Development Of Partial Discharge Automatic Test System For Stator Bar Of Large Generator

The large generator is an indispensable power equipment in the power system.The safety and stability of its operation is closely related to people's life.Every generator fault will cause huge economic loss,and the stator insulation fault caused by partial discharge is an important cause of generator accidents.When partial discharge occurs in the insulation system,it will lead to irreversible and accelerating deterioration of the insulation,and eventually damage the insulation.Therefore,the quality of stator bar insulation has an important impact on the operation of the generator,and it is very important to detect the partial discharge of the stator bar of the generator.According to the function and technical parameter index of generator stator bar partial discharge test,a set of large generator stator bar partial discharge automatic test system is developed by using pulse current method and virtual instrument software Lab VIEW,including the design of hardware system and software system.The hardware system includes pre signal conditioning circuit,power frequency signal conditioning circuit,analog-to-digital conversion circuit,central control circuit,serial port communication circuit and auxiliary power circuit,etc.,to achieve signal acquisition,program-controlled amplification,filtering,Analog-to-digital conversion,system control,data transmission and other functions.Based on Lab VIEW platform,the software part of the test system is designed,including data acquisition module,parameter setting module,digital filtering module,data storage module,statistical spectrum module,automatic test report generation module,etc.the functions of data acquisition,signal layered processing,data storage,spectrum display analysis and automatic test report generation are realized.In order to test the developed test system,this paper carried out the system construction and circuit debugging in the laboratory.The test results of each hardware module show that the partial discharge test system of generator stator bardeveloped in this paper meets the design requirements.After the system is built,the partial discharge waveform of generator stator bar is simulated,and the test system in this paper is used.The test results show that the test system can collect and process the discharge waveform,which verifies the availability of the system.