The optimal allocation of H-SFCL in MVDC SPS.

• An experiment for comparison of three different current limiting topologies is conducted. For the same tape consumption of 17 m, the limiting rates of R-SFCL, FC-SFCL and H-SFCL are 10 %, 28 % and 58 % respectively within the DC voltage range of 240–440 V. Both FC-SFCL and H-SFCL have good current limiting effect. Compared with FC-SFCL, the H-SFCL has stronger flexibility and adaptability, and there is no quenching recovery time, which makes it better cooperate with the DC circuit breaker to realize automatic reclosing. Therefore, H-SFCL is the most suitable superconducting current limiter for MVDC SPS. • This paper puts forward an optimal allocation method of H-SFCL on MVDC SPS. To solve the problem of optimizing the number and position of current limiters, a dual objective hierarchical optimization configuration method is proposed with the goal of minimizing the maximum allowable current and inductance energy of circuit breakers. The optimization of the number, position, and internal component parameters of current limiters is achieved on a four-terminal system. The results show that the proposed hierarchical optimization configuration method can effectively achieve the optimization of position and component parameters. • An improved four objective optimal allocation method suitable for circuit breakers and H-SFCLs is proposed to address the issue of the breaking sequence between the internal switch in H-SFCL and the external circuit breaker. The results showed that the maximum effective individual ratio within the first 20 generations of improvement was 88%; The improved iteration speed has significantly increased, and the effective individual ratio in the 5th generation can reach 100%, effectively improving the effective individual ratio in the optimization iteration process and achieving overall optimization of isolation and current limiting equipment. Medium voltage direct current shipboard power system (MVDC SPS) is the development trend of navy in the future. At present, one of the bottlenecks restricting the development of MVDC SPS is that the short fault. There is a lack of effective means to limit short fault current to protect MVDC SPS. This paper presents a method of applying a hybrid type superconducting fault current limiter (H-SFCL) to MVDC SPS protection. The architecture and system modeling of MVDC SPS are introduced, and the mechanism of bipolar DC short fault is analyzed. The topology and working principle of H-SFCL are introduced. The small-scale prototype experiment is done, the current limiting effect of H-SFCL is compared with resistive type superconducting fault current limiter (R-SFCL) and flux-coupling type superconducting fault current limiter (FC-SFCL) in the prototype test, so as to verify the superiority of H-SFCL. A dual objective hierarchical optimization configuration method is proposed, and the number and position of H-SFCLs are verified on a four-terminal system, as well as multi-objective optimization for H-SFCLs. A fault isolation and H-SFCL optimal allocation evaluation model is proposed; An improved method suitable for fault isolation and multi-objective optimal allocation of H-SFCLs is proposed to address the issue of breaking timing between internal switches in H-SFCLs and external circuit breakers in the optimization process. The research results indicate that the proposed optimal allocation method can optimize the inductance, resistance, and switch breaking time inside the current limiter, and can match the timing with the external circuit breaker; The proposed multi-objective optimization configuration method has a maximum effective individual ratio of 88% in the first 20 generations of improvement, and the improved iteration speed has significantly increased. In the 5th generation, the effective individual ratio can reach 100%. [ABSTRACT FROM AUTHOR]