| 引用本文: | 曾蕊,李保宏,刘天琪,闫鹤鸣,米志伟.受端多落点级联型混合直流输电系统协调控制策略[J].电力自动化设备,2021,41(2): |
| ZENG Rui,LI Baohong,LIU Tianqi,YAN Heming,MI Zhiwei.Coordinated control strategy of receiving-end multi-point cascaded hybrid DC transmission system[J].Electric Power Automation Equipment,2021,41(2): |
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| 摘要: |
| 针对受端多落点级联型混合直流输电系统发生交直流故障时，电流分配不平衡导致的功率反送、系统稳定性降低等问题开展研究，并提出改善系统稳定性的协调控制策略。该策略在发生故障时根据线路传输功率、逆变侧电网换相型换流器(LCC)输出功率以及采用定直流电压控制的模块化多电平换流器(MMC)稳态输出功率，对MMC的有功功率指令值进行调控，避免采用定直流电压控制的MMC由逆变改为整流，防止受端交流侧功率大范围转移现象的发生。同时在故障清除后仍可缓解系统恢复过程波动较大的问题，使系统能够快速平稳地恢复至额定运行状态。基于PSCAD/EMTDC建立仿真模型，仿真结果验证了所提协调控制策略可有效减小电压和功率的波动，系统在交、直流典型故障下均能实现平稳过渡，提升了受端系统的稳定性。 |
| 关键词: 多落点 级联 直流输电 MMC 控制策略 |
| DOI：10.16081/j.epae.202011011 |
| 分类号:TM721.1 |
| 基金项目:国家电网有限公司总部科技项目(多落点级联混合直流输电系统关键技术研究) |
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| Coordinated control strategy of receiving-end multi-point cascaded hybrid DC transmission system |
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ZENG Rui1, LI Baohong1, LIU Tianqi1, YAN Heming2, MI Zhiwei2
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1.College of Electrical Engineering, Sichuan University, Chengdu 610065, China;2.Global Energy Interconnection Research Institute Co.,Ltd.,Beijing 102209, China
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| Abstract: |
| When AC/DC fault occurs in receiving-end multi-point cascaded hybrid DC transmission system, the problems such as power reverse, system stability reduction caused by unbalanced current distribution are studied, a coordinated control strategy is proposed to improve the system stability. According to the line transmission power, the output power of LCC(Line Commutated Converter) at the inverter side and the steady-state output power of MMC(Modular Multilevel Converter) adopted the control of constant DC voltage, the active power command value is regulated to avoid the commutation mode of MMC adopted the control of constant DC voltage changing from inverter to rectifier, in case of the occurrence of the large-scale power transfer at the receiving-end AC side. At the same time, after the fault is cleared, the large-scale fluctuation problem in the system recovery process can be alleviated, and the system can quickly and smoothly recover to the rated operation state. The simulation model is built based on PSCAD/EMTDC, the simulative results show that the proposed coordinated control strategy can decrease the voltage and power fluctuation, the system can realize smooth transition under typical AC and DC faults, and the stability of the receiving-end system is improved. |
| Key words: multi-point cascaded DC transmission MMC control strategy |
