Enhancing Fault Ride Through Capability of Grid-Forming Virtual Synchronous Generators Using Model Predictive Control

This paper proposes a control method for virtual synchronous generator (VSG)-based grid-forming converters to improve the stability of power electronic-dominated power grids. Overcurrent protection and fault ride-through (FRT) are crucial for the control of converter-based generators, given the limitations of power electronics components. This paper introduces a finite-set model predictive control (FS-MPC)-based FRT control technique that ensures system stability during symmetrical and asymmetrical fault types by incorporating overcurrent protection and contribution to the system voltage, while maintaining the voltage mode functionalities of the grid-forming converters. Compared to conventional control methods, the proposed MPC control technique allows for faster and improved dynamics, which makes control objectives more accessible. Additionally, the approach coordinates voltage and current control and their limitations to ensure system stability during and after fault. The proposed method also adapts to different fault types and sizes without requiring fault type detection. Simulation results in MATLAB/Simulink illustrate the effectiveness of the proposed control method in limiting the current and ensuring high power quality by providing clean sinusoidal voltage and current waveforms. Hardware-in-the-loop (HIL) real-time simulation is also presented to validate the controller performance under fault conditions.