Pulse Width Modulated Inverters for Uninterruptible AC Power Systems Applications

This paper describes a PWM Static Inverter as used in Uninterruptible Power Systems having transfer times of 1/4 cycle or less. Such performance is extremely important in critical AC power applications for on-line process controls and computers where longer duration outages would result in very costly and extensive down time. A static switching bypass system is outlined, a comparison of inverter types is given and the compatibility and performance advantages of the PWM Static Inverter as used in this bypass system are presented.