Design Of GIS Partial Discharge Ultrasonic Detection System

Although the partial discharge is very feeble,it is very harmful to GIS(Gas Insulation Switch-gear)equipment.If it lasts for a good while,the insulation peculiarity of the equipment will be reduced and lead to a suite of security incidents.Therefore,it is very necessary to detect the partial discharge of the equipment.According to the discharge characteristics of GIS electrical equipment,a partial discharge detection system is designed,which is based on the study of ultrasonic detection method.By means of STM32F103VCT6 controller,the principle peripheral hardware circuits are constituted.Ultrasonic sensors are used to collect discharge signals and then the collected ultrasonic discharge signals can be amplified by the amplifying circuit which is based on INA128 chip with an adjustable amplification.In this design the band-pass filter is adopted,and it is the combination of low pass filter and high pass filter.As is to filter the signal noise,the butter-worth second-order high-pass filter chip AD8610 BR is used,which supports dual power supply and has a large frequency range.The rectifying circuit is used to convert AC signals into DC signals,which will be accessed by the controller.The communication circuit is based on RS485 for data communication.The collected discharge data is stored in the external memory.The signal acquisition,the signal processing and the data transmission of the lower computer of the detection system have been accomplished by the software design.And programming,debugging,positioning of the upper computer has also been completed by it.In addition,the database has been established,and it supports data to be added,deleted,changed and checked.In this system,Multisim13.0 is adopted to simulate and verify the amplifying circuit,filtering circuit and rectifier circuit in the signal processing.Single point test method and cross test method are used to test,and on this basis,partial discharge defects are simulated to verify the detection effect of the system on ultrasonic signal.The experimental results show that the performance of the system meets the design requirements.