CN106842097A - A kind of anti-DC performance detection means of current transformer and method - Google Patents

A kind of anti-DC performance detection means of current transformer and method Download PDF

Info

Publication number
CN106842097A
CN106842097A CN201710094830.9A CN201710094830A CN106842097A CN 106842097 A CN106842097 A CN 106842097A CN 201710094830 A CN201710094830 A CN 201710094830A CN 106842097 A CN106842097 A CN 106842097A
Authority
CN
China
Prior art keywords
current
transformer
current transformer
tested
sampling
Prior art date
Application number
CN201710094830.9A
Other languages
Chinese (zh)
Inventor
刘见
靳绍平
李东江
李敏
王浔
王英
杨爱超
吴宇
唐新宇
李欣
聂方明
Original Assignee
国网江西省电力公司电力科学研究院
国家电网公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 国网江西省电力公司电力科学研究院, 国家电网公司 filed Critical 国网江西省电力公司电力科学研究院
Priority to CN201710094830.9A priority Critical patent/CN106842097A/en
Publication of CN106842097A publication Critical patent/CN106842097A/en

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R35/00Testing or calibrating of apparatus covered by the preceding groups
    • G01R35/02Testing or calibrating of apparatus covered by the preceding groups of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating

Abstract

The present invention relates to a kind of anti-DC performance detection means of current transformer and method,Current lifting device output end constitutes alternating current branch road with noninductive capacitances in series,DC current generator current output terminal and reactor DC current branch road in series,The primary side that ac and dc current accesses tested current transformer is formed after alternating current branch road and DC current branch circuit parallel connection,Standard current transformer primary side seals in alternating current branch road,The secondary side of tested current transformer accesses the tested current transformer current input terminal of digital mutual inductor tester after being connected with current capacity case,The standard current transformer current input terminal of the secondary side joint digital mutual inductor tester of standard current transformer,By the proportion for adjusting DC current in the adjustable ac and dc current of DC current and alternating current size,To detect and evaluate the anti-DC performance that current transformer is detected under different specific weight DC component.The present invention solves non-punching and great current mutual inductor test problems.

Description

A kind of anti-DC performance detection means of current transformer and method

Technical field

The present invention relates to a kind of anti-DC performance detection means of current transformer and method, belong to current transformer detection technique Field.

Background technology

As nonlinear-load application is more and more universal, load current is also more and more containing DC component, and straightening high Stream transmission of electricity also makes power circuit contain DC component, and load current DC component makes current transformer core magnetic saturation, causes iron The Effective permeability of core reduces, and error significantly to negative value reserve migration will influence the accuracy of electric energy metrical, and inspection is needed for this Current transformer error characteristic under DC component influence is surveyed, the detection project is called anti-DC performance detection, anti-DC performance master It is the error that detection current transformer is flowed down in superposition DC component industrial-frequency alternating current to want detection method, has document to propose alternating current Flowing back to road and DC current return, to form the equivalent detection of power current containing DC component electric current through current transformer alone mutual The anti-DC performance of sensor, but this method is not suitable for the anti-DC performance detection of non-straight-through current transformer;Using any ripple Shape generating means can produce single turn industrial frequency AC containing DC component electric current, but the size of current for producing is limited, it is impossible to meet specified The anti-DC performance detection of the larger current transformer of electric current, for problem above, research is a kind of to be applied to all transformer types The anti-DC performance detection method of large-current electric current transformer to changing above-mentioned situation, with realistic meaning.

The content of the invention

The purpose of the present invention is, in order to solve single turn work containing DC component in the anti-DC performance detection process of current transformer The problem that frequency high current occurs, the half-wave current detection method for using at present, DC component contained by its waveform is difficult to be quantified Analysis, causes testing result limitation very big, DC stacked based on ratio the invention provides one kind in order to overcome this problem The anti-DC performance detection method of current transformer of method, and there is provided the anti-DC performance detection means of corresponding current transformer.

To achieve these goals, the technical solution adopted in the present invention is:

A kind of anti-DC performance detection means of current transformer, including it is pressure regulator, current lifting device, noninductive electric capacity, reactor, straight Stream current feedback circuit, standard current transformer, digital mutual inductor tester, current capacity case, the output termination of pressure regulator rise The input of device is flowed, current lifting device output end constitutes alternating current branch road with noninductive capacitances in series, and DC current generator electric current is defeated Go out end and reactor DC current branch road in series, alterating and direct current is formed after alternating current branch road and DC current branch circuit parallel connection Stream accesses the primary side of tested current transformer, and standard current transformer primary side seals in alternating current branch road, is detected electric current mutual The secondary side of sensor accesses the tested current transformer electric current input of digital mutual inductor tester after being connected with current capacity case End, the standard current transformer current input terminal of the secondary side joint digital mutual inductor tester of standard current transformer.

Preferably, the digital mutual inductor tester is by normalized current sampling channel, tested current sample passage, letter Number processing module and upper structure are into normalized current sampling channel includes precision current transformer, I/V converters, signal condition Circuit I, AD sampling modules, precision current transformer connection standard current transformer, precision current transformer connection I/V conversion Device, I/V converters connection signal conditioning circuit I, signal conditioning circuit I connection AD sampling modules, being detected current channel includes handing over Direct current zero-flux current transformer or Hall sensor, signal conditioning circuit II, AD sampling module, alternating current-direct current Zero flux electric current Transformer or the tested current transformer of Hall sensor connection, alternating current-direct current zero-flux current transformer or Hall sensor connect Connect signal conditioning circuit II, signal conditioning circuit II connection AD sampling modules, AD sampling modules connection signal processing module, signal Processing module connects host computer.The function of signal processing module is synchronous acquisition standard current transformer and tested current transformer Secondary side current signal, one is reduced into according to the tested current transformer, standard current transformer no-load voltage ratio that set by sampled data Secondary side current value, and transmit to host computer, host computer is responsible for being analyzed sampled data, calculates error result, and Display testing result.

Preferably, normalized current sampling channel, tested current sample passage share one piece of AD samplings of AD sampling modules Chip, can accomplish more accurately synchronized sampling.

It is anti-straight based on foregoing current transformer the invention provides a kind of anti-DC performance detection method of current transformer Stream device for detecting performance, the ratio of DC current in ac and dc current is can adjust by adjusting DC current and alternating current size Weight, to detect and evaluate the anti-DC performance that current transformer is detected under different specific weight DC component.

The present invention noninductive Capacitor apart DC current of utilization, short-circuit alternating current, to prevent DC current from sealing in current lifting device, Make current lifting device magnetic core saturation, cause current lifting device output current wave to distort;Increase the exchange of DC current branch road using reactor Reactance, makes AC great current not seal in DC current source, causes DC current source to damage, while ensureing that not increasing direct current flows back to Road reactance.

Preferably, digital mutual inductor tester includes normalized current sampling channel, tested current sample passage, resist straight Fluidity can refer to the ratio between normalized current sampling channel sampled value and tested normalized current sampling channel sampled value power frequency component Difference and phase difference.

Preferably, because non-synchronous sampling can influence detection accuracy, can by increasing sampling period and sampling number Reduce the influence of non-synchronous sampling, tested current sample passage and standard electric can be accurately calculated with reference to plesiochronous DFT algorithms Flow sampling channel electric current amplitude and phase, therefore host computer receive signal processing module transmission sample values after, adopt The amplitude and phase of tested current sample passage and normalized current sampling channel electric current are calculated with plesiochronous DFT algorithms, then The anti-direct current phase difference of current transformer being calculated accordingly and ratio being poor, specific calculating process is as follows:

Normalized current sampling channel current amplitude phase calculation:

Tested current sample channel current amplitude phase is calculated:

(1), f is power current frequency in (2) formula, usually 50Hz, I0N、IxNRespectively normalized current sampling channel is electric Stream amplitude, tested current sample passage power frequency component current amplitude,Respectively standard channel current phase, tested electric current are adopted Sample passage power frequency component current phase;

Calculated than difference:

F (%)=(IxN/I0N- 1) × 100% (3)

Phase difference calculating:

The beneficial effects of the invention are as follows, during the detection anti-DC performance of current transformer, using electric capacity separated by direct communication, inductance every The straight effect of traffic produces single turn AC great current containing DC component, solves non-punching and great current mutual inductor detection is asked Topic;Using digital mutual inductor tester, anti-DC error is calculated using plesiochronous DFT algorithms, solve non-synchronous sampling shadow The problem of error-detecting is rung, while also permitting deformation is different with tested current transformer ratio, measurement range is expanded;Use power frequency The angle of current weight is than the difference anti-DC performance of assessment, it is ensured that the uniformity of anti-DC detecting result and electric energy metrical.The present invention With method is simple, economic, science, practicality, workable, low cost and other advantages.

The present invention is applied to transformer detection technique field.

Brief description of the drawings

Fig. 1 is the anti-DC performance detection means schematic diagram of current transformer;

Fig. 2 is digital mutual inductor tester theory diagram.

Symbol in figure:

100 --- --- --- noninductive electric capacity C, 400 --- reactor L, 500 --- are straight for current lifting device, 300 for pressure regulator, 200 Stream current feedback circuit, 600 --- standard current transformer T0, 700 --- tested current transformer Tx, 800 --- current capacity case Z, 900 --- digital mutual inductor tester, IA--- alternating current, an IZ --- DC current, 901 --- are accurate --- --- signal conditioning circuit I, 904 --- AD sampling modules, 905 --- believe for I/V converters, 903 for current transformer, 902 Number processing module, 906 --- alternating current-direct current zero-flux current transformer or Hall sensor, 907 --- signal conditioning circuit II, 908 --- host computer.

Specific embodiment

Below in conjunction with accompanying drawing, the present invention is described in detail.

As shown in figure 1, a kind of anti-DC performance detection means of current transformer, including 100, up-flow of a pressure regulator 200, noninductive electric capacity C300 of device, reactor L400, DC current generator 500, a standard Current Mutual Inductance The digital mutual-inductor tester 900, one of device 600, current capacity case Z800.The output termination current lifting device of pressure regulator 100 200 input produces AC great current, the output end of current lifting device 200 and noninductive electric capacity C300 alternating current branch roads in series, The current output terminal of DC current generator 500 and reactor L400 DC current branch roads in series, alternating current branch road with it is straight Ac and dc current is formed after stream current branch parallel connection and accesses tested current transformer Tx700 primary side, by adjusting direct current Stream can adjust the proportion of DC current in ac and dc current with alternating current size, to detect and evaluate different specific weight DC component Tested current transformer T downx700 anti-DC performance;Standard current transformer T0600 primary sides seal in alternating current branch road, quilt Inspection current transformer Tx700 secondary side accesses the quilt of digital mutual inductor tester 900 after being connected with current capacity case Z800 Inspection current transformer current input terminal, standard current transformer T0The mark of 600 secondary side joint digital mutual inductor tester 900 Quasi- current transformer current input terminal.

The effect of noninductive electric capacity C300 is isolated DC electric current, short-circuit alternating current, to prevent DC current from sealing in up-flow Device 200, makes the magnetic core saturation of current lifting device 200, causes the output current wave of current lifting device 200 to distort;The effect of reactor L400 is to increase Plus the exchange reactance of DC current branch road, AC great current is not sealed in DC current source, cause DC current source to damage, while Guarantee does not increase DC current return reactance.

The alternating current technical parameter of the output of current lifting device 200:

(1) current range:5A~1000A

(2) distortion factor:Less than 5%

DC current generator 500 exports DC current parameter:

(1) current range:1A~130A

(2) ripple factor:Less than 1%

Under the influence of direct-current component, current transformer T is detectedx700 secondary currents are subject to Severe distortion, therefore tradition Electrician's formula mutual-inductor tester is not suitable for anti-DC performance detection, digital mutual inductor tester 900 of the invention such as Fig. 2 institutes Show, be made up of normalized current sampling channel, tested current sample passage, signal processing module 905 and host computer 908, standard electric Stream sampling channel includes precision current transformer 901, I/V converters 902, signal conditioning circuit I903, AD sampling module 904 Deng the connection standard current transformer of precision current transformer 901 T0600, the connection I/V converters of precision current transformer 901 The connection signal conditioning circuit of 902, I/V converter 902 I 903, the connection AD of signal conditioning circuit I 903 sampling module 904, is detected Current sample passage includes alternating current-direct current zero-flux current transformer or Hall sensor 906, signal conditioning circuit II 907, AD Sampling module 904 etc., alternating current-direct current zero-flux current transformer or the tested current transformer T of the connection of Hall sensor 906x700, Alternating current-direct current zero-flux current transformer or the connection signal conditioning circuit of Hall sensor 906 II 907, signal conditioning circuit II 907 connection AD sampling modules 904, the connection signal processing module 905 of AD sampling modules 904, signal processing module 905 connects upper Machine 908.One piece of AD that normalized current sampling channel, the current signal of tested current sample passage share AD sampling modules 904 is adopted Sample chip, can accomplish more accurately synchronized sampling;The function of signal processing module 905 is synchronous acquisition standard current transformer With tested Current Transformer Secondary side current signal, sampled data is reduced into by primary side according to the transformer conversion ratio for setting Current value, and transmit to host computer 908, host computer 908 is responsible for being analyzed sampled data, calculates error result, And show testing result.

Error calculation principle:According to electric energy computing formula, active energy can be just produced between the voltage x current of same frequency, led to Preferably, line voltage generally only contains power-frequency voltage, therefore tested current transformer T to the normal power network quality of power supplyx700 secondary side currents After distortion, only power current component can produce effective active energy, therefore, when the anti-DC performance of current transformer is detected, It is mutual electric current can be assessed with Current Transformer primary side power current component, the phase difference of secondary side power current component and than difference The anti-DC performance of sensor, in the present invention, anti-DC performance refers to standard channel sampled value and tested channel sample value power frequency point Ratio difference and phase difference between amount.

Because non-synchronous sampling can influence detection accuracy, by increase the sampling period and sampling number can reduce it is asynchronous The influence of sampling, tested current sample passage and normalized current sampling channel can be accurately calculated with reference to plesiochronous DFT algorithms The amplitude and phase of electric current, thus host computer 908 receive signal processing module 905 transmission sample values after, using standard Synchronous DFT algorithms calculate the amplitude and phase of tested current sample passage and normalized current sampling channel electric current, then accordingly Calculate the anti-direct current phase difference of current transformer and ratio is poor, specific calculating process is as follows:

Normalized current sampling channel current amplitude phase calculation:

Tested current sample channel current amplitude phase is calculated:

(1), f is power current frequency in (2) formula, usually 50Hz, I0N、IxNRespectively normalized current sampling channel is electric Stream amplitude, tested current sample passage power frequency component current amplitude,Respectively standard channel current phase, tested electric current are adopted Sample passage power frequency component current phase;

Calculated than difference:

F (%)=(IxN/I0N- 1) × 100% (3)

Phase difference calculating:

Concrete operation step is as follows:

The first step:Wiring is carried out as shown in Figure 1;

Second step:Regulation current capacity case Z800 payloads are tested current transformer Tx700 rated sencondaryloads, Tested current transformer T is set on digital mutual inductor tester 900x700th, standard current transformer T0The parameters such as 600 no-load voltage ratios are believed Breath, starts detection experiment;

3rd step:Regulation pressure regulator 100, makes current lifting device 200 export alternating current and is slowly increased to measurement point rated current It%;

4th step:Regulation DC current generator 500, I is risen to by DC component accounting β regulation DC current sourcesDC, now Tested current transformer primary side is electric current containing DC component, and standard current transformer is industrial frequency AC electric current;

5th step:Standard channel current sampling data I is read on digital mutual inductor tester0Adopted with tested channel current Sample value IX, and ratio difference f is recorded, phase difference δ;

6th step:Alternating current, DC current are slowly dropped to 0;

7th step:The revision of the convention is carried out to testing result, ratio difference remains into 0.01%, and phase difference remains into 0.1rad.

Claims (7)

1. a kind of anti-DC performance detection means of current transformer, including pressure regulator, current lifting device, noninductive electric capacity, reactor, direct current Current feedback circuit, standard current transformer, digital mutual inductor tester, current capacity case, the output termination up-flow of pressure regulator The input of device, it is characterized in that:Current lifting device output end constitutes alternating current branch road, DC current generator with noninductive capacitances in series Current output terminal and reactor DC current branch road in series, friendship is formed after alternating current branch road and DC current branch circuit parallel connection DC current accesses the primary side of tested current transformer, and standard current transformer primary side seals in alternating current branch road, is detected The secondary side of current transformer accesses the tested current transformer electricity of digital mutual inductor tester after being connected with current capacity case Stream input, the standard current transformer electric current input of the secondary side joint digital mutual inductor tester of standard current transformer End.
2. the anti-DC performance detection means of current transformer according to claim 1, it is characterized in that:The digital mutual inductance Device tester is by normalized current sampling channel, tested current sample passage, signal processing module and upper structure into normalized current Sampling channel includes precision current transformer, I/V converters, signal conditioning circuit I, AD sampling module, precision current transformer Connection standard current transformer, precision current transformer connection I/V converters, I/V converters connection signal conditioning circuit I, letter Number modulate circuit I connection AD sampling modules, being detected current channel includes alternating current-direct current zero-flux current transformer or hall sensing Device, signal conditioning circuit II, AD sampling module, alternating current-direct current zero-flux current transformer or the tested electric current of Hall sensor connection Transformer, alternating current-direct current zero-flux current transformer or Hall sensor connection signal conditioning circuit II, signal conditioning circuit II Connection AD sampling modules, AD sampling modules connection signal processing module, signal processing module connection host computer.
3. the anti-DC performance detection means of current transformer according to claim 2, it is characterized in that:Normalized current sampling is logical Road, tested current sample passage share one piece of AD sampling A/D chip of AD sampling modules, can accomplish more accurately synchronized sampling.
4. the anti-DC performance detection method of a kind of current transformer, it is characterized in that:Based on the current transformer described in claim 1 Anti- DC performance detection means, by adjusting DC current in the adjustable ac and dc current of DC current and alternating current size Proportion, to detect and evaluate the anti-DC performance that current transformer is detected under different specific weight DC component.
5. the anti-DC performance detection method of a kind of current transformer according to claim 4, it is characterized in that:The anti-direct current Performance refers to that the ratio between normalized current sampling channel sampled value and tested normalized current sampling channel sampled value power frequency component is poor And phase difference.
6. the anti-DC performance detection method of a kind of current transformer according to claim 5, it is characterized in that:Using plesiochronous DFT algorithms calculate the amplitude and phase of tested current sample passage and normalized current sampling channel electric current, then calculate accordingly Go out the anti-direct current phase difference of current transformer and ratio is poor.
7. the anti-DC performance detection method of a kind of current transformer according to claim 6, it is characterized in that:Normalized current is adopted Sample channel current amplitude phase is calculated:
Tested current sample channel current amplitude phase is calculated:
(1), f is power current frequency, I in (2) formula0N、IxNRespectively normalized current sampling channel current amplitude, tested electric current are adopted Sample passage power frequency component current amplitude,Respectively standard channel current phase, tested current sample passage power frequency component are electric Stream phase;
Calculated than difference:
F (%)=(IxN/I0N- 1) × 100% (3)
Phase difference calculating:
CN201710094830.9A 2017-02-21 2017-02-21 A kind of anti-DC performance detection means of current transformer and method CN106842097A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710094830.9A CN106842097A (en) 2017-02-21 2017-02-21 A kind of anti-DC performance detection means of current transformer and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710094830.9A CN106842097A (en) 2017-02-21 2017-02-21 A kind of anti-DC performance detection means of current transformer and method

Publications (1)

Publication Number Publication Date
CN106842097A true CN106842097A (en) 2017-06-13

Family

ID=59133921

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710094830.9A CN106842097A (en) 2017-02-21 2017-02-21 A kind of anti-DC performance detection means of current transformer and method

Country Status (1)

Country Link
CN (1) CN106842097A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109375133A (en) * 2018-09-17 2019-02-22 国网江西省电力有限公司电力科学研究院 A kind of resistance to DC performance detection device of current sensor and method
CN109581265A (en) * 2018-10-30 2019-04-05 国网江西省电力有限公司电力科学研究院 A kind of anti-DC performance detection method of current transformer based on power error

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2729742Y (en) * 2002-10-28 2005-09-28 广东省四会市互感器厂 Current sensor error detecting table
CN102053235A (en) * 2010-10-21 2011-05-11 中国南方电网有限责任公司超高压输电公司柳州局 On-site steady-state accuracy verification system for electronic current transformer and verification method thereof
JP4767907B2 (en) * 2007-05-22 2011-09-07 日本電気計器検定所 Transformer test equipment
WO2012002617A1 (en) * 2010-06-29 2012-01-05 한국전력공사 Power quality measuring device and method
CN102944860A (en) * 2012-10-31 2013-02-27 江苏省电力公司电力科学研究院 Method and device for comparing running errors of optical current transformer and electromagnetic current transformer in real time
CN203250019U (en) * 2013-06-04 2013-10-23 国家电网公司 750 kV substation instrument transformer on-site wireless calibrator
CN103837852A (en) * 2013-09-23 2014-06-04 国家电网公司 All-fiber electronic current transformer frequency characteristic testing device and testing method
CN105699818A (en) * 2016-03-24 2016-06-22 中国电力科学研究院 Error measurement apparatus and measurement method for current transformer

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2729742Y (en) * 2002-10-28 2005-09-28 广东省四会市互感器厂 Current sensor error detecting table
JP4767907B2 (en) * 2007-05-22 2011-09-07 日本電気計器検定所 Transformer test equipment
WO2012002617A1 (en) * 2010-06-29 2012-01-05 한국전력공사 Power quality measuring device and method
CN102053235A (en) * 2010-10-21 2011-05-11 中国南方电网有限责任公司超高压输电公司柳州局 On-site steady-state accuracy verification system for electronic current transformer and verification method thereof
CN102944860A (en) * 2012-10-31 2013-02-27 江苏省电力公司电力科学研究院 Method and device for comparing running errors of optical current transformer and electromagnetic current transformer in real time
CN203250019U (en) * 2013-06-04 2013-10-23 国家电网公司 750 kV substation instrument transformer on-site wireless calibrator
CN103837852A (en) * 2013-09-23 2014-06-04 国家电网公司 All-fiber electronic current transformer frequency characteristic testing device and testing method
CN105699818A (en) * 2016-03-24 2016-06-22 中国电力科学研究院 Error measurement apparatus and measurement method for current transformer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
谭炳源: "直流偏磁对电流互感器的性能影响研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109375133A (en) * 2018-09-17 2019-02-22 国网江西省电力有限公司电力科学研究院 A kind of resistance to DC performance detection device of current sensor and method
CN109581265A (en) * 2018-10-30 2019-04-05 国网江西省电力有限公司电力科学研究院 A kind of anti-DC performance detection method of current transformer based on power error

Similar Documents

Publication Publication Date Title
CN104076693B (en) Flexible direct-current transmission real-time simulation system and simulation method thereof
CN103078316B (en) Network voltage disturbance generating device and control method thereof
Emanuel Summary of IEEE standard 1459: definitions for the measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced, or unbalanced conditions
CN101149425B (en) Electronic electric energy meter debugging, checkout automated system
CN202583449U (en) Whole detection device of intelligent transformer station electric energy metering device
CN102621382B (en) Method for detecting frequency, phase and amplitude of electric signal in electric power system
CN106771556B (en) A kind of AC power difference measurement system and method based on quantum techniques
CN101493508B (en) Calibration test apparatus for extra-high voltage direct current transformer
CN103176142B (en) A kind of photovoltaic electric station grid connection adaptive testing method
CN106526328B (en) It is a kind of suitable for the generalized impedance of power grid and networked devices measurement and calculation method
CN101419254B (en) Uhv transmission line parameter measuring systems and method
US10338127B2 (en) Method and system for identifying full parameters of element by fault recording and fault locating method
CN103207335B (en) Island detection method based on phase-frequency positive feedback
CN103176147B (en) Current transformer remanence measurement system and method
CN103792465B (en) A kind of method of the range finding of the one-phase earthing failure in electric distribution network based on residual voltage
CN102621514B (en) Electronic transformer verifying device
CN201184911Y (en) Apparatus for calibrating locale error of electronic type mutual-inductor in digitalization transforming plant
CN101699301B (en) Method for measuring line parameter through induced electricity
CN101487861B (en) Detection method for electric voltage phase angle jump at network voltage dip
CN102135571B (en) Anti-interference measurement method for zero sequence impedance of super-high-voltage/ultrahigh-voltage multi-loop power transmission line
CN102928810A (en) System and method for evaluating accuracy of digital electric energy meter
CN108303590B (en) MW class wide-band impedance measuring device and its control method based on MMC
CN103714490B (en) Large power grid on-line data multi-thread rapid-integration method
CN203930043U (en) A kind of digitalized electric energy measuring apparatus correcting device
CN103983889B (en) Diagnosis method for active power filter switching device open-circuit fault based on model reference analysis

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20170613