Robust Operation of Four-Leg Voltage Source Inverter Using Model-Free Predictive Control

Abstract

This paper presents a novel model-free predictive control (MFPC) approach for precise voltage control in four-leg voltage-source inverters (4L-VSI). MFPC eliminates the need for complex system models, unlike traditional model predictive control (MPC) methods. It leverages the ultra-local model for controlled variable estimation, enabling robust performance without prior model information. The core contribution lies in a comprehensive mathematical model for the proposed MFPC strategy, encompassing all possible 4L-VSI switching states. This is contrasted with a detailed analysis of conventional MPC limitations for 4L-VSI control. Simulation results validate the effectiveness of MFPC in achieving accurate voltage control without explicit modeling. Furthermore, MFPC demonstrates superior robustness against parameter variations and model mismatches compared to conventional MPC. Hardware-in-the-loop testing with the RT-BOX platform strengthens the theoretical analysis. The achieved total harmonic distortion of 1.86% confirms compliance with IEEE standards, showcasing the practical effectiveness of the proposed MFPC approach.