Variable Switching Point Model Predictive Control for DC-Link Capacitance Minimization of Back-to-Back Converters

Abstract

This paper proposes a novel model predictive control method that is focusing on robustness to low DC-link capacitances in back-to-back converters. Therefore, a variable switching point approach is used. Choosing a variable switching point provides an additional degree of freedom to the control framework. The newly gained degree of freedom allows to cope with the large number of control variables that come with the system. In this case, the variable switching point is used to minimize the effects of low DC-link capacitances on the system. This can be either achieved by selecting a switching point which yields to low DC-link capacitor charging or by selecting a switching point which aims to keep the DC-link voltage close to the reference. The proposed method is verified by means of numerical MATLAB/SIMULINK simulations and compared to existing apporaches.