考虑电感型故障电流限制器的HVDC电网直流故障电流高效计算方法

Inductor-based solid-state fault current limiter (I-SSFCL) has promising potential in direct current (DC) fault protection of high-voltage direct current (HVDC) grid. However, switching of power electronic devices in I-SSFCL increases complexity of the equivalent model and limits the fault current calculation efficiency. In this article, an efficient calculation method of DC fault current considering I-SSFCL in HVDC grid is proposed. During the operation of I-SSFCL, the auxiliary branch of I-SSFCL is simplified as controlled voltage source. Therefore, the characteristics of different I-SSFCL topologies can be represented by a unified model, making the proposed method scalable. The discharging amount of modular multilevel converter (MMC) is estimated based on the assumption that the rising speed of DC fault current is linear. As a result, the fault current after I-SSFCL operation can be efficiently calculated. Based on proposed method and correlation analysis, it’s verified that the current limiting inductor is the main factor influencing the current limiting performance of I-SSFCL. Compared with conventional numerical-based methods, the proposed method is more time-efficient and suitable for design of I-SSFCL and DC circuit breaker (DCCB) in HVDC grid. Simulation results verify the feasibility of proposed method for different I-SSFCL topologies.