Simple algorithm with fast dynamics for cascaded H-bridge multilevel inverter based on model predictive control method

Abstract

Model predictive control (MPC) method with finite control set needs calculations according to the total number of voltage vectors made by multi-level converters. This operating principle of the MPC tends dramatically to increase the computational load and number of calculations when the level of cascaded H-bridge (CHB) inverters is increased. A new MPC algorithm is proposed in this paper for decreasing the number of calculation in multi-level CHB inverters, in which only three voltage vectors are evaluated to determine optimal vectors regardless of the level of CHB inverters. As a result, the proposed MPC method needs fewer calculations and decreases the computational load compared to the conventional MPC method for CHB inverters, without affecting the performance and dynamic response of 5-level CHB inverter.