Enhancing voltage stability of grid forming power converters based on model predictive controller

This research proposes an advanced control strategy based on Finite Control Set Model Predictive Control (FCS-MPC) for parallel-connected Voltage Source Inverters (VSIs) in standalone AC microgrids (MGs). The AC MGs, consisting of multiple VSIs, are designed to regulate output voltages at the point of common coupling (PCC) to meet local power demands. While traditional linear control approaches can achieve similar functions, they face challenges such as sensitivity to system variations and slow dynamic responses. The proposed FCS-MPC approach addresses these challenges effectively, ensuring stable and robust operation of Grid-Forming (GFM) inverters in AC MGs. By utilizing a cost function (CF) and droop control for power sharing among distributed generations, the strategy is validated through extensive simulations. Results demonstrate enhanced voltage stability, faster dynamic response, and improved power quality, with the system meeting international voltage stability and harmonic distortion standards.

Keywords: Voltage source inverters, Grid forming converters, Standalone operation, Model predictive control, AC microgrids.