Controllable DC Fault Current Limiter with Loss Reduction

The high rate of increase of the fault current in the DC network and the absence of zero current are two important reasons for using the fault current limiter (FCL) in this network. In FCLs based on core saturation, the lack of controllability in reducing the fault current causes the performance of other elements such as the DC Circuit Breaker (DCCB) to suffer. In other structures, high impedance before the fault causes losses in the system. In this article, a magnetic FCL with the ability to control the time of fault current reduction and the amount of fault current is presented. This structure consists of two windings, one on the network side and the other connected to a tunable control voltage source. The main contribution of this FCL is its controllability, which can reduce the fault current by connecting it to a control voltage source. To determine the time of fault current reduction and the amount of fault current reduction, tuning the control voltage can be used. Furthermore, power losses in the pre-fault state have a significant reduction in this structure due to the reduction in the number of network side winding. The proper operation of the proposed FCL on the DC network is evaluated using Finite Element (FE) simulations.