JPH03197877A - Partial discharge detecting device in electrical equipment - Google Patents

Abstract

PURPOSE:To surely detect partial discharge without being affected by disturbing light by providing a means which generates an alarm signal when photodetected light contains an about <=300nm wavelength component. CONSTITUTION:If the partial discharge occurs to the winding of a transformer main body 2, light with wavelength ranging from about >=180nm ultraviolet rays to infrared rays is included. When the light emitted by the partial discharge passes through an ultraviolet-ray transmission window 5, light with >=300nm wavelength is cut off, so ultraviolet rays with 180 - 300nm wavelength reaches an optical sensor 7 eventually. Consequently, a sensor driving circuit 8 outputs a photodetection signal according to the photodetection of the optical sensor 7 and a partial discharge detecting circuit 9 decides that the partial discharge occurs by the photodetection signal supplied from the sensor driving circuit 8 to turn on an indicating lamp. Therefore, the occurrence of the partial discharge can be decided. Ultraviolet rays of the sunshine which have <=300nm wavelength are absorbed by the atmosphere and do not reach the ground. The occurrence of the partial discharge can be detected without being affected by the sunshine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a partial discharge detection device that detects partial discharge using light generated in the windings of electrical equipment.

(Prior art) For example, in a transformer filled with sulfur hexafluoride gas (SF6), solid insulation is provided by an organic polymer material such as polyethylene terephthalate, and gas insulation is provided by 5F (i). However, with windings using such organic polymer materials, partial discharge may occur in the windings and the insulation performance may deteriorate, so care must be taken to prevent partial discharges from occurring in the windings as much as possible. Consideration has been taken in the design.

However, despite the above-described design to suppress the occurrence of partial discharge, partial discharge may occur in the windings due to long-term operation. When partial discharge occurs in this manner, it is desirable to prevent dielectric breakdown of the transformer by promptly addressing the deterioration of the insulation performance of the winding. For this reason, devices for detecting partial discharges occurring in the windings of electrical equipment have been proposed, and one example is a device for detecting light generated due to partial discharges. That is, an optical sensor is provided to receive light generated due to partial discharge, and partial discharge is detected based on the light reception state of the sensor.

(Problem to be Solved by the Invention) However, in the conventional example described above, the occurrence of partial discharge is detected based on the level of light received by the optical sensor. It may receive disturbance light such as waves, noise, sunlight, etc.
In this case, there is a risk that partial discharge may be erroneously detected based on the light receiving state of the optical sensor even though no partial discharge has occurred.

The present invention has been made in view of the above circumstances, and its purpose is to detect light generated due to partial discharge, but it is also possible to reliably detect partial discharge without being affected by ambient light. The purpose of the present invention is to provide a partial discharge detection device for electrical equipment that can be used.

[Structure of the Invention] (Means for Solving the Problems) The present invention is arranged so as to receive light accompanying partial discharge generated in the windings of electrical equipment, and has a reception wavelength of about 300 nm.
This device is equipped with a detection means that generates an alarm signal when the following wavelength components are included.

(Function) When partial discharge occurs in the windings of electrical equipment, light is emitted along with the partial discharge. Then, the detection means receives the light accompanying the partial discharge and determines whether or not it contains a wavelength component of about 3° Onm or less, and when it is determined that it contains a wavelength component, it issues an alarm signal. Occur. Therefore, the occurrence of partial discharge can be confirmed by outputting an alarm signal from the detection means.

At this time, even if the detection means receives disturbance light such as sunlight, the disturbance light contains almost no wavelength component of 300 rv or less, so the detection means converts the disturbance light into a partial discharge. There will be no false detection as accompanying light.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a tank 1 houses a transformer main body 2, which is an electrical device. The transformer main body 2 is formed by winding a winding 3, which is solid-insulated with polyethylene terephthalate, for example, around an iron core 4. tank 1
The inside is filled with SF8, and the filling causes the winding 3
is gas insulated. Further, an ultraviolet transmitting window 5 is provided in the tank 1 at a position facing the winding 3 of the transformer body 2. The ultraviolet light transmitting window 5 is set to specifically transmit light having a wavelength of 300 nm or less in the ultraviolet region.

Now, an optical sensor 7 is placed opposite the ultraviolet light transmitting window 5. The optical sensor 7 outputs a light reception signal to the sensor drive circuit 8, and the sensor drive circuit 8 outputs a light reception signal indicating the wavelength component of the light received by the optical sensor 7 and the level of the light reception. The partial discharge detection circuit 9 detects that the light reception signal sent from the sensor drive circuit 8 has a wavelength component of 30.
For example, an indicator light is turned on when it is determined that ultraviolet rays of On+m or less are shown at a predetermined light reception level or higher. Here, the optical sensor 7, the sensor drive circuit 8, and the partial discharge detection circuit 9 constitute a detection means 10.

Next, the operation of the above configuration will be explained with reference to FIG. 2 as well.

When a partial discharge occurs in the winding of the transformer body 2, light is emitted along with the partial discharge. Here, the relationship between the wavelength components of the light (wavelength components) and their reception levels is shown by the broken line in Figure 2.As shown in this figure, the light emitted along with the partial discharges It contains light with a wide range of wavelengths from ultraviolet to infrared with wavelengths of about 180 nm or more.

Therefore, when the light emitted due to the partial discharge passes through the ultraviolet transmitting window 5, the light with a wavelength of 300 rv or more is blocked, so that the optical sensor 7 has a wavelength of 18 On- or more to 300 n- UV rays reach up to. As a result, based on the light received by the optical sensor 7, the sensor drive circuit 8 outputs a light reception signal indicating that the wavelength of the received light is 300 nm or less. It determines that a partial discharge has occurred based on the light reception signal and lights up the indicator light. Therefore, by checking whether the indicator lamp of the partial discharge detection circuit 9 is lit, it is possible to determine whether a partial discharge has occurred.

Now, when the optical sensor 7 is provided in an electrical device such as a molded transformer that does not have a light shielding member such as a tank, sunlight may be received.

In such a case, since sunlight also contains ultraviolet rays, there is a risk that the partial discharge detection circuit 9 may erroneously detect that a partial discharge has occurred based on the light reception signal.

However, as can be seen from the solid line in Figure 2, which shows the relationship between the wavelength components of sunlight that reaches the ground and its received light intensity, most of the sunlight that reaches the ground contains ultraviolet rays with wavelengths of 300 nm or less. Not included. This is because ultraviolet rays contained in sunlight with a wavelength of 300 rv or less are absorbed by the atmosphere as they travel through the atmosphere and do not reach the ground. Therefore, even if the optical sensor 7 receives sunlight, unlike the conventional example in which the occurrence of partial discharge is determined only based on the light receiving state of the optical sensor, the received light contains ultraviolet rays with a wavelength of 3000- or less. By determining whether or not it is included, it is possible to detect the occurrence of partial discharge without being affected by sunlight. This results in
There is no need to provide a special shielding plate to prevent the optical sensor 7 from receiving sunlight.

Note that an optical filter that allows only ultraviolet light having a wavelength of 300 rv or less to pass may be placed in front of the optical sensor 7, and the optical sensor 7 may receive the light through the optical filter. In this case, the optical sensor 7 can only receive ultraviolet light with a wavelength of 30 On11 or less, so it can reliably receive light due to partial discharge that includes ultraviolet light with a wavelength of 30 On11 or less, and does not include light with a wavelength of 300 On11 or less. It is possible to avoid the influence of sunlight. Therefore, the function of the partial discharge detection circuit 9 is only to judge the level of light received by the optical sensor 7, and the wavelength selection function described above can be omitted.

Further, in the above embodiment, the partial discharge detection circuit 9 adjusts the received light wavelength to 300 nm based on the received light signal from the sensor drive circuit 8.
Although the indicator light is turned on when it is determined that ultraviolet rays of nm or less are included, instead of this, the received light wavelength component and the received light level indicated by the received light signal may be displayed using a spectrum analyzer. good.

[Effects of the Invention] As is clear from the above description, the partial discharge detection device for electrical equipment of the present invention is arranged to receive light associated with partial discharge generated in the winding of the electrical equipment, and We installed a detection means that generates an alarm signal when the wavelength contains a wavelength component of about 300 nm or less, so although it detects the light generated due to partial discharge, it also detects the effects of ambient light. This provides an excellent effect in that partial discharge can be reliably detected without being affected.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall block diagram, and FIG. 2 is a characteristic diagram showing the signal intensity of light accompanying sunlight and partial discharge according to wavelength components. In the figure, 2 is the transformer body (electrical equipment), 3 is the winding, 7 is the optical sensor, 8 is the sensor drive circuit, 9 is the partial discharge detection circuit,
10 is a detection means. Figure 1

Claims (1)

[Claims] 1. It detects partial discharge occurring in an electrical device having a winding, and is arranged to receive light associated with the partial discharge occurring in the winding of the electrical device, and has a wavelength of about 300 nm or less in the received light wavelength. 1. A partial discharge detection device for electrical equipment, comprising a detection means that generates an alarm signal when a component is contained.