Research On Ultrasonic Detection Of Partial Discharge Based On L-shaped Array And MEMP Algorithm

Partial discharge detection of the electrical equipment has important significance to the safe operation of power system. The detection method of partial discharge(PD) using ultrasonic array signals is a new method that applies array signal process technique(ASPT) and the array sensor to the PD detection.The formation of recently array sensor for partial discharge detection are linear, square and round etc. In this paper, the L-shaped array sensor is applied in partial discharge detection.Compared with linear array sensor, L-shaped array sensor has higher estimation accuracy. In contrast with the circular array and square array, L-shaped array sensor can improve the corresponding array aperture; L-shaped sensor array has smaller amount of calculation, simpler data processing and lower algorithm complexity.In the two-dimensional DOA estimation, MEMP method based on L-shaped array has the advantages of less sampling data, quick calculating speed and high precision calculation, which has received widespread attention and in-depth research. In this paper, based on L-shaped array and MEMP direction finding algorithm, we studied the partial discharge detection.Firstly, we built the L-shaped array signal model of the partial discharge ultrasonic signal. Since partial discharge is a typical broadband signals, we used RSS method to make it into a narrowband signal by focused processing and analyzed the performance of the algorithm of RSS. By the application of the MEMP, we realized DOA estimation and spatial localization of a multi-PD source by the use of L-shaped array and MEMP finding algorithm. On the basis, we studied the detection effec t of one partial diacharge under different SNR, PD source angles and MEMP of different numbers of array elements.of L-shaped array.Secondly, Gerschgorin(DGE) method was used to estimate the numbers of partial diacharge, and also we realized the DOA estimation and spatial localization of a multi-PD source by using L-shaped array and MEMP direction finding algorithm and carried out a large number of simulation.Finally, this paper designed a sensor of L-type PD ultrasonic array, improved PD ultrasonic testing experiment platform based on L array, and developed the corresponding software system. Also, we carried out a large number of experimental studies about PD detection of single and multi-source.