Soft Start and Protection of Bidirectional Buck-Boost Partial Power Converter

In this paper, an overview of the recent series partial power converters (S-PPCs) is carried out from the component point of view. Overdesigning the S-PPCs without any protection measures needed to avoid abnormal transient modes increases the size and cost of converter, which eliminates the advantage of PPC concept. To solve this problem, the abnormal operation conditions are explained, and possible solutions are proposed. It can be seen from the simulation results that the soft start of the converter can avoid any sudden current rise at the converter start. Adding a solid-state circuit breaker (SSCB) with a reaction time of 20 μs can limit the short circuit current in the Current Source (CS) side. Simultaneously, the CS side leg bypass prevents any voltage spikes due to violation of ZCS switching. The simulations are carried out in PSIM software to validate the correctness of the developed control procedure.