Development Of Ultrasonic Signal Detection System And Experimental Study For Partial Discharge

The normal operation of high voltage electrical equipment is the basis for the safe operation of the power system,partial discharge is one of the main causes of electrical equipment malfunction.Partial discharge detection of electrical equipment can detect the partial discharge signal of electric equipment inside which can prevent the occurrence of serious accidents in power system and improve the reliability of power supply.This paper designs a partial discharge ultrasonic signal detection system based on the principle of partial discharge ultrasonic detection and the design method of embedded system.With the application of virtual oscilloscope as the lower computer data acquisition,the LabVIEW software is the development platform for PC user interface and the PC user interface achieves the filtered waveform display and frequency domain waveform display function,voltage alarm function,calculating the signal time delay function.Considering the characteristics of ultrasonic signal the lower computer uses USB bus to achieve high-speed data uploading.The optical Transmitter and Receiver and the optical fiber convert the partial discharge ultrasonic signal into optical signal which makes the signal to transmit long distance.Signal's close distance transmis sion system makes the signal acquisition scheme more flexible.The partial discharge ultrasonic signal detection system can realize the distributed measurement of partial discharge signal and the on-line monitoring of partial discharge ultrasonic signal.In this paper,the design of partial discharge ultrasonic signal detection system has been applied to the experimental study.Use the oil insulation needle plate discharge model to test the function of ultrasonic signal detection system.This paper uses pulse current method and the partial discharge ultrasonic signal detection system to study the correlation between the voltage amplitude of the ultrasonic partial discharge signal and the discharge capacity.The generalized cross-correlation method is used to calculate the time delay of the acquisition signal and the reference signal,the genetic algorithm is used as the localization algorithm to locate the location of the partial discharge source by acoustic localization method.