Reduction Method of Zero-Sequence Current in 6-Step Operation on One Side of Dual Inverter with a Common DC-Bus

抄録

The paper proposes a method for reducing the zero-sequence current in a dual inverter with a common DC-bus. Motor drive systems are required to have higher efficiency, higher power, and smaller size in the electrification of industrial machinery. Hence, 6-step operation on one side of a dual inverter with a common DC-bus is effective. However, increasing the zero-sequence current is problem. Therefore, the proposed method effectively reduces the zero-sequence current in a 6-step operation on one side. The effectiveness of the proposed method is demonstrated by experimental results using an open-end winding PMSM and dual inverter with a common DC-bus. The proposed method reduces the peak-to-peak values of the zero-sequence current by 91.9% and improves the THD of the phase current by 68.7pt. compared to the conventional method. The reduction effect of the proposed method is also shown to be effective at higher motor speed. Therefore, the proposed control method achieves effective reduction of zero-sequence current in high-efficiency operation with the 6-step operation on one side.