Three-level Modulation Techniques to Reduce Instantaneous Common Mode Voltage in Induction Machines

Problems on inverter motor drives such as bearing currents are introduced due to common mode voltages. Different solutions are proposed on literature, for two-level or multilevel inverter. Instantaneous zero common mode voltage by using a three-level inverted could be achieved. This paper proposes a commutation strategy that allows zero common mode voltage by using medium vectors, and also a new representation as a plane on the commutation space is defined which is called zero common mode voltage plane. On this defined plane, every turning vector fulfil this property. Simulations and experimental results clearly show method’s efficiency.