基于PWM-CSC的混合直流输电系统电网故障穿越策略  

Research of grid fault ride-through strategy for PWM-CSC based hybrid HVDC transmission system

作　　者：夏冰[1,2,3] 李耀华 李子欣[1,2,3] 徐飞 高范强[1,2,3] XIA Bing;LI Yaohua;LI Zixin;XU Fei;GAO Fanqiang(Key Laboratory of Power Electronics and Electric,Chinese Academy of Sciences,Beijing 100190,China;Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China;College of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院电力电子与电气驱动重点实验室,北京100190 [2]中国科学院电工研究所,北京100190 [3]中国科学院大学电子电气与通信工程学院,北京100049

出　　处：《电力自动化设备》2019年第11期120-126,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51507167)~~

摘　　要：研究了一种整流侧采用传统电网换相换流器(LCC)、逆变侧采用脉宽调制型电流源换流器(PWM-CSC)的混合直流输电系统。为了降低开关频率和提高系统故障响应性能,提出了电网正常运行时采用特定谐波消除法(SHE)调制和电网故障时切换为正弦脉宽调制(SPWM)的调制策略。分析了电网故障情况下逆变侧PWM-CSC在αβ两相静止坐标系下的数学模型,提出了一种基于比例谐振控制器的控制策略并对控制器参数进行了设计,实现了负序电网电流的抑制和单位功率因数运行。此外,给出了电网故障情况下系统传输的最大有功功率的计算方法。在PSCAD/EMTDC中搭建了400 kV/1250 MW的单极混合直流输电系统仿真模型。仿真结果验证了所提控制策略的正确性和有效性。A hybrid HVDC(High Voltage Direct Current)transmission system adopting LCC(Line Commutated Converter)on rectifier side and PWM-CSC(Pulse Width Modulated-Current Source Converter)on inverter side is researched.To achieve low switching frequency and improve fault response performance,the SHE(Selective Harmonic Elimination)modulation strategy is adopted under normal state and the modulation method is switched to SPWM(Sinusoidal PWM)under grid fault state.Theαβstationary reference frame based mathematical model of the proposed system is deduced under grid fault state and a PR(Proportional Resonant)controller to eliminate the negative-sequence grid current and realize unity power factor operation is proposed.The PR parameters are designed.Besides,the calculation of the maximum transmission power under grid fault state is presented.Finally,a simulation model of 400 kV/1250 MW unipolar hybrid HVDC transmission system is built by PSCAD/EMTDC.The simulative results verify the correctness and effectiveness of the proposed control method.

关 键 词：混合直流输电 脉宽调制型电流源换流器 脉冲宽度调制 比例谐振控制器 最大传输功率 负序电流抑制 单位功率因数 

分 类 号：TM721.3[电气工程—电力系统及自动化]