摘要
整流侧为LCC、逆变侧为MMC的LCC-MMC特高压混合直流输电系统的换流站由高低压阀组串联形成,当系统采用“LCC定电流控制/MMC定电压控制”和“LCC定电压控制/MMC定功率控制”两种控制策略时,分别存在整流站LCC和逆变站MMC的高低压阀组直流电压和有功功率不平衡的现象。提出了高低压阀组之间存在的不平衡电流和阀组电压未直接受控是导致阀组间直流电压不平衡的原因,并分析了不平衡现象的机理过程。对此提出了基于高低压阀组实际电压与额定电压偏差修正控制目标的均压控制策略,使得阀组间直流电压能够得到均衡控制。最后在PSCAD/EMTDC平台上对提出的均压控制策略进行了有效性验证。
The converter station of the LCC-MMC hybrid UHVDC transmission system with the LCC rectifier and the MMC inverter is formed in series by high and low voltage valve groups.When this system uses two control strategies:“constant current control in LCC converter/constant voltage control in MMC converter”and“constant voltage control in LCC converter/constant eactive power control in MMC converter”,there is a phenomenon that the DC voltage and active power of the high and low valve groups of the LCC rectifier and the MMC inverter are unbalanced.This paper proposes that the unbalanced current between the high and low valve groups and the uncontrollable voltage of valve is the cause of the DC voltage imbalance between the valve groups,and analyzes the mechanism of the unbalance phenomenon.A voltage equalization control strategy using the deviation between the actual voltage of the valve group and the rated voltage is designed,so that the DC voltage between the valve groups can be balanced.Finally,the effectiveness of the proposed voltage equalization control strategy is verified on the PSCAD/EMTDC platform.
作者
周保荣
李选平
黎寿涛
洪潮
黄东启
姚文峰
夏成军
ZHOU Baorong;LI Xuanping;LI Shoutao;HONG Chao;HUANG Dongqi;YAO Wenfeng;XIA Chengjun(Electric Power Research Institute,CSG,Guangzhou 510663,China;Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System,Guangzhou 510640,China)
出处
《南方电网技术》
CSCD
北大核心
2022年第8期79-85,共7页
Southern Power System Technology
基金
国家自然科学基金项目(U1766213)
中国南方电网有限责任公司科技项目(ZBKJXM20170071)。
关键词
LCC-MMC
高低压阀组
不平衡电流
均压控制
LCC-MMC
high and low valve groups
unbalanced current
voltage equalization control
