High Frequency Dc Triport , an Uninterruptable Power System

Abstract

The High Frequency (HF) DC Triport is a new power supply concept intended for applications requiring uninterruptable regulated DC energy. The HF DC Triport conditions and transmits energy to a load from two independent energy sources, the commercial AC line and a battery. The HF DC Triport is an alternative power supply arrangement to a conventional rectifier-battery system. The advantages of this new concept are: 1. Significant energy savings can be achieved when powering resistive loads, since the load voltage level is independent of the battery terminal voltage. 2. Stabilized output voltage over wide variations in the AC line and battery voltage. Simple, more efficient, and economical conditioning techniques can be used to convert the output energy to logic voltage levels. 3. Inherent energy carry-over characteristics for several cycles without a battery. 4. Low inrush current during initial start-up typically less than six times full load current rating. The flow of energy is controlled by a power switch which has a dual role as an ac and dc switching regulator. The switching rate is independent of the line frequency and is usually selected above the audible frequencies. The system exhibits first-order dynamics and provides hitless transfers between the ac and dc sources. This paper provides an analysis of the HF DC Triport.