摘要
传统下垂控制没有考虑本地负荷和并联逆变器间线路阻抗等因素,无功功率不能实现准确分配,系统稳定性也会随之降低。为了实现对无功功率的合理分配,在微网系统传统下垂控制算法基础上,在电压电流双闭环控制中设计虚拟阻抗,以降低有功和无功耦合程度。然后针对低压微电网中线路阻性成分较大的问题,设计虚拟负阻抗的下垂控制算法,从而进一步降低了有功和无功耦合程度。仿真结果表明,改进下垂控制前后均可以实现对有功功率的合理分配。传统下垂控制的无功功率无法合理分配,偏差达到了20%。加入虚拟阻抗控制算法后提高了无功功率分配精度,引入虚拟负阻抗的控制算法可使该精度进一步提高。因此,相比传统下垂控制,加入该控制算法后逆变器可以获得更好的功率分配效果。
Traditional droop control does not take into account factors such as local load and line impedance between parallel invert⁃ers,reactive power cannot be accurately distributed,and system stability will be reduced accordingly.In order to realize the reason⁃able distribution of reactive power,based on the traditional droop control algorithm in the microgrid system,a virtual impedance is de⁃signed in the voltage and current double closed-loop control to reduce the degree of active and reactive coupling.Aiming at the prob⁃lem of large resistive components in low-voltage microgrids,we design a droop control algorithm of virtual negative impedance.Com⁃pared with virtual impedance,the degree of active and reactive coupling is further reduced.The simulation results show that the reason⁃able distribution of active power can be achieved before and after the droop control is improved.The reactive power of traditional droop control cannot be reasonably distributed,and the deviation reaches 20%.Adding the control algorithm of virtual impedance improves the accuracy of reactive power distribution,and the control algorithm of virtual negative impedance further improves the accuracy of re⁃active power distribution.Compared with traditional droop control,the inverter can obtain better power distribution effect by adding the proposed control algorithm.
作者
刘牮
马文良
LIU Jian;MA Wen-liang(School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《软件导刊》
2020年第5期159-163,共5页
Software Guide
关键词
逆变器并联
下垂控制
虚拟阻抗
虚拟负阻抗
无功功率分配
inverter parallel
droop control
virtual impedance
virtual negative impedance
power distribution
