A Virtual Array Extension Method for Multiple Partial Discharge Sources Localization Based on Fourth-order Cumulant and Signal Sparse Decomposition

[摘要] The localization of multiple partial discharges based on UHF signal is difficult to accomplish due to the excessive localization error. A virtual array extension method based on four-order cumulant and signal sparse decomposition is proposed in this paper. The virtually extended array has higher directional resolution and it could detect partial discharge sources with higher accuracy. The 2×2 UHF array that commonly used in existed partial discharge localization methods is virtually extended to 3×3 and 5×5 array. The virtual array extension is accomplished by extending the corresponding steering vector matrix of PD signal spatial spectrum to a overcomplete dictionary, which is then used to realize the sparse decomposition of the PD signal. Eventually the DOA estimation of multiple partial discharge sources is achieved. Simulation and field test results show that the virtually extended UHF array can detect and locate two PD sources simultaneously. The directional angel estimation error is about 6° and the pitch angle error is lower than 4°, which has proved the feasibility of the proposed method.

[发布机构] Electric Power Research Institute of State Grid Liaoning Power Supply Co. Ltd., Shenyang, China^1;Shenyang Kekai Electric Power Technology Co. Ltd., Shenyang, China^2;Shanghai Jiao Tong University, Shanghai, China^3

[效力级别] 电工学

[关键词] Directional resolution;Four order cumulant;Fourth order cumulant;Localization errors;Localization method;Over-complete dictionaries;Partial discharge sources;Sparse decomposition