摘要
当孤岛交流微电网中分布式电源的等效线路阻抗不一致时,运用下垂控制无法合理地分配无功功率,进而带来环流问题。为解决该问题,本文提出了基于模糊自适应虚拟阻抗的改进下垂方法。中央控制器计算各逆变器之间的无功差值和无功差值的变化量,然后发送到各逆变器进行本地控制。模糊控制器采集逆变器的无功信息自适应调整虚拟阻抗,以补偿因等效线路阻抗不一致引起的电压降落差,从而实现无功均分。同时为了应对逆变器输出端电压跌落问题,引入电压补偿环节,使输出电压恢复为额定值。最后通过MATLAB/Simulink仿真验证了所提出控制策略的有效性。
The line impedance between the DG units are always different in the islanded AC microgrid, which can result in circulating current and unreasonably sharing reactive power among inverters by using conventional droop control method. To solve this problem, an improved droop control strategy of adaptive virtual impedance based on fuzzy controller is proposed. The central controller calculates the reactive power difference between them and the variation of the reactive power difference. And then it sends the calculated results to each inverter. The fuzzy controller adaptively adjusts the virtual impedance by using the reactive power information of the inverter to compensate for the voltage drop difference caused by the inconsistent equivalent impedance, thereby achieving reactive power sharing. At the same time, in order to solve the problem of the voltage drop of inverter output voltage, a voltage compensation unit is introduced to restore the output voltage to the rated value. Finally, simulations are performed in MATLAB/Simulink to verify the validity of the proposed control strategy.
作者
姜恩宇
赵吉康
米阳
冷祥彪
李东东
JIANG Enyu;ZHAO Jikang;MI Yang;LENG Xiangbiao;LI Dongdong(College of Electrical Engineering,Shanghai University of Electric Power, Shanghai 200082, China;Electric Power Research Institute, CSG, Guangzhou 510663, China)
出处
《南方电网技术》
CSCD
北大核心
2019年第5期37-43,共7页
Southern Power System Technology
基金
国家自然科学基金项目(61873159)
上海绿色能源并网工程技术研究中心项目(13DZ2251900)~~
关键词
下垂控制
无功均分
模糊控制
自适应虚拟阻抗
电压恢复
droop control
reactive power sharing
fuzzy control
adaptive virtual impedance
voltage restore
