Real-Time HIL Comparison of Virtual Oscillator and Droop Control for Inverter-Based Resources

This paper compares Droop Control and Dispatchable Virtual Oscillator Control (dVOC) for grid-forming inverter-based resources (IBRs) of microgrids. With the increasing integration of inverter-interfaced renewable energy sources, robust grid-forming control is essential for ensuring voltage and frequency stability. The study examines system behavior under various scenarios, including islanded operation, parallel inverter coordination, and fault-induced disturbances. A practical scalar formulation of dVOC is implemented and compared with droop control using MATLAB/Simulink simulations and hardware-in-the-loop (HIL) testing with OPAL-RT and TI C2000 microcontrollers. Key performance metrics include voltage regulation, current response, and active power sharing. Results show that dVOC consistently outperforms droop control, providing faster transients, reduced overshoot, and smoother power transitions. These findings are validated across both simulation and real-time environments, demonstrating the effectiveness and suitability of the dVOC control for modern microgrid applications.