| 引用本文: | 王相飞,江琴,赵静波,李保宏,刘天琪.一种基于故障限流器的混合级联直流输电系统故障穿越方法[J].电力自动化设备,2022,42(3): |
| WANG Xiangfei,JIANG Qin,ZHAO Jingbo,LI Baohong,LIU Tianqi.Fault ride-through method of hybrid cascaded HVDC transmission system based on fault current limiter[J].Electric Power Automation Equipment,2022,42(3): |
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| 摘要: |
| 针对混合级联直流输电系统逆变侧低端模块化多电平换流器(MMC)易受过压、过流影响导致闭锁的问题，提出一种基于故障限流器(FCL)的混合级联直流输电系统故障穿越方法。所提方法既适用于交流故障使得逆变侧高端电网换相换流器(LCC)换相失败，从而导致低端MMC充电造成的过流场景，又适用于直流侧单极接地，导致MMC子模块放电造成的过流场景。通过逆变侧LCC换相失败和MMC单极接地故障导致过流原因的统一分析，明确了所提FCL的拓扑结构、工作机理、控制方法以及参数设计。LCC换相失败故障发生时，FCL将限流电阻接入，控制MMC直流电流在2倍额定电流内，防止MMC闭锁；MMC单极接地故障发生时，利用FCL自身拓扑阻断故障回路，防止子模块电容向故障点放电，保护MMC阀组。仿真结果表明，所提FCL在2类故障下均具备良好的穿越能力，工程应用价值良好。 |
| 关键词: 混合级联直流输电系统 换相失败 单极接地故障 FCL 过电流 故障穿越 |
| DOI：10.16081/j.epae.202112015 |
| 分类号:TM721.1;TM771 |
| 基金项目:江苏省电力科学研究院科技项目(SGTYHT/19-JS-215) |
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| Fault ride-through method of hybrid cascaded HVDC transmission system based on fault current limiter |
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WANG Xiangfei1, JIANG Qin1, ZHAO Jingbo2, LI Baohong1, LIU Tianqi1
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1.College of Electrical Engineering, Sichuan University, Chengdu 610065, China;2.Electric Power Research Institute, State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing 211103, China
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| Abstract: |
| Aiming at the problem that the MMC(Modular Multilevel Converter) at the low-end of inverter side of hybrid cascaded HVDC transmission system is prone to block due to overvoltage and overcurrent, a fault ride-through method of hybrid cascaded HVDC transmission system based on FCL(Fault Current Limiter) is proposed. The proposed method is applicable to not only the overcurrent scenarios resulting from the charging of low-end MMC, in which the inverter’s high-end LCC commutation failure is caused by AC fault, but also the overcurrent scenarios resulting from the discharge of MMC sub-modules, in which monopole grounding fault occurs in DC side. The topological structure, working mechanism, control method and parameter design of the proposed FCL are clarified through the unified analysis of the cause of overcurrent caused by inverter side LCC commutation failure and MMC monopole grounding fault. When LCC commutation falure occurs, the current-limiting resistor is connected by FCL to control the MMC DC current within twice the rated current to prevent MMC blocking. When MMC monopole grounding fault occurs, FCL’s topology is used to block the fault circuit, prevent the capacitance of sub-modules from discharging to the fault point and protect the MMC valve set. The simulative results show that the proposed FCL has good ride-through ability under both types of faults and has great engineering application value. |
| Key words: hybrid cascaded HVDC transmission system commutation failure monopole grounding fault FCL overcurrent fault ride-through |
