2012 Volume 132 Issue 12 Pages 1141-1148
This paper proposes a technique for reducing the leakage current that flows into a power source as conductive noise. Output voltages of an inverter system consist of a d-axis voltage that generates a flux current, a q-axis voltage that generates a torque current, and a zero-sequence voltage. The zero-sequence voltage does not affect the driving characteristics of the load. The proposed method applies a zero-sequence voltage to the output voltage references in a circuit containing grounding capacitors. As a result, the fundamental frequency component of the zero-sequence voltage produced by the inverter decreases and the leakage current reduces. This allows a decrease in the size of the common-mode chokes. The leakage current can be reduced further by increasing the additional zero-sequence voltage reference. The experimental results show that the proposed method can reduce the leakage current when the zero-sequence voltage is applied.