Report on Triport Uninterruptible Power System - (Triport System with Transistor Inverter)

High power single-phase, and three-phase triport uniterruptible power systems (triport UPS) employing transistor inverters with PWM control have been developed. The advantages of the triport UPS are high efficiency, high reliability, and low cost. The transient in accordance with switching for mode change is improved. The influence of the input dc voltage variation of the inverter on the system output is reduced.