A New Apparatus Study Applied To PD On-line Monitoring

Partial discharge is an important factor that affects the safty of the high voltage power equipment. Because power equipment work in a complex environment, detecting partial discharge signal has been the important part of partial discharge study. Then it affects fault diagnosis of power equipment. For handling the interference from complex environment, this thesis presents a kind of real time on-line monitoring system. The main works include:1. By consulting a lot of related documents, analyzing the time domain waveform , frequency-domain waveform and various detecting ways.2. By analyzing the partial discharge signals and the interferences and using high-speed filed programmable gate array(FPGA) and digital signal processor(DSP), a hardware and print circuit board have been designed3. Because period narrow band signals are the main part of background noises, this thesis uses hardware description language to design a multi-band finite impulse response filter(FIR) and downloads the program into filed programmable gate array to eliminate the period narrow-band interferences in the background noises. The FIR filter supplies a possible clean signal for further processing.4. By processing the sampled signal including contain noise and partial discharge signal, narrow band period signals are filtered, but some period impulse signals can't effectively be suppressed. So this thesis uses DSP(digital signal processor) as core processor in order to apply to process partial discharges. For further extracting the partial discharges the self adapted modeling has been given with MATLAB and the new filter can suppress the strong related signals. A self-adapting filter has been completed with the assembly language.