Multiple output uninterruptible alternating current power supplies for communications system

• US 6,288,916 B1
• Filed: 10/15/1999
• Issued: 09/11/2001
• Est. Priority Date: 10/15/1999
• Status: Expired due to Term

• Current Assignee: Alpha Technologies Services, Inc. (EnerSys)
• Original Assignee: Alpha Technologies Incorporated (EnerSys)
• Inventors: Vu, Lam, Han, Pu, Liu, Frank
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US09/419,220
• Time in Patent Office: 697 Days
• Field of Search: 363/34, 363/37, 363/71, 307/64, 307/66, 307/82
• US Class Current: 363/37
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02J 9/067 using multi-primary transformers, e.g. transformer having one primary for each AC energy source and a secondary for the loads
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A UPS system for communications systems. The UPS system comprises an input stage that generates primary and standby AC power signals. The primary and standby AC power signals are passed through an isolation transformer and through an output rectifier to obtain an output DC power signal. A plurality of output inverters are used to generate a plurality of output AC power signals from the output DC power signal. A switch circuit is provided to connect one or more of the output DC power signals to one or more loads of the communications system.

Claims

1. A UPS system for communications system comprising:

an input stage primary and standby AC power signals;

an isolation transformer operatively connected to receive the primary and standby AC power signals;

an output rectifier operatively connected to the isolation transformer for generating an output DC power signal based on the primary and standby AC power signals;

a plurality of output inverters, where each of the output inverters generates an AC power signal based on the output DC power signal;

a switch array arranged between the output inverters and one or more loads of the communications system, the switch array comprising a primary switch arranged between each of the output inverters and the load associated therewith, and at least one secondary switch arranged between two of the loads associated with the output inverters; and

switch control means for controlling the primary and secondary switches to connect one or more of the output AC power signals to one or more loads of the communication system.

2. A UPS system as recited in claim 1, in which the input stage comprises:

an input rectifier for generating an input DC power signal from a utility power signal;

an input inverter that generates the primary AC power signal from the input DC power signal; and

a battery inverter that generates the standby AC power signal from a battery.

3. A UPS system as recited in claim 2, further comprising a battery charger for charging the battery based on the input DC power signal.

4. A UPS system for a communications system comprising a plurality of loads, the UPS system comprising:

an input stage that generates primary and standby AC power signals;

an isolation transformer operatively connected to receive the primary and standby AC power signals;

an output rectifier operatively connected to the isolation transformer for generating an output DC power signal based on the primary and standby AC power signals;

a plurality of output inverters, where each of the output inverter generates an AC power signal for the load connected thereto based on the output DC power signal;

a switch array arranged between the output inverters and the loads of the communications system, the switch array comprising a primary switch arranged between each of the output inverters and the load associated therewith, and at least one secondary switch arranged between two of the loads associated with the output inverters; and

switch control means for controlling the switches to connect one or more of the output AC power signals to one or more loads of the communications system.

5. A UPS system as recited in claim 4, in which the input stage comprises:

an input rectifier for generating an input DC power signal from a utility power signal;

an input inverter that generates the primary AC power signal from the input DC power signal; and

a battery inverter that generates the standby AC power signal from a battery.

6. A UPS system as recited in claim 5, further comprising a battery charger for charging the battery based on the input DC power signal.

7. A method of supplying AC power to a communications system comprising the steps of:

generating primary and standby AC power signals;

passing the primary and standby AC power signals through an isolation transformer;

generating an output DC power signal based on the primary and standby AC power signals;

providing a plurality of output inverters, where each of the output inverters generates an AC power signal based on the output DC power signal;

arranging a switch array between the output inverters and one or more loads of the communications system, the switch array comprising a primary switch arranged between each of the output inverters and the load associated therewith, and at least one secondary switch arranged between two of the loads associated with the ouput inverters; and

controlling the primary and secondary switches to connect one or more of the output AC power signals to one or more loads of the communications system.

8. A method as recited in claim 7, in which the step of generating the primary and standby AC power signals futher comprises the steps of:

generating an input DC power signal from a utility power signal;

generating the primary AC power signal from the input DC power signal; and

generating the standby AC power signal from a battery.

9. A method as recited in claim 8, further comprising the step of charging the battery based on the input DC power signal.

10. A system operatively connected between a source of a utiity power signal and at least one load for generating an uninterruptible power signal for use in communications networks, the system comprising:

input terminals connected to the source of the utility power signal;

output terminals connected to the at least one load;

a transformer comprising first, second, and third windings;

an input DC bus;

an output DC bus;

a battery;

an input rectifier operatively connected between the input terminals and the first DC bus, where the rectifier generates a first DC power signal on the first DC bus based on the utility power signal;

a battery charger operatively connected between the first DC bus and the battery for charging the battery;

a first inverter operatively connected between the first DC bus and the first windings of the transformer for generating a primary AC power signal across the second windings;

a second inverter operatively connected between the third windings of the transformer and the second DC bus based on at least one of the primary AC power signal and the standby AC power signal;

a plurality of output inverters operatively connected between the second DC bus and the output terminals, where each output inverter generates an output AC power signal that energizes the at least one load;

a swutch array operatively connected between the output inverters and the output terminals, the switch array comprising a primary switch arranged between each of the output inverters and the load associated therewith, and at least one secondary switch arranged between two of the loads associated with the output iverters; and

a control circuit for controlling the switch array to connect a selected one of the plurality of output inverters to the at least one load.

11. A system as recited in claim 10, in which a load is connected to each of the plurality of output inverters.

12. A system as recited in claim 10, in which a load is connected to each of the plurality of output inverters.

13. A system as recited in claim 12, in which a load is connected to each of the plurality of output inverters.

14. A system as recited in claim 10, in which:

a load is associated with each of the plurality of output inverters; and

the switch array comprises

a secondary switch operatively connected between loads, and

a primary switch operatively connected between each of the output inverters and the load associated therewith;

wherein

the control circuit operates in

a first mode in which the secondary switch is opened and the primary switches are closed; and

a second mode in which the secondary switch is closed and one of the primary switches is opened.

15. A system as recited in claim 10, further comprising a filter circuit operatively connected between each of the output inverters and the at least one load.