This paper proposes an integrated ZVT auxiliary commutation circuit applied to the pre-regulator converter and to the battery charger of Uninterruptible Power Systems (UPS). With the proposed integrated ZVT auxiliary commutation circuit there are few auxiliary components and the overall efficiency increases. In addition, two control strategies, one analog control scheme and one digital control scheme, are analyzed, and performance and cost of these strategies are compared. The analog control system is implemented with several dedicated IC’s whereas the digital control system is implemented with a low cost single-chip DSP controller. A 580W closed-loop prototype, with universal input, has been implemented to evaluate the performance of the proposed system.
Soft-switching; digital control; battery charger; universal input; UPS
