Improved Hold-Up Time for WBG-based Single-Phase Converters

Hold-up time is required for the safe and uninterrupted operation of the power converters. This prevents unwanted resetting of the systems. In this paper, the hold-up time for a single-phase converter with siginificantly-reduced DC capacitors is investigated. The required de-link and auxiliary capacitors are selected to ensure a certain period of hold-up time after the input supply fails. To maximize the utilization of de-link voltage, this paper presents a simplified neutral leg control strategy and it has been ensured the converter control under hold-up operations. A trade-off design strategy is presented and the outcome has been compared with the solution without the auxiliary capacitor. Simulation studies were carried out to verify the hold-up time performance of the converters.