Hybrid One-Cycle Control Strategy for Buck+Boost PFC Battery Charger

Abstract

Electric vehicles emerge as a growing market. The utilization of electric vehicles will progressively create the need of high performance battery chargers. The buck+boost PFC rectifier comes out as an effective and efficient plug-in battery charger. Several works report application of this topology supported by digital controllers. These controllers normally employ input and output voltage sensors to perform input current reference and the operation mode decision, i.e. buck or boost modes, with continuous comparison between input and output voltages. On the other hand, analogical control solutions requires, besides the use of input and output voltage sensors, the use of analog multiplier to perform input current template and mode managing. This work proposes an analog control strategy based on the One-Cycle Control technique. Features of such technique includes the elimination of grid and output voltage sensors, elimination of analog multiplier and any current control loop design, spontaneous and smooth transition between buck and boost operation modes, and simple low cost circuitry. This paper carry out comparisons concerning the proposed and the existent control strategies, including cost, robustness and performance. Simulation results are carried out to a first validation of the proposal.