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Chongqing, China

Yang F.,Chongqing University | Yao D.-G.,Henan Electric Power Research Institute | Peng H.,Chongqing Power Grid | He W.,Chongqing University
Gaoya Dianqi/High Voltage Apparatus | Year: 2010

With the development of ultra-high-voltage (UHV) power grid in China, people have paid more and more attention to electronic pollution in transformer substations caused by power equipments. Therefore, evaluation of electronic field of power equipments becomes increasingly important. According to the national standard, measurement of electromagnetic environment in a 500 kV transformer substation was conducted, and the shielding effectiveness was computed based on the measured data. Results indicate that the current shielding uniform can almost completely shield the electric field, however the uniform has weak shielding effectiveness against magnetic field. The shielding effectiveness (SE) against electric field is 39.4 dB and 12 dB respectively at head and chest of the model, and the SE against magnetic field is 0.09 dB and 0.15 dB respectively, which indicate that the design of UHV shielding uniform should consider shielding power frequency magnetic field. Source

Yang F.,Chongqing University of Technology | Wu H.,Chongqing University of Technology | He W.,Chongqing University of Technology | Chen T.,Chongqing Electric Power Research Institute | Nie D.,Chongqing Power Grid
Applied Computational Electromagnetics Society Journal | Year: 2010

The electric field inverse problem of high voltage transmission lines is investigated in this paper. Firstly the equations for the electric field forward problem of transmission lines were formulated, then equations for the inverse problem were formulated according to the forward problem and the least square theory. A method to solve the inverse problem is presented in the paper, in which the global regularization was used to process the ill-posed characteristic of the inverse problem. The Damped Gauss-Newton iterative method was used to search the optimum solution. A 500kV double-circuit transmission line was taken as an example for the calculations of the inverse problem. The inverse problems for different situations were calculated, including the situation when the transmission lines were in normal operation, and the situation when the transmission lines were in faulty state. The solutions to the inverse problem with and without regularization were compared in the paper, and the results indicated that the global regularization can effectively eliminate the ill-pose of the inverse problem. The electric field inverse problem can be used to confirm the electrification state of the ultra high voltage transmission lines, and also can be used in the environmental assessment tests to reduce the measurement workload. © 2010 ACES. Source

Xiong C.-S.,Chongqing Power Grid | Chen T.,Chongqing Electric Power Research Institute | Yang F.,Chongqing University | Wu D.,Chongqing Power Grid
Gaoya Dianqi/High Voltage Apparatus | Year: 2012

For evaluating power frequency electromagnetic field in working corridor of a high voltage substation, a calculation model of power frequency electric field in working corridor of high voltage substation is proposed by combining boundary element method (BEM) and charge simulation method (CSM) and by considering the interference from switching equipment. According to the structural characteristics of equipment in substation, indirect boundary integral equation of the interface of the suspension electrode and the dielectric is deduced, and the corresponding algebraic equations and calculation formulas of matrix elements are presented. Calculation method of the power frequency electric field in substation is implemented. Furthermore, a typical 500 kV substation is taken as an example to calculate the power frequency electric fields of single equipment and single-phase equipment in the substation, and simulation is performed with the software IES-Coulomb to verify the correctness of the calculation. The proposed model and calculation method can be applied to design of UHV substation for estimating the power frequency electric field and improving the electric field distribution in working corridor. Source

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