A Hybrid Model Integrating Three-Terminal Switch with PNGV Battery Models for LiFePO4 Battery Chargers

This study A LiFePO₄ battery pack (LBP) rapid charger was developed and implemented in this study. Using the partnership for a new generation of vehicles (PNGV) battery and three-terminal switch models, this study can yield a small-signal system matrix from dynamic equations to derive transfer functions and further analyze frequency responses for the charge voltage and current loops. In order to stratify practical applications, the proposed equivalent model considered the wire resistance-inductance of the power cable. Moreover, the design features for implementing the constant-voltage and constant-current charges are presented, and the current overshoot during the start-up phase can be depressed using a novel proportional shifting proportional-integral control.