Component-Reuse Hybrid Filter Design for Effective Leakage Current Suppression in Parallel Inverter Motor Drive Systems

Common-mode (CM) leakage current in parallel-inverter motor drive systems degrades electromagnetic compatibility and system reliability. To address this issue, this paper proposes a component-reuse hybrid filtering topology that integrates passive and active functions through a unified design framework, eliminating the need for dedicated CM filtering components. The key contribution lies in a dual-level functional reuse strategy. At the magnetic level, the leakage inductance of the coupled inductor, originally used for circulating-current suppression, is directly reused as the CM filtering inductance, forming a unified passive attenuation path without additional magnetic components. At the circuit level, a voltage-sensing current-compensation (VSCC) active stage is implemented using a dual-channel operational amplifier, enabling shared sensing and injection while reducing hardware complexity. A frequency-domain model is developed to describe the sensing, amplification, and compensation stages, and the impedance-based mechanism of CM attenuation is analytically established. Experimental results demonstrate that, compared with the interleaved baseline, the proposed filter reduces CM leakage-current RMS and peak values by 64.2% and 71.9%, respectively, and suppresses the resonant peak by 29 dB. The results demonstrate the effectiveness of the proposed component-reuse hybrid filter for compact and wideband CM suppression in motor drive systems.