Power Loss Balancing Method of Single Source Dual Inverter

This paper proposes a novel pulse width modulation (PWM) method for suppression of zero sequence current (ZSC) and power loss balancing for an open-ended winding permanent magnet synchronous machine (OEW-PMSM) driven by a single source dual inverter. The proposed method is based on the dual space vector control that clamps three legs. However, the dual space vector method cannot be applied in the OEW-PMSM system with a third harmonic back electromotive force (3rd BEMF), due to overmodulation. Moreover, the power loss unbalance between insulated-gate bipolar transistors (IGBTs) occurs. Therefore, this paper proposes the new dual space vector method for the OEW-PMSM with 3rd BEMF. In addition, it achieves the power loss balance between IGBTs. The proposed method compensates for the overmodulation by injecting the offset voltage to the other inverter operated in the linear modulation region. Furthermore, by synthesizing the symmetrical reference voltage during two periods of the fundamental frequency, the identical current flow through the IGBT, resulting in the power loss balancing. The simulations with OEW-PMSM are conducted to verify the effectiveness of the proposed method.