System and Method for a Backup Power Supply

Abstract

A system and method for providing a backup power supply.

1 . A back up power supply, comprising:
 a current transformer connected an alternative current;   a medium voltage disconnect positioned between the alternating supply and the current transformer;   a circuit breaker attached to the current transformer that interrupts the alternative current suppled form the utility when the alternative current exceeds a limit;   an inverter connected to the direct current bus;   a clean alternating current bus attached to an output of the inverter;   an alternating current to direct current converter connected to an output of the clean alternating current bus;   a battery connected to the output of the alternating current to direct current that charges the battery.   
     
     
         2 . The system of  claim 1 , wherein the inverter creates a constant voltage and frequency output regardless of variations in the unfiltered alternating current power. 
     
     
         3 . The system of  claim 1 , wherein, depending on a required ride through time of devices connected to the backup power supply, batteries and capacitors are connected to the DC bus. 
     
     
         4 . The system of  claim 1 , further comprising a DC link connected between the battery and a battery inverter, wherein the battery utilizes a DC-DC converter to match the battery voltage to a DC link voltage supplying backup power to the inverter. 
     
     
         5 . A method for suppling back up power, the method comprising:
 providing an alternating current;   providing a current transformer connected to the unfiltered alternative current;   providing a protection and monitoring circuit attached to the current transformer that indicates power is present;   a circuit breaker attached to the current transformer that interrupts the unfiltered alternative current suppled from the utility when the unfiltered alternative current suppled from the utility exceeds a limit;   providing a clean alternating current power from a direct current bus formed on a diode output of the 18-pulse diode rectifier to an inverter connected to the direct current bus;   providing a clean alternating current bus attached to an output of the inverter to an alternating current to direct current converter connected to an output of the clean alternating current bus.   
     
     
         6 . The method of  claim 5 , wherein the inverter creates a constant voltage and frequency output regardless of variations in the unfiltered alternating current power supplied from the utility. 
     
     
         7 . The method of  claim 5 , wherein
 depending on the required ride through time; of devices connected to the backup power supply, batteries and/or capacitors are connected to the DC bus.   
     
     
         8 . The method of  claim 5 , further comprising a DC link connected between the battery and the inverter, wherein the battery utilizes a DC-DC converter in order to match the battery voltage to a DC link voltage.