Abstract: An uninterruptible power supply (UPS) includes an AC power source, a DC power source coupled to a DC bus, a load, a converter, an inverter and a controller. Responsive to the controller, the inverter receives power from the DC bus to supply the load a regulated voltage; the converter, operated in a hybrid mode, receiving power from the AC power source to supply the DC bus a regulated DC voltage in a double conversion mode or to supply the power to the load in a series-parallel mode, or a combination of the two modes. In the stored energy mode, with an additional bypass switch, both the converter and inverter receive power from the DC power source and jointly supply the load a high quality voltage. These configurations improve the efficiency and enable the UPS readily meet the VFI and the high quality output voltage requirements per IEC62040-3.

Abstract: An uninterruptible power supply (UPS) includes an AC power source, a DC power source coupled to a DC bus, a load, a converter, an inverter and a controller. Responsive to the controller, the inverter receives power from the DC bus to supply the load a regulated voltage; the converter, operated in a hybrid mode, receiving power from the AC power source to supply the DC bus a regulated DC voltage in a double conversion mode or to supply the power to the load in a series-parallel mode, or a combination of the two modes. In the stored energy mode, with an additional bypass switch, both the converter and inverter receive power from the DC power source and jointly supply the load a high quality voltage. These configurations improve the efficiency and enable the UPS readily meet the VFI and the high quality output voltage requirements per IEC62040-3.