Simulation study of integrated‐gate‐commutated‐thyristor based superconducting hybrid direct current circuit breaker

Abstract

With the development of a distributed generation, direct current (DC) load and energy‐storage equipment, voltage‐source‐converter‐based medium‐voltage DC systems (VSC‐MVDC) have attracted more attention due to its low power consumption, high reliability, independent power control and so on. However, VSC‐MVDC has the problem of DC fault isolation, which requires the fast‐acting DC circuit‐breakers to isolate faulty lines and ensure low cost. This problem can be solved by coordinating resistive type superconducting‐fault‐current‐limiter (R‐SFCL) and integrated‐gate‐commutated‐thyristor (IGCT) based hybrid circuit breaker. Based on this, IGCT based superconducting DC circuit breaker (SDCCB) is proposed and analysed. Combining R‐SFCL with IGCT could realise large current limiting and interruption and ensure low cost. In addition, the IGCT based hybrid DC circuit breaker (IGCT‐HDCCB) is compared with the traditional insulated gate bipolar transistor (IGBT) based hybrid DC circuit breaker (IGBT‐HDCCB) to evaluate which circuit breaker is more suitable for VSC‐MVDC. The results show that, coordination based on R‐SFCL and SDCCB, the fault current is successfully limited from 17.6 to 2.1 kA, and then interrupted within 3.8 ms. In addition, IGCT‐HDCCB overcomes the disadvantage that IGCT has less interrupting capacity than IGBT, retains the advantage of low cost of IGCT and is more suitable for MVDC system.

A novel controllable capacitor commutation based superconducting hybrid direct current breaker

“…The main circuit branch of CCCB-SDCCB consists of R-SFCL and an ultrafast disconnector switch (UDS), and the current commutation circuit is structured by IGCTs, thyristors, capacitors, and metal-oxide varistors (MOVs). As compared with the IGCT-HDCCB which requires pre-charging the capacitor before each short-circuit fault 28 , 29 , the bridge circuit composed of four thyristors can flexibly adjust the connection direction of the capacitor without setting up a separate pre-charging process. It fully utilizes the residual capacitor voltage from the previous fault stage to provide reverse shutdown voltage for the IGCTs in the next circuit breaking action, thereby ensuring the high current breaking capacity and low cost of the circuit breaker.…”

A Cost-Effective Current-Limiting Hybrid DC Circuit Breaker Based on Hybrid Semiconductors

“…As for HCB, it combines mechanical switches and power electronic switches. By transferring current to the current transfer branch, power electronic devices interrupt current and withstand transient interruption voltage (TIV) after interruption [17,18]. It has the advantage of fast interrupting speed.…”