JPH10319084A - Insulator contamination diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more precisely diagnose the contaminated state of an insulator and prevent an accident by flashover by measuring the natural environment around an insulator arranged part together with leak current. SOLUTION: A leak current iL flowing into an insulated insulator connecting part closest to the ground side of a multiple insulator 2 having a lower end connected to a high-voltage, special high charging path 1 and an upper end connected to a steel tower laid to a ground potential is guided to an insulator contamination diagnostic device 4 through a safety circuit 3, and inputted to a control part 43 through an A/D converter 42. A form pattern similar to the form of the insulator 2 to be measured is selected from a memory 47 and inputted to the control part 43. Further, a multiplexer 48 inputs the output of each sensor 5-9 of wind velocity, wind direction, rain, temperature, humidity set around the insulator 2 to the control part 34 through an LPF 49 and the A/D converter 42. The control part 43 performs the contamination diagnosis on the basis of the input data corresponding to a set mode, and gives an alarm when the danger of accident occurrence by flashover is high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing the contamination of insulators, particularly single insulators, multiple insulators, long trunk insulators, cylindrical insulators, etc., which are connected to a charging line of a high voltage, extra high voltage system. To a device that

[0002]

2. Description of the Related Art It has been pointed out that power plants and substations installed in places that are easily affected by the atmospheric environment, such as factories and coastal areas, have problems of insulator pollution and salt damage. Especially,
In a thermal power plant installed on the shore, a large number of insulators are arranged on an extra-high-charge line, so that the insulators are relatively likely to be subjected to salt damage and cause flashover.

Therefore, conventionally, the insulator portion is periodically sprayed with water and collected, the salt concentration contained in the collected water is measured, and if the measured value is a certain value or more, the entire insulator portion is washed. Prevents flashover from occurring. Such a system is called an equivalent salt system.

As shown in FIG. 7, in the case of a multiple insulator 2 connected to a charging line 1 of a high voltage / extra high voltage system, a leakage current is measured using an insulator connecting portion (metal portion) as a sensing portion. A diagnostic device has been proposed in which this is compared with a preset alarm set value by a comparator via an amplifier and a rectifier circuit to determine whether to drive the alarm circuit.

[0005]

However, the equivalent salt system is very poor in workability because it is manually operated, and cannot be said to have high diagnostic accuracy for contamination. Furthermore, the cause of flashover in the insulator part is
Not only the leakage current but also the contamination state and distribution (whether full or partial) of the insulator surface are greatly affected,
From the viewpoint of preventing this flashover, the equivalent salt method is not sufficient.

[0006] Similarly, the conventional pollution diagnostic device for measuring the leak current has a drawback that it is difficult to prevent an accident due to flashover because it measures only the leak current.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to more accurately diagnose the contamination state of an insulator by measuring the leakage current and the natural environment around the insulator placement portion, thereby preventing an accident due to flashover. To provide an insulator contamination diagnosis apparatus.

[0008]

According to the first aspect of the present invention, there is provided a leakage current detecting means for detecting a leakage current flowing through a metal portion of an insulator, and a sensor for measuring a natural environment around a portion where the insulator is disposed. And a determining unit for determining the contamination state of the insulator based on the output of the leakage current detecting means and the output of the sensor.

In the above insulator pollution diagnosis apparatus, the natural environment surrounding the insulator arrangement part such as wind speed, wind direction, rainfall, temperature, humidity, etc. is detected together with the leakage current, and the pollution state is comprehensively determined based on these detected values. Therefore, a dangerous contamination state can be predicted at an early stage before a flashover occurs. Insulators include single insulators, multiple insulators, long trunk insulators, and tubular insulators.

[0010] The determination unit may determine the contamination state based on the measured values of the natural environment around the insulator placement unit and further based on the external properties of the insulator itself such as the shape and inclination of the insulator itself. As a result of analyzing the past statistical data for the insulators already arranged, it is found that the degree of insulator contamination is influenced by the shape of the insulator itself or the inclination at the time of installation. Therefore, by previously classifying these patterns into several types and setting the external pattern of the insulator to be measured as a parameter for determining the contamination state,
Insulator contamination diagnosis can be made even more accurate.

[0011]

FIG. 1 is a block diagram showing an insulator contamination diagnosis apparatus according to an embodiment of the present invention. Here, a multiple insulator in which a number of suspension insulators are connected is exemplified as the insulator.

The lower end is connected to the high voltage / extra high charge line 1,
Leakage current flowing into the insulator connection part (metal part) closest to the ground side of the multiple insulator 2 whose upper end is connected to a tower or steel structure set to the ground potential, as a leakage current detection part i _L is input to the insulator contamination diagnosis device 4 via the security circuit 3. Each suspension insulator has a structure shown in FIG. 2, and one end of a lead wire L is connected to a metal portion 2a of the suspension insulator 2 by a bolt, a nut or the like. In order to stabilize the connection, it is also possible to use an appropriate fitting.

The insulator contamination diagnosis device 4 converts the leakage current i _L input from the security circuit 3 via a transmission line into an amplifier 40.
And amplifies the signal to an appropriate level. The control unit 43 includes a printing device 44 for printing out the result of the insulator contamination diagnosis, a display device 45 for displaying and outputting, and an alarm device 4.
9 and an input device 4 for inputting various input data
6 are connected. Further, in a part of the memory 47 connected to the control unit 43, a plurality of predetermined insulator shape patterns are set as A, B, C. The operator sets the shape pattern of the insulator 2 to be measured symmetrical from the plurality of insulator shape patterns displayed on the display device 45 based on the shape pattern data stored in the memory 47. Is selected and the code (ABC ...) is input from the input device 46.

The insulator contamination diagnosing device 4 is configured to be able to receive a plurality of inputs. The multiplexer 48 sequentially samples the plurality of inputs, converts the samples into digital data by the low-pass filter 49 and the A / D converter 50, and inputs the digital data to the control unit 43. The respective sensor outputs from the wind speed sensor 5, the wind direction sensor 6, the rainfall sensor 7, the temperature sensor 8, and the humidity sensor 9 which are set around the insulator 2 are guided to the multiplexer 48, and the sampling timing from the control unit 43. These sensor outputs are sequentially input to the low-pass filter 49 based on. The control unit 43 selects input data corresponding to the set mode from among the below-described modes 1 to 4 among the input data input from the A / D converter 42 and the A / D converter 50, A pollution diagnosis is performed based on the selected data. Then, as a result of the diagnosis, when there is a high risk of occurrence of an accident due to flashover, an alarm is issued by the alarm device 49.

The contamination diagnosis is performed in accordance with a mode (one of modes 1 to 4) previously input by the input device 46.

Mode 1 is a mode in which a contamination diagnosis is performed based only on the magnitude of the leakage current i _L. In this mode 1, the inputted leakage current i _L is compared with a preset threshold value (I _K ). If the leakage current is equal to or larger than the threshold value, an alarm is issued by the alarm device 49. Mode 2 is a mode for determining the area of the weather pattern. As shown in FIG. 3, five axes of wind speed, wind direction, rainfall, temperature, and humidity are set at equal angles from the center of the circle, and the corresponding sensor output is plotted on each axis. At this time, by connecting the plotted points, the area S of the polygon formed inside is obtained,
The area S is compared with a preset threshold value S _{K. If} the area S is equal to or larger than the threshold value S _K , it is determined that a flashover is in a dangerous state, and the alarm device 49 issues an alarm. Mode 3 is a mode in which a leakage current is further added to the weather pattern to determine a pattern area.
In addition, mode 4 is a mode in which the pattern area is determined using the value representing the external properties of the insulator, that is, the shape pattern of the insulator and the inclination (angle with respect to the vertical direction) of the insulator as parameters. This mode 4 is the most reliable mode for performing contamination diagnosis. FIG. 4 shows a pattern example of the mode 4. The description of each axis in this mode 4 is as follows.

As for the wind speed, the higher the speed, the higher the possibility that seawater will be rewound and blown off. Therefore, the relationship is such that the area S increases as the wind speed increases.

The greater the amount of rainfall, the greater the salt content on the insulator surface. Therefore, the relationship is such that the area S increases as the rainfall increases.

The higher the temperature, the higher the relative humidity in the atmosphere. Therefore, the relationship is such that S increases as the temperature increases.

Similarly, as the humidity increases, the possibility of flashover increases as the humidity increases. Therefore, the humidity is proportional to the size of the area S.

The inclination of the insulator and the insulator shape pattern are determined based on past statistical data. The wind direction data is also determined based on past statistical data of the area.

FIG. 5 is a schematic flowchart showing the contamination diagnosis operation of the control unit 43. This operation is always performed.

The control section 43 is constantly input with the leakage current i _L and the measurement data from each sensor. Input device 4
If the mode 1 is input in step 6, it is determined whether or not the leakage current i _L at that time is equal to or larger than a preset threshold value I _K. When i _L is greater than I _K , an alarm is issued by the alarm device 49.

When the mode 2 is input, the area S is calculated according to the pattern shown in FIG. 3, and it is determined whether or not the area S is equal to or larger than a predetermined threshold value S _K. If it is not less than the threshold value, an alarm is issued by the alarm device 49.

In the mode 3, the area of the leakage current is added to the pattern shown in FIG.
In this case, the area S in the pattern shown in FIG. 4 is obtained, and each area S is compared with a preset threshold value S _K. When the area S is equal to or _larger than S _K , an alarm is issued by the alarm device 49.

When the contamination diagnosis is performed by obtaining the area S in a pattern as shown in FIGS. 3 and 4 and comparing the obtained area S with a threshold value, the result varies considerably depending on the scaling of each axis. When scaling, it is important to determine a value based on past statistical data. However, once the geographical conditions are determined, the surrounding natural environment, including weather conditions, does not change significantly.
With proper scaling, the contamination status can be diagnosed with relatively high accuracy.

The sensor outputs include wind speed, wind direction,
It is not necessary to use all of rainfall, temperature, and humidity. By using at least one of them, it is possible to obtain a more reliable diagnosis than pollution diagnosis using only leakage current.

In the above embodiment, a multiple insulator is illustrated as an insulator. However, when a cylindrical insulator is used, a mounting bracket is used as a metal portion because there is no metal portion on the insulator surface. For example, as shown in FIG.
One mounting bracket 10 is used, and the tip of the lead wire L is mounted thereon. FIGS. 6A and 6B show a capacitor-type instrument transformer (P) having a cylindrical insulator 20 which is an insulating container.
D), the mounting bracket 10 for the lead wire L is shown, but since this PD has a grounding box 21 arranged at the lower part and the upper part is connected to the track, the mounting bracket is arranged around the lower part of the cylindrical insulator near the grounding side. 10 is wound so as to wind it, and the charging voltage of the line due to the capacitor partial voltage is taken out from here. The two semicircular mounting brackets 10 are fastened by bolts 11 and nuts 12 without loosening, and are formed of weather-resistant stainless steel.

[0029]

According to the present invention, the determination result of the insulator contamination state can be made more reliable by measuring the natural environment around the insulator placement portion.

[Brief description of the drawings]

FIG. 1 is a block diagram of an insulator fouling diagnosis device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a suspension insulator

FIG.

FIG. 4 is a diagram showing a pattern when performing contamination diagnosis in mode 2 and mode 4;

FIG. 5 is a flowchart showing the operation of the insulator contamination diagnosis device.

FIGS. 6A and 6B are diagrams showing a lead wire mounting structure when a lead wire is taken out from a capacitor-type instrument transformer and a cylindrical insulator.

FIG. 7 is a block diagram of a conventional insulator contamination diagnosis device.

Claims (3)

[Claims] 1. An apparatus comprising: at least: a leakage current detecting means for detecting a leakage current flowing through a metal part of an insulator; and a sensor for measuring a natural environment around a portion where the insulator is disposed, wherein an output of the leakage current detecting means and the sensor are provided. And a determining unit for determining a contamination state of the insulator based on the output of the insulator contamination diagnostic apparatus. 2. The insulator contamination diagnosis apparatus according to claim 1, wherein said determination unit further determines said contamination state based on values representing external properties of the insulator, such as the shape and inclination of the insulator. . 3. The sensor according to claim 1, wherein the sensor comprises: wind speed, wind direction, rainfall, temperature,
3. The insulator contamination diagnosis apparatus according to claim 1, wherein at least one of humidity is measured.