Uninterruptible transfer switch

• US 6,630,752 B2
• Filed: 09/12/2001
• Issued: 10/07/2003
• Est. Priority Date: 09/12/2001
• Status: Expired due to Fees

• Current Assignee: Qualmag, Inc.
• Original Assignee: Qualmag, Inc.
• Inventors: Fleming, David J., Yarpezeshkan, Hassan
• Primary Examiner(s): Jackson, Stephen W.
• Assistant Examiner(s): DeBeradinis, Robert L
• Application Number:
  US09/955,405
• Publication Number:
  US 20030048004A1
• Time in Patent Office: 755 Days
• Field of Search: 307/64, 307/80, 307/85, 307/66, 307/70
• US Class Current: 307/64
• CPC Class Codes: H02J 3/007 Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing uninterruptable power supply H02J9/00
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems

Abstract

An uninterruptible transfer switch (UTS) coupled to two or more power sources and a load, said UTS including switches and an inverter, powered through one of several sources routed through rectifiers, capable of sensing power quality of two or more power sources and automatically switching sources when the primary power source is degraded to a predetermined limit and the switching of sources occurring without appreciable power loss on the load side of the UTS.

Claims

1. An uninterruptible transfer switch coupled to at least two power sources and a load comprising:

a first switch having a first and second end, said first end coupled to a first power source, said second end coupled to said load;

a second switch having a first and second end, said first end coupled to a second power source, said second end coupled to said load;

a control module coupled to said first and second switch, said control module capable of actuating said first and second switch in order to select said power sources received by said load;

an inverter for providing power to said load when said control module actuates said first and second switches;

a first rectifier, having a first and second end, said first end coupled to said first end of said first switch, said second end of said rectifier coupled to said inverter;

a second rectifier, having a first and second end, said first end coupled to said first end of said second switch, said second end of said second rectifier coupled to said inverter.

2. An uninterruptible transfer switch as recited in claim 1 wherein said first and second switches comprise contactors.

3. An uninterruptible transfer switch as recited in claim 1, wherein said first and second switches comprise SCRs.

4. An uninterruptible transfer switch as recited in claim 1, further including a remote monitoring unit coupled to said control module for transmitting and receiving system information.

5. An uninterruptible transfer switch coupled to at least one power source from a utility and a load comprising:

a first switch having a first and second end, said first end coupled to said power source from a utility, said second end coupled to said load;

an alternate power source;

a second switch having a first and second end, said first end coupled to said alternate power source, said second end coupled to said load;

a control module coupled to said first and second switch, said control module capable of actuating said first and second switch in order to select power sources received by said load;

an inverter for providing power to said load when said control module is actuating said first and second switches;

a first rectifier, having a first and second end, said first end coupled to said first end of said first switch, said second end of said rectifier coupled to said inverter;

a second rectifier, having a first and second end, said first end coupled to said first end of said second switch, said second end of said second rectifier coupled to said inverter.

6. An uninterruptible transfer switch as recited in claim 5, wherein said alternative power source comprises a generator.

7. An uninterruptible transfer switch as recited in claim 5, further including an energy source, said energy source coupled to said inverter, said energy source for providing power to said inverter when said control module is actuating said first and second switches.

8. An uninterruptible transfer switch as recited in claim 7, wherein said energy source comprises a generator.

9. An uninterruptible transfer switch as recited in claim 7, wherein said energy source comprises a fuel cell.

10. An uninterruptible transfer switch as recited in claim 7, wherein said energy source comprises a super capacitor.

11. An uninterruptible transfer switch coupled to at least two power sources and a load comprising:

a first switch having a first and second end, said first end coupled to a first power source, said second end coupled to said load;

a second switch having a first and second end, said first end coupled to a second power source, said second end coupled to said load;

a choke coupled to said load, said first and second switch for electrically isolating said power sources and said inverter during switching of said power sources;

A control module coupled to said first and second switch, said control module capable of actuating said first and second switch in order to select power sources received by said load;

an inverter for providing power to said load when said control module actuates said first and second switches;

an inductor coupled to said load, said first and second switch, said inductor electrically isolating said power sources and said inverter from said load during switching of said power sources;

a first rectifier, having a first and second end, said first end coupled to said first end of said first switch, said second end of said rectifier coupled to said inverter;

a second rectifier, having a first and second end, said first end coupled to said first end of said second switch, said second end of said second rectifier coupled to said inverter.

12. The uninterruptible transfer switch recited in claim 11 wherein said inductor comprises a transformer.

13. The uninterruptible transfer switch recited in claim 11 wherein said inductor comprises a choke.

14. The uninterruptible transfer switch recited in claim 11 further including surge suppressors coupled to said first ends of said first and second switch.

15. An uninterruptible transfer switch coupled to a first power source, a second power source and a load comprising:

a first switch means for transferring power to said load, said first switch means having a first and second end, said first end coupled to a first power source, said second end coupled to said load;

a second switch means for transferring power to said load, said second switch means having a first and second end, said first end coupled to a second power source, said second end coupled to said load;

control means for actuating said first and second switch in order to select the power source received by said load, said control means coupled to said first and second switch;

inverter means for providing power to said load when said control means actuates said first and second switches in order to alternate power source received by said load;

an inductor means for electrically isolating said sources and inverter means during switching of power from one power source to another, said inductor means coupled to said load, said first and second switch, and said inverter;

a first rectifier means for providing power to said inverter means, said rectifier having a first and second end, said first end coupled to said first end of said first switch means, said second end of said rectifier coupled to said inverter means;

a second rectifier means for providing power to said inverter means, said rectifier having a first and second end, said first end coupled to said first end of said second switch means, said second end of said second rectifier coupled to said inverter means.

16. A method of switching power sources from a primary power source to an alternative power source without appreciable power loss to the load comprising:

monitoring power quality of a preferred power source and an alternate power source;

determining from a predefined set of power quality variables that the power quality from the primary source has degraded to an unacceptable level;

opening all switches that route the primary power source to the load;

supplying power to the load from the inverter at the time that the primary power source is disconnected from the load so that no appreciable power loss occurs on the load;

slewing amplitude and phase of power provided by the inverter to the load so that it substantially matches the amplitude and phase of alternative power source;

closing the switch that routes power from the alternative power source to the load;

taking the inverter off line so that the load receives power from the alternative power source without appreciable power loss on the load.