Effect of varistors for overvoltage protection in inverter-fed drives on the voltage distribution in the stator winding

The use of varistors for overvoltage protection in inverter-fed drives can be a promising alternative to common solutions like filters. In this contribution the varistor´s influence on the voltage distribution in the stator winding is presented under certain aspects such as cable type and varistor type. The results of different measurements are shown and the main aspects are discussed. It is shown voltage amplitudes and voltage distribution can be affected positively to increase life time of the winding insulation of the machine.