| Abstract |
The general purpose of single-phase UPS topologies are indispensable for the
considerable reduction of hannonic current components in AC mains as well as realization of unity power factor correction (PFC). In particular, the single phase PFC rectifier with a high-frequency isolation transformer link has some advantages as an electrically-isolated
AC!DC conversion circuit for small scale UPS. This UPS is capable of eliminating
harmonic currents, leak current components and realizing an isolation between AC input and DC output power stage as well as matching the DC voltage of the PWM inverter by means
of incorporating a compact high frequency transformer into high-frequency intermediate
state. Three types of isolated PFC rectifiers designed for 2kVA, 3kVA and 5kVA-UPSs are put into the practical uses respectively, as new topology. This paper presents a high frequency
link PFC rectifier, its related operating principle and control strategy, together
with the steady-state and dynamic state performances of these types of UPS s developed from a practical point of view. |
