Nonlinear-model predictive control based bidirectional converter for V2G battery charger applications

Abstract

This paper presents a new bidirectional Buck and Boost converter with nonlinear-model predictive controller (NMPC) for vehicle-to-grid (V2G) battery charger applications. The proposed converter consists of bidirectional modes; Buck mode for charging the battery, and Boost mode for discharging to the grid from the battery. The converter is designed with two separated inductors to make the current control easier and inductor design more flexible. The new current controller is also developed using closed-form nonlinear predictive control. With analytical modeling and control, the proposed converter achieved over the wide input voltage and load current range. In additions, the converter showed better and more accurate performance in both steady state and transient state than linear control methods. Simulation demonstrates the effectiveness of the proposed NMPC to a 2kW DC-DC converter.