The On-line Monitoring System Design On Partial Discharge

In recent years, 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 power transformer in the power network. The insulated state is one of the most important problems of large power transformer safely running in power system. According to the statistics, insulation accident happened by power transformer mostly is connected with partial discharge. The most efficient method in monitoring the running transformer's insulated state is to extract partial discharge signals in real-time. Therefore, In this paper, the essentiality of developing online partial discharge monitoring, the actuality and develop trend in home and abroad are discussed. In order to solve the problem in online monitoring system, a high effective detection PD circuit is designed; implement monitoring the operational state judging the condition on-line to transformer.Based on analyzing the noise in the partial discharge pulses, pulse current method is used to inspect PD signals; the paper used the software and hardware method to suppress the noise. In hardware circuit implementation, notice to choose signal sensors, signal magnify circuit and filter circuit are reasonably designed, at the same time, high-speed data sampling circuit and large capability storage circuit are designed, and the software method was simulated under MATLAB 7. 1. Accurate drawing puts up Partial Discharge pulse signal, the data collect, analysis system are centering on the TMS320VG5402 chip that the TI Company produces. And will collect the data to transformer Partial Discharge by serial end upload till PC, to carry out analysis on Partial Discharge pulse conveniently.Finally, simulated examination is done after the hardware and software design. The simulation results show the designed PD signal detection unit and adopted software process method is effective. The method's turn to be able to detecting having effect putting up Partial Discharge pulse signal, accuracy height, cost low, have the fairly good pragmatism and the vast application prospect.