Control system for a transformer or reactor

Abstract

A universal control and diagnostic system for a transformer that may be retrofit with existing control and tap-changer equipment, the system providing for remote monitoring and control of the equipment and for measuring various criteria associated with the tap-changer to substantially minimize damage to the equipment during a maneuver and for substantially avoiding carbonization of a connected contact.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one advantageous embodiment of the present invention.

FIG. 2 is a block diagram according to FIG. 1, illustrating another advantageous embodiment of the present invention.

FIG. 3 is a block diagram according to FIG. 1, illustrating still another advantageous embodiment of the present invention.

FIG. 4A is a flow diagram of one advantageous embodiment of the present invention according to FIG. 1.

FIG. 4B is a continuation of the flow diagram according to FIG. 4A.

FIG. 5 is a flow diagram of one advantageous embodiment of the present invention according to FIG. 1.

Claims

1. A universal monitoring and diagnostic control system for a transformer or tap-changer comprising: an electronic board rack for receiving various electronic boards;a plurality of boards positioned in said electronic board rack, said plurality of boards selected to variously send and/or receive analog and/or digital signals to and from an existing transformer;said plurality of boards each having at least one channel;said analog and digital input and output signals directly coupled said control system via a network connection by means of said plurality of boards;said analog and digital input and output signals being individually configurable on each channel on each board.

2. The universal control system according to claim 1, wherein said plurality of boards comprises a main processor board and at least one peripheral board.

3. The universal control system according to claim 1, wherein said analog and digital input and output signals are sent and received via an interface converter from TCP/IP over said network.

4. The universal control system according to claim 3, wherein said network connection comprise a serial communication to Ethernet.

5. The universal control system according to claim 1, further comprising at least one sensor, positioned to detect temperature changes and a first threshold temperature value at which an alert is generated.

6. The universal control system according to claim 5, wherein said at least one sensor communicates with the universal control system via a Control Area Network bus.

7. The universal control system according to claim 5, further comprising a second threshold temperature value at which electrical power to the tap-changer is interrupted.

8. The universal control system according to claim 7, wherein first and second threshold temperature values are remotely set on an individual basis via said network.

9. The universal control system according to claim 5, wherein cooling control configurations of a cooler group for the transformer are made from a remote location via said network.

10. The universal control system according to claim 9, wherein multiple cooler groups are provided.

11. The universal control system according to claim 10, wherein a starustop for the cooler groups is set and controlled such that the least used cooler group starts at the first temperature threshold.

12. A diagnostic system for protecting a tap-changer comprising: a sensor, positioned to detect temperature changes;an initial measured temperature, indicating an initial temperature measured by said sensor prior to initiating a tap change;a calculated temperature value, calculated according to the particular tap change to take place;a threshold value determined based on said initial measured temperature and said calculated temperature value, at which an alert is generated;a second measured temperature indicating an actual temperature measured by said sensor after a tap change has been initiated;said alarm generated by the diagnostic system if said second measured temperature exceeds said threshold value.

13. The diagnostic system according to claim 12, further comprising a second threshold value above which, flow of electrical power through said tap-changer will be interrupted.

14. The diagnostic system according to claim 13, in which said second threshold value is higher than said first threshold value.

15. A diagnostic system for preventing degradation to electrical contacts in a tap-changer comprising: a contact measurement device for measuring a contact position;a contact signal generated by said contact measurement device, indicative of whether the contact is open or closed;a threshold time value related to a maximum amount of time that the contact may be in the contact position;a controller for receiving the contact signal and generating a closed time value based on the contact signal;said controller comparing the closed time value to said threshold time value to determine if the closed time value exceeds said threshold time value;a warning message generated by the diagnostic system indicating that said threshold time value has been exceeded.

16. The diagnostic system according to claim 15, further comprising a temperature sensor located in the vicinity of the contact to measure temperature and generate a temperature signal, said controller receiving the temperature signal and determining whether the warning message should be generated based on both the threshold time value and the temperature signal.

17. The diagnostic system according to claim 16, wherein the higher the temperature signal, the shorter the threshold time value must be for the system to generate the warning message.

18. The diagnostic system according to claim 15, further comprising a current sensor to measure current through the contact and generate a current signal, said controller receiving the current signal and determining whether the warning message should be generated based on both the threshold time value and the current signal.

19. The system according to claim 18, wherein the higher the current signal, the shorter the threshold time value must be for the system to generate the warning message.

20. The diagnostic system according to claim 15, further comprising: a temperature sensor located in the vicinity of the contact to measure temperature and generate a temperature signal;a current sensor to measure current through the contact and generate a current signal;said controller receiving the temperature signal and the current signal and determining whether the warning message should be generated based on, the threshold time value, the temperature signal, and the current signal.

21. The system according to claim 20, wherein the higher the temperature signal and/or the higher the current signal, the shorter the threshold time value must be for the system to generate the warning message.