LC Parameter Analysis of a Novel IGCT-Based Hybrid DCCL

DC current limiter (DCCL)is a key device in DC power grid, it can effectively inhibit the rising rate of shortcircuit current to protect the further turn-off process. However, the traditional solid-state DCCL tends to have massive throughcurrent loss and the commutation capability of semiconductor still needs to be improved. Therefore, this article adopts a hybrid DCCL containing high-speed switch (HSS) which not only to realize fast short-circuit current limitation, but also has low line loss. Specifically, this hybrid DCCL realizes current sharing as well as current freewheeling through reverse series connection of IGCTs which to help HSS to get better dielectric recovery time. In this article, the analysis of the operation principle of the IGCT-based hybrid DCCL has been made firstly. Then, we find that the dielectric recovery time of the HSS is increasing as the inductor value decreases and the capacitor value increases. However, at the same time, the peak value of the pulse current on the IGCTs also increases due to the increased energy storage on the LC branch. Finally, through the simulation of the key parameters of the LC path branch, a reasonable range of inductor and capacitor values were proposed as a reference for design.