摘要
在低压微网孤岛运行中,基于下垂控制策略的逆变器并联控制会因控制器参数和线路阻抗的差异等因素出现功率耦合,难以精确分配输出功率,出现系统环流等问题。文中提出了一种引入虚拟阻抗的改进下垂控制策略。引入虚拟阻抗的负阻性部分减小线路的阻性分量,虚拟阻抗的感性部分增大系统的感性成分,减弱功率的耦合程度,提高功率分配精度和环流抑制效果。并在无功下垂控制中引入电压反馈和电压补偿环节,抬高逆变器的输出电压,减小电压降落,使逆变器并联运行拥有良好的供电质量。由Matlab/Simulink仿真验证了文中改进控制方法的有效性。
In the island operation of low-voltage micro-grid,the parallel control of inverter based on the droop control strategy will cause such problems as power coupling,difficult distribution of output power and system loop current due to the difference of controller parameters and line impedance.In this paper,a kind of improved sag control strategy by way of introducing virtual impedance is proposed.The negative resistive part of the virtual impedance is introduced to reduce the resistive component of the line,and the inductive part of the virtual impedance increases the inductive component of the system,weakens the degree of power coupling and improves the power distribution accuracy and loop suppression effect.The voltage feedback and voltage compensation in the reactive power droop control is introduced to increase the output voltage of the inverter,reduce the voltage drop and keep the parallel operation of the inverter have a good power supply quality.The effectiveness of the improved control method in the paper is verified by Matlab/Simulink simulation.
作者
吴振奎
罗洋
WU Zhenkui;LUO Yang(School of Information Engineering,Inner Mongolia University of Science and Technology,Inner Mongolia Baotou 014010,China)
出处
《电力电容器与无功补偿》
2021年第6期166-172,共7页
Power Capacitor & Reactive Power Compensation
基金
内蒙古自治区自然科学基金(2018LH05023)。
关键词
微电网
逆变器并联
下垂控制
虚拟阻抗
无功功率
环流
新能源
micro-grid
parallel inverter
droop control
virtual impedance
reactive power
circulation current
new energy
