Robust Long-Horizon Direct Model Predictive Control for Converters Connected to a Distorted Grid

Abstract

Long-horizon finite control set model predictive control (FCS-MPC) is known for its superior performance, especially when applied to complex, higher-order systems. This paper proposes an FCS-MPC method for converters connected to a distorted grid via LCL filters. The presented method relies on a prediction model that accounts for the harmonic content of the grid voltage. This allows for effective control of the output variables of the system, namely the grid and converter currents and the filter capacitor voltage. Moreover, by supplementing the controller with an estimation algorithm for the grid-side reactance, its robustness is enhanced, ensuring favorable system performance under all conditions. The presented results demonstrate the excellent steady-state and dynamic performance of the discussed control method.