Research And Development Of Partial Discharge On-line Monitoring System Based On The AE

Partial discharge is one of the main causes of high voltage electrical fault. The primary means of electrical equipment operation detection is to detect the characteristics of partial discharge signal. There are a variety of methods in partial discharge detection. Detecting the ultrasonic signal is a method which is very important. The structure\performance\function of ultrasonic detection system is limited greatly because of their MCU with storage space, running rate and low integration rate etc. Because ARM MCU is provide with the performance of high—frequency, multi-purpose, low power and low cost, the plan that STM32f107is applied to the design of partial discharge detection system in electrical equipment is proposed. Acquiring and analyzing the partial discharge ultrasonic signal. This system realizes the detection function through acquiring and analyzing the PD ultrasonic signal basically. Compared with the detection system with other MPU, it is provide with the excellence of high speed, simple structure, convenient for carry etc.This paper first discusses the mechanism of the ultrasonic signal generated by the partial discharge and the principle of detecting partial discharges by ultrasonic signal. The analog signal pretreatment circuit is designed, which is constituted of third-level amplifying circuit and Butterworth band-pass filter with80to300KHZ. They can adjustment peak-to-peak value to request scope of A/D input signal scope, and suppress massive low frequency and the high frequency cycle unwanted signal. The functional modules of signal acquirement, graphical display, correspondence, control and data storage are designed based on the multi-control interfaces of STM32f107. The application software of frequency analysis, digital filter and wavelet. This system is tested with the analog signal of PD ultrasonic which is from arbitrary signal generator of MULTSIM and added to high frequency, low-frequency cycle disturbance and white noise. The results show that the filter circuit call suppress and attenuate massive low frequency and high frequency cycle unwanted signal in excess of80to300KHZ; the amplifier Call adjustment peak-to-peak value to request scope of A/D input signal scope.finally, studied the calculation methods of the digital filtering and ultrasound location, designed of the software architecture of the system and gives the programming ideas of acquisition module.