Control of Parallel Connected Voltage Source Inverters in a Microgrid for Experimental Testing

This article describes the primary and secondary controls of voltage source inverters that are part of a custom-made AC microgrid for testing control strategies. The conceptual and physical structure of the microgrid is described. A cascade voltage-current control and a state feedback control are implemented for inverters with LCL output filters. Also, the conventional droop controls are implemented for power sharing. Simulation and experimentation results are presented of voltage, current and load sharing controls between two inverters of the microgrid, which validate these control strategies for teaching of microgrid control strategies.