• CSCD核心库收录期刊
  • 中文核心期刊
  • 中国科技核心期刊

电力建设 ›› 2017, Vol. 38 ›› Issue (8): 52-.doi: 10.3969/j.issn.1000-7229.2017.08.007

• 运行与控制技术 • 上一篇    下一篇

 基于混合型MMC和直流开关的柔性直流电网直流故障保护研究

 张峻榤1,向往1,林卫星1,2,文劲宇1 

 
  

  1.  (1. 强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院),武汉市430074;2. 特变电工新疆新能源股份有限公司,乌鲁木齐市830011)
     
  • 出版日期:2017-08-01
  • 作者简介:张峻榤(1992),男,硕士研究生,主要研究方向为柔性直流输电系统运行与控制等分号 向往(1990),男,博士,本文通讯作者,主要研究方向为模块化多电平换流器、直流电网运行与控制等分号 林卫星(1986),男,博士,主要研究方向为直流电网、直流-直流变换器、直流输电等分号 文劲宇(1970),男,教授,主要研究方向为电力系统运行与控制、电能存储与电力安全、多端直流输电与直流电网、新能源并网与规划等。
  • 基金资助:
     国家重点研发计划项目(2016YFB0901002)

 DC Fault Protection of VSC-HVDC Grid Based on Hybrid MMC and DC Switch
 

 ZHANG Junjie1, XIANG Wang1, LIN Weixing1,2, WEN Jinyu1

 
  

  1.  (1. State Key Laboratory of Advanced Electromagnetic Engineering and Technology (School of Electrical and Electronic Engineering, Huazhong University of Science and Technology), Wuhan 430074, China; 2.TBEA Sunoasis Co., Ltd., Urumchi 830011, China)
     
  • Online:2017-08-01
  • Supported by:
     Project supported by National Key Research and Development Program (2016YFB0901002)

摘要:  摘要:提出了采用混合型模块化多电平换流器(hybrid modular multilevel converter, hybrid MMC)和直流开关构建柔性直流电网进行架空线远距离电能传输的方案。针对由全桥型子模块和半桥型子模块组成的混合型MMC,分析了其拓扑结构、基本运行原理和直流电压运行区间,提出了混合型MMC的三自由度控制架构,并详细分析了直流故障穿越控制策略,进而设计了混合型MMC构成的柔性直流电网的故障清除策略和多次重启动时序。故障期间,混合型MMC无须闭锁IGBT,可控制故障电流至0,从而保持不间断运行、持续向交流系统提供无功支撑。3次重启动失败后,架空柔性直流电网配置的直流开关在零故障电流下开断以隔离故障电流通道,直流电网重启,线路潮流发生转移。最后在PSCAD/EMTDC仿真平台验证了所提出的故障清除策略及重启动时序的可行性。

 

关键词: 架空线, 柔性直流电网, 混合型模块化多电平换流器(hybrid MMC), 故障保护

Abstract:  ABSTRACT: To transmit the bulk renewable power using overhead lines, this paper proposes a VSC-HVDC grid transmission system based on hybrid modular multilevel converter (hybrid MMC) and DC switch. According to the hybrid MMC composed of half bridge sub-modules and full bridge sub-modules, this paper analyzes its topology, basic operating principle and DC voltage operating region, proposes a control framework embedding three-channel control freedom for hybrid MMC, analyzes the DC fault ride through control strategy in detail, and then designs the fault clearing method and multiple restart sequence of the VSC-HVDC DC grid based on hybrid MMC. During the DC fault, hybrid MMC can control the fault current to be zero without tripping the IGBTs. Therefore, the DC grid remains continuous operation to provide reactive power to the AC system. During post-fault, if the system fails to restart after three restart attempts, the DC switches installed at the overhead lines will be tripped to isolate the fault path at zero DC current. After fault clearance, as the change of network topology, the power flow will be re-distributed. At last, the feasibility of the fault clearing strategy and restart sequence is validated in PSCAD/EMTDC.

 

Key words: overhead lines, VSC-HVDC grid, hybrid MMC, fault protection

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