MMC换流器 | A Modular Multilevel Converter Integrated With DC Circuit Breaker
Song, Qiang; Zeng, Rong; Yu, Zhanqing; Liu, Wenhua; Huang, Yulong; Yang, Wenbo; Li, Xiaoqian
(Department of Electrical Engineering, Tsinghua University, Beijing; 100084, China)
Abstract:
The direct-current (dc) fault-clearance capability of the modular 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 cost-effective 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-HVDC system. Compared with an MMC that uses half-bridge SMs, the IDCB-MMC only requires few additional capacitors and switching devices and a simple MS, thereby resulting in several advantages, such as low cost, footprint requirements, and additional conduction losses.
Published in: IEEE Transactions on Power Delivery ( Volume: 33 , Issue: 5 , Oct. 2018 )
Page(s): 2502 - 2512
Date of Publication: 13 March 2018
Cite this:
Q. Song et al., "A Modular Multilevel Converter Integrated With DC Circuit Breaker," in IEEE Transactions on Power Delivery, vol. 33, no. 5, pp. 2502-2512, Oct. 2018.