Rotational Rest Control for Static Current Balancing in Parallel SiC Bridge Arms

Silicon carbide (SiC) MOSFETs are increasingly employed in energy storage systems for their high switching frequencies and low switching losses. Due to the limited current capability of an individual SiC MOSFET module, multiple modules are connected in parallel for high power applications. However, the on-resistances of different SiC MOSFETs can vary by up to 15%. The variation leads to unbalanced static current distribution among parallel arms. To mitigate the static current imbalance, this paper proposes a rotational rest control (RRC) algorithm. By putting each parallel arm into a rest mode and adjusting its rest period dynamically based on the multi-agent consensus control, the static current imbalance is almost eliminated. Simulation results in Matlab/Simulink confirm the effectiveness of the proposed method.