Comments on “Common-Mode Noise Reduction by Parasitics Capacitance Cancellation in the Three-Phase Inverter”

This article comments on the published article titled “Common-mode noise reduction by parasitics capacitance cancellation in the three-phase inverter” authored by Zhang and Wu (2019). The three-terminal electromagnetic interference (EMI) filter can effectively suppress the EMI noise on the output side in the paper. The numerical analysis and the relationship of converting negative inductance into capacitance at high frequency are discussed in detail. Zhang and Wu (2019) presented a parasitic capacitance cancellation method to reduce the conducted emissions exiting a three-phase inverter. The idea of parasitic capacitance cancellation is not novel, and Wang and Lee (2007, 2010) originally applied it to reduce the common mode noise exiting a boost PFC converter. The parasitic capacitance cancellation of inductors is discussed in papers by Neugebauer and Perreault (2006) and Piboonwattanakit and Khan-Ngern (2008). These papers should be cited in the introduction and the references.