| 引用本文: | 陆书豪,贾秀芳.LCC-FHMMC混合直流输电系统阀侧故障特性及保护策略[J].电力自动化设备,2021,41(11): |
| LU Shuhao,JIA Xiufang.Grounding fault characteristics of converter valve-side and protection strategy in LCC-FHMMC hybrid DC transmission system[J].Electric Power Automation Equipment,2021,41(11): |
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| 摘要: |
| 送端采用电网换相换流器(LCC)、受端采用半桥与全桥混合型模块化多电平换流器(FHMMC)的LCC-FHMMC混合直流输电系统，在受端发生阀侧单相接地故障时，具有与半桥或全桥型MMC不同的故障特性。分别从交流电源贡献、直流电源贡献以及高低端阀组差异3个角度对阀侧单相接地故障下子模块过电压机理进行了分析。随后，针对FHMMC混合直流输电系统直流侧无直流断路器的特点，提出了一种基于选相型单向晶闸管旁路支路的故障隔离策略，以及适用于LCC-FHMMC混合直流输电系统阀侧单相接地故障的保护策略。最后，基于PSCAD/EMTDC仿真平台搭建了相关模型，通过仿真验证了理论分析的正确性以及所提保护策略的有效性。 |
| 关键词: LCC-FHMMC混合直流输电 换流器 阀侧接地故障 晶闸管旁路支路 |
| DOI：10.16081/j.epae.202105018 |
| 分类号:TM721.1;TM771 |
| 基金项目:国家自然科学基金资助项目(51777072) |
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| Grounding fault characteristics of converter valve-side and protection strategy in LCC-FHMMC hybrid DC transmission system |
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LU Shuhao, JIA Xiufang
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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: |
| LCC-FHMMC hybrid DC transmission system, in which the sending end adopts LCC(Line Commutated Converter) and the receiving end adopts FHMMC(Full-bridge and Half-bridge Modular Multi-level Converter),has different characteristics from half bridge MMC or full bridge MMC when a single-phase grounding fault occurs on the converter valve-side at the receiving end. The overvoltage mechanism of the sub-module under the grounding fault on converter valve-side is analyzed from three perspectives of AC power contribution, DC power contribution and the difference between high-and low-valve groups. According to the characteristics of non-DC circuit breaker on the DC side of LCC-FHMMC hybrid DC transmission system, a fault isolation method based on phase selection type unidirectional thyristor bypass branch and a protection strategy suitable for single-phase grounding fault occurs on the converter valve-side in LCC-FHMMC hybrid DC transmission system are proposed. Finally, a related model is built based on the PSCAD/EMTDC simulation platform, and the correctness of the theoretical analysis and the effectiveness of the proposed protection strategy are verified by simulation. |
| Key words: LCC-FHMMC hybrid DC transmission system electric converters converter valve-side grounding fault thyristor bypass branch |
