| 引用本文: | 杨硕,郑安然,彭意,郭春义,赵成勇.混合级联型直流输电系统直流故障特性及恢复控制策略[J].电力自动化设备,2019,39(9): |
| YANG Shuo,ZHENG Anran,PENG Yi,GUO Chunyi,ZHAO Chengyong.DC fault characteristic analysis and recovery control strategy for hybrid cascaded HVDC system[J].Electric Power Automation Equipment,2019,39(9): |
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| 摘要: |
| 整流侧采用LCC、逆变侧采用MMC与LCC串联的混合级联型直流输电系统可实现直流故障穿越、换相失败抑制和大容量功率传输。建立混合级联型直流输电系统模型，设计系统整体控制策略，并利用PSCAD/EMTDC仿真软件研究系统功率阶跃时的动态特性，验证控制策略的有效性。对系统的直流故障特性进行仿真分析，发现若不采取合适措施，系统发生直流故障时会出现由于并联MMC之间的电流分配不均衡而产生过电流现象以及故障清除后系统恢复过程波动大的问题，为此，提出系统故障期间及故障清除后的恢复控制策略，仿真验证了该控制策略的有效性。 |
| 关键词: 混合级联型直流输电系统 功率阶跃特性 直流故障特性 恢复控制策略 |
| DOI：10.16081/j.epae.201909049 |
| 分类号:TM721.1 |
| 基金项目:国家自然科学基金资助项目(51877077) |
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| DC fault characteristic analysis and recovery control strategy for hybrid cascaded HVDC system |
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YANG Shuo, ZHENG Anran, PENG Yi, GUO Chunyi, ZHAO Chengyong
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State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
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| Abstract: |
| The hybrid cascaded HVDC system composed of LCC at rectifier side and MMC in series with LCC at inverter side can realize DC fault ride-through, commutation failure suppression and large capacity power transmission. The model of hybrid cascaded HVDC system is established and an overall control stra-tegy is designed. The dynamic characteristics of the system with step power are researched by PSCAD/EMTDC simulation software, which verifies the effectiveness of the proposed control strategy. The DC fault characteristics of the system are simulated and analyzed, and it is found that if proper measures are not taken, the over-current phenomenon caused by unbalanced current distribution between parallel MMCs when DC fault occurs and large fluctuation problem in system recovery process after fault clearing will appear, for which, a fault recovery control strategy during fault and after fault clearing is proposed, and simulation verifies the effectiveness of the control strategy. |
| Key words: hybrid cascaded HVDC system power step characteristic DC fault characteristic recovery control strategy |
