摘要
传统的二、三电平变换器无法满足高电压、大容量光伏发电系统的要求,因此提出一种基于模块化多电平拓扑(MMC)的光伏发电系统。在此系统中,光伏阵列通过Boost电路后集成于MMC的各个子模块中,这样将有效地降低了开关管的电流应力和电压应力,并且增加了系统的电压和容量。针对系统的控制策略进行研究,通过改变子模块Boost电路中开关管的占空比来稳定子模块电容电压,并网系统的MPPT控制和并网控制则通过逆变电路来实现。此外,提出了该系统的保护控制策略。最后,搭建基于MMC光伏并网发电系统的仿真模型和实验样机,仿真和实验结果有效地证明了控制策略的正确性。
The traditional two or three level converter can not meet requirements of high voltage and high power capacity for PV system. Therefore, the system which is based on modular multilevel converter （MMC） has been proposed. In this system, the PV array is connected to sub-module through Boost circuit. Compare with the traditional converter, the new structure can reduce current stress and voltage stress, meanwhile it increase the system voltage and capacity due to the expansibility of sub- module. The system control strategy is proposed, the sub- module capacitor voltage regulation is achieved through the double closed-loop control strategy of Boost circuit and the MPPT control is achieved through the inverter. In addition, the protective strategy is proposed. Lastly, the simulation model and the experimental prototype of the system are built and the results verify the correctness of the proposed control strategy.
出处
《高压电器》
CAS
CSCD
北大核心
2018年第3期146-153,共8页
High Voltage Apparatus
基金
江苏省电力公司科技项目(J2017118)
教育部博导类博士点基金(20130092110041)~~
关键词
模块化多电平变换器
光伏并网发电系统
电流应力
MPPT控制
保护控制策略
modular multilevel converter（MMC）
photovohaic （PV） grid-connected inverter
current stress
MPPT control
control and protection strategy
