CN104569672A - Power frequency superposition harmonic wave testing device for capacitor - Google Patents

Power frequency superposition harmonic wave testing device for capacitor Download PDF

Info

Publication number
CN104569672A
CN104569672A CN201410848165.4A CN201410848165A CN104569672A CN 104569672 A CN104569672 A CN 104569672A CN 201410848165 A CN201410848165 A CN 201410848165A CN 104569672 A CN104569672 A CN 104569672A
Authority
CN
China
Prior art keywords
capacitor
loop
tested
examination
harmonic wave
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.)
Pending
Application number
CN201410848165.4A
Other languages
Chinese (zh)
Inventor
黄镜明
王崇祜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SHANGHAI SIYUAN POWER CAPACITOR CO Ltd
Original Assignee
SHANGHAI SIYUAN POWER CAPACITOR CO Ltd
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 SHANGHAI SIYUAN POWER CAPACITOR CO Ltd filed Critical SHANGHAI SIYUAN POWER CAPACITOR CO Ltd
Priority to CN201410848165.4A priority Critical patent/CN104569672A/en
Publication of CN104569672A publication Critical patent/CN104569672A/en
Pending legal-status Critical Current

Links

Abstract

The invention provides a power frequency superposition harmonic wave testing device for a capacitor. The power frequency superposition harmonic wave testing device for the capacitor is composed of a power frequency testing loop, a harmonic wave testing loop and a test loop. The power frequency testing loop is composed of a transformer, a power frequency adjustable electric reactor and a voltage regulator. The harmonic wave loop is composed of a frequency converter, a smoothing device and a parallel resonance transformer. The test loop is composed of an accompanying testing capacitor, a tested capacitor, a capacitive voltage divider and an oscilloscope. The transformer is in parallel connection with the power frequency adjustable electric reactor. The position between the frequency converter and the parallel resonance transformer is in series connection with the smoothing device. A bridge loop is formed by the accompanying testing capacitor and the tested capacitor. A low voltage arm of the capacitive voltage divider is in parallel connection with the oscilloscope. The test loop accesses to the position between the power frequency testing loop and the harmonic wave testing loop. The power frequency load and the harmonic wave load are jointly exerted on a capacitor unit by the power frequency testing loop and the harmonic wave testing loop. A waveform is monitored and analyzed through the capacitive voltage divider and the oscilloscope after the harmonic wave is superposed by the power frequency.

Description

The industrial frequency superimposed harmonic test device of capacitor
Technical field
The present invention relates to high-voltage power capacitor test field, particularly, relate to a kind of industrial frequency superimposed harmonic test device of capacitor simulating actual track environment.
Background technology
Along with the raising of commercial production levels and living standards of the people, non-linear electrical equipment puts into operation in a large number in electrical network, and the proportion that the harmonic component causing electrical network accounts for is increasing.It not only increases the current supply loss of electrical network, and disturbs the protective device of electrical network and the normal operation of automation equipment, causes malfunction and the tripping of these devices, directly threatens the safe operation of electrical network.Generally use passive filtration unit (LB) at present, carry out harmonic wave control, capacitor is then the important component part of passive filtration unit (LB), the quality of power supply of the whole piece circuit of its fine or not direct relation run.The pilot projects such as the standard GB/T/T20094-2007 " HVDC (High Voltage Direct Current) transmission system shnt capacitor and ac filter capacitor " of present implementation and GB/T20093-2012 " HVDC (High Voltage Direct Current) transmission system DC filter capacitors and neutral bus impact capacitor " all do not simulate actual working conditions, lack and carry out as performance tests such as heat stabilization test, endurancing and noise test under harmonic environment capacitor unit.But just current, still lack the test unit of mature and reliable.
Summary of the invention
For defect of the prior art, be the operating characteristic of research capacitor unit under harmonic wave, the invention provides a kind of industrial frequency superimposed harmonic test device of capacitor simulating actual track environment.
According to the industrial frequency superimposed harmonic test device of a kind of capacitor provided by the invention, comprising: industrial frequency experiment loop, test loop and harmonic wave test loop;
Described test loop comprises first and accompanies that examination capacitor (C2) is accompanied in examination capacitor (C1), second, escort services try capacitor (C3), tested capacitor (Cx), capacitive divider (CFY) and oscillograph (SCOPE);
Wherein, described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3) and described tested capacitor (Cx) forms bridge type return, in this bridge type return, described first accompanies examination capacitor (C1), second to accompany examination capacitor (C2), tested capacitor (Cx) and escort services to try capacitor (C3) arranges successively; Described capacitive divider (CFY) is in parallel with described tested capacitor (Cx); Described capacitive divider (CFY) comprises two capacitors be connected in series; The low-voltage arm of described capacitive divider (CFY) is in parallel with described oscillograph (SCOPE);
Described industrial frequency experiment loop applies power frequency load to described tested capacitor (Cx);
Described harmonic test loop applies harmonic load to described tested capacitor (Cx).
As prioritization scheme, described industrial frequency experiment loop input side joint AC power, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and the other end of outgoing side is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx).
As prioritization scheme, described industrial frequency experiment loop comprises pressure regulator (TY), transformer (B), power frequency REgulatable reactor (L1);
The input end of described pressure regulator (TY) connects AC power, the output terminal of described pressure regulator (TY) is connected with the parallel connection of primary windings of described transformer (B), and described power frequency REgulatable reactor (L1) is parallel to the secondary coil of described transformer (B); One end of the secondary coil of described transformer (B) is connected to described first and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and another output terminal is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
As prioritization scheme, described harmonic wave loop input side joint alternating source, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and escort services to try between capacitor (C3), and the other end of outgoing side is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx).
As prioritization scheme, described harmonic wave loop comprises frequency converter (BP), filter (LB) and parallel resonance transformer (XB);
Described frequency converter (BP) connects alternating source, the output terminal of described frequency converter (BP) is connected to the input end of described filter (LB), and the output terminal of described filter (LB) is connected to the two ends of the primary coil of described parallel resonance transformer (XB); One end of the secondary coil of described parallel resonance transformer (XB) is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx), and the other end is connected to described first and accompanies examination capacitor (C1) and escort services to try between capacitor (C3); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
As prioritization scheme, it is identical with described tested capacitor (Cx) electric capacity that described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3).Compared with prior art, the present invention has following beneficial effect:
1, can selected harmonic frequency and industrial frequency superimposed arbitrarily;
2, industrial frequency experiment loop and harmonic test loop is mutually isolated is independent of each other;
3, adopt reactive-load compensation loop that the power of whole testing equipment and power supply can be made to greatly reduce;
4, test unit debugging is convenient, easily realizes industrial frequency superimposed harmonic wave.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, obviously, accompanying drawing in the following describes is only some embodiments of the present invention, for those skilled in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.In accompanying drawing:
Fig. 1 is a kind of capacitor industrial frequency superimposed harmonic test apparatus structure schematic diagram in embodiment;
Oscillograph (SCOPE) waveform when Fig. 2 is industrial frequency superimposed 3 subharmonic in embodiment;
Oscillograph (SCOPE) waveform when Fig. 3 is industrial frequency superimposed 11 subharmonic in embodiment.
In figure, sequence number represents: TY-pressure regulator, B-duplex frequency boostering transformer, XB-harmonic wave parallel resonance transformer, L1-power frequency REgulatable reactor, C1-first accompany examination capacitor, C2-second accompanies examination capacitor, C3-escort services try capacitor, the tested capacitor of Cx-, CFY-capacitive divider, SCOPE-oscillograph, LB-filter, BP-frequency converter.
Embodiment
Hereafter in the mode of specific embodiment, the present invention is described in detail by reference to the accompanying drawings.Following examples will contribute to those skilled in the art and understand the present invention further, but not limit the present invention in any form.It should be pointed out that the embodiment that can also use other, or the amendment on 26S Proteasome Structure and Function is carried out to the embodiment enumerated herein, and can not depart from the scope and spirit of the present invention.
As shown in Figure 1, in the embodiment of the industrial frequency superimposed harmonic test device of a kind of capacitor provided by the invention, comprising: industrial frequency experiment loop, test loop and harmonic wave test loop.
Described test loop comprises first and accompanies that examination capacitor (C2) is accompanied in examination capacitor (C1), second, escort services try capacitor (C3), tested capacitor (Cx), capacitive divider (CFY) and oscillograph (SCOPE).
Wherein, described first accompany examination capacitor (C1), second accompany examination capacitor (C2), escort services try capacitor (C3) and described tested capacitor (Cx) forms bridge type return.In this bridge type return, described first accompanies examination capacitor (C1), second to accompany examination capacitor (C2), tested capacitor (Cx) and escort services to try capacitor (C3) arranges successively.Described capacitive divider (CFY) is in parallel with described tested capacitor (Cx); Described capacitive divider (CFY) comprises two capacitors be connected in series.The low-voltage arm of described capacitive divider (CFY) is in parallel with described oscillograph (SCOPE).
Described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3) and specifically refer to the bridge type return that described tested capacitor (Cx) forms: described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), tested capacitor (Cx) tries capacitor (C3) with escort services and is connected successively, and described escort services try capacitor (C3) and described first accompany examination capacitor (C1) be connected, described industrial frequency experiment loop and harmonic wave test loop are accessed on the connecting line of these four capacitors.This bridge type return can effectively prevent power frequency and harmonic wave from mutually disturbing, and power frequency and harmonic wave are independent of each other as the simulation test of described tested capacitor (Cx) provides good industrial frequency superimposed harmonic environment.
Described capacitive divider (CFY) comprises two capacitors be connected in series.
The present embodiment applies power frequency load and harmonic load to tested capacitor unit jointly by described industrial frequency experiment loop and described harmonic test loop, and isolates the impact between industrial frequency experiment loop and harmonic wave test loop.Waveform after monitoring industrial frequency superimposed harmonic wave by described capacitive divider (CFY) and described oscillograph (SCOPE) is also analyzed.
Described capacitive divider (CFY) is for acquisition test voltage, described oscillograph (SCOPE) is for the display of industrial frequency superimposed harmonic wave forms and analysis, what can obtain different power frequency and harmonic wave by regulating the humorous wave transformer of described parallel connection (B) superposes situation, and laboratory technician can obtain the display of real-time waveform from described oscillograph (SCOPE), be respectively as shown in Figures 2 and 3 industrial frequency superimposed 3 times and 11 subharmonic time oscillograph (SCOPE) waveform.
The present embodiment in conjunction with touch panel monitor system, can also carry out automatic controlling and monitoring to whole superposition test.
Described industrial frequency experiment loop applies power frequency load to described tested capacitor (Cx);
Described harmonic test loop applies harmonic load to described tested capacitor (Cx).
As prioritization scheme, described industrial frequency experiment loop input side joint AC power, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and the other end of outgoing side is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx).
Described industrial frequency experiment loop comprises pressure regulator (TY), transformer (B), power frequency REgulatable reactor (L1).
Described pressure regulator (TY) provides power frequency supply for described industrial frequency experiment loop; Described transformer (B) is for promoting power-frequency voltage; Described power frequency REgulatable reactor (L1) accompanies for compensating first the capacitive reactive power that examination capacitor (C2) is accompanied in examination capacitor (C1), second, escort services try capacitor (C3) and described tested capacitor (Cx).
The input end of described pressure regulator (TY) connects AC power, the output terminal of described pressure regulator (TY) is connected with the parallel connection of primary windings of described transformer (B), and described power frequency REgulatable reactor (L1) is parallel to the secondary coil of described transformer (B); One end of the secondary coil of described transformer (B) is connected to described first and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and another output terminal is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
The REgulatable reactor of power frequency described in the present embodiment (L1) and described transformer (B) and bridge type return is in parallel realizes power frequency parallel resonance, make the power frequency power of test loop and electric current minimum.The present embodiment regulates the capacitive reactive power of lagging reactive power compensation condenser by described power frequency REgulatable reactor (L1), reduces the capacity of transformer (B), pressure regulator (TY) and power supply described in industrial frequency experiment loop.
As prioritization scheme, described harmonic wave loop input side joint alternating source, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and escort services to try between capacitor (C3), and the other end of outgoing side is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx).
As prioritization scheme, described harmonic wave loop comprises frequency converter (BP), filter (LB) and parallel resonance transformer (XB).
Described frequency converter (BP) for providing Harmonic Current for described harmonic wave loop, and can provide multiple harmonic frequency.
Described frequency converter (BP) connects alternating source, the output terminal of described frequency converter (BP) is connected to the input end of described filter (LB), and the output terminal of described filter (LB) is connected to the two ends of the primary coil of described parallel resonance transformer (XB).One end of the secondary coil of described parallel resonance transformer (XB) is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx), and the other end is connected to described first and accompanies examination capacitor (C1) and escort services to try between capacitor (C3); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
Parallel connection described in the present embodiment is shaken, and humorous transformer (B) is in parallel with described bridge type return realizes harmonic wave parallel resonance, make the harmonic power of test loop and electric current minimum.
As prioritization scheme, it is identical with described tested capacitor (Cx) electric capacity that described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3).
The foregoing is only preferred embodiment of the present invention, those skilled in the art know, without departing from the spirit and scope of the present invention, can carry out various change or equivalent replacement to these characteristic sum embodiments.In addition, under the teachings of the present invention, can modify to adapt to concrete situation and material to these characteristic sum embodiments and can not the spirit and scope of the present invention be departed from.Therefore, the present invention is not by the restriction of specific embodiment disclosed herein, and the embodiment in the right of all the application of falling into all belongs to protection scope of the present invention.

Claims (6)

1. the industrial frequency superimposed harmonic test device of capacitor, is characterized in that, comprising: industrial frequency experiment loop, test loop and harmonic wave test loop;
Described test loop comprises first and accompanies that examination capacitor (C2) is accompanied in examination capacitor (C1), second, escort services try capacitor (C3), tested capacitor (Cx), capacitive divider (CFY) and oscillograph (SCOPE);
Wherein, described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3) and described tested capacitor (Cx) forms bridge type return, in this bridge type return, described first accompanies examination capacitor (C1), second to accompany examination capacitor (C2), tested capacitor (Cx) and escort services to try capacitor (C3) arranges successively; Described capacitive divider (CFY) is in parallel with described tested capacitor (Cx); Described capacitive divider (CFY) comprises two electric capacity be connected in series; The low-voltage arm electric capacity of described capacitive divider (CFY) is in parallel with described oscillograph (SCOPE);
Described industrial frequency experiment loop applies power frequency load to described tested capacitor (Cx);
Described harmonic test loop applies harmonic load to described tested capacitor (Cx).
2. device according to claim 1, it is characterized in that, described industrial frequency experiment loop input side joint AC power, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and the other end of outgoing side is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx).
3. device according to claim 2, is characterized in that, described industrial frequency experiment loop comprises pressure regulator (TY), transformer (B), power frequency REgulatable reactor (L1);
The input end of described pressure regulator (TY) connects AC power, the output terminal of described pressure regulator (TY) is connected with the parallel connection of primary windings of described transformer (B), and described power frequency REgulatable reactor (L1) is parallel to the secondary coil of described transformer (B); One end of the secondary coil of described transformer (B) is connected to described first and accompanies examination capacitor (C1) and second to accompany between examination capacitor (C2), and another output terminal is connected to described escort services and tries between capacitor (C3) and tested capacitor (Cx); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
4. device according to claim 1, it is characterized in that, described harmonic wave loop input side joint alternating source, one end of outgoing side is connected to described first respectively and accompanies examination capacitor (C1) and escort services to try between capacitor (C3), and the other end of outgoing side is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx).
5. device according to claim 4, is characterized in that, described harmonic wave loop comprises frequency converter (BP), filter (LB) and parallel resonance transformer (XB);
Described frequency converter (BP) connects alternating source, the output terminal of described frequency converter (BP) is connected to the input end of described filter (LB), and the output terminal of described filter (LB) is connected to the two ends of the primary coil of described parallel resonance transformer (XB); One end of the secondary coil of described parallel resonance transformer (XB) is connected to described second and accompanies between examination capacitor (C2) and tested capacitor (Cx), and the other end is connected to described first and accompanies examination capacitor (C1) and escort services to try between capacitor (C3); Described escort services try capacitor (C3) and tested capacitor (Cx) indirectly.
6. device according to claim 1, is characterized in that, it is identical with described tested capacitor (Cx) electric capacity that described first accompanies examination capacitor (C1), second to accompany tries capacitor (C2), escort services try capacitor (C3).
CN201410848165.4A 2014-12-31 2014-12-31 Power frequency superposition harmonic wave testing device for capacitor Pending CN104569672A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410848165.4A CN104569672A (en) 2014-12-31 2014-12-31 Power frequency superposition harmonic wave testing device for capacitor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410848165.4A CN104569672A (en) 2014-12-31 2014-12-31 Power frequency superposition harmonic wave testing device for capacitor

Publications (1)

Publication Number Publication Date
CN104569672A true CN104569672A (en) 2015-04-29

Family

ID=53086206

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410848165.4A Pending CN104569672A (en) 2014-12-31 2014-12-31 Power frequency superposition harmonic wave testing device for capacitor

Country Status (1)

Country Link
CN (1) CN104569672A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105974216A (en) * 2016-05-05 2016-09-28 国网天津市电力公司 Current injection circuit for power capacitor noise test
WO2022083788A1 (en) * 2020-12-28 2022-04-28 无锡市电力滤波有限公司 Composite voltage test device for dc link capacitor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101793922A (en) * 2010-03-25 2010-08-04 南方电网技术研究中心 Audible noise measuring circuit and method of power capacitor
CN101893682A (en) * 2010-06-25 2010-11-24 珠海和佳医疗设备股份有限公司 Method for testing resonant power amplifying circuit
CN201796095U (en) * 2010-09-09 2011-04-13 苏州工业园区海沃科技有限公司 Capacitor bank fault tester
CN202351302U (en) * 2011-11-25 2012-07-25 华北电网有限公司张家口供电公司 Testing instrument for simulating unbalance current of serial compensating device
CN203069684U (en) * 2013-03-07 2013-07-17 南方电网科学研究院有限责任公司 Multi harmonic frequency simultaneous loading circuit for capacitor unit noise testing
CN204374327U (en) * 2014-12-31 2015-06-03 上海思源电力电容器有限公司 The industrial frequency superimposed harmonic test device of capacitor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101793922A (en) * 2010-03-25 2010-08-04 南方电网技术研究中心 Audible noise measuring circuit and method of power capacitor
CN101893682A (en) * 2010-06-25 2010-11-24 珠海和佳医疗设备股份有限公司 Method for testing resonant power amplifying circuit
CN201796095U (en) * 2010-09-09 2011-04-13 苏州工业园区海沃科技有限公司 Capacitor bank fault tester
CN202351302U (en) * 2011-11-25 2012-07-25 华北电网有限公司张家口供电公司 Testing instrument for simulating unbalance current of serial compensating device
CN203069684U (en) * 2013-03-07 2013-07-17 南方电网科学研究院有限责任公司 Multi harmonic frequency simultaneous loading circuit for capacitor unit noise testing
CN204374327U (en) * 2014-12-31 2015-06-03 上海思源电力电容器有限公司 The industrial frequency superimposed harmonic test device of capacitor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105974216A (en) * 2016-05-05 2016-09-28 国网天津市电力公司 Current injection circuit for power capacitor noise test
WO2022083788A1 (en) * 2020-12-28 2022-04-28 无锡市电力滤波有限公司 Composite voltage test device for dc link capacitor

Similar Documents

Publication Publication Date Title
CN102269787B (en) Detection method of harmonic characteristic of electronic voltage transformer and detection device thereof
CN202854255U (en) Capacitor type potential transformer testing device
CN103616574B (en) A kind of electric automobile anti-alone island detection system of energy storage combining inverter and detection method
CN205068942U (en) Experimental hybrid simulation system of high -voltage electrical
CN104569702A (en) Testing system of unified power quality controller and testing method thereof
CN103487679A (en) AIS electronic transformer testing system and testing method thereof
CN103558536A (en) Circuit for testing overload tolerance capacity of series capacitor and working method of circuit
CN104865549A (en) Reliability evaluation method and system of electric energy metering device
CN204374327U (en) The industrial frequency superimposed harmonic test device of capacitor
CN203870168U (en) Device for measuring inductance of reactor in active power filter
CN103884953B (en) A kind of capacitance type potential transformer damping circuit fault diagnosis system
CN103267917B (en) A kind of method and apparatus of high-capacity reactive compensation device full-load test
CN104569672A (en) Power frequency superposition harmonic wave testing device for capacitor
RU112525U1 (en) AUTOMATED DIAGNOSTIC AND MONITORING SYSTEM OF POWER CABLE LINES INSULATION
CN107632259A (en) A kind of testing station for realizing multimode multi-parameters test generating set
CN202502205U (en) Variable frequency series resonance withstand voltage test apparatus
CN205067670U (en) A anti -interference medium simulator for high -voltage electrical is experimental
CN202057735U (en) Autotracking compensation arc suppression coil complete device experimental station
CN203849352U (en) Apparatus for diagnosing fault of damping loop of capacitor voltage transformer
CN204065770U (en) A kind of Large Copacity exchanges adjustable simulation test load control system
CN204556744U (en) The detection platform of a kind of APF of 380V electric pressure
CN105974216A (en) Current injection circuit for power capacitor noise test
CN107015084A (en) A kind of distribution reactive power compensator analogue test platform
CN203811755U (en) A testing apparatus used for a triple-frequency withstand voltage test for a voltage transformer
CN203502551U (en) Circuit capable of testing overloading tolerance capability of capacitors connected in series

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20150429

WD01 Invention patent application deemed withdrawn after publication