A virtual Point of Common Coupling voltage for improved droop control in microgrids

A droop controller was previously developed employing parallel voltage and current control algorithms [1]. The control scheme was shown to balance reactive power but required the measurement of the Point of Common Coupling (PCC) voltage. This paper extends [1] to create a Virtual PCC voltage by exploiting deadbeat control theory. The creation of a Virtual PCC allows only local measurements to be utilised whilst balancing reactive power. Further, the deadbeat current controller design is extended to include an LCL output filter and accommodate any X/R ratio of the coupling. SABER simulations and dSPACE hardware results are provided for a two inverter microgrid to show the correct operation of the control scheme.