Research on motor overvoltage issues in metallurgical environments using three-level inverters

Industries such as nuclear power plants and underground mining are characterized by space constraints,forcing the use of long-wire cables to power motors.The impedance mismatch between long-wire cables and motors leads to overvoltage phenomena at motor terminals,especially when the cable length is long or the transmission frequency is high. In this paper by analyzing the expressions of the peak voltage at the motor terminal of the two-level and threelevel inverters,we explain the mechanism of the three-level inverter to suppress the overvoltage at the motor terminal,and build the inverter-long-line cable-motor system for simulation to verify the correctness of the conclusion.