Research On Automatic Detection Method Of Surge And Transient Pulse Group For Relay Protection Device

With the rapid development of Smart Grids and Ultra High Voltage,the electromagnetic environment in which relay protection devices operate becomes increasingly severe.Electromagnetic compatibility testing needs to be carried out during the entire cycle of the development and design,quality inspection and operation and maintenance of relay protection devices.However,there are many types of ports for relay protection devices,and the existing electromagnetic compatibility test methods can hardly meet the requirements of the new product for the development cycle.At the same time,when the transient pulse is injected into one port of the relay protection device,it will interfere with other ports and affect the detection results of electromagnetic immunity.In this thesis,based on the existing standards and methods of surge and electrical fast transient pulse group immunity test,the electromagnetic compatibility automatic test system of relay protection device is developed to improve the test efficiency and accuracy,which is helpful to shorten the product development cycle,improve the product quality test level and test speed,and better serve the safe and stable operation of power grids.The main research contents are as follows:Firstly,the operating characteristics of the power circuit,AC circuit,input circuit and output circuit of the relay protection device are analyzed.Besides,the current status of electromagnetic compatibility test of relay protection devices is studied,and the mechanism,hazards,test standards and methods of surge and electrical fast transient pulse groups are analyzed.Based on these research foundations,the influence of surge impact and transient pulse group on the power supply port,AC input port,switch input port and switch output port of the relay protection device are studied.Secondly,a multi-conductor transmission line model for the relay protection device detection system is established.Besides,the crosstalk characteristics between various types of cables in the relay protection device detection system are analyzed.Based on these research foundations,the method of extracting the electromagnetic parameters of multi-conductor transmission lines based on geometric dimensions and finite element methods,and the effects of the height of the multi-conductor transmission lines from the ground and the distance between them on crosstalk are studied.Thirdly,an automatic detection method for surge protection immunity and electrical fast transient pulse group immunity of relay protection devices is proposed in the thesis.Besides,the automatic test platform and the switch matrix which can automatically apply transient conduction pulse in the power circuit,AC circuit,input circuit and output circuit are designed.At the same time,the transient pulse waveform and crosstalk characteristics of the power port,the AC input port,the switch input port and the switch output port of the relay protection device are analyzed in the process of applying surge and electrical fast transient pulse group.According to the actual test needs,the automatic test software is developed,and the test flow is designed.On this basis,the instruction set of automatic test software is obtained.Finally,an automatic detection platform for surge protection immunity and electrical fast transient pulse group immunity of relay protection devices is designed and built.In addition,the high-frequency characteristics of each port of the switch matrix are studied through experiments.Based on these research foundations,a certain type of relay protection device is used as an experimental object to carry out automatic detection of surge immunity and electrical fast transient pulse group immunity.The experimental results show that,compared with the manual test,the proposed method and test system can meet the standards of GB/T 17626.4 and GB/T 17626.5,and effectively improve the detection efficiency of transient conduction immunity.