Simulation of switching overvoltage in mine production unit

The problem of overvoltage is particularly important for underground coal mine electric power supply systems as degradation of insulation may lead to electric faults, power outages, fire and explosion of methane and coal dust. This paper is dedicated to simulation of overvoltage in vacuum circuit breaker caused by emergency deenergization of mine production unit. A computer model of the vacuum circuit breaker was made in Simulink MATLAB in order to estimate possible overvoltage level and electric power quality problems. The model of circuit breaker represents processes in switching off vacuum breaker, such as arc ignition, existence of chopping current, electric arc and arc re-ignition in case of insufficient recovery voltage. Developed model of vacuum breaker was applied for simulation of overvoltage in mine production unit as a part of the mine electric power system model.