Interruption characteristic of self-triggering low voltage hybrid DC circuit breaker with non-polarized bidirectional breaking

Abstract

The global new photovoltaic installed capacity reached 345.5GW in 2023. As the installed capacity of photovoltaic power generation systems increases worldwide, there is a growing demand for circuit breakers to withstand higher voltages on the DC side of these systems. A self-triggering hybrid circuit breaker with non-polarized bidirectional breaking is proposed. The distinguishing feature of this structure is conduction of the IGBT is determined by arc voltage. In addition, the non-polarized bidirectional arc-breaking is realized by the new transfer branch structure. To closely replicate the actual interruption process, a semi-physical simulation is used to validate the breaking performance. The breaking of 15kA fault current under DC1500V can be realized. Compared with the mechanical circuit breaker for PV system, the peak current of the breaking fault decreased, and shorten the interruption time by the self-triggering hybrid DC circuit breaker, which effectively improves the service life. And the factors affecting interruption characteristics are also analyzed. According to the MOPSO algorithm, the stray inductance of transfer branch getting little and the reference voltage of MOV is set to 3.7 kV is the best. The self-triggering hybrid DC circuit has applications in higher voltage level systems, which leads to new concepts for circuit breaker schemes using hybrid structures in future PV systems.