Current-Balance Mode-Based Unified Common-Mode Voltage Elimination Scheme for Dual Three-Phase Motor Drive System

The two-level voltage source inverter fed dual three-phase motor (DTPM) induces the high-frequency common-mode voltage (CMV) and generates the unwanted adverse effects. As one of the effective common-mode suppression methods, the conventional CMV elimination (CMVE) pulsewidth modulation (PWM) schemes are generally based on the voltage-balance mode for DTPM systems which suffer from the parameter asymmetry induced phase current imbalance. This article proposes two current-balance mode unified CMVE PWM schemes which has no restriction on the reference voltages and angle displacement between the two sets of three-phase windings. Thus, the proposed methods can be utilized in different types of DTPMs with different angle displacements between the two winding sets, and the CMVE effect can be retained both in the conditions of symmetrical and asymmetrical system parameters which is more practical than conventional CMVE schemes in real application. The function and performance of the proposal is proved by simulations and experiments.