A Modular Multilevel Converter Integrated With DC Circuit Breaker

作者：Song, Qiang^*; Zeng, Rong; Yu, Zhanqing; Liu, Wenhua; Huang, Yulong; Yang, Wenbo; Li, Xiaoqian

来源：IEEE Transactions on Power Delivery, 2018, 33(5): 2502-2512.

DOI：10.1109/TPWRD.2018.2815550

• Voltage source converter-based high-voltage DC (VSC-HVDC)
• modular multilevel converter
• DC circuit breaker
• DC short-circuit fault
• DC fault clearance

The direct-current (dc) fault-clearance capability of themodular multilevel converter(MMC) is a key issue for overhead line applications of voltage source converter-based high-voltage dc (VSC-HVDC) transmission systems. An MMC integrated with a dc circuit breaker (IDCB-MMC) is proposed to provide a costeffective DC fault clearance and isolation solution. A mechanical switch (MS) and a load commutation switch are connected in series as the main branch of the dc circuit breaker. DC fault currents can be forced to transfer to converter-and line-side energy absorbing branches when submodule bypass protection and dc circuit breaker interrupting operations are coordinated. Therefore, the bulky and costly solid-state branch that uses numerous semiconductor devices and surge arresters can be eliminated. The dc fault clearance and isolation capability of the IDCB-MMC were verified through the simulation results for one pole of a 1000 MW/+/- 320 kV VSC-HVDCsystem. Compared with anMMCthat uses half-bridge SMs, the IDCB-MMC only requires few additional capacitors and switching devices and a simpleMS, thereby resulting in several advantages, such as low cost, footprint requirements, and additional conduction losses.

• 出版日期2018-10
• 单位清华大学