Analysis of Modulation Schemes for Balanced Inverter

With the adoption of wide bandgap devices (WBGs), motor drive systems become more power-dense and efficient. However, the high switching frequency and the high switching speed introduce severe electromagnetic interference (EMI), which can significantly affect the system function. The balanced inverter was introduced to improve the EMI performance by canceling the common-mode voltage at the motor end with ideal switching conditions. In this paper, the operation principle of the balanced inverter under ideal operating conditions is summarized. Then a detailed analysis of possible switching states under non-ideal switching conditions is provided, and an alternative novel space vector modulation scheme with non-ideal switching states is proposed considering the common-mode cancelation requirement. Finally, the verification results for the proposed modulation scheme are demonstrated.