CN2427812Y - Three phase measuring loop monitoring instrument - Google Patents

Three phase measuring loop monitoring instrument Download PDF

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Publication number
CN2427812Y
CN2427812Y CN 99244219 CN99244219U CN2427812Y CN 2427812 Y CN2427812 Y CN 2427812Y CN 99244219 CN99244219 CN 99244219 CN 99244219 U CN99244219 U CN 99244219U CN 2427812 Y CN2427812 Y CN 2427812Y
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CN
China
Prior art keywords
phase
loop
signal
wire
current
Prior art date
Application number
CN 99244219
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Chinese (zh)
Inventor
徐铭
李奕
徐钰岗
曹建平
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北京华奥电力设备有限公司
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Application filed by 北京华奥电力设备有限公司 filed Critical 北京华奥电力设备有限公司
Priority to CN 99244219 priority Critical patent/CN2427812Y/en
Application granted granted Critical
Publication of CN2427812Y publication Critical patent/CN2427812Y/en

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Abstract

The utility model relates to a three-phase measuring loop monitoring instrument used for monitoring an electric larceny action. The utility model uses a signal coupler to convert a square wave signal with a frequency which is larger than 50 Hz into perturbation electromotive force in an auxiliary side loop of a load current mutual inductor, and temporal perturbation current is caused in the loop. The intensity of the current reflects whether the current mutual inductor is connected in a short circuit way. A real time clock circuit of the utility model measures the time. After amplified, filtered, shaped and sampled in an A/D way, the data processing of a voltage and current signal is carried out by a microprocessor. The utility model can sense and record the occurrence time and the accumulated time of states, such as pressure loss, wrong wiring, short circuit connection of the current transformer, etc. The utility model is a powerful weapon in the field of anti-electric larceny.

Description

Three phase metering loop monitor
A kind of three phase metering loop monitor is used to monitor the correctness of three-phase electricity measurement loop wiring, and being used to monitor with the wiring of incorrect three-phase electricity measurement loop in other words is the behavior that means are carried out stealing.
The metering of three-phase electricity basically is exactly correct measurement three-phase mains voltage and threephase load electric current and electricity consumption time, just can calculate three phase electric power and three-phase electric energy (power consumption) thus.The measurement loop of three-phase electricity, a side is a signal source: each phase voltage signal provides through the supply voltage mutual inductor of a rated transformation ratio separately, and each phase load current signal provides through the load current mutual inductor of a rated transformation ratio separately; Opposite side is the input stage of measuring instrument: the input stage of accepting voltage signal is attempted by on the secondary of above-mentioned supply voltage mutual inductor, and the input stage of accepting current signal is connected in the secondary loop of above-mentioned load current mutual inductor.
Utilize the measurement loop incorrect cabling to carry out the gimmick of stealing, be broadly divided into three classes:
The first kind: decompression: at normal power supply with use electricity condition, disconnect the voltage input signal in electric energy meter or the measurement loop.
Second class: error connection: going into end and going out end and exchange (make electric current anti-phase) with current signal; Perhaps each phase voltage signal order of connection transposing.
The 3rd class: short circuit load current mutual inductor is secondary: making current signal is zero (or being approximately 0).
Application number is 99200177.3 utility model, it is by microprocessor 1, real-time clock 3, local voltage transformer (VT) 4_i (i=1,2, or 3), local current transformer 5_i (i=1,2, or 3), multiway analog switch 6_1, amplifying circuit 7_1 partly form with 7_2, shaping circuit 9_1 and 9_2, A/D transducer 8_1 and 8_2 etc.
Each mutually local voltage transformer (VT) (three-phase three-wire system is with 2, and three-phase four-wire system is with 3) is attempted by on the secondary of each phase supply voltage mutual inductor.
Each mutually local current transformer is connected in the secondary loop of each phase load current transformer.Multiway analog switch is under real-time clock and microprocessor control, time grate phase voltage and current signal by the microprocessor acquisition process, are obtained the effective value of electric current and voltage after amplification, shaping, A/D conversion, phase differential between them, active power and accumulative total electric weight; In addition, should point out especially it can judge whether the above-mentioned first kind and the second class electricity filching behavior are arranged.
Regrettably above-mentioned prior art can not be differentiated aforementioned the 3rd class electricity filching behavior, promptly can not distinguish following two kinds of different situations: be that not electricity consumption or load current mutual inductor secondary are by short circuit
The purpose of this utility model is the deficiency that will remedy prior art, provides a kind of and whether can differentiate load current mutual inductor secondary by the technology of short circuit.
Basic ideas of the present utility model are to apply the disturbance electromotive force that a certain frequency of of short duration amplitude is higher than 50Hz in the load current loop of measurement loop, the current perturbation that this disturbance electromotive force causes in the loop, its size is relevant with the impedance in loop: when load current mutual inductor secondary during by short circuit, current perturbation is big, otherwise current perturbation is little.As seen, whether just can differentiate load current mutual inductor secondary by short circuit from the size of current perturbation.Certainly, this disturbance should be limited in the scope of precision permission the influence of measuring instrument.Suitably improve the frequency of disturbing signal, the intensity of restriction disturbance and shortening disturbance duration just can reduce the influence of disturbance to measuring accuracy.
Be the technical scheme that realizes above-mentioned design below.
Be on the basis of 99200177.3 utility model at application number, increase an oscillator 14, it has the start-stop of a control end may command vibration, and the control signal of vibration start-stop is sent by microprocessor; Increase by 2 (for three-phase three-wire system) or 3 (for three-phase four-wire system) signal converter 12_1,12_2,12_3, they are connected in the secondary loop of load current mutual inductor of each phase separately; Other increases a multiway analog switch 6_2, and it is connected the output of oscillator 14 and the input end of signal converter 12_i (i=1,2 or 3) under real time clock circuit and microprocessor control.Current perturbation is strobed into amplifying circuit 7_3 through local current transformer 5_i (i=1,2 or 3) output by multiway analog switch 6_2, send A/D transducer 8_3 again behind filtering and rectification circuit 13, send the microprocessor judgement that performs an analysis at last.
Regularly carry out under the programmed control of microprocessor to the sampling of voltage, current signal with to the disturbance of current return, for example carried out once in one minute.To the analysis of making comparisons of adjacent double sampling data, have or not ANOMALOUS VARIATIONS as can be known, if find to have ANOMALOUS VARIATIONS, then just these data are comprised that changing the time of taking place deposits storer in as exception record, in order to inquiry.For example: have or not decompression or recover normal by decompression; Have or not error connection or recover normal wiring; Load current mutual inductor secondary has or not short circuit or recovers normal or the like by short circuit.
The utility model has adopted computer technology, the effective value of the effective value of energy measurement three-phase voltage, threephase load electric current, active power, meritorious electric weight, also have analysis-by-synthesis and memory capability, can perception and when write down decompression and decompression cumulative time, when measurement loop error connection and duration thereof take place, when short circuit load current mutual inductor and short circuit duration, in a word can perception and write down the type of stealing and the cumulative time of time of origin and stealing, the utility model will be as the powerful mean in the field of opposing electricity-stealing.
Description of drawings
Fig. 1 is the structured flowchart of three phase metering loop monitor, wherein 1 is microprocessor, the 2nd, storer, the 3rd, real time clock circuit, 4_1,4_2,4_3 are local voltage transformer (VT), 5_1,5_2,5_3 are local current transformers, 6_1,6_2 are multiway analog switches, and 7_1,7_2,7_3 are amplifying circuits, and 8_1,8_2,8_3 are the A/D transducers, 9_1,9_2 are shaping circuits, the 10th, palm PC, the 11st, microcomputer, 12_1,12_2,12_3 are signal converters, the 13rd, filtering and rectification circuit, the 14th, oscillator.
Fig. 2 is a three phase metering loop monitor three-phase four-wire system input circuit wiring diagram.Wherein A, B, C are each phase firewire, and N is a center line.LPT1, LPT2, LPT3 are 4_1,4_2, the 4_3 among Fig. 1, are local voltage transformer (VT).LCT1, LCT2, LCT3 are 5_1,5_2, the 5_3 among Fig. 1, are local current transformers.ST1, ST2, ST3 are 12_1,12_2, the 12_3 among Fig. 1, are signal converters.CT1, CT2, CT3 are the load current mutual inductors.
Fig. 3 is a three phase metering loop monitor three-phase three-wire system input circuit wiring diagram.Wherein A, B, C are live wires.PT is the supply voltage mutual inductor, and CT1, CT3 are the load current mutual inductors.LPT1, LPT3 are 4_1, the 4_3 among Fig. 1, are local voltage transformer (VT).LCT1, LCT3 are 5_1, the 5_3 among Fig. 1, are local current transformers.ST1, ST3 are 12_1, the 12_3 among Fig. 1, are signal converters.
Embodiment
By the three phase metering loop monitor that technical characterictic of the present utility model is formed, its input circuit connection such as Fig. 2 or Fig. 3.
Fig. 2 is suitable for three-phase four-wire system, and Fig. 3 is suitable for three-phase three-wire system.
LPT1, LPT2, LPT3 are local voltage transformer (VT), LCT1, LCT2, LCT3 are local current transformers, ST1, ST2, ST3 are signal converter (coupling transformers of a rated transformation ratio), 6_1,6_2 are multiway analog switches, can adopt two four to select one analog switch 4052, the X passage of 6_2 is used for oscillator signal is strobed in the electric current measurement loop of certain phase, and the Y passage of 6_2 is used for the current perturbation of gating phase to amplifying circuit 7_3.
Oscillator 14 can adopt 7555 multivibrators of forming, its repetition frequency fo (for example: 1kHz fo 5kHz).7555 pin 4 connects certain I/O pin of microprocessor, with the start-stop of control vibration.
It is the bandpass filter series connection of fo that wave filter can adopt 50Hz trapper and centre frequency.

Claims (2)

1, a kind of three phase metering loop monitor is used to monitor electricity filching behavior, and it has:
(1.1) local voltage transformer (VT) is connected in parallel on respectively on the secondary of each phase supply voltage mutual inductor for 3 of three-phase four-wire system need for 2 of three-phase three-wire system need,
(1.2) local current transformer needs 2 for three-phase three-wire system, needs 3 for three-phase four-wire system, be connected on separately in the secondary loop of each phase load current transformer,
(1.3) multiway analog switch, the secondary of its input side and local voltage transformer (VT) and local current transformer links, its outgoing side connection amplifying circuit,
(1.4) amplifying circuit, shaping circuit,
(1.5) A/D transducer,
(1.6) real time clock circuit,
(1.7) microprocessor is characterized in that also having:
(1.8) frequencies are higher than the oscillator of 50Hz, under real time clock circuit and microprocessor control, regularly send the disturbing signal of of short duration certain amplitude,
(1.9) signal coupler, need 2 for three-phase three-wire system, need 3 for three-phase four-wire system, elementary (1.10) described multiway analog switch of each signal coupler links with (1.8) described oscillator output end, each signal coupler secondary is connected on respectively in the secondary loop of each phase load current transformer
(1.10) another multiway analog switch in order to some in (1.9) described signal coupler above the gating under the control of real time clock circuit and microprocessor, and is coupled to disturbing signal in the secondary loop of certain phase load current transformer,
(1.11) whether relevant the size of the current disturbing signal of said fixing frequency is with load current mutual inductor secondary short circuit, and this signal reaction is secondary (1.2) described current transformer, after amplification filtering, shaping, by the microprocessor acquisition process.
2, according to the described three phase metering of claim 1 loop monitor, it is characterized in that said oscillator by 7555 multivibrators of forming, its pin 4 is used to control the start-stop of vibration, and its oscillation frequency is selected within 1kHz~5kHz.
CN 99244219 1999-09-07 1999-09-07 Three phase measuring loop monitoring instrument CN2427812Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 99244219 CN2427812Y (en) 1999-09-07 1999-09-07 Three phase measuring loop monitoring instrument

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 99244219 CN2427812Y (en) 1999-09-07 1999-09-07 Three phase measuring loop monitoring instrument

Publications (1)

Publication Number Publication Date
CN2427812Y true CN2427812Y (en) 2001-04-25

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Application Number Title Priority Date Filing Date
CN 99244219 CN2427812Y (en) 1999-09-07 1999-09-07 Three phase measuring loop monitoring instrument

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010081280A1 (en) * 2009-01-13 2010-07-22 中国计量科学研究院 Three-phase electric energy measurement apparatus
CN104991151A (en) * 2015-06-24 2015-10-21 国家电网公司 Method and device for analyzing wrong wiring of three-phase four-wire electric energy metering device
CN105259381A (en) * 2015-10-28 2016-01-20 江苏省电力公司常州供电公司 Portable active electric energy metering device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010081280A1 (en) * 2009-01-13 2010-07-22 中国计量科学研究院 Three-phase electric energy measurement apparatus
US8823359B2 (en) 2009-01-13 2014-09-02 National Institute Of Metrology P.R. China Three-phase electric energy measurement apparatus
CN104991151A (en) * 2015-06-24 2015-10-21 国家电网公司 Method and device for analyzing wrong wiring of three-phase four-wire electric energy metering device
CN105259381A (en) * 2015-10-28 2016-01-20 江苏省电力公司常州供电公司 Portable active electric energy metering device
CN105259381B (en) * 2015-10-28 2017-05-10 江苏省电力公司常州供电公司 Portable active electric energy metering device

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