CONTACTOR HEALTH MONITORING SYSTEMS AND METHODS

• US 20180233884A1
• Filed: 02/10/2017
• Published: 08/16/2018
• Est. Priority Date: 02/10/2017
• Status: Active Grant

• Current Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Joshi, Ashutosh, Pal, Debabrata
• Granted Patent: US 10,177,542 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 31/008 on air- or spacecraft, railway rolling stock or sea-going vessels
• CPC Class Codes: G01R 31/3277 of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
• CPC Class Codes: H01H 11/0062 Testing or measuring non-electrical properties of switches, e.g. contact velocity monitoring contacts H01H1/0015; monitoring gas density H01H33/563; monitoring vacuum H01H33/668; calibrating H01H69/01; adjusting H01H71/74; testing of electrical properties G01R31/333
• CPC Class Codes: H01H 2011/0068 measuring the temperature of the switch or parts thereof
• CPC Class Codes: H01H 2071/044 Monitoring, detection or measuring systems to establish the end of life of the switching device, can also contain other on-line monitoring systems, e.g. for detecting mechanical failures
• CPC Class Codes: H01H 71/08 Terminals; Connections
• CPC Class Codes: H01H 71/125 characterised by sensing elements, e.g. current transformers for differential protection H01H83/144
• CPC Class Codes: H01H 9/0271 structurally combining a switch and an electronic component for relays H01H50/021
• CPC Class Codes: H02B 1/04 Mounting thereon of switches or of other devices in general, the switch or device having, or being without, casing
• CPC Class Codes: H02B 1/24 Circuit arrangements for boards or switchyards

Abstract

A contactor arrangement includes a post, a fastener and a temperature sensor. The post defines a post axis. The fastener is fixed to the post along the post axis. The temperature sensor is in thermal communication with the contactor conductor and post through the fastener and is electrically insulated from the post for monitoring resistive heat generation in a contactor fixed to the post by the fastener.

Claims

1. A contactor arrangement, comprising:

a post defining a post axis;

a fastener configured to electrically attach a conductor of a contactor to the post, the fastener fixed to the post along the post axis; and

a temperature sensor positioned and configured to be in thermal communication with the conductor, the sensor in thermal communication with the post through the fastener and electrically insulated from the post.

2. The arrangement as recited in claim 1, wherein the sensor is bonded to the fastener along the post axis by an epoxy joint.

3. The arrangement as recited in claim 1, wherein the fastener has a head and a threaded segment arranged at opposite ends, the threaded segment seated in the post, the head protruding from an end of the post and seating the sensor.

4. The arrangement as recited in claim 3, wherein the head has cavity, the sensor being potted within the cavity by an epoxy.

5. The arrangement as recited in claim 3, further comprising a wave washer seated between the head of the fastener and the post.

6. The arrangement as recited in claim 3, wherein the head includes a plurality of flats arranged circumferentially about the fastener for preloading the fastener.

7. The arrangement as recited in claim 1, further comprising washer with a radially extending tab seated along a post axis defined by the post between the fastener and the post.

9. The arrangement as recited in claim 1, further comprising a bus bar fixed to an end of the post opposite the conductor.

10. The arrangement as recited in claim 1, wherein the sensor includes one or more of a thermistor, a thermocouple, and a semiconductor device.

8. The arrangement as recited in claim 8, wherein the sensor is bonded to the tab by an epoxy joint.

11. A power distribution panel, comprising:

a contactor arrangement including;

a post defining a post axis;

a fastener configured to electrically attach a conductor of a contactor to the post, the fastener fixed to the post along the post axis and; and

a temperature sensor positioned and configured to be in thermal communication with the conductor, the sensor in thermal communication with the post through the fastener and electrically insulated from the post;

a contactor fixed between the fastener and an end of the post by the conductor of the contactor;

a bus bar fixed to an end of the post opposite the conductor; and

a control module in communication with the contactor, the temperature sensor and the power distribution panel.

12. The power distribution panel as recited in claim 11, further comprising a contactor temperature lead connecting the control module to the sensor to provide temperature information to the control module,

13. The power distribution panel as recited in claim 11, further comprising a load lead connected to the bus bar and arranged to provide a signal indicative of magnitude of current flowing through the bus bar.

14. The power distribution panel as recited in claim 11, further comprising a panel temperature lead connecting the control module to provide a signal indicative of temperature of the power distribution panel ambient environment.

15. The power distribution panel as recited in claim 11, wherein the control module is a bus power control unit disposed in communication with a memory having instructions recorded thereon that cause the control module to:

receive a contactor health signal;

determine contactor temperature;

compare the contactor temperature to a predetermined value; and

monitor the contactor temperature when the contactor is determined healthy, and flag the contactor for service when the contactor is determined to be unhealthy.

16. The power distribution panel as recited in claim 15, wherein the memory has recorded thereon predetermined values includes a warning limit, a design limit that is higher than the warning limit, and a specification limit that is higher than the design limit.

17. A method of monitoring health of a contactor, comprising:

monitoring ambient temperature around the contactor;

monitoring current passing across the contactor;

monitoring temperature of the contactor while current is passing thereacross; and

determining a health state of the contactor based on empirical data gathered on similar contactors under similar conditions of ambient temperature and current load.

18. The method as recited in claim 17, wherein determining a health state includes comparing the temperature of the contactor with a specification limit, and further comprising flagging the contactor for service if the temperature of the contactor exceeds the specification limit.

19. The method as recited in claim 17, wherein determining a health state includes comparing the temperature of the contactor with a design limit, and further comprising flagging the contactor as degraded if the temperature of the contactor exceeds the design limit.

20. The method as recited in claim 17, wherein determining a health state includes comparing the temperature of the contactor with a warning limit, and further comprising flagging the contactor for service if the temperature of the contactor exceeds the warning limit.