低电压逆变器并联改进下垂控制技术

Improved droop control technology of low voltage inverter parallel

低电压逆变器并联系统在容量不等和线路阻抗不同的情况下,针对输出无功功率无法实现精确分配,并出现较大无功环流的问题,提出了一种改进的逆变器并联下垂控制方法。该方法中采用了线路压降补偿和电压反馈相结合来解决逆变器输出无功功率分配精确度低和系统环流较大的问题,在分析中综合考虑了无功功率分配精度和电压跌落的约束关系确定控制方法中的虚拟阻抗值。通过仿真和实验分析,该方法可以实现无功功率的精确分配,能有效抑制逆变器并联时引起的无功环流问题,同时加快了系统的动态响应速度,提高系统的稳定性和可靠性。

The inverter parallel system is in the case of different capacities and different line impedances in low voltage.Accurate distribution cannot be achieved for output reactive power,and there is a problem of large reactive current circulation.An improved inverter parallel sagging control method is proposed.The method used the combination of line voltage drop compensation and voltage feedback to solve the problem that the inverter output reactive power distribution accuracy is low and the system circulation is large.In the analysis,the virtual impedance value in the control method was determined by considering the reactive power distribution accuracy and the voltage drop constraint relationship.Through simulation and experimental analysis,this method achieves accurate distribution of reactive power,effectively suppresses the reactive circulation problem caused by inverter parallel connection,accelerates the dynamic response speed of the system,and improve the stability and reliability of the system.