JPH011408A - Maintenance monitoring method for power cables using infrared images - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to power cables, and particularly to a method for maintaining and monitoring power cables such as Cv cables.

[Conventional technology]

Conventionally, for example, a 275 kilovolt (kV) power transmission line is the most important part of a power transmission system, and it is necessary to prevent failures from occurring in advance in order to improve the reliability of the power transmission line. 275
Power cables for KV lines are OF cables or C■ cables, but Cv cables, which have particularly excellent insulation performance, are becoming the main type of application. Therefore, there is a need for a system for monitoring Cv cable systems.

Conventional monitoring systems employ sensors for temperature, humidity, pressure, and smoke. These sensors are
C. They are provided at predetermined intervals along the length of the cable, and information from these sensors is displayed on a monitor or recording paper via a computer.

[Problem that the invention seeks to solve]

However, in the conventional monitoring system, the sensor is a point, and the distribution in the length direction of the Cv cable is monitored using a collection of points, but this has the problem that the Cv cable cannot be sufficiently monitored.

In addition, in recent years, there has been a demand for continuous and three-dimensional monitoring of C■ cables.

The present invention has been made in order to solve the above problems, and uses an infrared camera to maintain and monitor the power cable system laid in a cave or manhole, and calculates the temperature from the image information from the infrared camera. It is an object of the present invention to provide a method for maintaining and monitoring power cables using infrared images, which allows sufficient maintenance and monitoring of changes in power cables and their connections due to humidity, pressure, and smoke.

[Means for solving problems]

In order to achieve the above object, the present invention provides a power cable (
At least one infrared camera is placed at a geometric position in each predetermined section of the power cable line in a power cable system in which cables (including connections) are laid in tunnels and manholes, and information is input to an image data processing device through an optical cable to form a thermograph,
The main feature of infrared rays is to read the surface temperature of the power cable or connection part from the thermograph and monitor the longitudinal distribution of the conductor temperature and the ambient temperature or temperature of the structure by displaying or recording it on an image output device. This is a method for maintaining and monitoring power cables using images.

In addition, from the thermograph, the cable offset, snake part, and connection part in the normal operating state of the power cable are recognized as three-dimensional images of changes in shape 1 position, displayed on the screen or recorded on the image output device, and inputted in advance. Data that compares the amount of change in temperature and power cable with the tolerance value entered in advance, and issues an alarm if an abnormality occurs, or compares the amount of change in temperature and power cable with the tolerance value entered in advance. This is a method for maintaining and monitoring power cables using infrared images, which is characterized by recording.

[For production]

According to the above-mentioned means, in a power cable system in which power cables (including connections) are laid in caves and manholes, at least one infrared camera is placed at a geometric position in a predetermined section of the cable line. Information from the infrared camera is input to an image data processing device through an optical cable to form a thermograph, and the surface temperature of the power cable or connection part is read from the thermograph to determine the longitudinal distribution of conductor temperature. Since the ambient temperature or the temperature of the structure is monitored on an image display or on recording paper, sufficient maintenance and monitoring of the power cable can be performed.

In addition, from the thermograph, the cable offset, shape, and position changes of the snake part and the connection part under normal cable operation conditions are recognized as three-dimensional images and displayed on the screen or recorded with an image output device. It compares the temperature and cable variation with the allowable values and issues an alarm if an abnormality occurs, allowing you to quickly find out about power cable abnormalities and perform ideal power cable maintenance monitoring. .

Further, from the image data of the thermograph or the thermograph, the cable offset, shape and position changes of the snake part and the connection part in the normal cable operation state are recognized as three-dimensional images and displayed on the screen or recorded on the image output device. , and records data comparing the allowable values input in advance and the amount of temperature and cable change.
It is possible to carry out ideal maintenance monitoring of power cables, and to investigate the causes of abnormalities and failures at a later date.

〔Example〕

An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view illustrating a schematic configuration of a maintenance monitoring system for a Cv cable and a connection section arranged in a manhole to which the present invention is applied.

The maintenance monitoring system of this embodiment, as shown in FIG.
Cv cables (11 cables) and their connection parts 9 are supported by vertical metal fittings 10 and horizontal metal fittings 14 and laid. In addition, the C cable 8 is connected from the man hole 11 to the trough 12 (F
RP), etc., and is installed within the tunnel 13. Then, one or more infrared cameras 1 are arranged. When multiple infrared cameras are installed, their geometric positions can be determined by triangulation, etc.

The infrared camera 1 employs, for example, a high-performance thermograph using a semiconductor sensor or a high-resolution linear array sensor, and a one-type two-dimensional array sensor can be applied. The information from the infrared camera 1 is then input to an image data processing device 2 consisting of a computer or the like through an optical fiber (optical cable) 7 and converted into one image data. This image data is input to the main computer 3 together with the current value from the current detection device 15, and the conductor temperature of the Cv cable 8 and its connection part 9 is calculated.
For example, the image output device 4 such as a CRT display with a memory or a printer with a memory is used to display or record on the screen and monitor the temperature of components such as the vertical bracket 10°, the horizontal bracket 14, and the trough 12. The ambient temperature of Road 13 is monitored.

Furthermore, an input image is stored in advance from the geometrical position obtained by triangulation using a plurality of infrared cameras 1, and Cv
Changes in the shape of the cable 8 and its connecting portion 9 are made into a three-dimensional image and displayed or recorded on the image output device 4. In this case, the feature matching method,
There is a method of making correspondence based on the positions of the three infrared cameras 1, etc.

By doing this, the thermal behavior of the Cv cable 8 and its connection part 9 can be displayed three-dimensionally on the screen, so when monitoring the Cv cable 8 and its connection part 9, information for determining what to do in case of an abnormality can be displayed. More can be provided appropriately.

By applying the high field of view type, zooming, etc. of the infrared camera 1, the temperature distribution is displayed three-dimensionally on the screen, so that a fire accident or a ground fault of the Cv cable 8 can be instantly determined.

Displaying or recording on an image output device a three-dimensional image of the cable offset, the shape 1 position change of the snake part and the connection part in the normal C■ cable operating condition from the image data of the thermograph or the thermograph, and , pre-entered tolerance values, temperature and C
The amount of change in the v-cable 8 is compared, and if an abnormality occurs, a warning device 6 such as an alarm is provided to issue a warning.

Also, from the image data of the thermograph or the thermograph, the cable offset, shape, and position changes of the snake part and the connection part in the normal operating state of the Cv cable 8 are displayed or recorded as a three-dimensional image on an image output device. In addition, data comparing the amount of change in temperature and Cv cable 8 with the allowable value input in advance is stored in an image storage device F15 such as a magnetic disk device.

Here, the advantages of applying the infrared camera 1 will be explained.

FIG. 2 is a graph showing the gain obtained from the temperature difference between the target object and the background at the peak wavelength (μm) of the infrared sensor of the infrared camera 1. FIG.

The infrared camera 1 detects infrared rays naturally emitted from objects, so it can detect infrared rays that are naturally radiated from objects, so it can be used to detect infrared rays in the air regardless of day or night.

Can see objects through fog, etc. and.

As shown in Figure 2, the peak wavelength of the infrared sensor is 3 to 5 (μm) to identify objects with large temperature differences, and 10 to 12 (μl) to identify objects with small temperature differences.
11) is used with a shaft.

Note that the gain A obtained from the temperature difference between the target object and the background shown in FIG. 2 can be expressed by the following equation (1).

The unit of formula (1) is (Hz·am-').

As can be seen from the above description, according to one embodiment, Cv
The cable 8 and its connecting portion 9 are connected to the tunnel 13 and the manhole 11.
In a power cable system installed in a power cable system, at least one infrared camera 1 is arranged at a geometric position in each predetermined section of the line of a Cv cable 8, and this infrared camera 1
The information from the Cv cable 8 is inputted to the image data processing device 2 through the optical fiber 7 to form a thermograph, and the surface temperature of the Cv cable 8 or its connection part 9 is read from this thermograph to determine the longitudinal distribution of the conductor temperature and the ambient temperature. Alternatively, since the temperature of the structure is monitored on the screen display, sufficient maintenance and monitoring of the Cv cable 8 or the connecting portion 9 can be performed.

Furthermore, since the cable offset, shape, and position changes of the snake portion and the connection portion in the normal operating state of the Cv cable 8 are displayed or recorded as a three-dimensional image on the image output device 4 from the thermograph, the Cv cable 8 Alternatively, ideal maintenance and monitoring of the connection portion 9 can be performed.

In addition, the allowable value, temperature and Cv input in advance
Since the amount of change in the cable 8 or the connection part 9 is compared and an alarm is issued if an abnormality occurs, it can be quickly known that an abnormality has occurred in the CV cable 8 or the connection part 9 thereof.

In addition, an image output device is provided that uses the image data of the thermograph or the thermograph as a three-dimensional image of the cable offset, shape 1 position change of the snake part and the connection part in the normal operating state of the Cv cable 8! 4, as well as the allowable values, temperature and Cv that have been entered in advance.
Since the data comparing the amount of change in the cable 8 or the connection part 9 is stored in the image storage device 115, the Cv cable 8
Alternatively, it is possible to carry out ideal maintenance and monitoring of the connecting portion 9, and also to reproduce and observe when investigating the cause of an abnormality or failure.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

For example, in the embodiment described above, a CRT display device with a memory and a printer with a memory are used as the single image output device 4, but any device may be used as long as it performs the same function.

The present invention can also be applied as a means for monitoring special power cable locations such as shafts.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be achieved.

(1) Based on surface information from an infrared camera, the conductor temperature distribution of the power cable system and temperature changes in the installation space and structures are displayed or recorded on the screen, and changes in three dimensions are captured, so the power cable system ideal maintenance and monitoring.

(2) By arranging multiple infrared cameras at geometric positions, the thermal behavior of power cables and their connections can be displayed three-dimensionally on the screen. It is possible to judge in what direction and state the behavior changes, and whether the behavior is in the dangerous area.

(3) An infrared camera can be used to visually recognize changes in temperature, object position, and shape.

(4) Compare the temperature and the amount of change in the power cable or connection with the tolerance values entered in advance.

Since an alarm is issued when an abnormality occurs, it is possible to quickly know that an abnormality has occurred in the power cable or its connection portion.

(5) Pre-entered tolerance values, temperature and C
Since the data comparing the amount of change in the Cv cable or connection part is stored in the image storage device, ideal maintenance and monitoring of the Cv cable or connection part can be performed, and the cause of abnormality or failure can be investigated at a later date. If you do it, please reproduce it! can be understood.

[Brief explanation of drawings]

Figure 1 is a perspective view illustrating the schematic configuration of a maintenance and monitoring system for Cv cables and connections arranged in manholes to which the present invention is applied; Figure 2 is a peak wavelength of an infrared sensor of an infrared camera; (
2 is a graph showing the gain obtained from the temperature difference of the target object with respect to the background in μm). In the figure, 1... infrared camera, 2... image data processing device, 3... main computer, 4... image output device. 5... Image storage device, 6... Alarm device, 7... Optical fiber (optical cable), 8... Cv cable (power cable), 9... Connection part, 10... Vertical metal fitting, 1
1... human hole part, 12... trough, 13... cave passage,
14... Horizontal metal fitting, 15... Current detection device.

Claims (4)

[Claims] (1) In a power cable system where power cables (including connections) are laid in tunnels and manholes, at least one infrared camera is placed at a geometric position in each predetermined section of the power cable line. Information from the infrared camera is input to an image data processing device through an optical cable to form a thermograph, and the surface temperature of the power cable or its connection is read from the thermograph to determine the longitudinal distribution of the conductor temperature and the surrounding area. A method for maintenance and monitoring of power cables using infrared images, characterized by monitoring the temperature or the temperature of a structure by displaying or recording it on an image output device. (2) The step of reading the surface temperature of the power cable and its connection part from the thermograph to monitor the longitudinal distribution of the conductor temperature, the ambient temperature, and the temperature of the structure is performed by a computer. A method for maintaining and monitoring power cables using infrared images according to item 1. (3) The plurality of infrared cameras are arranged at geometrical positions in each predetermined section of the power cable line, and the image information of the three-dimensional geometrical positions of the plurality of cameras is first sent to an image data processing device. The information from the infrared camera is then input through an optical cable to a dual image data processing device to form a thermograph, from which information about cable offsets, snakes and connections under normal power cable operating conditions can be obtained. A method for maintaining and monitoring power cables using infrared images according to claim 1 or 2, characterized in that changes in shape and position are recognized three-dimensionally as images and displayed or recorded on an image output device. . (4) In a power cable system where power cables (including connections) are laid in tunnels and manholes, at least one infrared camera is placed at a geometric position in each predetermined section of the power cable line. Information from the infrared camera is input to an image data processing device through an optical cable to form a thermograph, and from the image data of the thermograph or the thermograph, cable offsets, snake portions, and connections in normal power cable operating conditions are determined. 3D image recognition of changes in shape and position of parts is displayed on the screen or recorded on an image output device, and temperature and cable change amounts are compared with pre-input tolerance values to detect abnormalities when they occur. A method for maintaining and monitoring power cables using infrared images, characterized by issuing an alarm or recording data comparing temperature and cable variation with the pre-input allowable values.