DC-link Capacitor Voltage Balancing Control for Series Half Bridge LLC Resonant Converter

摘要

This paper presents control methods that achieve DC-link capacitor voltage balance of a series half bridge (SHB) LLC resonant converter operating at different modulation schemes. The principle of the proposed balancing control method is analyzed and studied based on six normally used operation modes of the SHB LLC converter. DC-link capacitor voltage balancing strategies are developed separately for two common modulation schemes in SHB topology. The performance of the proposed voltage balancing control method is experimentally verified on a 7.5-kW SHB LLC DC/DC converter prototype under different operating conditions.