Passive Cancellation of Input and Output Common-Mode Noise in Three-Phase PWM Inverter-Fed Motor Drive Systems

This article presents an input/output passive common-mode noise canceller to suppress common-mode (CM) currents on the input and output sides of a three-phase pulse-width-modulation inverter-fed motor drive system. Unlike conventional configurations where common-mode transformers (CMTs) are concentrated only on the input or output side of the inverter, the proposed method distributes CMTs on both sides. The proposed configuration enables the CM current flowing through the heat sink ground wire of the inverter to be suppressed effectively. Consequently, the proposed method improves the CM current attenuation characteristics of conventional methods. Experimental results demonstrate the effectiveness of the proposed method.