Frequency Dividing Droop Controllers With the Function of Voltage Stabilization and Circulation Control

There is still room for improving the DG droop controller in terms of voltage adjustment, circulation inhibition, nonlinear load solution and power distribution accuracy by using the droop control strategy. On the issues that parallel circulation and power allocation accuracy of the inverter is low, the equivalent output impedance was redesigned to reduce differences of impedances between parallel operation inverters, bring down parallel circulation and improve the accuracy of power allocation. The public connection point voltage feedback loop was introduced to avoid the voltage drop. The design of frequency dividing droop control can cope with specific harmonics well. Simulations prove that the robust frequency dividing droop controller can improve the voltage regulation, reduce the harmonic and increase the accuracy of power allocation. Experiments show that the controller can effectively reduce the harmonic content in the contact line.