Modular multilevel converter composite submodule topology and control

• Published in: Journal of engineering (Stevenage, England) Vol. 2019; no. 16; pp. 2643 - 2648
• Main Authors: Zhang, Jianpo, Jiang, Chang, Han, Yanan
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01-03-2019; Wiley
• Subjects: AC/DC circuit breaker; bridge arm damper; capacitor voltage balancing control; capacitors; circuit breakers; control strategies; DC fault current; DC transmission; DC-side short-circuit fault suppression characteristics; different location; different operation modes; fault currents; fault diagnosis; full-bridge SM; HVDC power convertors; HVDC power transmission; improved composite SM topology; MMC submodule topologies; modular multilevel converter composite submodule topology; multilevel capacitor storage structures; network topology; power convertors; power transmission faults; self-blocking capability; short-circuit currents; SM topologies; study first analyses three possible suppression schemes; switching convertors; technical problem; The 14th IET International Conference on AC and DC Power Transmission (ACDC 2018); voltage control; HVDC power convertors; fault diagnosis; improved composite SM topology; fault currents; DC transmission; short-circuit currents; DC-side short-circuit fault suppression characteristics; HVDC power transmission; control strategies; switching convertors; power transmission faults; circuit breakers; AC/DC circuit breaker; multilevel capacitor storage structures; self-blocking capability; power convertors; modular multilevel converter composite submodule topology; technical problem; DC fault current; full-bridge SM; network topology; bridge arm damper; capacitor voltage balancing control; different location; SM topologies; study first analyses three possible suppression schemes; capacitors; MMC submodule topologies; different operation modes; voltage control
• ISSN: 2051-3305; 2051-3305
• DOI: 10.1049/joe.2018.8660

The DC-side short-circuit fault suppression of modular multilevel converter (MMC) applied to DC transmission has been a technical problem. According to the different location of cutting off fault current, this study first analyses three possible suppression schemes: AC/DC circuit breaker, bridge arm damper, and MMC submodule (SM) topologies and their respective features. Then, characteristics of SM topologies with DC fault current self-blocking capability are summarised, and an improved composite SM topology is designed based on the full-bridge SM and multilevel capacitor storage structures. The suppression characteristics of the proposed topology under different operation modes, capacitor voltage balancing control during blocking, and self-starting process are also studied. Finally, a simulation model is built in the PSCAD/EMTDC to verify the DC-side short-circuit fault suppression characteristics and control strategies.