中文说明：
(1>分析低压微电网中逆变器输出阻抗特性，采用了虚拟阻抗的控制方法对逆变器输出阻抗进行构造，又从微电网本身特点考虑，构造逆变器的输出阻抗为阻性，使得Pv/QF的反下垂控制方法可以被合理使用。 (2>对逆变器功率外环进行小信号建模，分析当输出阻抗性质发生变化时系统。
English Description：
(1> The output impedance of inverter in low-voltage microgrid is analyzed, and the control method of virtual impedance is used to construct the output impedance of inverter. Considering the characteristics of microgrid, the output impedance of inverter is constructed as resistance, so that the anti droop control method of PV / QF can be reasonably used.