Abstract
Utility-connected microgrids (MGs) provide ancillary services using distributed energy resources (DERs). However, existing DER control strategies are complex and may not yield reliable results under diverse MG configurations. To address this challenge, this paper presents a unified secondary control strategy for effective real and reactive power regulation of dispatchable energy sources. These configurations are simulated based on the practical setup of the industry-grade MG at the Center for Microgrid Research (CMR). Real and reactive power regulation strategies based on a unified proportional-integral-derivative (PID) scheme across DERs are developed and evaluated for providing secondary control at the point of common coupling (PCC). Proportional power sharing algorithms for the DERs are implemented within the PCC control, incorporating the constraints of variable renewable energy such as solar photovoltaic (PV) arrays. The proposed strategies are assessed using time-domain simulations for multiple source configurations in the real-time simulator.