Research On Detection And Verification Technology Of Switchboard Based On Ground Wave

Switchgear is a kind of electrical equipment widely used in power distribution network and low-voltage substations.It mainly includes circuit breakers,load switches,disconnectors,earthing switches,automatic reclosing and sectionalizers,operating mechanisms,protective devices,and explosion-proof devices.Distribution equipment and other equipment are mainly used in the system to close and open normal lines and fault circuits,control and protection.In the long-term operation of the switchgear,partial discharge may occur.Currently,partial discharge detectors are widely used to perform partial discharge detection of the switchgear.However,there is a lack of research on the verification of the partial discharge detector,which results in that the partial discharge device cannot be accurately calibrated,and the partial discharge detection of the switchgear has an uncertain influence.In this paper,the partial discharge model of the switchgear cabinet and the mechanism of TEV signal generation are studied in depth.The generation and propagation characteristics of the TEV signal in the switchgear cabinet are simulated and a switchgear station placement experimental platform is built.The typical defects in the switchgear cabinet are established.The partial discharge signal produced by it was studied experimentally.Based on the operating characteristics of the switchgear PD detector,a calibration scheme for the switchgear PD detector was proposed,a verification device for the accuracy check of the switchgear PD detector was developed,and a checksum was applied in the actual application scenario.The device performs a verification test on the partial discharge detector.The results achieved are as follows:(1)Based on CST simulation software,a simulation model of the switchgear is established.The generation of TEV signals and the propagation characteristics on the surface of the switchgear cabinet are studied systematically.The influence of the severity of the partial discharge and the speed and speed on the TEV signal is studied.The results show that the TEV detection method has higher detection capability for faster discharge and more intense partial discharge.(2)Set up a switchgear PD experimental platform,make three typical defect models of the switchgear,conduct partial discharge tests in a laboratory environment,and collect discharge signal data through PD and TEV testers.Based on the data,the characteristics of the discharge signals of different defect models are summarized.(3)The use environment and performance parameters of the transient ground voltage partial discharge calibrator are proposed.On this basis,the overall design of the transient ground voltage partial discharge calibrator is proposed,and the corresponding hardware and software design is proposed and implemented.Finally,the performance test of the linearity and stability of the transient ground voltage partial discharge calibrator is performed.The test results show that the nonlinearity of the transient ground voltage partial discharge calibrator is ±1dB,and the maximum stability error is positive.Negative 1dB,to meet the design requirements.This article designs and implements a ground-based radio-controlled switchgear PD test calibrator that satisfies the needs of portable PD testing technology and is suitable for PD test verification tests in various scenarios...