Model predictive control method for CHB multi‐level inverter with reduced calculation complexity and fast dynamics

Abstract

Finite control set model predictive control (MPC) method needs calculations corresponding to the total number of voltage vectors made by power converters. This operating principle of the MPC leads to an increase in the computational load and number of calculations, which dramatically increase proportional to the increase in the level of cascaded H-bridge (CHB) inverters. However, it is difficult to consider all voltage vectors to find the optimal vector for high-level CHB inverters because of the short sampling time. This study proposes a new MPC algorithm to reduce the number of calculations for multi-level CHB inverters, in which only three voltage vectors are considered as optimal vectors regardless of the level of CHB inverters. Consequently, compared with the conventional MPC method for CHB inverters, the proposed MPC method requires fewer calculations and reduces the computational load without affecting the system performance and dynamic response.