Patent ID: 9172271
Filing Date: 2015-10-27
Classification: H02J

Abstract:
1. A method of operating an Uninterruptable Power Supply (UPS) system having a first UPS and a second UPS coupled in parallel to provide output power to a load from a power source, each of the first UPS and the second UPS having an inverter and having a bypass switch, with each UPS configured to operate in one of an inverter mode in which output power is derived from the power source through the inverter, and a bypass mode in which output power is derived from the power source bypassing the inverter, the method comprising: powering on the first UPS and the second UPS in the inverter mode; designating one of the first UPS and the second UPS as a master UPS; controlling, in the inverter mode, the bypass switch of the first UPS and the bypass switch of the second UPS using the master UPS; and controlling, in the inverter mode, output current of the inverter of the first UPS and output current of the inverter of the second UPS using the master UPS.