Comparison of overvoltage mitigation methods in industrial drives with long cables

This work analyses via simulation and experimental results the impact on the motor terminal voltage of inverter-fed industrial drives. After the validation of the modeling some overvoltage mitigation techniques are implemented and evaluated. In several industrial plants the cable connecting the converter and the machine may have a length of some hundreds of meters. While for conventional steady-state studies a lumped-circuit may be used to represent the cable, this is not true for power electronics application where harmonics exist in steady-state. The effect on the machine terminal voltage is increased with the length of the cable. To accurately access the motor terminal overvoltage and to implement an efficient mitigation method one needs to model the cable with the highest precision possible. In this paper a detailed frequency dependent cable is used to analyse the motor terminal voltage. Experimental results are carried out to validate the simulation models of cable and the plant. Some filter solution are analysed together with another converter configuration in order to minimize the inverter terminal voltage.