A Novel Coordinated Control Approach for Commutation Failure Mitigation in Hybrid Parallel-HVDC System with MMC-HVDC and LCC-HVDC

Abstract

This paper proposes a novel coordinated control approach for the hybrid parallel-HVDC system that is composed of a line commutated converter-based high-voltage direct current (LCC-HVDC) link and a modular multi-level converter-based HVDC (MMC-HVDC) link in parallel. With the presented control approach, the reactive power of MMC-HVDC is regulated flexibly based on the extinction angle of LCC-HVDC to mitigate the commutation failure of LCC-HVDC and improve the fault recovery performances of the overall system during fault and post-fault periods. A hybrid parallel-HVDC system is developed in PSCAD/EMTDC to evaluate the effects of the proposed control approach. The transient performances of the hybrid parallel-HVDC, under single-phase and three-phase to ground faults at the inverter AC busbar are investigated. Commutation failure immunity index (CFII) and fault recovery time are used as measures to evaluate the effects of the proposed control approach. The results show that the proposed coordinated control approach can make the LCC-HVDC less susceptible to commutation failure in hybrid parallel-HVDC system and effectively improve the fault recovery performances of the overall system.

Keywords::

• Hybrid parallel-HVDC
• MMC-HVDC
• LCC-HVDC
• VSC-HVDC
• commutation failure
• fault recovery performance
• coordinated control
• commutation failure immunity index
• fault recovery time
• commutation failure probability
• reactive power control

Funding

This work was supported by the National Science Foundation of China under Grant 51507060.

Additional information

Notes on contributors

Chunyi Guo

Chunyi Guo received the B.S. and Ph.D. degrees in power system and its automation from North China Electric Power University (NCEPU), Beijing, China, in 2007 and 2012, respectively. He is currently an Associate Professor of Power Grid with New Energy Institute, NCEPU and is a Member of IEEE. His research interests include LCC-HVDC, VSC-HVDC, and AC/DC interaction analysis.

Zhizhong Yang

Zhizhong Yang is currently working toward the M.Sc. degree in electrical engineering. His research interests include LCC-HVDC and MMC-HVDC.

Linru Ning

Linru Ning is currently working toward the M.Sc. degree in electrical engineering. His research interests include LCC-HVDC and MMC-HVDC.

Chengyong Zhao

Chengyong Zhao received the B.S., M.S., and Ph.D. degrees from North China Electric Power University (NCEPU) in 1988, 1993, and 2001, Beijing, China, respectively. He is a currently a Professor and the Director of Power Grid with New Energy Institute, NCEPU and is also a Senior Member of IEEE. His research interests include HVDC and FACTS.