Backstepping-Based Control of Vienna Rectifier for Electric Vehicle DC Ultra-Fast Charger

This study consists in developing a new nonlinear controller for a battery electric vehicle (BEV) ultra-fast charger based on three-phase Vienna rectifier topology. The control method of the studied AC-DC rectification stage is performed in order to achieve four objectives: (i) Ensuring a unity power factor during the ultra-fast charging process, (ii) Regulating the DC output voltage to its reference value, (iii) Realizing the neutral point voltage balance of the three-level converter, and (iv) Providing global asymptotic stability of the studied system. Based on the mathematical model of three-level converter in (dq) frame, a Backstepping-based (BS) control with simplified Space Vector Pulse Width Modulation (SVPWM) has been designed. In order to evaluate dynamic performance of the new nonlinear controller, the achieved results have been compared to the traditional Proportional Integral (PI) control method under load variations. The obtained results prove a good performance of the proposed control strategy. The nonlinear controller has a faster tracking speed, higher quality of dynamic performance, and a total harmonic current distortion (THDi) less than 5% to meet the IEEE 519-2014 standard.