Automatic transfer switch spacing monitoring within an electrical device

Patent metadata

Field	Value
Publication number	US-9685786-B1
Application number	US-201313946916-A
Country	US
Kind code	B1
Filing date	Jul 19, 2013
Priority date	Jul 19, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

An automatic transfer switch (ATS) is described that includes a multi-structure of relays that together provide proper spacing, within the ATS, between a first power feed and a second power feed. A monitor circuit is also described that monitors output ports of relays in the first stage of the multi-stage structure and detects that there is or is not proper spacing between the first power feed and the second power feed, within the ATS.

First claim

The invention claimed is:

1. An electronic device comprising:
a power supply that couples to a first alternating current (AC) power feed and a second AC power feed;
an automatic transfer switch (ATS) comprising a multi-stage structure of relays, wherein a spacing between output ports of relays of a first stage of the multi-stage structure and a spacing between input ports of relays of a second stage of the multi-stage structure is less than a spacing threshold for preventing shock from coupling of the first AC power feed and the second AC power feed, wherein a sum of the spacing between output ports of one of the relays of the first stage and the spacing between input ports of one of the relays of the second stage is greater than or equal to the spacing threshold, and wherein the ATS is configured to output AC voltage from one of the first AC power feed and the second AC power feed, wherein the relays of the first stage are coupled to respective ones of the first and second AC power feeds, wherein the relays of the first stage comprise a first relay having one input port and two output ports, wherein the relays of the second stage comprise a second relay having two input ports and one output port, and wherein a first output port of the output ports of the first relay is connected to at least one of the input ports of the second relay, and a second output port of the output ports of the first relay is not coupled to any of the relays of the second stage; and
a monitor circuit configured to monitor at least one of the output ports of the relays of the first stage, and detect, based on the monitoring, that a spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, wherein the monitor circuit is configured to monitor at least one output port, of respective ones of one or more relays of the first stage, that is not coupled to any of the relays of the second stage.

2. The electronic device of claim 1 , wherein the spacing between output ports of relays of the first stage comprises an air gap between the output ports, and wherein the spacing between input ports of relays of the second stage comprises an air gap between the input ports.

3. The electronic device of claim 1 , wherein to detect that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, the monitor circuit is configured to detect, based on the monitoring, whether a switch in at least one relay of the first stage is in an incorrect position such that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold.

4. The electronic device of claim 1 , wherein to detect that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, the monitor circuit is configured to detect, based on the monitoring, whether the spacing between a power line of the first power feed and a power line of the second power feed is less than the spacing threshold.

5. The electronic device of claim 1 , wherein to detect that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, the monitor circuit is configured to detect, based on the monitoring, whether the spacing between a neutral line of the first power feed and a neutral line of the second power feed is less than the spacing threshold.

6. The electronic device of claim 1 , wherein the monitor circuit is configured to output a fault signal if the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold.

7. The electronic device of claim 1 , wherein the monitor circuit is configured to:
monitor a value of a control signal to at least one relay of the first stage;
receive a value indicative of a value at an output port of the at least one relay of the first stage; and
compare the received value to an expected value based on the monitored value of the control signal,
wherein to detect that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, the monitor circuit is configured to detect that the spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold based on the comparison.

8. The electronic device of claim 1 , wherein the monitor circuit is configured to:
determine a first time instance when a value of a control signal to at least one relay of the first stage changed;
determine a second time instance when a value at the output port of the at least one relay of the first stage changed;
determine a switch-over period of the at least one relay of the first stage based on a time difference between the first time instance and the second time instance;
determine whether the switch-over period is longer than a switch over period threshold; and
when the switch over period is longer than the switchover period threshold, output information indicating that the switch over period is longer than the switch over period threshold based on the determination.

9. The electronic device of claim 1 , wherein the power supply comprises a first power supply, the ATS comprises a first ATS, the multi-stage structure of relays comprises a first multi-stage structure of relays, and wherein the monitor circuit comprises a first monitor circuit, the electronic device further comprising:
a second power supply comprising:
a second ATS that includes a second multi-stage structure of relays; and
a second monitor circuit.

10. The electronic device of claim 1 , wherein the monitor circuit is configured to monitor at least one of a voltage and an impedance at the at least one of the output ports of the relays of the first stage.

11. The electronic device of claim 1 , wherein the power supply includes the ATS and the monitor circuit.

12. A power supply comprising:
an automatic transfer switch (ATS) that couples to a first alternating current (AC) power feed and a second AC power feed and comprises a multi-stage structure of relays, wherein a spacing between output ports of relays of a first stage of the multi-stage structure and a spacing between input ports of relays of a second stage of the multi-stage structure is less than a spacing threshold for preventing shock from coupling of the first AC power feed and the second AC power feed, wherein a sum of the spacing between output ports of one of the relays of the first stage and the spacing between input ports of one of the relays of the second stage is greater than or equal to the spacing threshold, and wherein the ATS is configured to output AC voltage from one of the first AC power feed and the second AC power feed, wherein the relays of the first stage are coupled to respective ones of the first and second AC power feeds, wherein the relays of the first stage comprise a first relay having one input port and two output ports, wherein the relays of the second stage comprise a second relay having two input ports and one output port, and wherein a first output ports of the output ports of the first relay is connected to at least one of the input ports of the second relay, and a second output port of the output ports of the first relay is not coupled to any of the relays of the second stage; and
a monitor circuit configured to monitor at least one of the output ports of the relays of the first stage, and detect, based on the monitoring, that a spacing between the first power feed and the second power feed, within the ATS, is less than the spacing threshold, wherein the monitor circuit is configure

Assignees

• Juniper Networks Inc

Inventors

• Owen David K

Classifications

• H02J9/068

  Electronic means for switching from one power supply to another power supply, e.g. to avoid parallel connection · CPC title

• H02J3/0073

  by providing alternative feeding paths when the main path fails · CPC title

• H02J3/00

  Circuit arrangements for AC mains or AC distribution networks · CPC title

• H02J2105/12

  supplying households or buildings · CPC title

• H02J2009/068

  Electricity · mapped topic