| 引用本文: | 戴志辉,朱惠君,苏怀波,刘雪燕,金丽萍,陈曦.考虑交直流侧协调的模块化多电平换流站直流线路保护方案[J].电力自动化设备,2019,39(9): |
| DAI Zhihui,ZHU Huijun,SU Huaibo,LIU Xueyan,JIN Liping,CHEN Xi.DC line protection scheme for modular multi level converter station considering coordination of AC and DC sides[J].Electric Power Automation Equipment,2019,39(9): |
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| 摘要: |
| 在换流站保护中，交直流保护之间往往缺乏配合，且存在直流保护的速动性难以满足要求、故障区域难以确定等难点。为此，根据模块化多电平换流器(MMC)闭锁前后直流二次谐波电流与交流负序电流特征，提出了换流站交直流故障辨识方法，可有效区分交、直流故障，确定故障区域。在此基础上，提出了交、直流侧协调配合的换流站直流保护方案。最后，结合光伏直流汇集接入系统的PSCAD/EMTDC模型，验证了交直流故障辨识方法的可行性以及交、直流侧协调配合的直流保护方案的可靠性。结果表明，所提方法能有效识别交、直流故障，且受过渡电阻的影响较小。 |
| 关键词: 模块化多电平换流器 交直流故障识别 继电保护 保护配合 2次谐波 负序分量 |
| DOI：10.16081/j.epae.201909011 |
| 分类号:TM773;TM721.1 |
| 基金项目:国家自然科学基金资助项目(51877084)；国家重点研发计划项目(2016YFB0900203)；河北省自然科学基金资助项目(E2018502063)；中央高校基本科研业务费专项资金资助项目(2017MS096) |
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| DC line protection scheme for modular multi level converter station considering coordination of AC and DC sides |
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DAI Zhihui1, ZHU Huijun1, SU Huaibo1, LIU Xueyan1, JIN Liping2, CHEN Xi2
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1.Hebei Key Laboratory of Distributed Energy Storage and Microgrid, North China Electric Power University, Baoding 071003, China;2.State Grid Baoding Power Supply Company, Baoding 071000, China
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| Abstract: |
| In the protection of converter station, the coordination between AC and DC protections has not been fully addressed, and the tripping speed of DC protection is not quick enough and the fault area is difficult to be identified accurately. Therefore, an approach for discriminating AC and DC faults near MMC(Modular Multilevel Converter) station is proposed based on characteristics of DC-side second harmonic current and AC-side negative-sequence current before and after the blocking of MMC, which can effectively distinguish AC faults from DC ones and determine the fault area. On this basis, a DC protection scheme for MMC station considering the coordination between AC and DC side protections is proposed. Finally, the feasibility of the AC/DC fault discrimination approach and the reliability of the DC protection scheme considering the coordination between AC and DC side protections are verified by the PSCAD/EMTDC model of a photovoltaic grid-connected system. Results demonstrate that the proposed approach can discriminate AC and DC faults while being slightly affected by the transition resistance. |
| Key words: modular multilevel converter identification of AC and DC fault relay protection protection coordination second harmonic negative-sequence component |
