TEMPERATURE MEASUREMENT IN SWITCHGEAR STATIONS

Abstract

The invention relates to a device for measuring temperature in a high-voltage portion of a switchgear station, characterised in that it comprises: at least one temperature sensor (21, 22, 23, 24) located at a point on the high-voltage portion of which the temperature is to be monitored, at least one antenna (25) connected to the at least one temperature sensor, a control module (26) located in a low-voltage portion of the switchgear station, and at least one antenna (27) connected to the control module. The at least one temperature sensor (21, 22, 23, 24) is suitable for transmitting a signal representative of a temperature measurement and the control module (26) is suitable for receiving the representative signal, via the antennas, and for processing said signal in order to produce a message.

Claims

1. Disconnector in a high-voltage switchgear station of the AIS type, comprising: a high-voltage portion comprising contacts, a low-voltage portion, separated from the high-voltage portion by air, at least one temperature sensor located in the high-voltage portion, on the contacts and being suitable to measure the temperature of the point where it is located, at least one antenna connected to the at least one temperature sensor, a control module located in a low-voltage portion of the switchgear station, at least one antenna connected to the control module, the at least one temperature sensor being suitable for transmitting a signal representative of the temperature measurement and the control module being suitable for receiving the representative signal, via the antennas, and processing it in order to produce a message.

2. Disconnector according to claim 1, wherein the at least one temperature sensor is a passive sensor.

3. Disconnector according to claim 1, wherein the at least one temperature sensor is powered by the control module via the antennas.

4. Disconnector according to claim 1, wherein the control module is suitable to take into account the time constant τ of the disconnector.

5. Temperature measurement method in a disconnector in a high-voltage switchgear station of the AIS type, the disconnector comprising a high-voltage portion comprising contacts and a low-voltage portion separated from the high-voltage portion by air, the method comprising steps of: temperature measurement by at least one temperature sensor located on the contacts of the disconnector, transmission of a signal representative of the temperature measurement by the at least one temperature sensor via at least one antenna connected to the at least one temperature sensor, reception of the representative signal by a control module located in a low-voltage portion of the switchgear station, via at least one antenna connected to the control module, processing of the representative signal by the control module in order to produce a message.

6. Computer program comprising instructions for carrying out the steps of the method according to claim 5 when said program is run by a computer.

7. Computer-readable recording medium, on which a computer program is recorded, including instructions for carrying out the steps of the method according to claim 5.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other features and advantages will appear in the following description of a preferred embodiment provided as a non-limiting example, described in reference to the figures, wherein:

[0035] FIG. 1 shows a temperature measurement device in a switchgear station, according to an embodiment of the present invention,

[0036] FIG. 2 shows a method for temperature measurement in a switchgear station, according to an embodiment of the present invention,

[0037] FIG. 3 shows a control module of a temperature measurement device in a switchgear station, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0038] According to a preferred embodiment shown in FIG. 1, a disconnector 1 equipped with a temperature measurement device is schematically shown.

[0039] The disconnector and the operation thereof are known to a person skilled in the art and are not described here. The disconnector is classically one of the elements of a switchgear station. For example, it is sought to measure the temperature of four hot spots of the disconnector 1, which are the two terminals 11 and 12, the contacts 13 and the main cutter 14.

[0040] These elements are in a high-voltage portion of the disconnector. The disconnector also comprises a low-voltage portion, separated from the high-voltage portion by air. These three portions (high-voltage, air and low-voltage) are separated schematically by dotted lines in FIG. 1.

[0041] The temperature measurement device first comprises a set of temperature sensors. The temperature sensors are arranged near hot spots of the disconnector 1 to be monitored.

[0042] According to the example of an embodiment of the invention shown in FIG. 1, the disconnector 1 is equipped with four temperature sensors. Two sensors 21 and 22 are near terminals 11 and 12 of the disconnector. One sensor 23 is near contacts 13, and a last sensor 24 is near the main cutter 14. Of course, the number of temperature sensors is adapted as needed and may be much higher. For example, several hundred temperature sensors may be provided in a switchgear station.

[0043] Sensors 21 to 24 are connected by wire to an antenna 25. The antenna 25 is preferably shielded so as to be protected from electromagnetic fields normally existing in the disconnector due to currents passing through it. Thus, there is no disturbance on the radio transmission in the range of 500 kHz to 1 MHz due to electromagnetic interference. Similarly, the various electronic circuits that process the electrical signals exchanged are placed in shielded boxes so as also to be protected from the electromagnetic fields.

[0044] An antenna may be connected to a single sensor or to a plurality of sensors, for example ten. Similarly a plurality of antennas similar to antenna 25, each connected to one or more sensors, may be provided in the high-voltage portion of the disconnector.

[0045] In the low-voltage portion of the disconnector 1, a control module 26 is connected to an antenna 27.

[0046] The temperature sensors 21 to 24 measure the temperature of the point where they are respectively placed. The quantities measured are sent by radio to the control module 26.

[0047] The sensors 21 to 24 are passive and the energy necessary for them to perform a measurement is electromagnetic energy transmitted from the control module 26 via antenna 27 and received via antenna 25. This energy is stored in adapted circuits of the sensors so as to be used by the sensors to measure the temperature and transmit a signal via antenna 25.

[0048] The module 26 processes the data that it receives to determine whether or not the temperatures in the high-voltage portion of the disconnector 1 are normal. This determination is, for example, performed by comparing the measured temperatures with nominal temperatures.

[0049] The module 26 may also take into account information provided by other sensors, for example a temperature sensor located at the module 26 itself, or a temperature sensor located outside the disconnector 1. The module 26 may also take into account other characteristics of the disconnector 1, for example its time constant, an overload margin, or maintenance constraints.

[0050] It is thus possible to define and monitor overload parameters of the disconnector. For example, at each measurement time, and for each measurement point, it is possible to determine the difference ΔT between the measured temperature and a limit temperature.

[0051] It is also possible to take into account the time constant τ of the disconnector. Thus, the maximum current I.sub.max that may be tolerated by the disconnector is given by the formula:

I.sub.max=K.Math.e.sup.−t/τ

[0052] where K is a constant.

[0053] This formula makes it possible to verify the time constant τ in order either to correct the formula above if there are slight variations in the time constant, or to generate an alert if the value of the time constant varies significantly.

[0054] On the basis of the result of the processing performed by the module 26 on the temperatures measured, the module 26 produces a message intended for supervision of the disconnector 1 or more generally the switchgear station.

[0055] The message may take different forms and contain more or less information. For example, it is a visual or sound alarm if the temperature is too high. This alarm may also include information on an estimated admissible overload period.

[0056] The message may also be information indicating that the disconnector requires maintenance, for example if the temperatures measured are high while the currents are normal.

[0057] FIG. 2 shows a temperature measurement method implemented by the device described above. The method comprises steps E1 to E5.

[0058] Step E1 is the sending of a measurement control from the control module 26 to the temperature sensors 21 to 24, by radio. Alternatively, the measurement control is selective and controls only the selected sensor(s). The measurement control is, for example, periodic. The period may be 1 minute.

[0059] It is noted that the energy needed for the sensors 21 to 24 to operate is transmitted from the control module 26 by radio. The sending of energy may or may not be associated with the sending of the measurement control.

[0060] In the next step E2, the temperature sensors 21 to 24 receive the measurement control and measure the temperature of the point where they are respectively placed. A signal representative of the temperature measurement is formed and the next step E3 is the transmission of the representative signal by the temperature sensors via antenna 25 to the control module 26. The quantities measured are thus sent by radio to the control module 26.

[0061] In the next step E4, the module 26 receives the signal transmitted via antenna 27. The module 26 processes the measurement data in order to determine whether or not the temperatures measured in the high-voltage portion of the disconnector are normal. This determination is, for example, performed by comparing measured temperatures with nominal temperatures.

[0062] It is possible to define and monitor overload parameters of the disconnector. For example, at each measurement time, and for each measurement point, it is possible to determine the difference ΔT between the measured temperature and a limit temperature.

[0063] It is also possible to take into account the time constant τ of the disconnector. Thus, the maximum current I.sub.max that may be tolerated by the disconnector is given by the formula:

I.sub.max=K.Math.e.sup.−t/τ

[0064] where K is a constant.

[0065] This formula makes it possible to verify the time constant τ in order either to correct the formula above if there are slight variations in the time constant, or to generate an alert if the time constant varies significantly.

[0066] In the next step E5, the module 26 produces a message intended for supervision of the disconnector. The message is dependent upon the result of the processing performed by the module 26 on the measured temperatures. The message is transmitted to a human-machine interface.

[0067] The process according to the invention is implemented by a dedicated integrated circuit or by programmable processors, or in the form of a computer program stored in the memory of a computer.

[0068] Thus, FIG. 3 shows a particular embodiment of the control module 26 according to the invention.

[0069] This module has the general structure of a computer. It comprises in particular a processor 100 running a computer program implementing the method according to the invention, a memory 101, an input interface 102 and an output interface 103.

[0070] These different elements are classically connected by a bus.

[0071] The input interface 102 is connected to the antenna 27 and is intended to receive the data to be processed.

[0072] The processor 100 performs the processing operations described above. These processing operations are performed in the form of computer program code instructions that are stored by the memory 101 before being executed by processor 100.

[0073] The memory 101 may also store the results of the processing operations performed.

[0074] The output interface 103 provides the measured temperature processing results.