Evaluation of Virtual Synchronous Generator and Droop Control in Microgrids Using Real-Time Hardware-in-the-Loop for Inverter-Based Resources

This paper compares droop control and Virtual Synchronous Generator (VSG) control strategies for grid-forming inverter-based resources (IBRs) in microgrid applications. A modular microgrid system comprising two parallel inverters supplying local and common loads is modeled and implemented in both MATLAB/Simulink and a real-time Hardware-in-the-Loop (HIL) testbed using OPAL-RT and Texas Instruments C2000 microcontrollers. Three representative operating cases are considered: islanded operation, synchronized parallel operation, and fault-induced reconfiguration with load variation. Performance metrics, including PCC voltage regulation, current waveform quality, and active power sharing, are analyzed under step changes in load. Results show that VSG control consistently outperforms droop control by providing faster dynamic response, improved voltage and current regulation, and superior load-sharing accuracy. The findings are validated across both simulation and HIL environments, confirming VSG control's effectiveness and real-time viability. VSG control's effectiveness and real-time viability for resilient and stable operation in inverter-dominated microgrids.