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International Conference on High Voltage Engineering and Application, ICHVE

作者： Xudong Li Jian Li Jing Zhang Hehuan Ran Yan Wang State Key Laboratory of Power Transmission Equipment & System and New Technology Chongqing University Chongqing China State Grid Hangzhou Power Supply Company Hangzhou China

ISBN: (纸本)9781509004973

The valve side Wingdings of converter transformers withstand complex electric stress, and the minor insulation of converter transformers withstand combined fundamental AC and harmonic voltages. Surface partial discharge is a main form of discharge occurring in minor insulation and there is a severe lack of empirical research on surface partial discharge in oil-impregnated insulation paper at harmonic superimposed AC voltages. In this paper, the surface partial discharge experiments of oil-impregnated insulation paper were executed under different type of harmonic superimposed AC voltages. The results show that: a) when using harmonic superimposed AC voltages, PDIV values decrease with the increase of harmonic order and THD, b) PD patterns are closely related to the waveform of applied voltage, and the maximum discharge magnitude increases with the increase of harmonic order and THD, while the PD number per period doesn't change significantly with the change of order or THD of voltage under the voltage with same amplitude.

关键词： Partial discharges Harmonic analysis Surface discharges Discharges (electric) power transformer insulation Oil insulation

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Fast Fault Detection and Current Limiting Strategy of HVDC Circuit Breaker

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IOP Conference Series: Materials Science and Engineering 2018年第4期394卷

作者： Wei Li Xueguang Wu Dong Liu Bin Chang Le Zou School of Electronic Engineering North China Electric Power University Changping District Beijing 102206 China State Key Lab of Advanced Power Transmission Technology (Global Energy Interconnection Research Institute Co. Ltd.) Changping District Beijing 102209 China Beijing Key Laboratory of DC Grid Technology and Simulation (Global Energy Interconnection Research Institute Co. Ltd.) Changping District Beijing 102209 China Global Energy Interconnection Research Institute Co. Ltd. Changping District Beijing 102209 China

HVDC transmission has become the most valuable engineering technology because of its own advantages. But the rapid detection and isolation of DC side faults has been one of the major technical matters in the development of DC grids. Highvoltage DC circuit breaker is an important equipment to solve this problem, and becomes the current research hotspot. According to the process of HVDC breaker, this paper analyzes the fault detection and current limiting control of HVDC breakers, and proposes a fault detection method based on ROCOV (Rate Of Change Of Voltage) and a current limiting strategy of operation of arresters by sequence. It can reduce the operation time of the circuit breaker and the peak value of the fault current. Finally, simulation analysis is performed on the PSCAD/EMTDC to verify the correctness of the method.

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Test and Diagnosis on a Secondary Voltage Loss Fault of a 220kV Capacitor Voltage Transformer

Test and Diagnosis on a Secondary Voltage Loss Fault of a 22...

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International Conference on High Voltage Engineering and Application

作者： Zhi Zhou Chuan Cai Hu Zhu Xinchun Yang Feifei Wu Hongbo Liu State Grid Chengdu Power Supply Company Sichuan Electric Power Corporation State Grid Tianfu New Area Power Supply Company Sichuan Electric Power Corporation State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University

ISBN: (纸本)9781509004973

A 220 kV Capacitor Voltage Transformer (CVT) quitted operation because of losing secondary voltage. After the accident, power-off diagnostic testing was performed and it was found that several data were abnormal such as the transformation ratio, the secondary winding's DC resistance and the capacitance values, showing various types of fault characteristics. However, according to the CVT's internal structure, further tests in different conditions revealed these abnormal data were not caused by multiple independent faults, but showing a relationship of mutual support. The common pointed cause of the failure was a short circuit between the metal shell and the initial terminal of the intermediate transformer. And the judgment of the fault was fully confirmed through the inspection and test under disassembled condition. Moreover, the reasons of the fault were analyzed. In addition, strengthening the operation monitoring and improving the structure of CVT were suggested to prevent such risk, and test methods for the similar fault were recommended.

关键词： CVT Secondary voltage Fault Short circuit Intermediate transformer

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Reliability evaluation of electrical collector system of wind farm based on sequential Monte Carlo

Reliability evaluation of electrical collector system of win...

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International Conference on Probabilistic Methods Applied to power Systems (PMAPS)

作者： Lili Wen Manli Wang Ping Zhou Qian Zhou Bo Hu Yinghao Ma Yun Xia Ruosong Xiao Bo Li State Grid Chongqing Economic Research Institute Chongqing China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China State Grid Chongqing Electric Power Company Chongqing China

ISBN: (纸本)9781509019717

In order to study the influence of electrical collector system of wind farm from the perspective of four typical topological structures of electrical collector system of wind farm, sequential Monte Carlo model is established for reliability evaluation of electrical collector system of wind farm with consideration of multiple faults of wind turbine generator (WTG) and collection circuit in wind farms. The influence of cable fault on outage of WTG as well as separating and switching operations of the switch is studied. A comparison of four typical topological structures in probability distribution of number of WTGs under effective operation, total outage probability of WTGs, annual energy output of wind farm and other reliability indexes is conducted through actual calculating-examples analysis. Sensitivity analysis of collection circuit fault rate is then implemented. Calculating-example results verifies the correctness and applicability of the model proposed in this paper.

关键词： Wind farms Reliability Decision support systems Monte Carlo methods Wind speed Indexes Manganese

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Analysis of acetic acid dissolved in transformer oil based on laser Raman spectroscopy

Analysis of acetic acid dissolved in transformer oil based o...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Lingling Du Weigen Chen Zhaoliang Gu Jingxin Zou Fu Wan Pinyi Wang Chong Pan State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China Chengdu Power Supply Company of State Grid Chengdu China

ISBN: (纸本)9781509004973

Acetic acid produced in oil-paper insulation aging process would greatly reduce the quality of insulation performance of a transformer, and seriously affect the healthy operation of the transformer. The monitoring of acetic acid content dissolved in the transformer oil is of great significance for ensuring the safe and reliable operation of the transformer. Laser Raman spectroscopy is a molecular analysis technology based on the Raman effect, which can directly perform non-contact measurement to acetic acid dissolved in the transformer oil by a laser with single frequency. Compared to the conventional methods, laser Raman spectroscopy method is more simple and time-saving. In this paper, the application of laser Raman spectroscopy in the detection of acetic acid dissolved in the transformer oil was studied. Firstly, Gaussian 09W simulation was applied to analyze the Raman spectrum of acetic acid. The spectral peaks and Raman vibration modes of acetic acid were analyzed and assigned. Acetic acid dissolved in the transformer oil was directly detected based on the laser Raman spectroscopy liquid detection test platform. Acetic acid was characterized by Raman signal at 618cm -1 , where no spectral interferences caused by oil-derived Raman signals occur. And the qualitative and quantitative analysis methods for the acetic acid based on the characteristic spectra and the least squares method were established. The results show that laser Raman spectroscopy can be used in the analysis of acetic acid dissolved in the transformer oil with good detection stability, which lays a good foundation for quantitative detection and the online monitoring of acetic acid dissolved in the transformer oil with laser Raman spectroscopy.

关键词： Oil insulation Oils power transformer insulation Raman scattering Vibrations Statistical analysis

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Laser Raman spectroscopy applied in detecting dibenzyl disulfide(DBDS) in transformer oil

Laser Raman spectroscopy applied in detecting dibenzyl disul...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Zhou Fan Weigen Chen Jingxin Zou Lingling Du Chong Pan State Key Laboratory of Power Transmission Equipment &System Security and New Technology Chongqing University Chongqing China Chengdu Power Supply Company of State Grid Chengdu China

ISBN: (纸本)9781509004973

Recently, copper sulfide which was formed by corrosive sulfur in transformer oil reacting with copper windings caused many faults of high voltage electric equipments. Online detection of dibenzyl disulfide (DBDS) has become a new way of avoiding happening major accident. Comparing with the traditional monitoring technologies, Laser Raman spectroscopy (LRS) has incomparable advantages, such as non-contact detection, quickly integrated detection of multiple characteristic substances, using single-frequency laser, which are necessary to achieve online monitoring. Based on the basic principle of LRS, we build up a platform using LRS for quantitative and qualitative analysis and develop the relevant experimental methods. Thermal aging tests are done at 140 °C with an air atmosphere up to 48h with copper strip. The test results indicate that Laser Raman spectroscopy can be applied to identify corrosivity of mineral oil for a running power transformer.

关键词： Oils Copper Strips Raman scattering power transformers Oil insulation Sulfur

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Influence of copper particles on frequency domain spectroscopy characteristics of mineral oil

Influence of copper particles on frequency domain spectrosco...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Dali Huang Jing Zhang Jian Li Qiang Fu Mengjun Wang Tiansheng Chen Electric Power Research Institute of Guangdong Power Grid Co Guangzhou China State Key Laboratory of Power Transmission Equipment & System and New Technology Chongqing China

ISBN: (纸本)9781509004973

The dielectric properties of transformer oil are greatly threatened by particles especially the metallic particles. In order to obtain the influence of metallic particles on frequency domain spectroscopy (FDS) of mineral oil, we chose copper particles to contaminate the mineral oil artificially. The dielectric properties such as relative permittivity, dielectric loss tangent and volume resistivity of contaminated mineral oil versus frequency with various copper volumetric concentrations were measured by dielectric spectrometer. Measurement results show that the relative permittivity, dielectric loss tangent and volume resistivity of contaminated mineral oil all reduce with increasing frequencies from 10 -2 Hz to 10 6 Hz. Moreover, the relative permittivity and dielectric loss tangent increase with increasing copper volumetric concentration, and the volume resistivity decreases with the increase of copper volumetric concentration. The difference is more obvious at low frequencies than those at high frequencies. These results are then discussed with polarization and classical conduction theories.

关键词： Oils Copper Minerals Conductivity Permittivity Dielectric losses

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Overvoltage measurement based on the electro-optic E-field sensor

Overvoltage measurement based on the electro-optic E-field s...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Maoqiang Bi Yongfu Li Jin Fu Gaolin Wu Huadong Peng Yongliang Ji YiQun Sun Shangpeng Sun Junde Ran State Grid Chongqing Electric Power Co. Electric Power Research Institute Chongqing China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China State Grid Chongqing Electric Power Company Chongqing China State Grid Chongqing Electric Power Company Maintenance Branch Chongqing China

ISBN: (纸本)9781509004973

Overvoltage measurement has been an important field of high voltage engineering. In this paper, an optical intense E-field sensor which is based on the electro-optic effect of lithium niobate, has been studied comprehensively. First, the principles and key issues in sensor design are presented. Second, after fabrication, the input/output characteristics of the sensor are obtained and calibration under lightning impulse. Then, the designed electric field sensor is applied in overvoltage measurement.

关键词： Electric fields Voltage measurement transmission line measurements Electrooptical waveguides Voltage control Crystals

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Analysis of methyl ethyl ketone dissolved in transformer oil using laser Raman spectroscopy

Analysis of methyl ethyl ketone dissolved in transformer oil...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Zhaoliang Gu Weigen Chen Lingling Du Jingxin Zou Zhenze Long State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China Sichuan Electric Power Research Institute State Grid Chengdu China

ISBN: (纸本)9781509004973

Methyl ethyl ketone dissolved in transformer oil can be used as the mark of thermal insulation degradation. As an effective detecting method for trace liquid, Laser Raman Spectroscopy (LRS) is more suitable for in-situ detecting methyl ethyl ketone concentration than traditional detection methods. The application of LRS in detecting methyl ethyl ketone concentration has been studied. Firstly, the structure model of methyl ethyl ketone molecule was built by Gauss View 5.0. Then, the Raman spectrum of methyl ethyl ketone was analyzed by Gaussian 09W software theoretically. And the liquid test platform was built based on confocal Raman technology in the lab. The Raman characteristic peak of methyl ethyl ketone dissolved in oil was selected by testing standard samples of transformer oil directly. Moreover, applying the least square method, the quantitative analysis method was built between the areas of Raman characteristic peak and the concentrations. The experimental results showed that LRS can be used to effectively detect the concentration of methyl ethyl ketone dissolved in transformer oil. Therefore, a new detection tool is presented for transformer health diagnosis.

关键词： Oil insulation Oils Raman scattering power transformer insulation Vibrations Statistical analysis

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Study on simulator of ultra-high frequency partial discharge signal

Study on simulator of ultra-high frequency partial discharge...

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International Conference on High Voltage Engineering and Application, ICHVE

作者： Dingjun Wen Guangdong Zhang Xiubin Zhang Dawei An Lin Du Shuncheng Liu State Grid Gansu Electric Power Research Institute Gansu China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China

ISBN: (纸本)9781509004973

Because of the available Ultra-high frequency (UHF) PD signal simulator has the problem that the parameters cannot be adjusted, this paper presents a method to generate UHF signals by multichannel signal synthesizing based on magnitude-frequency characteristics and phase-frequency characteristics of PD, from which we have developed a signal device. The principle and system structure of signal device is elaborated, and then measured analysis is given to the performance of device. The result of the experiment analysis shows that the analog signal which contains the time-frequency and phase characteristics of the UHF PD signal. The frequency of the output electromagnetic signal ranges from 0.3GHz to 1.429GHz while the phase distribution characteristic is similar to the power frequency signal. The signal frequency, output power and φ-q, φ-n spectrogram can be adjusted smoothly, the real output is high enough to 25dBm. This simulator build discharge type database by obtain real PD signal, we can also modify and add live data of PD easily. In this way, the signal simulator can generate multiple types of PD UHF signals efficiently.

关键词： Partial discharges Discharges (electric) Frequency modulation Antenna measurements UHF measurements Time-frequency analysis

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