Digital Sliding Mode Control of a 3-Phase AC-DC rectifier for Ultra-Fast Charging of EV Battery⁎

This paper describes a digital sliding mode control (SMC) technique applied to a three-phase four-wire rectifier operating at a fixed frequency for ultra-fast charging of electric vehicle (EV) battery. The control algorithm employs three decoupled sliding mode controllers to achieve loss-free resistor (LFR) behavior in each phase for power factor correction (PFC). The design of the sliding mode controller is twofold. The first one is to guarantee convergence of the sliding variable to zero. The equivalent control and the discrete-time dynamic model of the rectifier are obtained by imposing sliding-mode regime in discrete-time. The second one is to stabilize the inner-loop under the obtained control law. Theoretically, the resulting inner-loop is stable with a deadbeat behavior in the inner current loop. The results are validated by numerical simulations using on a 350 kW AC-DC rectifier for EV battery ultra-fast charging applications. The numerical simulation results performed on the switched model implemented in PSIM© software are in close agreement with the theoretical analysis.