Battery Charging With Model Predictive DPC based-Converter Using Dynamic DC-link Reference

Abstract

The wide use of the delicate Lithium-ion battery in electric vehicles (EVs), UPS, etc. needs delicate charging systems operating at high power quality. The Direct Power Control (DPC), owing to its quicker transient response, serves as a good alternative for the control of PWM rectifiers in a battery charging system that is integrated into the grid. The classical way of designing the charging system includes separate stages of rectification and charging voltage control (using dc-dc converters). This paper proposes a mechanism that uses a dynamic dc-link voltage reference in the PWM rectifier to eliminate the dc-dc converter from the conventional system. This results in reduced size, weight, and cost for the whole system because of fewer hardware requirements. To select the switching vector for the PWM rectifier, here the model predictive control is used because not only does it avoid additional PWM generation block but it also has the ability to be versatile enough to accommodate different non-linear constraints in its algorithm. To validate the proposed method, the simulation model is designed using MATLAB/Simulink and the results are presented.