An Investigation on Active and Reactive Power Flow Control Based on Grid-tied Parallel Inverters

This paper presents an investigation of the single-phase microgrid system with improved power flow control for accurate power sharing for the inverter. The proposed controller has been developed based on abc-alpha beta transformation calculation that being integrates into distributed generation (DG) system for power delivery to the local loads as combined with the grid power flow. In the meantime, the current control also has been placed to the inverter as for the injected current from the DGs can be controlled. Therefore, this paper has used a structure comprising two constant DGs with the converter connected to the loads and grid supply at the point of connection. The advantage of this control strategy is where it allows for the inverter to have active and reactive power distribution equal to the load. The inverter is based on a voltage source inverter (VSI) circuit and operated in active-reactive (P-Q) power mode. Hence, the VSIs should meet the total demand so that the DGs unit shared the power according as instructed by the control strategy. Simulation results are presented to prove the validity and improvements achieved by the proposed controller. Finally, it shows that a reasonable agreement on power-sharing performance.