A New Hybrid UPS Inverter

This paper introduces the concept of a unique new static inverter for incorporation into an uninterruptible power system. In inverter design and configuration, overall performance is a compromise between various parameters such as range of DC input voltage, output impedance, transient response of voltage to load changes and input source changes & total harmonic distortion. This inverter concept is in effect a combination of pulse width modulation and stepwave designs. In this way it maintains a good measure of the transient capability and load compatability of the former with the high efficiency of the latter. This is further enhanced by the use of high voltage DC. It has been found to be a more optimum approach to the mid power range UPS systems, typically rated around 250 KVA. Illustrations of inverter systems of this type are presented and comparisons are made to other contemporary techniques.