| Abstract |
Several methods of interfacing a dc bus to a critical load, for uninterruptible power
supply (UPS) applications, can be employed. In order to minimize the size, weight and cost of the magnetic components, the power conversion is normally achieved through a high-frequency (HF) link. This paper presents and compares between three different schemes for establishing this HF link in the dc-ac converters used in small and medium size UPS systems
(less than lkV A). The HF link voltage can be either of a· sinusoidal pulse-width modulated (PWM) type or of a resonant type such that switching loss, switch stresses and EMI can be reduced. Simulation of the three schemes are carried out using PSpice and verified with
experimental results for a 350Hz link frequency. The merits and drawbacks of each scheme are also mentioned. |
