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Ma Q.,China Electric Power Research Institute | Cui X.,North China Electrical Power University | Ren C.,Xian XD Power Capacitor Co. | Wang Z.,Guilin Power Capacitor Co. | And 2 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2014

To improve the manufacture technique, transient performance, and reliability of ultra high voltage(UHV) capacitor voltage transformers(CVT), we studied its impedance measurement and wideband circuit modeling method based on frequency-domain data. In order to obtain the frequency-dependent impedance, we adopted various methods to measure the impedance of two types of CVT capacitor voltage dividers, namely, the compression type and the welding type. The wideband impedance measurement results were validated using the two different impedance measurement methods. Thereby, we developed a CVT wideband equivalent circuit model with physical denotation, which was verified through comparing with the measurements. Furthermore, we defined several electrical network functions and analyzed the sensitivity of CVT circuit parameters, such as accumulation resistance, accumulation inductance, capacitor capacitance, capacitor conductance, and ground capacitance of grading ring. The results could be used as references for optimizing design, fabrication technology and transient performance analysis for UHV CVTs.

Zhang X.,Guilin University of Electronic Technology | Fan X.-M.,Guilin University of Electronic Technology | Fan X.-M.,Sunrise Group | Zou Q.-T.,Sunrise Group | And 2 more authors.
Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV | Year: 2012

A new type controlled switching device is introduced, which based on vacuum circuit-breaker (VCB) and power electronic switch(IGBT) to form the combination switch module. The structure and working principle of provided combination switch were emphatically expounded, especially the open and closing process and controlling strategy were discussed in detail. The researched VCB with permanent magnet actuator, and the synchronous controller of combination switch module based on the digital signal processor, in which the algorithm of average series for zero-crossover phase difference is adopted, so the phase information of power grid can be extracted rapidly and accurately, and synchronous tracing pulses can be procreated. When remote control instructions are received, according to the phase information of power grid the combination switch acts synchronously to ensure that the operation time of combination switch opened and closed in right position. The application of introduced combination switch for power quality control and improvement is present in this research also. In this control device, the real-time acquisition of electrical parameters is adopted and the crossover point of reference signal is detected by average series for zero-crossover phase difference algorithm. Accompanied with improved appropriate switching strategy, the device can operate shunt capacitor banks on expected target point. © 2012 IEEE.

Huang Z.-C.,Guilin University of Electronic Technology | Yan H.-Y.,Guilin University of Electronic Technology | Fan X.-M.,Guilin University of Electronic Technology | Fan X.-M.,Sunrise Group | And 3 more authors.
Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV | Year: 2012

Partial discharge (PD) is the initial sign of power capacitor insulation failure, and an effective extraction and analysis method of PD signal in power capacitor can improve the effectiveness of the on-line fault monitoring. The method which based on wavelet threshold denoising and mathematical morphology alternate mixing filter is put forward in this paper. First, the PD signal which includes noise is wavelet decomposed with the proper wavelet function and scale, and each layer of wavelet coefficients is extracted. Then appropriate flat structure element is chosen aimed at the scales of wavelet coefficients, and the mathematical morphology alternate mixing filter is used to filter out the noise and get a new wavelet coefficients. Choosing the appropriate threshold rules for the new wavelet coefficients, the wavelet coefficients after the threshold treatment is wavelet reconstructed and the PD signal after denoising is got. The wave distortion mean square error eMSE and SNR are chosen as the indicators to analyze and compare the denoising effects of wavelet threshold denoising method and the fusion denoising method. The results show that the fusion method can effectively remove the noise and keep the original shape characteristic of the signal better. © 2012 IEEE.

Zhang X.,Guilin University of Electronic Technology | Fan X.-M.,Guilin University of Electronic Technology | Fan X.-M.,Sunrise Group | Huang Z.-C.,Guilin University of Electronic Technology | And 3 more authors.
Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV | Year: 2012

Triggered vacuum switches (TVS), have found fast growing applications in the field of power system and pulse power. The key to perform synthetic making test at full rated voltage for high voltage switches is the making device of current source, so the chief aim of this research is to investigate the triggering feature of TVS, a series experiments have been carried out on the sample TVS especially with AC load between the main electrodes. The triggering and delay characteristics were emphatically expounded. An elaborated circuit for controlling the TVS is proposed herein. The triggering energy of the controller can be adjusted conveniently. By means of changing the triggering energy, the experimental results show that the delay and jitter times decrease with increasing trigger energy. The delay and jitter times decreases magnificently with the increasing voltage in the main gap. By increasing the main-gap voltage, the triggered probability increases. At last, theoretically and experimental research has been carried out of TVS used for high voltage circuit breakers synthetic making test equipment. The analyzing and test results are presented also, and which indicate TVS was suitable for high voltage circuit breakers synthetic making test. © 2012 IEEE.

Duan X.,Hebei Electric Power Research Institute | Zhu M.,Anhui University | Hu W.,Hebei Electric Power Research Institute | Zhou W.,Hebei Electric Power Research Institute | And 3 more authors.
Dianwang Jishu/Power System Technology | Year: 2014

The capacitor voltage transformer (CVT) has been widely used in the power system; However, it is hard to measure correctly the system harmonic with CVT because of its structure containing capacitors and non-linear inductors. This article describes a harmonic impedance model of CVT and derives its complete transfer function, considering the CVT manufacturing parameters and stray capacitance and other factors. The accuracy of the model was verified by comparing the CVT model simulating results and measured results of harmonic, then the impact of key parameters of CVT on its harmonic transfer characteristics was analyzed by simulation. Also, certain reference function is provided for accurate measurement of CVT harmonics, CVT design, manufacturing and process optimization. ©, 2014, Power System Technology Press. All right reserved.

Huang G.X.,Hefei University of Technology | Li Z.Y.,Hefei University of Technology | Huang Y.,Guilin Power Capacitor Co.
Applied Mechanics and Materials | Year: 2014

Power capacitor is one of the key equipments of the high-voltage direct current (HVDC) transmission system. It is also the main noise source difficult to control. Presently in the world, there are none explicit requirement and regulation on the evaluation and measurement of the noise generated by the power capacitor, which has seriously restricted the development of the further research on the noise control in power capacitor. So the research on the noise measurement method and technology has extremely important significance in scientifically evaluating the noise of power capacitor. Power capacitor in HVDC Converter Station under practical conditions has apparent fundamental frequency and rich harmonic frequency components. In order to simulate this condition, a whole condition loaded bridge circuit of noise measurement on power capacitor has been designed and studied. Two arms of the bridge are used to load fundamental frequency and a parallel resonance compensation inductance is used to reduce the fundamental current, while the other two arms are used to load harmonic frequency. The harmonic frequency load power supply composed of harmonic signal generator and power amplifier which can simultaneously load any combination of harmonics under 48th to simulate the various actual working conditions. The tests indicated that the noise spectrum measured under the designed circuit completely accorded with the one in HVDC Converter Station. © (2014) Trans Tech Publications, Switzerland.

Liao Y.,China Electric Power Research Institute | Pang M.,Guilin Power Capacitor Co. | Gu F.,Guilin Power Capacitor Co. | Li R.,China Electric Power Research Institute
Gaoya Dianqi/High Voltage Apparatus | Year: 2014

According to the characteristics of the compact assembling shunt capacitor, a series of tests are analyzed, including the discharge test of assembling shunt capacitor body with YN connection, the temperature rise test, the device temperature rise test, the discharge coil error test, the induction withstand voltage test, and the withstand voltage test of capacitor's secondary terminal to the ground. Conclusion is drawn from the analysis of the discharge test that the discharge test should be conducted on separate phase instead of on shunted three phases. Through the analyses on the temperature rise test of the assembling shunt capacitor body and the device, a feasible test method is proposed for the present test condition. According to the test results, it is suggested that the error test of discharge coil should be performed after the discharge coil is installed in the capacitor, and the ground withstand voltage test should be conducted once more for the assembling capacitor's secondary terminals, while the rest tests for discharge coil are conducted before its installation.

Guo Q.,Guilin University of Technology | Xie X.L.,Guilin University of Technology | Li Y.,Guilin University of Technology | Chen X.Y.,Guilin Power Capacitor Co.
Applied Mechanics and Materials | Year: 2013

This paper is for the problems of the 400V low voltage power capacitor reactive power compensation and for the problems existing in the transient process, resuming the principle of lowvoltage capacitor intelligent technology and its implementation briefly. Propose a synchronization of reactive compensation capacitor switching on-off control system based on the micro controller and adaptive control. Real-time monitoring system is used to access system active and reactive power changes in order to extract the zero voltage signals; intelligent control algorithm is used to realize the intelligence of capacitor reactive power compensation on-spot and cutting, which greatly reduce the over-voltage and flow phenomenon produced by the capacitor in the cutting process. The result checked by actual measured shows that the device is stable, reliable, and can be effective to on-site system reactive power compensation and realize intelligent cutting. © (2013) Trans Tech Publications, Switzerland.

Huang K.,Guilin Power Capacitor Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2010

DC filter capacitors often damage inrecent years in Tianshengqiao converter station. Some of the damaged capacitors were analyzed via disassembly in this study, consequently two counter measures against the frequent damage were proposed. In the first measure, one or several original imported DC filter capacitors are replaced with the capacitors made in China; and in the second measure, the whole DC filter capacitors set is reformed. The first measure is superior to the second one in cost and applicability, and has been taken successfully in Tianshengqiao converter station. In China, DC filter capacitors in converter stations have long been depending on imported ones. Substituting single or some China-made DC filter capacitors for the imported ones in Tianshengqiao converter station is an attempt, and the dependence on these imported capacitors is abandoned. In addition, this study may benefit the application of the China-made DC filter capacitors in converter station of HVDC transmission projects.

Li Z.,Guilin Power Capacitor Co. | Luo R.,Guilin Power Capacitor Co. | Chen S.,Guilin Power Capacitor Co. | Li X.,Guilin Power Capacitor Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2015

By the experimental study of series capacitors used in the first ultra high voltage (UHV) series compensation installation in China, including the physic-chemical property, electrical performance of domestic and foreign polypropylene films, the element breakdown voltage and the special withstand voltage tests of the series capacitors, the conclusion is obtained that there is no regularity difference between the domestic and foreign polypropylene films and the films impregnated C101D or M/DBT. ©, 2015, Gaoya Dianqi/High Voltage Apparatus. All right reserved.

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