Improved Control Strategy for DC Fault in Modular Multi-Level Converter-HVDC System

被引：0
|
作者：
Yao J. [1 ]
Tan Y. [1 ]
Pei J. [1 ]
Xiong X. [1 ]
Ouyang J. [1 ]
机构：
[1] State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing
来源：
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | 2018年 / 33卷 / 14期
关键词：
DC faults; Fault ride-through control; Full-bridge sub-module; MMC-HVDC transmission;
D O I：
10.19595/j.cnki.1000-6753.tces.170614
中图分类号：
学科分类号：
摘要：
Aiming at the direct current (DC) faults of the full-bridge modular multi-level converter-high voltage direct current (MMC-HVDC) transmission system, the detailed mathematical model is established. In addition, the mechanism and progress of the over-voltage or over-current stress of MMC-HVDC system are analyzed in depth. The results show that, during the DC pole-to-pole and unipolar earth fault, the positive- and negative-pole DC bus voltages of MMC-HVDC system mismatch the DC components of the MMC upper and lower arm voltages, which leads to rapid discharge of the arm capacitance. Consequently, the system will suffer serious over current. Therefore, an improved control strategy is proposed by separately controlling the upper and lower arms of the MMC during the DC fault. With the proposed method, the DC components of the upper and lower arm voltages will follow the change of the positive- and negative-pole DC bus voltages, which ensures the safe and stable operation of the MMC-HVDC system. The proposed control strategy realizes the effective simplification and unification of fault ride-through control under three typical DC faults. In addition, in order to further improve the economic operation capability of the MMC-HVDC system under the DC unipolar earth and disconnection faults, an optimized power allocation strategy is proposed. Finally, the simulation results in PSCAD/EMTDC verify the correctness and feasibility of the proposed improved control strategy and optimized power allocation strategy for the MMC-HVDC system under DC faults. © 2018, Electrical Technology Press Co. Ltd. All right reserved.
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页码：3306 / 3318
页数：12
相关论文
共 26 条
  • [1] Xiao X., Basic problems of the new complex AC-DC power grid with multiple energy resources and multiple conversions, Transactions of China Electrotechnical Society, 30, 15, pp. 1-14, (2015)
  • [2] Yu X., Xu X., Chen S., Et al., A brief review to integrated energy system and energy internet, Transactions of China Electrotechnical Society, 31, 1, pp. 1-13, (2016)
  • [3] Wang B., Chen H., Overview study on improving protection methods of distribution network with distributed generation, Power System Pro- tection and Control, 45, 12, pp. 146-157, (2017)
  • [4] Cheng S., Liu J., Xiang Y., Et al., Research on optimal coordinated operation for microgrid with hybrid energy storage and diesel generator, Power System Protection and Control, 43, 7, pp. 42-50, (2015)
  • [5] Xu D., Liu Y., Wu J., Review on control strategies of multi-terminal direct current transmission system, Transactions of China Elec- trotechnical Society, 30, 17, pp. 1-12, (2015)
  • [6] Hiroaki K., Yushi M., Toshifumi I., Low-voltage bipolar-type DC microgrid for super high quality distribution, IEEE Transactions on Power Electronics, 25, 12, pp. 3066-3075, (2010)
  • [7] Song Q., Zhao B., Liu W., Et al., An overview of research on smart DC distribution power network, Proceedings of the CSEE, 33, 25, pp. 9-19, (2013)
  • [8] Wang S., Zhou X., Tang G., Et al., Analysis of submodule overcurrent caused by DC pole-to-pole fault in modular multilevel converter HVDC system, Proceedings of the CSEE, 31, 1, pp. 1-7, (2010)
  • [9] Han P., Wang S., Parameter coordination of modular multilevel converter for robust design during DC pole to pole fault, 2012 China International Conference on Electricity Distribution, pp. 1-4, (2012)
  • [10] Zhang G., Qi X., Chen Y., Et al., Analysis of DC pole-to-pole fault characteristics of modular multilevel converter, Automation of Electric Power Systems, 40, 12, pp. 151-157, (2016)
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