An active power and reactive power sharing control method between distributed generators(DGs)in the unit output-power control(UPC)and feeder flow control(FFC)modes is analyzed. In the UPC mode
the output power of a DG is constantly regulated
which can follow the given value to achieve active power sharing between DGs. In the FFC mode
the active power flow on the feeder is regulated constantly
which also can follow the given value to achieve constantly exchanged power flow between the microgrid and the grid. However
affected by the line impedance and the local load
the output voltages of DGs are different
and hence the generation of the reactive power circulation. To solve this problem
this paper proposes a control strategy for suppressing the reactive power circulation. In this strategy
a voltage compensation element is injected into the droop control of reactive power and voltage
to achieve the purpose of suppressing the reactive power circulation. This method effectively eliminates the reactive circulation between inverters. Finally
the influences of different line impedance and local load on the reactive power circulation of a microgrid are analyzed
and simulations are carried out to verify the effectiveness and feasibility of the control strategy.This work is supported by National Natural Science Foundation of China(No. 514771487)and Hebei Provincial Natural Science Foundation of China(No. E2013203380).