模块化多电平光伏并网逆变器的不对称容错控制策略  

Unbalance fault-tolerant control strategy of modular multilevel photovoltaic grid-connected inverter

作　　者：刘一琦[1] 李丹华 王庆博 宋文龙[1] 郑纲[1] 谢文浩[3] 王建赜[3] LIU Yiqi1, LI Danhua2, WANG Qingbo1 , SONG Wenlong1 , ZHENG Gang1 , XIE Wenhao3, WANG Jianze3(1. College of Mechanical and Electrical Engineering,Northeast Forestry University,Harbin 150040, China; 2. Maintenance Branch Company,State Grid Chongqing Electric Power Company,Chongqing 400039,China; 3. School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, Chin)

机构地区：[1]东北林业大学机电工程学院,黑龙江哈尔滨150040 [2]国网重庆市电力公司检修分公司,重庆400039 [3]哈尔滨工业大学电气工程及自动化学院,黑龙江哈尔滨150001

出　　处：《电力自动化设备》2018年第4期126-132,138,共8页Electric Power Automation Equipment

基　　金：中央高校基本科研业务费专项资金资助项目(2572017BB13);哈尔滨市科技局创新人才基金资助项目(2017RAQXJ044)~~

摘　　要：建立了容错控制时采取热备用形式下模块化多电平换流器(MMC)的平均开关模型。针对MMC子模块发生故障时剩余子模块不足以支撑直流母线电压导致逆变器不能继续运行的问题,提出一种只旁路故障子模块的新型容错策略,通过改变子模块电容电压值和载波移向角的方法,保证环流中的主要成分不改变,同时降低故障后逆变器并网电流的谐波畸变率,使MMC能够继续运行。改进了容错时的最大功率点跟踪控制环节,解决了容错时直流母线电压的恢复时间长的问题。利用MATLAB/Simulink搭建了MMC的仿真模型,验证了所提控制策略的有效性。The average switch model of MMC （Modular Multilevel Converter） is built when hot backup is adopted as a fault-tolerant control. When the sub-module in MMC encounters fault,the rest sub-modules in MMC cannot support DC bus voltage,which results in interruption of the inverter operation. In terms of this problem, a novel fault-tolerant control strategy of bypassing the fault sub-module is proposed, which revalues the sub-module capacitor voltage and carrier phase-shift angle to maintain the main components of circulating current, while reducing the total harmonic distortion rate of grid current to enable the normal operation of MMC. The maximum power point tracking control strategy in fault tolerance is improved to solve the problem of long restore time when fault occurs. The simulation model of MMC is built by MATLAB/Simulink to prove the validity of the proposed control strategy.

关 键 词：光伏并网 模块化多电平换流器 容错控制 环流 最大功率点跟踪 

分 类 号：TM615[电气工程—电力系统及自动化] TM46