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Research on measuring equipment of single phase electricity stealing with long distance monitoring function

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Research on measuring equipment of single phase electricity stealing with long distance monitoring function Research on measuring equipment of single phase electricity stealing with long distance monitoring function Document Transcript

  • Research on Measuring Equipment of Single-phaseElectricity-Stealing with Long-distance MonitoringFunctionZheng DezhiSchool of Instrument Science and Opto-electronicsEngineeringKey Laboratory of Precision Opto-mechatronicsTechonology Ministry of EducationBeijing University of Aeronautics and AstronauticsBeijing, Chinamickeyzheng@163.comWang ShuaiSchool of Instrument Science and Opto-electronicsEngineeringKey Laboratory of Precision Opto-mechatronicsTechonology Ministry of EducationBeijing University of Aeronautics and AstronauticsBeijing, Chinashuai841007@yahoo.com.cnAbstract— The power distribution monitor is an important researchin electric power system, and electricity-stealing defense is one of thechief steps in distribution network reconstruction. Due to the kind ofelectricity-stealing and actual demand of defending stealingelectricity, based on a digital single-phase electric energy meter, themetering equipment of electricity-stealing with long-distancemonitoring function is designed, which adopts a low powerconsumption MSP430 singlechip as the control core, uses thestandard electricity measure module as the basis of accurate measureof the electricity-stealing quantity, takes use of the output impulse ofstandard electricity measure module and user electric energy meter tocalculate and judge whether happen electricity-stealing, transmits thecurrent time and the number of electricity-stealing to the remoteterminal facility through GSM network. The system also realizes theuser’s measuring pocket monitoring, the image acquisition about theillegal on-off state of the user’s measuring pocket by using theCMOS image sensor, provides positive proof to handle lawbreakerswith the behavior of electricity-stealing. Results of the userapplication show that the system not only realizes monitoring thebehavior of electricity-stealing, accurately recording the time ofelectricity-stealing occur and finish, the quantity ofelectricity-stealing and image information of on-spotelectricity-stealing, but also realizes long-distance monitor thebehavior of electricity-stealing, which is convenient for centralizedmanagement .In addition, the system offers a solving method to thedata of meter reading.Keywords-electricity-stealing; long-distance monitoring; single-phase; digital electric energy meterI. IntroductionThe power distribution monitor is an important researchin electric power system, and electricity-stealing defense isone of the chief steps in distribution network reconstruction.Electricity-stealing is a long term problem, however, eachpower supply department has made huge investments ofmanpower and material, the phenomenon of defendingstealing electricity has increased and not abated, and themethod of electricity-stealing is continuously improved,some areas even appear the phenomenon of sellingelectricity-stealing product and special tool. The behaviorof electricity-stealing not only makes the power industrysuffering huge financial losses but also threatens the mainpower supply security and reliability [1-3].Due to the kind of electricity-stealing and actualdemand of defending stealing electricity, and based on adigital single-phase electric energy meter, the meteringequipment of electricity-stealing with long-distancemonitoring function is designed, which not only monitorsthe time electricity-stealing occur but also offers theelectricity-stealing quantity and image information ofelectricity-stealing locale, provides positive proof to handlelawbreakers with the behavior of electricity-stealing.II. The Analysis of Electricity-Stealing MethodThe metering of single-phase electric energy meter ismainly according to the relationship with voltage, electriccurrent and power-factor angle. if any factor is changed,electric energy meter slow turning, stalling and evenreversal will be caused, so the purpose ofelectricity-stealing is attained. According to theinvestigation analysis, there have been dozens of theelectricity-stealing trick about single-phase electric energymeter, the methods could be approximately divided intoundervoltage, undercurrent, phase-shifted and differenceexpansion (DE) to their principles.A. Stealing electricity by undervoltage technologyElectricity-stealer adopts all kinds of technology todeliberately change the wire splice of voltage circuit whichmetered by electrical energy, or make malfunction ofmeasuring voltage circuit, voltage curve of pressure loss orboth side of voltage decrease about the electric energymeter are caused, thus less measuring electric power ishappened. Here are some more common tricks [4]:1) Unhooking technology of electricity-stealing.Secretly destroy the lead sealing of electric energy meter,open voltage hook of terminal in junction box, and makeno electric current through, all using quantity of electricitysteal.Supported by AFR (Aviation Research Foundation) (2007ZD51050)978-1-4244-2487-0/09/$25.00 ©2009 IEEE
  • 2) Loose zero curve technology. Open input zero curveof meter, ground output zero curve of meter.3) One fire one ground technology. Take the groundwire as naught line, generally take the water pipe orcaliduct as ground wire, the risk is bigger.4) Violated wire connection.B. Stealing electricity by undercurrent technologyElectricity-stealer adopts all kinds of technology todeliberately change the wire splice of electric currentcircuit which is metered by electrical energy, or makesmalfunction of measuring electric current circuit, causescurrent curve of the electric energy meter through with noor part of electric current, thus less measuring electricpower is happened. Here are some more common tricks:1) Loop of short electric current, which makes theelectric energy meter shift slow.2) Cross meter to connect wire, added bypass to reelacross electric energy meter, which makes no or lesselectric current through, stall or less measurement.3) Exchange fire wire and zero wire.C. Stealing electricity by phase-shifted technologyElectricity-stealer adopts all kinds of technology todeliberately change normal wire connection of electricenergy meter, takes use of specifically connecting methodof inductance or capacitance to change the normal phaserelationship of voltage and current in the loop of electricenergy meter, thus the electric energy meter shift slow evenreversal is happened. Here are some more common tricks:1) Reverse the in and out fire wire. Make electriccurrent in the current coil reverse, and the electric energymeter reverse.2) Make the electric meter reverse by using externalpower supply. Adopt hand generator with voltage andcurrent output or inverter power supply to joint into theelectric meter, make the electric energy meter reverserapidly.D. Stealing electricity by difference expansion (DE)technologyElectricity-stealer disconnects electric energy meterprivately, adopts all kinds of technology to change innerstructural performance of electric energy meter to causeitself error increase. Make use of current or mechanicalforce to destroy electric energy meter, and change itsinstallation conditions, to make less electric energy record.Besides this above four electricity-stealing methods, theworst is that the user in private draw or connect wiredisorderly to steal electricity without reporting enter, thisstealing method with no meter always causes peopleinjuring and fire accident easily, and so on. They should beenforced and punished strictly.III. System Hardware RealizationA. System compositionThe system has two parts, they are the on-the-spotmonitoring facility and remote terminal facility in controlroom, principle as shown in the Fig.1, Fig.1 (a) is theremote terminal facility in control room, Fig.1 (b) is theon-the-spot monitoring facility.(a) Remote terminal facility in control room(b) On-the-spot monitoring facilityFig.1 Equipment principle block diagramThe remote terminal facility in control room is made upby personal computer (PC) and GSM communicationmodule. The special monitoring software is installed in PCto realize monitoring quantity of electricity in one pot andthe state of electricity-stealing in long-distance.The on-the-spot monitoring facility is made up bysinglechip, GSM communication module, image sensor,monitoring module of door switch in the user’s measuringpocket, and standard electricity measure module.Singlechip applies a low-power-consumption 16 bitsMSP430 to realize image signal acquisition, GSMcommunication module control, output frequency signal ofthe standard electricity measure module count, and on-offstate of the user’s measuring pocket monitoring [5].Image sensor is controlled by the singlechip, and takescharge of collecting image information when the door ofmeasuring pocket is opened, generally be set as illegal openof the measuring pocket and continuous collects five piecesof image information of 320*240 pixels.GSM communication module realizes the wireless datatransmission by using GSM mobile networks, transportsthe data to the remote terminal facility in control room inreal time, these data contain the time of electricity-stealing ,quantity of electricity-stealing, open time of measuring
  • pocket door, and image information, and so on [6].Standard electricity measure module adopts the innercore components of single-phase electric energy meter,which is fiducial by the measurement department, to realizethe accurate measurement of the user’s electricity quantity.B. The principle of system implementation1) Link method of on-spot monitoring facilityIn series link method is used between on-spotmonitoring facility and the user’s single-phase electricenergy meter, standard electricity measure module isconnected in series between the user single-phase electricenergy meter and fire wire, zero wire of enter user, theoutput of standard electricity measure module and theuser’s single-phase electric energy meter are separatelyphotoelectric isolated, then outputted to the singlechip tomeasure electricity. The link principle is shown in Fig.2.Fig.2 Facility link schematic2) Electricity-stealing defense principle of on-spotmonitoring facilityThe using circuital voltage and current are monitored bystandard electricity measure module in real time. Whenloaded by using electricity, standard electricity measuremodule outputs impulse which has a proportionalrelationship with power (the number of output impulse perkilowatt), the output of user single-phase electric energymeter also has a proportional relationship with power. Ifelectricity-stealing is took place, the user single-phaseelectric energy meter cannot measure accurately, thendiscrepancies will come up between the number of outputimpulse in standard electricity measure module and usersingle-phase electric energy meter in unit time, it isconsidered electricity-stealing happen or user electricenergy abnormal when the discrepancies accumulative totalarrives certain level.When the abnormity of electricity measure impulse intwo paths is monitored by singlechip, current time is record,the beginning time of electricity-stealing and alarminformation are transmitted to the remote terminal facilitythrough GSM network. At the same time, system separatelycounts the output impulse of standard electricity measuremodule and user electric energy meter, calculates thecurrent real electric consumption and electric energyconsumption record by user electric energy meter, this twodifference value are the number of user electricity-stealingafter stealing electricity. When electricity-stealing isfinished, standard electricity measure module outputimpulse is in keeping with user single-phase electric energymeter, system considers electricity-stealing finish, andtransmits the current time and the number ofelectricity-stealing to the remote terminal facility throughGSM network.System makes a monitor to the state of user’s measuringpocket. When measuring pocket door is illegal opened,magnetoelectricity which installed in measuring pocket iscut down by switch due to loose the magnetic field action,and imparts that measuring pocket door illegal opened tothe singlechip, the monitoring system begins to collect fivepieces of image information every one second, which aresent to the remote terminal facility in control room in theform of multimedia messaging service through GSMnetwork. If workers of electricity department need to do arelevant check to the user’s measuring pocket, they cansend the special command to on-spot monitoring facility bytelephone or remote terminal facility in control room, soalarm is relieved, the normal overhaul and process are did.IV. System Software DesigningA. The software of remote terminal facility in control roomThe software of remote terminal facility in control roomadopts VC++ language, calls the “Rui-Fang super SMScontrol” of third- party to realize processing short messages.At the same time, the image information is memorized inthe form of *.JPG into the catalog which established bycomputer, to realize saving the evidence on the ground.Control software interface is showed in Fig.3.Fig.3 Remote software interface in control roomB. The software of on-the-spot monitoring facilityThe software of on-the-spot monitoring facility adoptsC language, realizes collecting the output impulse signal ofstandard electricity measure module and user single-phaseelectric energy meter by using two paths of the terminalsignal in external, realizes the control of CMOS imagesensor by parallel port and I/O signals, and also realizes thecontrol of GSM communication module by using serialport. Fig.4 gives out software control flow.
  • Fig.4. Software flow block diagram of on-the-spot monitoring facilityAfter system is powered on, firstly the initializationwork of singlechip memory and each module are carried,the initialization parameters of each memory and functionalmodule are set up. Later, the system will separately judgesthe state of receive data of GSM communication module;the door of measuring pocket; and two paths of impulsesignal, once the change of each state is tested, thecorresponding function subprogram will be run, theyconclude the command of receiving data, imagesacquirement and alarm when the door of measuring pocketis opened, computation about electricity quantity and thestate of electricity-stealing, GSM alarms remotely whenelectricity-stealing and memory of the quantity ofelectricity-stealing are happened, and so on.V. System experimentIn order to test the system performance, standard userelectric system is constructed in library; artificial behaviorof electricity-stealing is imitated. When electricity-stealingstarts, on-spot monitoring facility begins to alarmelectricity-stealing to the remote terminal facility in controlroom. After finishing electricity-stealing, on-spotmonitoring facility sends the quantity of electricity-stealingand finish time to the remote terminal facility in controlroom. Make use of the standard electric energy meter ofclass 0.5 in the library to monitor the quantity ofelectricity-stealing, the five times measuring results showedin table 1.It can be seen that the maximal relative error is +0.57%in the five times simulation from Table I, the accuracy isreached with the metrical requirement of electric energymeter.Table I. Contrast data of quantity of electricity-stealingSerialnumberThe devicequantity (kWh)Standard electricitymeasures quantity (kWh)Error(kWh)1 1.056 1.050 0.0062 1.118 1.123 -0.0053 1.106 1.104 0.0024 1.008 1.004 0.0045 1.020 1.022 -0.002VI. ConclusionDue to the kind of electricity-stealing and actualdemand of electricity-stealing defending, and based on adigital single-phase electric energy meter, the meteringequipment of electricity-stealing with long-distancemonitoring functional is designed, which realizesmonitoring the time of electricity-stealing occur and finish,offering accurate compute of electricity-stealing quantity,collecting image information of electricity-stealing, andremote alarm function based on GSM network. It turns outthat, the system can accurate monitors the behavior ofelectricity-stealing, giving alarm prompt in time, reduceslosses of electricity-stealing to the minimum, decreasescountry property loss. In addition, system offers a solvingmethod to the data of meter reading.AcknowledgementThe author would like to thank Mr. Fan Daxiang forsharing his ideas on system design, and Mr. Li Yinwu fortheir valuable assistance and technical discussions.References[1] LV Zhi-an, XIAO Yan-ping. Design and development of an intelligentanti-steal-electricity-power instrument. Electronic measurement technology,2006, Vol.29, No.5: pp.93-95.[2] CHEN Yong-qiang, QIAN Wei, WANG Fang-bin. Anti-stealingController of Power Gauge Based on ARM. Instrumentation Technology,2007, Vol.1: pp.46-47.[3] SUN Feng-jie, LIU Zheng-fang, ZHANG Yong-can. Research onelectricity anti-stealing system based on GPRS wireless communication.Telecommunications for Electric Power System, 2006, Vol.28, No.171:pp.53-56.[4] HE Xiao-rong, DONG Chun, LIU Shu-xi. The new technology andapplication of single-phase electric energy meter defense electricity-stealing.Power supply, 2007, Vol.24, No.2: pp.70-71, 74.[5] Uros Bizjak, Drago Strle. IEC class 0.5 electronic watt-hour meterimplemented with first-order sigma-delta converters. International Journalof Electronics and Communications, 2005, Vol.59: pp.447-453.[6] ZHOU Wei, ZHU Rui-de, WANG Jin-quan. GSM-based monitoring andcontrol system against electricity stealing. Electric Power AutomationEquipment, 2004, Vol.24, No.2: pp.64-66.