Abstract: The present disclosure relates to an uninterruptible power supply (UPS) for monitoring and prioritizing use of available power. The UPS has an electronic controller with a memory and a software control module. The UPS also has a battery, a rectifier for rectifying available AC power from a primary external AC power source to produce DC power, an inverter in communication with the rectifier for generating AC power from the DC power provided by the rectifier, and a DC/DC converter in communication with the rectifier for producing a DC charging current for use in charging the battery. The electronic controller and the software control module are configured to dynamically prioritize the use of available power from at least one of the primary AC power source and from the battery, to maintain adequate power to a load being supported by the UPS, as well as to charge the battery of the UPS when predetermined operating conditions are met.

Abstract: A system and method is presented for lowering inrush current to an uninterruptible power supply. During a startup phase, an AC voltage is applied to the secondary winding of a transformer interposed between an input power supply and a rectifier. An active rectifier coupled to the secondary winding of the transformer is operated as an inverter and supplies the voltage to the secondary winding of the transformer during the startup phase. The magnitude of the AC voltage applied to the secondary winding of the transformer is initially less than the magnitude of the input voltage and is increased gradually over time until it reaches the magnitude of the AC input voltage. In this way, the magnetizing flux of the transformer is increased from zero to a steady-state without having the transformer saturate.