JPH0824087B2 - Internal temperature measuring device for electrical equipment - Google Patents

Description

Detailed Description of the Invention

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal temperature measuring device for various electric equipment such as a substation device, and more particularly to an internal temperature measuring device of a type using a thermocouple for internal temperature measurement.

[0003]

2. Description of the Related Art Conventionally, in transformers, reactors and other substations, it has been required to measure and monitor temperature during operation. However, from the viewpoint of withstand voltage and measurement system reliability, the resistance Also, thermometers such as dial thermometers are only commonly used. Since such a temperature measuring resistor and a dial thermometer have drawbacks such as a complicated temperature sensing part, a larger size than a thermocouple, and a difficulty in closely adhering to a temperature measuring object, It is not used for temperature measurement and monitoring of specific points (including spot-like measurement points).

On the other hand, in recent years, thermocouples have attracted attention as a technique for measuring and monitoring the temperature at such a specific point in substation equipment, and a temperature measuring device using the thermocouple has been put into practical use. There is. In particular, the use of thermocouples is strongly desired for measuring the internal temperature of the cores of transformers and reactors. Such a thermocouple will be described below with reference to FIG.

The basic connection of a thermocouple is as shown in FIG.
It is composed of a thermocouple, a compensating lead wire, and a measuring instrument, and this structure is specified in JISC1602.
More specifically, the thermocouple terminal (compensation contact) and the reference contact (cold contact) of the measuring instrument are connected by a pair of compensating lead wires having thermoelectromotive force characteristics substantially equal to those of the thermocouple. The reason for using such a special compensating conductor is to avoid the inconvenience that occurs when using a normal conductor. In other words, if the two contacts are connected with a normal conductor, a different thermocouple will be formed due to the different materials and an error will occur.Therefore, in order to avoid such inconvenience, use a compensation conductor. are doing.

[0006]

However, when measuring and monitoring the temperature of a specific point inside the substation equipment,
In the case of applying an internal temperature measuring device using a thermocouple, there have been the following problems conventionally.

That is, the thermocouple has a simple structure and is an extremely small element, but as described above, it has a problem that an error occurs unless the compensation lead wire is used. In particular, in the case of intending to measure the heat generating portion of the contents contained in the container, the problem of temperature measurement error due to the structure of the conductor penetrating portion of the conductor, the problem that the selection of the compensating conductor is limited,
In addition, there was a problem of temperature measurement error due to the presence of the relay terminal box. These problems will be described below.

First, the container penetrating portion of the substation must maintain the pressure resistance of the internal and external pressure applied to the container (in the case of the substation, the internal pressure is 1 to 8 kgf / cm ² from the vacuum resistance).
Long-term reliability of 0 to 20 years is required. Therefore, it is rare to adopt a simple structure in which the thermocouple wire is provided with only a sealing structure and penetrates as it is, as a structure of the container penetrating part, and in general, a sufficiently reliable penetrating terminal part. Has been adopted. And, in such a highly reliable through-hole terminal part, since the terminal is made of a metal different from the compensating lead wire for the thermocouple, when the thermocouple-using internal temperature measuring device is applied. Causes a problem of temperature measurement error due to the inclusion of dissimilar metals.

Further, since the substation equipment is continuously operated outdoors for a long period of time, there is a regulation of withstand voltage and weather resistance on auxiliary equipment, relays and accessory wiring under the guidance of the Ministry of International Trade and Industry. It is also required to withstand the tension when running through the duct. Therefore, in the external wiring from the container penetration part of such substation equipment to the measuring instrument, it is necessary to fully comply with the above rules and requirements, so when applying an internal temperature measuring device using a thermocouple Causes a problem that the selection of the compensating lead wire for the thermocouple is extremely limited.

Further, the external wiring from the container penetrating portion to the measuring instrument as described above may have a length of several tens of meters, and in addition, in the case where the instruments are located away from the main body of the instrument. Generally, there is a relay terminal box in terms of construction and maintenance. Therefore, if an internal temperature measuring device using a thermocouple is to be applied when there is a relay terminal box as described above, a problem of temperature measurement error due to the interposition of the relay terminal box occurs.

The above-mentioned problems are not limited to the case of the substation equipment, but when the internal temperature measuring device using a thermocouple is applied as a device for measuring and monitoring the temperature during the operation of various electric equipment. Occurred similarly.

The present invention has been proposed in order to solve the problems of the prior art as described above, and an object thereof is to make it possible to sufficiently exhibit the characteristic advantages of thermocouples. To provide an excellent internal temperature measuring device for electric equipment, which is highly reliable and has a small error. A more specific purpose for achieving this purpose is the problem that has occurred in the past when the thermocouple was applied, that is, the problem of temperature measurement error due to the structure of the container penetrating part and the interposition of the relay terminal box, and the compensating lead wire. Is to solve the problem of limited selection.
Further, it is a special object of the present invention to provide an internal temperature measuring device which is optimal as a device for measuring and monitoring the temperature during operation of the substation equipment.

[Constitution of Invention]

[0014]

An internal temperature measuring device for an electric device according to the present invention is an internal temperature measuring device for an electric device for monitoring or measuring the temperature of a component contained in the container of the electric device. A first thermocouple, a comparative temperature-sensing element part, and a second thermocouple attached to the comparative temperature-sensing element part are provided, and a comparative temperature-sensing element part and a comparative temperature-sensing element part are provided outside the container. It is characterized in that a comparison / correction means for comparing the temperatures of the second thermocouple and correcting the temperature measurement value of the first thermocouple is provided.

Specifically, the type of the penetration terminal or the lead wire or other components in the wiring of the first thermocouple to the outside of the container, and the type of the penetration terminal or the lead wire or the like in the wiring of the second thermocouple to the outside of the container. Make the types of components the same.

[0016]

When actually measuring the internal temperature of the electric device by using the internal temperature measuring device of the electric device of the present invention, the first thermocouple is arranged at the temperature measurement target portion inside the container, and the inside of the container is measured. The temperature sensor for comparison and the second thermocouple are arranged at different positions, and temperature is measured for each. Then, an externally provided comparison / correction means compares the temperature measurement values of the comparative temperature-sensing element and the second thermocouple, and corrects the temperature measurement value of the first thermocouple to obtain the temperature measurement target. It is possible to obtain an accurate temperature measurement value of the part.

That is, in the present invention, the terminal of the container penetrating portion is formed of a metal of a different type from the compensating lead wire, a normal lead wire is used as the compensating lead wire, and a relay terminal box is provided in the middle of the external wiring. Even in the case where it is provided, since the temperature measurement error due to these influences can be easily corrected based on the comparison of the measured values as described above, the accurate temperature measurement value of the temperature measurement target portion can be easily obtained. .

Therefore, the terminal of the container penetrating portion is formed of a metal of a different kind from that of the compensating lead wire to improve its reliability, and the compensating lead wire also has a reliability that can be sufficiently adapted to various regulations and requirements. Since it is possible to use highly conductive ordinary conductors, it can contribute to the improvement of the reliability of the entire equipment.

The internal temperature measuring device of the present invention having the above-described operation is optimal as a device for measuring and monitoring the temperature during operation of the substation equipment.

[0020]

Embodiments of the internal temperature measuring device for electric equipment according to the present invention will be specifically described below with reference to FIGS. 1 and 2.

First, FIG. 1 is a diagram showing a first embodiment in which the present invention is applied to measure and monitor the internal temperature of a transformer or a reactor. As shown in this FIG.
The contents (heat-generating part) 1 of the transformer or the reactor are parts that generate heat during operation. This content (heat generating part) is housed in a container 2, and this container 2 is generally filled with an insulating medium such as insulating oil or insulating gas.

As shown in FIG. 1, a thermocouple (first thermocouple) 3 is inserted into an iron core of a transformer or a reactor and is located at an arbitrary temperature measurement target portion of a laminated portion of silicon steel sheets. ing. The correction thermocouple (second thermocouple) 4 is attached at the same location as the temperature sensing part of the temperature measuring resistor 5 for measuring the temperature of an insulating medium such as insulating oil or insulating gas, and therefore, the correction thermocouple The pair (second thermocouple) 4 and the temperature sensing part of the resistance temperature detector 5 are
Under the same temperature conditions. That is, in the present embodiment, the temperature measuring resistor 5 corresponds to the comparative temperature sensitive element portion in the present invention.

Further, the container penetrating portions 6 and 7 of the thermocouple (first thermocouple) 3 and the correction thermocouple (second thermocouple) 4 are
The terminals of the same type are used, and the wirings of the thermocouple (first thermocouple) 3 and the correction thermocouple (second thermocouple) 4 are made of a general material and have the same type of high reliability. Conductor 8
Is used. Similarly, the material of the temperature-measuring resistor (comparative temperature-sensitive element portion) 5 and its wiring are also made of general materials.
The conductor 9 having high reliability is used. The conductors 8 and 9 may be the same type or different types. Further, the conducting wires 8 and 9 are wired to a measuring instrument 10 provided outside the container.

The measuring device 10 is a device using a CPU, and includes a thermocouple (first thermocouple) 3, a correction thermocouple (second thermocouple) 4, and a temperature measuring resistor (comparative sensor). Temperature element part) 5
Each temperature measurement value from is input via the conductors 8 and 9, and after the correction / comparison processing according to the present invention, the corrected temperature measurement value of the thermocouple 3 parts and the temperature measurement value of the temperature measurement resistor 5 part are output. Is set to. That is, the CPU of the measuring instrument 10 corresponds to the comparing / correcting means in the present invention, and the temperature measurement value of the temperature measuring resistor (comparative temperature sensitive element) 5 and the correcting thermocouple (second thermocouple).
The comparison circuit for comparing the temperature measurement value of No. 4 and the correction circuit for correcting the temperature measurement value of the thermocouple (first thermocouple) 3 based on the comparison result are respectively incorporated.

When the internal temperature measuring device of the first embodiment having the above structure is used to measure the internal temperature of the iron core of the transformer or reactor, an accurate measured value output can be obtained. . The operation of the device according to the first embodiment will be described below.

First, since the temperature sensing parts of the correction thermocouple (second thermocouple) 4 and the temperature measuring resistance (comparative temperature sensing element part) 5 are mounted at the same location, an error may occur during signal transmission. If there is no cause that causes the above, the same temperature measurement value should be logically input to the measuring device 10. On the other hand, actually, in the connection of the correction thermocouple (second thermocouple) 4, an element different from the basic connection shown in FIG. 3, that is, a dissimilar metal and its contact point are interposed. Therefore, an error occurs in the temperature measurement value signal of the correction thermocouple (second thermocouple) 4 input to the measuring instrument 10 by that amount. On the other hand, temperature measuring resistance (comparative temperature sensing element) 5
Since the temperature measurement value signal of is input as a change in circuit resistance, it indicates a correct temperature measurement value. Therefore, only the difference between the temperature measured value of the temperature measuring resistor (comparative temperature sensitive element) 5 and the temperature measured value of the correction thermocouple (second thermocouple) 4 causes an error in the connection of the correction thermocouple 4. There will be. Further, this error amount also occurs in the thermocouple (first thermocouple) 3 as well, and the temperature measurement value corrected for this error indicates the correct temperature measurement value of the thermocouple 3. become.

That is, when the temperature measuring value signal from each part is input, the measuring device 10 firstly detects the temperature measuring resistance (comparative temperature sensitive element) by the comparison circuit built in the CPU based on the above theory. (Part) 5 and the correction thermocouple (second thermocouple) 4 are compared, and the difference (error) is calculated. After that, the measuring instrument 10 corrects the temperature measurement value of the thermocouple (first thermocouple) 3 based on the calculated difference (error amount) by the correction circuit incorporated in the CPU. By such comparison / correction processing, finally, two kinds of accurate temperature measurement values, that is, the corrected temperature measurement value of the thermocouple 3 parts (temperature measurement value of the temperature measurement target part) and the temperature measurement resistance 5 parts Of temperature (the temperature of the insulating medium in the container) is obtained and output to the outside of the measuring instrument 10. Although the first embodiment is configured to output such two kinds of values, the signal to be output is not limited to this, and other various signals may be output as necessary. Is possible as well.

As described above, in the first embodiment, the thermocouple (first thermocouple) 3, the correction thermocouple (second thermocouple) 4, the temperature measuring resistor (comparative temperature sensing element section). 5 and a simple configuration using the measuring device 10, it is possible to easily obtain an accurate temperature measurement value using a simple comparison / correction process. Further, in the first embodiment, since the temperature measuring resistor 5 for measuring the temperature of the insulating medium is also used as the comparative temperature sensitive element section, it is not necessary to provide a dedicated comparative temperature sensitive element section, There is also an advantage that the configuration is simplified by that much.

Next, FIG. 2 is a diagram showing a second embodiment in which the present invention is applied to measure and monitor the internal temperature of a transformer or a reactor, as in the first embodiment. . As shown in FIG. 2, this second embodiment is a container 2
As a means for measuring the temperature of the insulating medium therein, the temperature measuring resistor 5 of the first embodiment is used in place of the temperature measuring resistor 5, and the thermometer temperature sensing section 11 of the temperature measuring dial thermometer 12 is used. Is the same as that of the first embodiment.

Since the dial thermometer 12 used in this second embodiment generally operates in a sealed liquid or gas, it shows an accurate temperature value independent of other factors. In this case, although FIG. 2 shows a case where the thermometer temperature sensing unit 11 of the dial thermometer 12 is not provided with a protection tube, it is of course possible to provide the thermometer temperature sensing section 11 inside or outside the protection tube. Moreover, an accurate temperature value can be obtained. Therefore, in the second embodiment of FIG. 2 in which such a dial thermometer 12 is used, the correction thermocouple (second thermocouple) 4 is set with the indicated value of the dial thermometer 12 as a correct value. The error is calculated and the temperature measurement value of the thermocouple (first thermocouple) 3 is corrected. Also in the second embodiment, it is possible to obtain the same effects as the first embodiment.

The present invention is not limited to the first and second embodiments described above. For example, the structure of the temperature sensing element for comparison can be appropriately selected, and a special feeling for comparison. A configuration in which the temperature element section is provided is also possible. On the other hand, the electric device targeted for temperature measurement and monitoring is not limited to a transformer or a reactor, and the present invention is applicable to measurement and monitoring of internal temperature in various electric devices in general, and similarly, An excellent effect can be obtained.

[0032]

As described above, according to the present invention, the first thermocouple, the comparative temperature-sensitive element portion, and the second thermoelectric element attached to the comparative temperature-sensitive element portion are provided in the container. Comparing the temperature of the first thermocouple by compensating the temperature of the comparative thermosensitive element and the temperature of the second thermocouple outside the container by providing a pair.
With a simple configuration of providing a correction means, the characteristic advantages of the thermocouple can be fully exerted, so that an excellent internal temperature measuring device for electric equipment with high reliability and little error is provided. be able to.

That is, in the present invention, the problems that have conventionally occurred when the thermocouple is applied, that is, the temperature measurement error based on the structure of the container penetrating portion, the interposition of the relay terminal box, and the selection of the compensating lead wire are easily corrected. Therefore, the accurate temperature measurement value of the temperature measurement target portion can be easily obtained. Also,
Since these constituent elements can be configured regardless of errors, there is also an advantage that the reliability of the entire equipment can be improved. The internal temperature measuring device of the present invention having such excellent advantages is optimal as a device for measuring and monitoring the temperature during operation of the substation equipment.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an internal temperature measuring device for an electric device according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of an internal temperature measuring device for an electric device according to the present invention.

FIG. 3 is a basic connection diagram showing a conventional thermocouple usage method.

[Explanation of symbols]

 1 Contents (heating part) 2 Container 3 Thermocouple (1st thermocouple) 4 Correction thermocouple (2nd thermocouple) 5 Resistance temperature detector (comparative temperature sensing element) 6 (Thermocouple) container penetration Part 7 (compensation thermocouple) container penetration part 8 (thermocouple and correction thermocouple) lead wire 9 (temperature measuring resistance) lead wire 10 measuring instrument (comparison / correction means) 11 thermometer temperature sensing part (for comparison) Temperature sensing element) 12 dial thermometer

Claims (2)

[Claims] 1. An internal temperature measuring device for an electric device for monitoring or measuring the temperature of a component contained in the container of the electric device, comprising: a first thermocouple and a comparative temperature-sensing element in the container. And a second thermocouple attached to the comparative temperature-sensitive element section are provided, and the temperatures of the comparative temperature-sensitive element section and the second thermocouple are compared outside the container to determine the first thermocouple. An internal temperature measuring device for an electric device, comprising a comparison / correction means for correcting the temperature measured value of a thermocouple. 2. A type of a through terminal or a lead wire and other constituent elements in the wiring of the first thermocouple to the outside of the container;
2. The internal temperature measuring device for an electric device according to claim 1, wherein the type of the through terminal, the lead wire, and other components in the wiring of the thermocouple to the outside of the container is the same.