal that are ASK or FSK modulated signal. Since the line impedances change quite often, devices are fitted with another device called Line trap, which helps in manipulating the line impedance for the signal to reach destination properly. Since the modulation technique used on power line was
restricted to FSK, speed of communication could not increase and become a
slowly discarded entity as far as communication was concerned. High speed
communication could be possible on power line only when other communication
technology can be used like spread spectrum and OFDM etc. However using
this technology with existing coupler could not yield speed of communication
because of LC component, which has to cater to band of frequencies as
compared to particular frequency in the existing art. Hence we developed new
design as shown in figure-4 so that this bottleneck is handled both for band of
operation and voltage levels. In our design we have removed the LC component
and introduced a bleeder resistor (R) circuit which is used to tap the signal out
and a parallel Capacitor and bleeder resistor ( R C) combination is used to trap
power frequency. Very low capacitance along with another bleeder resistor is
Bleeder Resistors are resistors that are subject to hlgh voltages. Signal is trapped around the bleeder resistor of thin carbon film and is injected in high frequency Coupling transformer (CT) with amplifier. This helps in getting wide band of signal communicated on power line effectively. Subsequently this helps in getting very large through put.
SALIENT FEATURES OF THE COUPLER
1. 11KV, 22KV, 33KV design change is only in the RC unit (Cpacitor-Resistor) unit for the rating but not for the value. Other units are not to be changed for these voltage levels.
2. Broad band signals can be injected on 11 kv, 22kv, and 33Kv power line network because a resistive network is put into use instead of LC tuned network.
3. Rx/ Tx and Signal return path are different as compared to existing design where in Rx / Tx lines are multiplexed. Distinction between Rx and Tx is based on the impedance at the modem end. Hence DSSS and OFDM based modems can be effectively used.
4. Scalability in terms of distance can be provided by having signal voltage
amplification as an addon. 5. Since the power inductors are not used for the sake of efficiency, cost of entire product also comes down.
Explanation to Figure-4
1. RYB-N shows distribution system, consider it be 11KV, 22KV or any 33KV network.
2. If voltage level is changing then, the only block-1 composed of RC (Capacitor - Resistor) need to be changed for appropriate voltage rating. However our design value of capacitance in the range of 4.7nF to 7.5nF is important. Block-1 (RC) behaves like power trap.
3. Block-2 consisting of resistive circuit along with protection and grounding system and component.
4. A low rating coupling transformer unit is connected to block-3 to tap signal and also push the signal in the coupler unit.
5. Rx (receive) / Tx (Transmit) signals are tapped out and is fed to modem or to soft modem.
GLOSSARY OF TERMS AND THEIR DEFINITIONS
PLC: Power line communication.
DSSS: Direct sequence spread spectrum
OFDM: Orthogonal Frequency Division Multiplexing.
FSK: Frequency shift Keying
LC: tuned Inductor-Capacitor combination (referred both for series and parallel
CT: Coupling transformer.
RC: Resistive Capacitor series network.
TABLE-1 : BOM (with reference to figure-4)
Preliminary BOM with Suppliers for 11KV AC Coupler
1.) Insulated Feed Thru Terminals, by Lunday Ma.02703, Tel: +508-226-6012, Fax: +508- 226-6013. Page 16, # 4755,18Kv flashover, conductor head-style to 10-24 threaded top and bottom, material copper, 3 pes. Each assembly
a.) Commercial 1-24 x plated copper Nuts x 12 pes.
b.) Commercial size #10 flat copper washers x 12 pes.
c.) Commercial size # 10 solder lugs x 12 pes.
d.) Commercial Vi-20 plated copper hex nut x % in Lg. x 1 pc
e.) Commercial %-20 plated copper hex nut x 2 pes.
f.) Commercial V* in flat copper washer x 2 pes.
2.) Vishay Cera-Mite High Voltage Capacitors, 30DK series
a.) # 30DKD47,4700pf at 7KV RMS x 2.3 in. dia. x 1.18 in high x 6 pes.
b.) # 75-134A, Terminal adapters x 12 pes.
c.) Commercial plated copper nuts size # 8 x 12 pes
3.) Evox Rifa XI metallized Polypropylene, series PHE 844, with 22.5mm lead space a.) PHE844RD633MR06L2, 0.33uf x440VAC = 1 pc. b.) PHE844RD633MR06L2 0.47uf x440VAC = 3 pes
4.) Commercial Monolithic Ceramic Capacitors, 50V x l.Ouf x 0.2 spaced leads, x 4 pes ******
5.) High Voltage Resistors by Micro-Ohm RV series a.) RV-100,1W x 7KVrms x 5M ohm x 3 pes. b.) RV-50,1/2W x 2.5KVrms x 5M ohm x 4 pes.
6.) Commercial Carbon Film Resistors 1/2W x 350V *****
a.) 1 ohm x l/2w x 8 pes. *****
7.) Commercial Low inductance Movistors
a.) Movistor 175VAC x 4500A x 2 pes. ***** b.) Movistor 480VAC x 4500A x 3 pes.*****
8.) Element Surge Arrestor Gas Discharge Tube
a.) BH 350, 350V x PH 10KA x 4 pes.
9.) Commercial TVS devices
a.) 1.5KE27CA, bidirectional x 1500W x 27V x 5 pes. ***** b.) P6KE27CA, bidirectional x600Wx 27V x 2 pes. *****
10.) Connectors by Phoenix or similar
a.) Phoenix GMSTBVA 2.5/ 7- 7.62, male solder terminal x lpc. *****
b.) Phoenix mating part GMSTB 2.5/7- ST- 7.62 x lpc. *****
c.) Phoenix MSTBVA 2.5/5 - G x 2pcs. *****
d.) Phoenix mating part MSTB 2.5/5 - ST *****
11.) SKINTOP Non Metallic Strain Relief Connector SL-13
Part # SI 113x3 pes.
12.) Coupling transformers FMT - X3422 x 2 pes. *****
13.) Printed Circuit Board # PD01 Rev. A, dated January 29,2004 *****
14.) Assembly instructions for # PD01 Rev. A dated January 29,2004 ******
15.) Level # 2 Assembly data and part list
16.) Level #2 Partlist = Enclosure, gasket, top cover, stand offs, and hardware, including Mounting hardware for installation on test site, presently unknown.
End of preliminary part list,
1. A coupling system for high speed communication on powerline for different voltages comprising of powerline modem unit and coupler unit wherein said coupler unit has capacitor with 11/22kv rating of value in the range of 4.7nF to 7.5nF in parallel combination with bleeder resistor for trapping power frequency and a resistive network having a bleeder resistor for signal tapping.
2. A system as defined in claim 1 further comprising of protection and grounding equipments.
3. A system as defined in claim 1 where in the said modems are adapted for DSSS and for any existing modems.
4. A system as defined in claim-1 wherein said bleeder resistor used for trapping signal frequency is carbon thin film resistor..
5. A system as defined in claim 1 wherein movistor and surge arrestor gas discharge tube of appropriated rating is used in protection unit.
6. A system as defined in claim 1 further comprising of signal voltage amplifier for providing scalibility.
7. A system for high speed communication on power line substantially as herein defined and illustrated in the accompanying drawings.
|Indian Patent Application Number||852/MUM/2004|
|PG Journal Number||43/2007|
|Date of Filing||09-Aug-2004|
|Name of Patentee||MATRIX ENERGY SOLUTIONS PVT.LTD.|
|Applicant Address||C/O V.R.MOMAYA & ASSOCIATES, ARMY & NAVY BUILDING, 3RD FLOOR,148,M.G.ROAD, MUMBAI 400 001,|
|PCT International Classification Number||H04M9/00 H04B3/56|
|PCT International Application Number||N/A|
|PCT International Filing date|