Robust dichotomy solution-based model predictive control for the grid-connected inverters with disturbance observer

Abstract

This paper proposes a robust dichotomy-based model predictive control (DS-MPC) with a fixed switching frequency for the grid-connected inverter (GCI). The proposed fast dichotomy algorithm can select and deduce the optimal voltage vector dynamically through the space vector plane. Therefore, the proposed DS-MPC strategy could ensure dynamic performance and steady-state performance as well. Also, the current control robustness can be improved through DS-MPC with disturbance observer (DO) based on the extended Kalman filter (EKF). The novelty of this control is that the current control with fast dynamic response can be realized in the weak grid, even if the grid voltages are greatly distorted. Simulation and hardware experiments on the weak grid validate the effectiveness of the proposed DS-MPC with the EKF observer approach.

Keywords

• dichotomy solution-based model predictive control (ds-mpc)
• three-phase grid-connected inverter (gci)
• weak grid
• voltage vector dichotomy