UPS having a dual-use boost converter
View Patent ↗An uninterruptible power supply (UPS) system includes a rectifier having inputs connectable to an input AC power line to receive AC power therefrom. The output of the rectifier is connected to the input of an inverter. A dual-purpose battery is connected to function as a battery boost when the rectifier is receiving AC power from the AC power line. If the UPS is switched to operate in battery mode, the battery provides input voltage to the inverter when the rectifier is not receiving AC power from the AC power source.
1. A UPS system, comprising:
a rectifier having inputs connectable to an input AC power source;
an inverter connected to the rectifier;
a battery connected to function as part of a battery boost converter when the rectifier is receiving AC power from the AC power source, and to provide input voltage to the inverter when the rectifier is not receiving AC power from the AC power source.
2. The UPS system of claim 1 , further comprising a switching arrangement for selectively switching the battery between functioning as the battery boost converter and providing input voltage to the inverter.
3. The UPS system of claim 2 , wherein the switching arrangement includes thyristers.
4. The UPS system of claim 2 , wherein the switches are activated in response to losing the AC power source.
5. The UPS system of claim 1 , wherein the UPS system is a three-phase system.
6. The UPS system of claim 1 , wherein the battery is simultaneously connected to the rectifier and the inverter.
7. The UPS system of claim 1 , wherein the boost converter is functional both when the rectifier is receiving AC power from the AC power source and when the rectifier is not receiving AC power from the AC power source.
8. The UPS system of claim 1 , wherein the rectifier and the inverter are independently operable and substantially continuously connected to each other.
9. The UPS system of claim 1 , wherein the battery functions as part of the battery boost converter to provide input voltage to the inverter when the rectifier is receiving AC power from the AC power source.
10. A method of operating a UPS system, comprising:
connecting a battery to a rectifier to function as a battery boost converter when the rectifier is receiving AC power from an AC power source and connecting the battery to function as a back up power source when the rectifier is not receiving AC power from the AC power source.
11. The method of claim 10 , wherein connecting the battery to function as a back up power source includes activating a switch in response to loss of the AC power source.
12. The method of claim 10 , wherein the battery functions as part of the battery boost converter to provide input voltage to an inverter when the rectifier is receiving AC power from the AC power source.
13. A UPS system, comprising:
a three-phase rectifier having inputs connectable to an input AC power source;
a battery connected the rectifier such that together they function as a boost converter when the rectifier is receiving AC power from the AC power source;
a three-phase inverter connected to the rectifier; and
wherein the battery is further operable to provide input voltage to the inverter when the rectifier is not receiving AC power from the AC power source.
14. The UPS system of claim 13 , further comprising a switching arrangement for selectively switching the battery between functioning as the boost converter and providing input voltage to the inverter.
15. The UPS system of claim 13 , wherein the battery functions as part of the battery boost converter to provide input voltage to the inverter when the rectifier is receiving AC power from the AC power source.