A Novel Z-Source Current Limiter Topology

In order to inhibit the rate of rising fault current and reduce the current stress to protect the further current shut-down process, direct current current limiting (DCCL) technology is receiving more and more attention. While the traditional DCCL tends to have high through-current loss, and the control circuit is complex and costly. Therefore, to solve the above problems, the scheme of Z-source DCCL has been put forward, which has a simple structure, and could realize the fast and automatic current limiting without detecting and controlling circuits. Thus, this paper adopts a novel bi-directional Z-source DCCL topology. Theoretical analysis was made firstly. Then, making simulation analysis, the simulation results successfully limit the fault current to less than 1.7kA. And next, the simulation of different values of current-limiting resistor was made and the simulation results were analyzed and compared. It was found that with the increase of the value of current-limiting resistor, the current-limiting factor continues to decrease, the current-limiting time is firstly decreasing and then increasing and the peak value of the thyristor reverse voltage continues to increase.