Research And Implementation On The On-Line Partial Discharge Monitoring Method For Electric Apparatus

Due to increasing capacity of electric network and grades of voltage, power supply departments regard improving power reliability as their main aim. The security of power system is related to the operation of various electric apparatus in the power network. In statistics, most insulation accidences are related to partial discharge. So it is effective to judge the operating condition of electric apparatus by implementing on-line partial discharge monitoring on them.The paper researched an on-line partial discharge monitoring method for electric apparatus. Based on analyzing the noise in the partial discharge pulses, the paper used the software and hardware method to suppress the noise. The hardware method employed differential balanced circuit, phase shifting circuit and amplitude modulating circuit. The software method employed wavelet transform as main means to suppress noise. And the software method was simulated under MATLAB 6.1. For extracting the partial discharge pulses exactly, the data acquisition and analysis system employed TMS320VC5402 that was made by T1 as core chip. And the partial discharge data was transferred to PC by RS-232 serial communication port. The host computer program employed Delphi to design user interface to analyze partial discharge pulses.The method can detect partial discharge pulses effectively. And it has high accuracy and low cost. It processes preferably practicability and wide application foreground in power system.