Simulation of Cross-shaped Ultrasonic Array Applied to Partial Discharge Location in Oil

A study on a combined sensor was made for partial discharge(PD) location in oil. The sensor includes a cross-shaped ultrasonic phased array of 13 elements and an ultra-high frequency (UHF) electromagnetic conformal array of 4 elements. The ultrasonic array can achieve the array performance of 61 elements with high-order cumulant processing technology. It can improve the array aperture and direction sharpness of the sensor and greatly reduce the following circuit and manufacturing costs. The method of PD location which use expanded ultrasonic array accompanied with UHF electromagnetic array has better location performance. The spatial spectrum comparing with MUSIC(multiple signal classification) method shows that virtual expanding array of the fewer number array elements with high-order cumulant processing technology has strong ability to suppress colored Gaussian noise interference. This provides the possibility for the practical application of array technology in power equipment.