Electric Power ›› 2018, Vol. 51 ›› Issue (12): 48-55.DOI: 10.11930/j.issn.1004-9649.201706130

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Relationship between the Power Loss of Modular Multilevel Converter and Transmission Voltage Level

RONG Fei1, WANG Yazhou1, RAO Hong2, ZHOU Baorong2, LI Hongxin2, LI Wenjun1   

  1. 1. College of Electrical and Information Engineering, Hunan University, Changsha 410082, China;
    2. State Key Laboratory of HVDC, Electric Power Research Institute, China Southern Power Grid, Guangzhou 510620, China
  • Received:2017-06-30 Revised:2018-03-28 Online:2018-12-05 Published:2018-12-13
  • Supported by:
    This work is supported by the National Key Research and Development Program of China (No.2016YFB0901001).

Abstract: Normally MMC (modular multi-level converter) is adopted in the flexible HVDC transmission system. The power loss of converter is one of the most important indexes to evaluate the performance of flexible HVDC system. In this paper, an analytical expression for the on-state and switching loss of MMC is derived. As can be seen from the expression, the power loss of converter is not only related to the number of MMC sub modules, but also the capacity and voltage level of the flexible HVDC transmission system. In this paper, a detailed investigation of the influence of the capacity and voltage level of HVDC system on the power loss of converter is carried out, so as to identify the optimal voltage class that reduces the power loss to a minimum. Simulation results show that the proposed method can be used to find out the voltage level that helps lower the power loss.

Key words: modular multilevel converter, flexible HVDC transmission, transmission voltage, converter loss

CLC Number: