基于阻抗功率下垂的并联逆变器功率均分策略

A Power Sharing Method for Parallel Inverters Based on Impedance-power Droop

传统下垂控制逆变器并联时,因为线路阻抗差异导致负载功率分配不均。在此提出了一种基于阻抗功率下垂的功率均分策略,该控制策略使用了合适的前馈信号消除了逆变器固有阻抗的影响,然后使用逆变器输出的视在功率作为调整其虚拟阻抗的基准,从而实现了虚拟阻抗的自适应调节。该方法不需要高带宽的通信线路,即可有效提高逆变器并联时的负载均分能力,并且具有较好的动态性能。仿真与实验结果验证了所提方法的有效性。

When the traditional droop control inverters are connected in parallel,the load power distribution is uneven due to the difference in line impedance.A power sharing method based on impedance-power droop is proposed,it uses an appropriate feedforward signal to eliminate the effect of the inverter’s inherent impedance,and use the apparent power output from the inverter as a reference to adjust its virtual impedance,so the virtual impedance is adaptively adjusted.This method does not require high-bandwidth communication lines,the load sharing capability when the inverters are connected in parallel can be effectively improved and have a better dynamic performance.Simulation and experiment test the validity of the proposed method.