Continuous Control Set Model Predictive Control for Multilevel Packed E-Cell Inverter

Abstract

This paper introduces a continuous control-set model predictive control (CCS-MPC) for the grid-tied multilevel Packed E-Cell inverter known as PEC to achieve a low and constant switching frequency with reduced complexity, while dc-link capacitors are tuned in an integrated manner into the utilized modulator without requiring their dynamic models. The proposed CCS-MPC is founded on defining a cost function and minimalizing its derivative concerning the PEC-generated voltage. The produced continuous control signal is then applied to a hybrid pulse width modulation (PWM) technique that supports the PEC inverter multilevel operation. Although utilization of a modulation method is essential through the designed CCS-MPC, its cost function only considers the injected current regulation, and tuning several weighing factors is not required. Besides, by employing the proposed CCS-MPC as a simplified model predictive-based controller, a reduced number of voltage sensors are employed which increases the system reliability and reduces its implementation cost. Nonetheless, in this paper, the CCS-MPC technique for the multilevel PEC inverter in a grid-connected mode is defined thoroughly. Finally, provided simulation/experimental results demonstrate the feasibility and operation of the proposed controller applied on a single-phase PEC inverter.