基于单极MMC拓扑的光伏并网系统仿真分析  

Simulation Analysis of Photovoltaic Grid-Connected System Based on MMC Topology

作　　者：彭华厦[1] 阳鹏飞 肖会芹[1] PENG Huaxia;YANG Pengfei;XIAO Huiqin(Hunan University of Technology,Zhuzhou Hunan 412008,China)

机构地区：[1]湖南工业大学

出　　处：《浙江电力》2019年第11期16-21,共6页Zhejiang Electric Power

基　　金：国家自然科学基金项目（61703153）

摘　　要：针对传统的二电平、三电平变换器不能满足高电压、大容量光伏并网发电系统的要求,以及一般MMC(模块化多电平换流器)不具备子模块保护能力的问题,提出一种具有子模块保护能力的单极MMC光伏并网系统。介绍了基于MPPT(最大功率点跟踪)技术的双闭环控制策略、光伏并网原理以及MMC换流器拓扑结构的特点、工作原理、调制方式。采用CPS-SPWM(载波移相正弦脉宽调制)方式来调制MMC,利用PSCAD/EMTDC电力系统电磁暂态仿真软件搭建9电平的MMC光伏并网模型。仿真结果表明,设计的MMC具有保护子模块的能力,CPS-SPWM调制方式谐波少、开关频率低,光伏阵列通过MMC平稳并网。The traditional two and three-level converter cannot meet the requirements of high-voltage and large-capacity photovoltaic grid-connected generation system, and the general MMC(modular multi-level converter) has no sub-module protection capacity. The paper proposes a monopole MMC photovoltaic grid-connection system with sub-module protection capacity. Double closed-loop control strategy and photovoltaic gridconnection principle based on MPPT(maximum power point tracking), and topology characteristics, operation principle and regulation mode of MMC are introduced. The CPS-SPWM(carrier phase-shifted unipolar sinusoidal pulse width modulation) is adopted to modulate MMC, and the 9-level MMC photovoltaic grid-connected model is built by using PSCAD/EMTDC. The results show that MMC has protection ability of submodule. CPS-SPWM modulation has the characteristics of fewer harmonics and low switching frequency. The PV array is smoothly connected to the grid through MMC.

关 键 词：模块化多电平换流器 光伏并网 最大功率点跟踪 PSCAD/EMTDC 

分 类 号：TM615.2[电气工程—电力系统及自动化]