Micro-source Inverters With Capacitive Equivalent Output Impedance for Improving Micro-grid Voltages

The reactive power and voltage regulation of micro-source inverters with capacitive equivalent output impedance is an inverse process of the distribution network.This feature makes the micro-source inverter easily participate in the common connection point voltage adjustment..We compare the droop control characteristics of three types of inverters with inductive,resistive and capacitive equivalent output impedances respectively.In a certain sense,the inverter has the similar ability like generators running in leading phase operation condition.For a power droop control structure with a voltage-current inner loop,an improved power droop robust control method is proposed which is significantly against the voltage deviation.Simulation and experimental results show the improved controller has some advantages in precise power allocation and voltage fluctuation inhibition.