Research on a Secondary Active Limiting DC Fault Current Limiter Topology

The current-limiting performance of the smoothing reactor is weak. The traditional saturated core-type fault current limiter (TFCL) is better, but will cause the dc circuit breaker (DCCB) to endure high overvoltage, energy absorption and also increase the current fall time. When DCCB recloses on the permanent fault, the whole dc system will face a harmful second shock that cannot be solved effectively by TFCL. To solve the above problems, a secondary active limiting fault current limiter (SAFCL) topology is proposed. It can reduce the DCCB overvoltage and energy absorption greatly. Meanwhile, it can store fault energy and uses it to active limit the current when the DCCB recloses on the permanent fault. The secondary active current limiting effect is better than the first and the DCCB breaking electric stress is lower than the first. First of all, the topology and principle of the SAFCL are introduced. The main electromagnet parameters are then analyzed. The performance of different FCLs are simulated comparatively to verify the superiority of the SAFCL. Final, the experiment is carried out, the comparison with simulations verifies the feasibility of the SAFCL.