Study On Partial Discharge On-line Mornitoring Of High Voltage Switchgears

High voltage switchgears were widely used in power generation,transmission,distribution,power conversion,consumption and other sessions,having functions on switching,control and protection.Partial discharge is not only the characterization of insulation aging and degradation,but also one of the reasons of it.On-line partial discharge monitoring of high voltage switchgears can detect design,manufacture and installation defects and can make an evaluation of insulation aging,which can improve the safety of operation.The study of this subject has considerable application value and important scientific significance.By studying the related research at domestic and foreign,an on-line monitoring system for partial discharge of high voltage switchgears is designed by using the method of ultra high frequency(UHF).(1)In hardware system,choose microstrip antenna as UHF antenna.With the aid of Filter Solutions 10.0,the band-pass filter circuit was designed.The design of low noise amplifier was based on ATF-54143.The design of detection circuit was based on AD8313 ARM chip.The project of high speed data acquisition module used FPGA as the control core and AD9446 as A/D conversion chip.The power circuit module used the UC3842 as the core.(2)The system software is an important part of the online monitoring system,this paper presents a scheme of system monitoring software.(3)On line monitoring system needs strong anti-interference ability.In this paper,the hardware and software anti-interference methods are designed.The software anti-interference method is simulated.(4)UHF antenna is the core component of the whole on-line monitoring system,and it is the most prominent feature of the UHF method on line monitoring.According to the structure characteristics of high voltage switchgears and the requirements of on-line monitoring,this paper designed an UHF rectangular microstrip antenna with HFSS design simulation software.In this paper,the design of the hardware system circuit can meet the design requirements.On line monitoring system was realized.System anti-interference methods can achieve preferable results.The resonant frequency of the antenna is 1GHz,with the 370 MHz bandwidth,and has a good direction which can meet the requirements of practical applications.