EFT/B interference transmission model and method of anti-interference in a coal mine monitoring substation

Coal mining monitoring system has been enforcing tests for the immunity of Electromagnetic Compatibility(EMC) since 2006.However,not all monitoring substations can pass the Electrical Fast Transient/Burst(EFT/B) immunity test and the explosion-proof test simultaneously.In order to enhance EMC,the EFT/B interfere transmission model was presented at the substation power port,after the EFT/B test method was used to analyze the monitoring substation power ports.Hence,a low-pass filter was designed by using the simulation software PIPICE and an anti-jamming method was proposed by way of a parallel connection of the discharge interfere circuit and the low-pass filter.The improved complex EMI filter was made up of an interference discharge device and a filter.The dynamic equivalent circuit was proposed for the EFT/B immunity test.As a result,the monitoring substation has passed the EFT/B immunity and explosion-proof tests with the complex filter.It is concluded that the complex EMI filter has significantly enhanced the immunity of the coal mining monitoring system.