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Liu C.,Zhengzhou University | Wang K.,Zhengzhou University | Cui W.,Zhengzhou University | Liu W.,Shangqiu Power Supply Company
2012 International Conference on Systems and Informatics, ICSAI 2012

Precise results of eigenvalues can be obtained in order reduction approach for special modes. To improve calculation efficiency, the order reduction approach is analyzed in this paper. In the process of order reduction, every set made up of retained state variables is shared by different modes, which reduces calculation amount. Based on real number expression of complex matrix, the expression of outer iteration is reformed. Factor table formed by the sequence elimination can be used to solve inverse matrix quickly. The function of parallel computation in Open Multi-Processing is introduced to accelerate calculation on multi-core computers. The improved effect of retained sets, sparse technique and parallel computation is tested and analyzed by a 105-machine system. © 2012 IEEE. Source

Li J.,Shenyang Institute of Engineering | Wang S.-H.,Shangqiu Power Supply Company | Gu C.-L.,Shenyang Institute of Engineering
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control

Reactive power optimization algorithm in distribution network based on genetic algorithm with distributed generation is proposed. Reactive power optimization mathematical model including distributed power generation system is constructed, the smallest loss and node voltage constraints are also taken into account, and reactive power output for distributed generation is optimized by using genetic algorithms. Simulation result shows that the optimization algorithm can effectively reduce the power loss and improve voltage quality. Source

Guo Y.-Z.,Henan Electric Power Research Institute | Shi G.,Henan Electric Power Research Institute | Ding W.-H.,Shangqiu Power Supply Company | Liu W.,Henan Electric Power Research Institute | Wu C.-H.,Henan Electric Power Research Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control

The paper analyzes the major problems of the high frequency channel in high frequency protection, introduces the testing method of high frequency channel with electrical power, researches and designs relevant testing equipment and solves the testing problem of high frequency channel with electrical power. It analyzes separately the judgment standard of high frequency channel test, the emulational calculation and the anti-jamming problem of site test in transformer substation. It puts forward the practical site testing method and standard according to the data derived from the emulational test, and proves the validity and practicability of the testing method. This testing method can judge the status of the high frequency channel quickly and accurately without line outage and realize the quick fault orientation, which improves the security and stability of the operation of electrical grid. Source

Li M.,Shangqiu Power Supply Company | Liu X.,Shangqiu Power Supply Company | Zhang X.,Chongqing University
2010 International Conference on High Voltage Engineering and Application, ICHVE 2010

The fault diagnosis of Gas Insulated Switchgear (GIS) partial discharge (PD) is significant for mastering the essence of defects within the GIS accurately and guiding its maintenance. This paper designed four kinds of GIS defection models. The GIS gray intensity images were constructed based on mass specimens gathered by the ultra-high frequency and high speeds systems. Aimed at the PD characteristics and its defections, a PCA-FDA method is put forward based on PD images. Firstly, the principal component analysis is employed to condense the dimension of PD images, then the optimal sets of statistically uncorrelated discriminant vectors are extracted, and the minimum distance classifier was constructed as classifier. The identified results showed that this method can effectively elevate the discrimination of the four kinds of defects in GIS PD. ©2010 IEEE. Source

Zheng X.,Shangqiu Power Supply Company | Cao H.,Shangqiu Power Supply Company | Tang J.,Chongqing University | Zhang X.,Chongqing University
2010 International Conference on High Voltage Engineering and Application, ICHVE 2010

Based on the structure of power transformer, a sleeve monopole antenna for partial discharge detection in transformer was designed. In this paper, the structure of the antenna is described, the calculation principle and method of the antenna parameters are presented. Through optimizing the structure parameters, which change the input impedance of the antenna, good VSWR characteristic, high gain and steady pattern are obtained. According to simulation analysis and actual measurement, the bandwidth of the antenna is 350-500 MHz, and the center~equency is 425 MHz, the average gain reaches 2.16 dBi and varies little in the whole bandwidth. The laboratory measurement result shows that the sleeve monopole antenna can satisfy the requirement of partial discharge detection, and detect the partial discharge signals in effective band with high sensitivity and good directivity. ©2010 IEEE. Source

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