CN101666846B - System and method for detecting anomaly of secondary wiring of current mutual inductor - Google Patents
System and method for detecting anomaly of secondary wiring of current mutual inductor Download PDFInfo
- Publication number
- CN101666846B CN101666846B CN200910190298A CN200910190298A CN101666846B CN 101666846 B CN101666846 B CN 101666846B CN 200910190298 A CN200910190298 A CN 200910190298A CN 200910190298 A CN200910190298 A CN 200910190298A CN 101666846 B CN101666846 B CN 101666846B
- Authority
- CN
- China
- Prior art keywords
- mutual inductor
- current mutual
- coil
- wiring
- digital
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The invention relates to the field of electricity metering and charging, and discloses a system and a method for detecting anomaly of the second wiring of a current mutual inductor. The system for detecting the anomaly of the second wiring of the current mutual inductor comprises a detection circuit, an analog-to-digital converter (ADC), a digital high-pass filter and an anomaly judging module; the detection circuit comprises an external current mutual inductor, an internal current mutual inductor, a coil, an iron core, a resister and a high-frequency signal source; and the external current mutual inductor, the internal current mutual inductor, the coil, the iron core, the resister and the high-frequency signal source are electrically connected. The invention has the beneficial effects of: not relying on the vector relation of three-phase voltage and current, being applied to a single-phase measuring circuit besides being used in a three-phase measuring circuit; reliably recognizing the situations of non-loaded current wiring and open circuit wiring; conducting 24-hour online detection and real-time monitoring, and having keen reaction, low implementation cost addition, and convenience and simplicity.
Description
Technical field
The present invention relates to electricity consumption metering and billing field, particularly a kind of system and method that detects anomaly of secondary wiring of current mutual inductor.
Background technology
In the electricity consumption metering and billing; Usually to use the voltage transformer (VT) summation current transformer; Voltage transformer (VT) converts high voltage to low-voltage, and current transformer becomes little electric current with big current conversion, and metering unit calculates electricity consumption according to small-signal; Multiply by no-load voltage ratio at last and obtain real power consumption. voltage transformer (VT), whether the secondary connection of current transformer correctly has crucial influence to accurate metering.The secondary connection situation common methods that detects current transformer is the phase relation through inspection three-phase voltage electric current and zero-sequence current, judges the whether short circuit of certain phase current.Current detection method commonly used adopts the pure software detection method; But its computing method are complicated; A zero-sequence current threshold value need be set, and whether the setting of this value threshold value is rationally relevant with field condition. and simultaneously, these class methods also can't be differentiated open circuit situation and no-load current situation.
Summary of the invention
In order to solve the problems of the prior art, the invention provides a kind of system and method that detects anomaly of secondary wiring of current mutual inductor, solve the problem that can't differentiate open circuit situation and no-load current in the present detection method, reach easy to detect, purpose efficiently.
The present invention solves the technical scheme that the prior art problem adopted: design and make a kind of system that detects anomaly of secondary wiring of current mutual inductor, comprise testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module; Said testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module connect successively; Said testing circuit comprises outside, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source; Said outside, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source are electrically connected.
The present invention further improves: said coil is a secondary coil; Said iron core, secondary coil and internal current mutual inductor are formed new current transformer.
The present invention further improves: the secondary coil of said new current transformer comprises first secondary coil and second subprime coil; Said first secondary coil is connected with said resistance; Said second subprime coil is connected with said high-frequency signal source.
The present invention further improves: said ADC analog to digital converter converts AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal and feeds back in the said unusual judge module.
The present invention provides a kind of method that detects anomaly of secondary wiring of current mutual inductor again, comprises the steps, (S1) carries out the circuit connection and generates AC signal and high-frequency signal; (S2) analog to digital converter carries out analog to digital conversion; (S3) digital high-pass filter separates digital signal; (S4) unusual judge module detects the wiring situation of foreign current mutual inductor.
The present invention further improves: in the said step (S1), with testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module connect respectively; Said testing circuit comprises foreign current mutual inductor, internal current mutual inductor, resistance, iron core, coil and high-frequency signal source; Said internal current mutual inductor, iron core and coil are formed new current transformer.
The present invention further improves: said analog to digital converter converts the mixed signal of AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal.
The present invention further improves: in the said step (S4), said unusual judge module detects from the high-frequency signal of digital high-pass filter feedback and judges the wiring situation of foreign current mutual inductor.
The present invention further improves: said wiring situation comprises short circuit, open circuit and wiring normal condition.
The present invention further improves: said new current transformer comprises two iron cores of vertically arranging; Said both sides unshakable in one's determination are respectively primary coil and secondary coil; Said secondary coil comprises first secondary coil and second subprime coil; Said first secondary coil is connected with resistance; Said second subprime coil is connected with high-frequency signal source.
The invention has the beneficial effects as follows: through simple modifications metering mutual inductor; Inject a high-frequency signal source; In conjunction with the DSP technology, solved the decision problem of the various wiring abnormal conditions of power current transformer secondary, following advantage is arranged: the vector correlation that does not rely on the three-phase voltage electric current; Except that can be used for the three-phase metering circuit, also can be used in the single-phase metering circuit; Tell the situation of no-load current wiring and open circuit wiring reliably; Can online detection in 24 hours, monitoring is quick on the draw in real time; The implementation cost increase seldom, and is convenient and easy.
Description of drawings
Fig. 1 is the system chart that the present invention detects anomaly of secondary wiring of current mutual inductor.
Fig. 2 is the system's block diagram commonly used that detects anomaly of secondary wiring of current mutual inductor.
Fig. 3 is the process flow diagram that the present invention detects the method for anomaly of secondary wiring of current mutual inductor.
Embodiment
Below in conjunction with accompanying drawing the present invention is described further.
A kind of system that detects anomaly of secondary wiring of current mutual inductor comprises testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module; Said testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module connect successively; Said testing circuit comprises outside, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source; Said outside, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source are electrically connected.
Said coil is a secondary coil; Said iron core, secondary coil and internal current mutual inductor are formed new current transformer.
The secondary coil of said new current transformer comprises first secondary coil and second subprime coil; Said first secondary coil is connected with said resistance; Said second subprime coil is connected with said high-frequency signal source.
Said ADC analog to digital converter converts AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal and feeds back in the said unusual judge module.
Fig. 2 is a typical current measuring principle block diagram in the electronic metering; TA0 is external power current transformer (promptly being requirement current transformer to be detected), A, and 2 right sides of B are metering units; TA1 is the internal measurement Current Transformer; It further converts current signal to littler small-signal, and R1 is a sample resistance, converts analog voltage signal to digital signal through ADC after converting the current signal of TA1 output to voltage signal.
Fig. 1 is an enforcement illustration among the present invention; This scheme is improved metering internal current mutual inductor TA1, has increased an iron core, a secondary winding and a high-frequency signal source S1; The frequency range of choice of high-frequency signal source S1 is at 1.5KHZ-2KHZ; Be between 30 frequencys multiplication～40 frequencys multiplication of alternating current 50HZ, according to Nyquist's theorem, sampling rate is recovered out with high-frequency signal at the ADC of 8Kbps converter easily.
The present invention provides a kind of method that detects anomaly of secondary wiring of current mutual inductor again, comprises the steps, S1 carries out the circuit connection and generates AC signal and high-frequency signal; The S2 analog to digital converter carries out analog to digital conversion; The S3 digital high-pass filter separates digital signal; The unusual judge module of S4 detects the wiring situation of foreign current mutual inductor.
Among the said step S1, with testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module connect respectively; Said testing circuit comprises foreign current mutual inductor, internal current mutual inductor, resistance, iron core, coil and high-frequency signal source; Said internal current mutual inductor, iron core and coil are formed new current transformer.
Said analog to digital converter converts the mixed signal of AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal.
Among the said step S4, said unusual judge module detects from the high-frequency signal of digital high-pass filter feedback and judges the wiring situation of foreign current mutual inductor.
Said wiring situation comprises short circuit, open circuit and wiring normal condition.
Said new current transformer comprises two iron cores of vertically arranging; Said both sides unshakable in one's determination are respectively primary coil and secondary coil; Said secondary coil comprises first secondary coil and second subprime coil; Said first secondary coil is connected with resistance; Said second subprime coil is connected with high-frequency signal source.
In implementation process,,, establish the number of primary turns N1 of TA1, N2 in conjunction with the DSP technology like Fig. 2; The secondary coil number of turn is respectively N3, N4, and N1 wherein, N3 is former metering section; N2, N4 is two parts of same coil for newly-increased part .N2 with N1, normally during wiring, A; 2 of B connect the foreign current mutual inductor, constitute the circuit loop of a closure, and it is high frequency ac signal that impedance loop is made as R1. signal S1, are coupled to elementary (secondary that is TA0 is surveyed) of TA1 through mutual inductor TA1.
If the magnetic resistance of N4 is R4, the magnetic flux that high-frequency signal S1 produces on N4 is φ (t),
φ(t)＝N4*I4(t)/R4，
Electromotive force E=N2*d φ (t)/dt that φ (t) responds on N2;
Electromotive force E produces induction current I2, I2=E/R1 in the closed-loop path;
High-frequency ac current signal I2 is coupled to N3 through TA1, is made as I3;
Through high-speed ADC, the mixed signal of 50HZ AC signal and S1 signal is converted to digital signal;
Separate 50HZ signal and S1 signal very easily through DSP digital filter (iir filter);
Can judge the wiring situation of foreign current mutual inductor very easily through the S1 signal that detects feedback; As outside A, in the time of the short circuit of B point, impedance loop R1 diminishes, and then I2=E/R1 diminishes, and then I3 also diminishes, and according to the amplitude that diminishes, can judge degree of short circuit (shunting) very easily;
As outside A, in the time of B point open circuit, can measure i3 (i1 is coupled to the 50HZ alternating current of N3)=0; I3=0; Can be judged as open circuit;
If wiring is normal, but i1 (outside mutual inductor secondary current) actual be 0, then can measure i3=0; I3 is slightly larger than 0; It is normal to be judged as wiring; This is because work as A, when the B point has the foreign current of access mutual inductor, can introduce a high frequency noise sources; Make that I3 is not 0, in the time of open circuit, do not have noise source; For the good adc circuit of design, measurement result is similar to 0, and the mean value in the desirable time window compares.
Through above method, whether the secondary connection that can detect current transformer accurately is unusual.Through improving the metering mutual inductor, inject a high-frequency signal source, in conjunction with the DSP technology, solved the decision problem of the various wiring abnormal conditions of power current transformer secondary.Do not rely on the vector correlation of three-phase voltage electric current, except that can be used for the three-phase metering circuit, also can be used in the single-phase metering circuit.
Above content is to combine concrete preferred implementation to the further explain that the present invention did, and can not assert that practical implementation of the present invention is confined to these explanations.For the those of ordinary skill of technical field under the present invention, under the prerequisite that does not break away from the present invention's design, can also make some simple deduction or replace, all should be regarded as belonging to protection scope of the present invention.
Claims (7)
1. a system that detects anomaly of secondary wiring of current mutual inductor comprises testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module; Said testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module connect successively; Said testing circuit comprises foreign current mutual inductor, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source; Said foreign current mutual inductor, internal current mutual inductor, coil, iron core, resistance and high-frequency signal source are electrically connected, and it is characterized in that: said ADC analog to digital converter converts AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal and feeds back in the said unusual judge module.
2. according to the system of the said detection anomaly of secondary wiring of current mutual inductor of claim 1, it is characterized in that; Said coil is a secondary coil; Said iron core, secondary coil and internal current mutual inductor are formed new current transformer.
3. according to the system of the said detection anomaly of secondary wiring of current mutual inductor of claim 2, it is characterized in that: the secondary coil of said new current transformer comprises first secondary coil and second subprime coil; Said first secondary coil is connected with said resistance; Said second subprime coil is connected with said high-frequency signal source.
4. a method that detects anomaly of secondary wiring of current mutual inductor is characterized in that: comprise the steps, (S1) carry out the circuit connection and generate AC signal and high-frequency signal; (S2) analog to digital converter carries out analog to digital conversion; (S3) digital high-pass filter separates digital signal; (S4) unusual judge module detects the wiring situation of foreign current mutual inductor; In the said step (S1), testing circuit, ADC analog to digital converter, digital high-pass filter and unusual judge module are connected respectively; Said testing circuit comprises foreign current mutual inductor, internal current mutual inductor, resistance, iron core, coil and high-frequency signal source; Said internal current mutual inductor, iron core and coil are formed new current transformer; Said new current transformer comprises two iron cores of vertically arranging; Said both sides unshakable in one's determination are respectively primary coil and secondary coil; Said secondary coil comprises first secondary coil and second subprime coil; Said first secondary coil is connected with resistance; Said second subprime coil is connected with high-frequency signal source.
5. according to the method for the said detection anomaly of secondary wiring of current mutual inductor of claim 4, it is characterized in that: said analog to digital converter converts the mixed signal of AC signal and high-frequency signal to digital signal; Said digital high-pass filter separates said AC signal and high-frequency signal.
6. according to the method for the said detection anomaly of secondary wiring of current mutual inductor of claim 4; It is characterized in that: in the said step (S4), said unusual judge module detects from the high-frequency signal of digital high-pass filter feedback and judges the wiring situation of foreign current mutual inductor.
7. according to the method for the said detection anomaly of secondary wiring of current mutual inductor of claim 6, it is characterized in that: said wiring situation comprises short circuit, open circuit and wiring normal condition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910190298A CN101666846B (en) | 2009-09-25 | 2009-09-25 | System and method for detecting anomaly of secondary wiring of current mutual inductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910190298A CN101666846B (en) | 2009-09-25 | 2009-09-25 | System and method for detecting anomaly of secondary wiring of current mutual inductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101666846A CN101666846A (en) | 2010-03-10 |
| CN101666846B true CN101666846B (en) | 2012-09-12 |
Family
ID=41803550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910190298A Expired - Fee Related CN101666846B (en) | 2009-09-25 | 2009-09-25 | System and method for detecting anomaly of secondary wiring of current mutual inductor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101666846B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103941146B (en) * | 2014-03-27 | 2016-03-02 | 云南电网有限责任公司昆明供电局 | A kind of apparatus and method detecting and distinguish each Secondary Winding accuracy rating of 10kV current transformer that do not have a power failure |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101937048B (en) * | 2010-07-27 | 2012-10-03 | 上海诺雅克电气有限公司 | Wire-break self diagnosis method and device for current transformer secondary coils |
| CN102520309A (en) * | 2011-12-07 | 2012-06-27 | 宁波三星电气股份有限公司 | Method for judging open circuit of secondary loop of current transformer |
| CN103163409B (en) * | 2011-12-19 | 2016-01-27 | 上海安科瑞电气股份有限公司 | Anti-bearing calibration and device is connect for the wiring of on-the-spot electric instrument electric current |
| CN102967792B (en) * | 2012-11-19 | 2015-07-08 | 北京交通大学 | System and method for monitoring open-circuit faults of secondary circuit of current transformer in traction substation |
| CN104297611B (en) * | 2014-01-14 | 2017-10-27 | 许昌智能继电器股份有限公司 | A kind of mutual inductor sample circuit |
| CN104330762B (en) * | 2014-11-21 | 2017-05-10 | 无锡韩光电器股份有限公司 | Line fault detection circuit for current transformer |
| CN106226638A (en) * | 2016-08-26 | 2016-12-14 | 四川和中电力科技有限公司 | A kind of low voltage mutual inductor measurement loop state on_line monitoring system |
| CN107861093B (en) * | 2017-11-18 | 2023-12-15 | 深圳供电局有限公司 | Portable electric energy metering wiring verification device |
| CN108152784A (en) * | 2017-12-29 | 2018-06-12 | 江苏林洋能源股份有限公司 | A kind of circuit and method that external CT states are detected for mutual inductor access electric energy meter |
| CN109100603A (en) * | 2018-09-30 | 2018-12-28 | 中国电力科学研究院有限公司 | The detection device and method of secondary loop of mutual inductor short circuit |
| CN110221239A (en) * | 2019-06-28 | 2019-09-10 | 深圳市锐能微科技有限公司 | Three-phase current detection circuit, method and electric energy computation chip |
| CN112285618A (en) * | 2019-12-20 | 2021-01-29 | 青岛鼎信通讯股份有限公司 | Scheme for detecting CT secondary side wiring state |
| CN112415460A (en) * | 2020-09-07 | 2021-02-26 | 青岛鼎信通讯股份有限公司 | Current transformer fault self-diagnosis system and method |
| CN113640727A (en) * | 2021-01-21 | 2021-11-12 | 青岛鼎信通讯股份有限公司 | CT secondary circuit detection method based on PWM excitation and fixed frequency analysis |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1632606A (en) * | 2004-12-29 | 2005-06-29 | 重庆龙源科技产业发展有限公司 | Current transformer failure metering and electric larceny proof real-time on-line detection method and apparatus |
-
2009
- 2009-09-25 CN CN200910190298A patent/CN101666846B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1632606A (en) * | 2004-12-29 | 2005-06-29 | 重庆龙源科技产业发展有限公司 | Current transformer failure metering and electric larceny proof real-time on-line detection method and apparatus |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103941146B (en) * | 2014-03-27 | 2016-03-02 | 云南电网有限责任公司昆明供电局 | A kind of apparatus and method detecting and distinguish each Secondary Winding accuracy rating of 10kV current transformer that do not have a power failure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101666846A (en) | 2010-03-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101666846B (en) | System and method for detecting anomaly of secondary wiring of current mutual inductor | |
| CN110174625B (en) | Insulation monitoring system and monitoring algorithm for resistance of power battery pack | |
| CN110333427B (en) | IGBT open-circuit fault diagnosis method for sending end converter of flexible direct-current transmission system | |
| CN101609116B (en) | New method for detecting input phase failure | |
| CN102590587A (en) | Device and method for identifying short-circuit current of medium-voltage high-current direct current circuit breaker | |
| CN109001577A (en) | A kind of electrical energy measurement live data analysis method and system | |
| CN105891606A (en) | Device for testing tower grounding resistance through disassembly-free ground lead | |
| CN103063895B (en) | Pliers-shaped anti-interference current transformer and transformer iron core grounding current testing system | |
| CN105182126B (en) | Improved distribution transformer energy efficiency metering detection method | |
| CN201233423Y (en) | Electric network voltage detection device | |
| CN102393480A (en) | Electric quantity compensation method during live replacement of electric energy meter | |
| CN201107394Y (en) | Electrical signal insulating testing apparatus of permanent magnetism synchronous electric machine | |
| CN103424622B (en) | A kind of detection of fractional harmonic source and determination methods | |
| CN207149352U (en) | Transformer demagnetization instrument with remanent magnetism quantitative analysis function | |
| CN106707028A (en) | Transformer short-circuit impedance on-line monitoring method and device | |
| CN108594155A (en) | A kind of electrical energy meter electricity current transformer supersaturation characterisitic parameter measuring system and method | |
| CN203216993U (en) | Power-grid harmonic real-time online monitor | |
| CN106990381A (en) | A kind of transformer magnetic saturation detection means | |
| CN103743941A (en) | Wireless communication clamp alternating current ammeter without power supply | |
| CN201804052U (en) | Integrative testing device for low frequency and frequency conversion current transformer | |
| CN207398818U (en) | No-load transformer phased switch system | |
| CN102095924A (en) | Detection device for power utilization and measurement of high-voltage circuit | |
| CN114944638A (en) | Electronic release and method suitable for three-phase alternating current circuit breaker | |
| CN107479016A (en) | A kind of flexible direct current power network direct current high-speed measuring device method for testing performance and system | |
| CN203502494U (en) | Power grid harmonic online detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210623 Address after: 518000 Room 202, block B, aerospace micromotor building, No.7, Langshan No.2 Road, Xili street, Nanshan District, Shenzhen City, Guangdong Province Patentee after: Shenzhen LIAN intellectual property service center Address before: Five, T2 building, 518057 South District, Nanshan District science and Technology Park, Guangdong, Shenzhen Patentee before: Shenzhen Clou Electronics Co.,Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120912 Termination date: 20210925 |