Analysis and Protection of DC Short Circuit Fault in True Bipolar MMC-HVDC System

2019 4th Asia Conference on Power and Electrical Engineering

能源学;电工学

Liu, N.M.^1 ; Ning, L.H.^1 ; Wu, D.^1 ; Su, Y.^1 ; Teng, H.D.^1 ; Gao, L.^1

Smart Power Grid Shanxi Key Laboratory, Xi'An Jiaotong University, Xi'an

710049, China^1

关键词: Analytical calculation;    Current characteristic;    Fault recovery time;    High voltage direct current transmission;    Line transmissions;    Modular multi-level converters;    Protection methods;    Short-circuit fault;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/486/1/012006/pdf
DOI  :  10.1088/1757-899X/486/1/012006

来源: IOP

【 摘 要 】

With the introduction of modular multilevel converter (MMC), the development of high voltage direct current transmission (HVDC) technology has been promoted. As flexible DC transmission technology is gradually extended to overhead line transmission, DC fault clearing and fault protection issues have become particularly important. In this paper, the current characteristics of different stages of DC short-circuit faults are studied for the overhead line true bipolar MMC-HVDC system. The simulation model of the true bipolar system is built by PSCAD/EMTDC software. The simulation results verify the correctness of the analytical calculation. Finally, in order to suppress the sudden increase of bridge arm current during fault, a bridge arm protection method for DC short-circuit fault is proposed. The simulation results show that the protection method can effectively protect the sub-module device in case of fault, and can Shorten the fault recovery time, this protection method effectively protects the devices of the AC system and sub-modules.