High-Capacity MVDC Interruption Based on IGCT Current Sharing Integrated With Freewheeling

Medium-voltage dc (MVdc) distribution systems have the advantages of high power density, low line loss and fast system response. However, the high rise rate and large peak value of short circuit current make the fault current interruption a critical problem in MVdc systems. To solve this problem, a novel circuit breaker scheme based on integrated gate-commutated thyristor (IGCTs) current sharing integrated with freewheeling is proposed in this article, which not only can ensure a high breaking capacity and short interruption time in the full current range, but also have superior vacuum interrupter recovery performance and high breaking reliability. The analysis of key factors, including stray parameters, inductance-capacitance (LC) parameters and arcing time, on the current commutation characteristics is presented, and the optimal design principle of the circuit breaker parameters is obtained. Finally, the proposed MVdc circuit breaker is verified with a 64.2 kA/10 kV fault current interruption experiment.

Automated summary

Medium-voltage dc (MVdc) distribution systems have advantages of high power density and fast system response, but face challenges with fault current interruption. A novel circuit breaker scheme based on IGCTs is proposed in this study to address this issue, providing high reliability in interrupting short circuit currents.