Parallel-operated inverters (POI) can achieve superior output performance, making them suitable for driving flywheel energy storage motors (FESM). However, the inherent interleaved switching states of the POI cause high-frequency circulating currents (HFCC), which undermines current balance among POI and degrades the output quality. To address this issue, this paper proposes an optimized carrier-based modulation strategy for three-level POI, aiming to mitigate both HFCC and common-mode voltage (CMV). Firstly, within the integrated five-level plane, low-CMV vector sequences are selected in each sector to suppress the slope of HFCC. Secondly, by injecting specific zero-sequence components into the reference signals and applying the carrier phase-shift strategy according to different sectors, the selected sequences can be synthesized with low computational burden. Finally, compared with several existing modulations, a series of simulations and experimental validations on a 300-kW POI fed FESM demonstrate the effectiveness of the proposed strategy.

Common-mode voltage (CMV),Flywheel energy storage motors (FESM),High-frequency circulating current (HFCC),Parallel-operated inverters (POI)