JPH04160369A - Transformer - Google Patents

Abstract

PURPOSE:To maintain the inner pressure of a measuring instrument constant and decrease its output error by providing pressure regulating means for keeping the inner pressure of the measuring instrument constant on the basis of the detection data of inner pressure detecting means. CONSTITUTION:A gas pressure and a gas temperature inside a measuring instrument are detected by a pressure sensor 23 and a temperature sensor 24, respectively, which are attached to a lower tank 3 and a pressure regulating valve 21 and a pump 22 are regulated so that the gas pressure and the gas temperature inside the measuring instrument can be kept always constant. Since, as a result, the gas pressure and temperature of a spatial transmission portion in a power detecting unit 5 can be also kept constant, a light transmission state can be kept to a constant condition and therefore power measurement error due to a change in the conditions in the measuring instrument can be prevented from being generated. Thus, the power measurement error is prevented from being generated whereby measurement accuracy can be sharply improved.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a power transformer that performs measurement using optical principles, and particularly relates to a transformer that reduces measurement errors thereof. It is related to.

(Conventional technology) Conventionally, in transformers, voltage and voltage are measured using electromagnetic induction phenomena by placing an iron core in the main circuit to be measured.
It was measuring the current. In addition, in recent years, by utilizing optical principles without using the above-mentioned iron core, power loss can be reduced.
Transformers that require less installation space are being developed.

An example of such a transformer is shown in FIG. That is, the transformer includes an upper tank 1, a support device 2, and a lower tank 3. The upper tank 1 is provided with a conductor 4 for energizing the main circuit and a power detection section 5. Further, an optical cable 6 is connected to the power detection unit 5, and this optical cable 6 passes through the support device 2 and is connected to an airtight terminal 8 of an optical cable terminal box 7 provided on the side of the lower tank 3. . Furthermore, an optical cable 9 is connected to the airtight terminal 8, and is connected to a measuring device 10 provided at a location away from the transformer. Note that gas is sealed inside the transformer in order to maintain insulation and prevent contamination.

In the transformer configured in this manner, the power to be measured is measured in the following manner. That is, the optical signal generated by the measuring device 10 passes through the optical cable 9, the airtight terminal 8, and the optical cable 6, and reaches the power detection section 5. Then,
In the power detection unit 5, the optical signal changes depending on the degree of power of the conductor 4 for energizing the main circuit, and the changed optical signal is sent to the measuring device 10 again through a reverse path. Then, in the measuring device 10, the power of the main circuit is measured by comparing the transmitted optical signal and the returned optical signal.

Note that the power detection section 5 is configured as shown in FIG. That is, a plurality of optical elements 11a, llb, l
lc is attached to a base 12, and the conductor 4 is disposed through the center of the base 12. Furthermore, a receptacle 13 for connecting the optical cable 6 is attached to the lower part of the base 12. Furthermore, the same gas as the upper tank and the lower tank is sealed in the power detection unit 5 in order to prevent dew condensation and clouding of the optical elements. Then, the optical signal is transmitted through these optical elements 11a to 1.
It is configured to perform spatial transmission between 1c and 1c.

(Problems to be Solved by the Invention) However, the conventional transformer as described above has the following problems to be solved. That is, in order to spatially transmit an optical signal, the molecular density on the optical signal transmission path changes due to pressure changes within the container, and as the molecular density increases, the resistance to the optical signal increases and the optical signal is attenuated. This internal pressure easily changes depending on the external conditions of the transformer (for example, sunlight, snowfall, wind, amount of current, etc.). Despite this, conventional transformers were only equipped with a device to monitor the pressure of the gas sealed inside, so there was no way to deal with changes in pressure due to external conditions. , the attenuation and change of the optical signal could not be prevented. Therefore, errors were likely to occur when measuring power.

The present invention was proposed in order to eliminate the above-mentioned □disadvantages□.The purpose of the present invention is to maintain the internal pressure of the transformer constant and reduce the output error of the transformer. Our goal is to provide high quality transformers.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an internal pressure detection means for detecting pressure inside the transformer, and an internal pressure detection means for detecting pressure inside the transformer in a transformer that performs measurement using an optical principle. , and pressure adjustment means for keeping the internal pressure of the transformer constant. - (Function) In the transformer of the present invention, the internal pressure of the transformer can be kept constant based on the detection data of the internal pressure detection means, thereby preventing attenuation and changes in the optical signal due to changes in the internal pressure. Therefore, accurate power measurement can be performed at all times.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIG. Incidentally, the same members as those of the conventional type shown in FIG. 4 are given the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG. 1, a pressure adjustment chamber 20 is provided on the side of the lower tank 3 as a pressure adjustment means, and a pressure adjustment chamber 20 is provided between the lower tank cutout 3 and the pressure adjustment chamber 20. A pressure regulating valve 21 and a pump 22 are installed to regulate the pressure inside the tank. Furthermore, a pressure sensor 2, which is an internal pressure detection means, is installed at an appropriate location in the lower tank 3.
3 and a temperature sensor 24 are attached, and the pressure regulating valve 21 and pump 22 can be adjusted based on the detection data by these sensors so that the pressure inside the container can always be maintained in a constant state. It is composed of

In the transformer of this embodiment, the upper tank 1, the lower tank 3, and the power detection unit 5 are all in the same gas compartment, so even if the sensor is installed only in the lower tank 3, the upper Gas pressure and gas temperature in the tank 1 and the power detection unit 5 can be detected.

In the transformer of this embodiment having such a configuration, the pressure sensor 23 and temperature sensor 24 attached to the lower tank 3 detect the gas pressure and gas temperature inside the transformer, and keep these constant at all times. The pressure regulating valve 21 and pump 22 are adjusted so that the As a result, the gas pressure and gas temperature of the space transmission section inside the power detection section 5 can also be maintained constant, so the optical transmission state can be maintained at a constant condition, and power measurement errors due to state changes inside the transformer can be maintained. can be prevented.

In this way, according to this embodiment, a sensor is provided to detect the gas pressure and gas temperature inside the transformer, and the internal gas pressure is adjusted based on the detected data, thereby preventing power measurement errors. This can significantly improve measurement accuracy.

Note that the present invention is not limited to the above-described embodiment, and the pressure sensor 23 and temperature sensor 24 may be installed in the upper tank 1, as shown in FIG. Also in this case, the configuration is such that detection data from both sensors is sent to the pressure regulating valve 21 and the pump 22. Moreover, the number of installed pressure sensors and temperature sensors may be plural. Furthermore, the present invention can also be applied to a gas insulated switchgear as shown in FIG. That is, a conductor 31 and a power detection section 32 are arranged inside the tank 30 that constitutes the gas insulated switchgear, and an optical cable 34 is connected between the power detection section 32 and the airtight terminal 33 provided in the tank 30. connected by. Further, a pressure sensor 23 and a temperature sensor 24 are attached to the tank 30, a pressure adjustment chamber 20 is provided adjacent to the tank 30, and a pressure adjustment valve 21 and a pump 22 are installed between the tank 30 and the tank 30. There is. Note that the tank 30 and the power detection unit 3
2 is filled with SF6 gas.

In this case as well, the state of the SF6 gas inside the tank 30 can be kept constant by adjusting the pressure regulating valve 21 and the pump 22 based on the detection data of both sensors as in the above embodiment. It is possible to prevent a change in the state of the optical signal path such as the power detection unit 32, and to prevent power measurement errors from occurring. In addition, by optimizing the type and mounting position of the temperature sensor 24, it is possible to detect the temperature of the conductor, so by combining it with current measurement, it is also possible to detect abnormality in conductor energization.

[Effects of the Invention] As described above, according to the present invention, there are provided internal pressure detection means for detecting the pressure inside the transformer, and pressure adjustment means for keeping the internal pressure of the transformer constant based on the detected data. By including the following, it is possible to provide a highly accurate transformer that can reduce output errors of the transformer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the transformer of the present invention, and FIG.
3 is a sectional view showing another embodiment of the present invention, FIG. 4 is a sectional view showing an example of a conventional transformer, and FIG. 5 is a schematic diagram showing another embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of a detection section. DESCRIPTION OF SYMBOLS 1... Upper tank, 2... Support device, 3... Lower tank, 4... Conductor, 5... Power detection part, 6...
Optical cable, 7... Optical cable terminal box, 8... Airtight terminal, 9... Optical cable, 10... Measuring device, 11
... Optical element, 12 ... Base, 13 ... Receptacle, 20 ... Pressure adjustment chamber, 21 ... Pressure adjustment valve, 22 ... Pump, 23 ... Pressure sensor, 24
...Temperature sensor, 30...Tank, 31...Conductor, 32...Power detection unit, 33...Airtight terminal, 34...
・Optical cable.

Claims (1)

[Claims] In a transformer that performs measurement using optical principles, it is equipped with an internal pressure detection means for detecting the pressure inside the transformer, and a pressure adjustment means for keeping the internal pressure of the transformer constant based on this detection data. A transformer featuring: