基于坐标变换的微源逆变器虚拟复阻抗功率分配方法

Virtual Complex Impedance Power Distribution Method for Micro-Source Inverter Based on Coordinate Transformation

微电网中线路的阻抗特性与微源逆变器的功率解耦控制、环流抑制、电能质量等问题密切相关。针对传统虚拟阻抗控制容易引起公共连接点电压幅值跌落、控制鲁棒性差以及线路电阻漂移造成系统失稳等不足,提出基于坐标变换的微源逆变器虚拟复阻抗功率分配方法,通过引入虚拟复阻抗控制环实现并联运行的微源逆变器功率输出的精确解耦以及等效线路阻抗的匹配,从而使得负荷功率按微源逆变器容量比例进行精确分配。仿真和实验结果验证了所提控制方法的有效性。

The impedance characteristics of the line in microgrid are closely related to the power decoupling control of micro sources inverter, circulation suppression, power quality and so on. Traditional virtual impedance control can easily cause voltage drop of common connection point, control robustness difference, and the deficiency of system instability caused by line resistance drift, a virtual complex impedance power sharing method for micro sources inverter based on coordinate transformation is proposed, the power output of parallel micro sources inverter is decoupled precisely and the equivalent line impedance is matched by virtual complex impedance control loop, the load power is effectively distributed according to the capacity ratio of the micro sources inverter. Simulation and experimental results verify the proposed method.