Robust Switching Predictive Control for Three-Phase VSCs Based on Switched Affine Models

Three-phase voltage source converters (VSCs) are canonical examples of switched systems. Under the switched systems framework, the operational dynamics of the three-phase VSCs are considered as the switching between different subsystems, and the switching rule is designed to select the optimal subsystem in each control cycle. However, the control mode involving direct subsystem switching may result in an unfixed switching frequency. To address this issue while considering system delays and uncertainties in circuit parameters, a robust switching predictive control (RSPC) method is proposed for three-phase VSCs based on switched affine model. The main contributions of work are: 1) a fixed switching frequency control of three-phase VSCs is achieved based on switched model-based control framework; 2) a novel off-line switching table is established to eliminate unstable switching dynamic under system delay in existing switching control methods; and 3) a state-dependent switching control with observer method is proposed to improve the control performance of system under circuit parameters uncertainty conditions. The simulation and experimental outcomes confirm the efficacy and advantages of the proposed approach.