JP3200224B2 - Insulator life monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for monitoring the life of an insulator for monitoring the degree of fatigue of the insulator and notifying the same.

[0002]

2. Description of the Related Art As insulators are used for a long period of time, they are subjected to a tensile load and a compressive load and deteriorate, so that even if the load is considerably lower than the breaking strength, the insulator may be broken. This is a so-called fatigue failure. To prevent this fatigue failure,
Conventionally, a design is made in advance with a margin (safety factor) based on past fatigue test data. The reason for manufacturing insulators with such a margin is that it is practically difficult to accurately measure the degree of fatigue once the insulator device has been assembled and installed in the power transmission and distribution equipment, and workers can visually recognize the appearance. This is because there was a situation that only the damage state was determined.

[0003]

However, designing in anticipation of the margin increases uneconomical aspects such as the necessity of increasing the wall thickness more than necessary. It is troublesome and inefficient for an operator to make a round of inspection. In addition, for inspection, a test line may be installed separately from a commercial power transmission line, a load cell is attached to the insulator device at the time of inspection, and the frequency distribution of the fluctuating load is measured to measure deterioration. However, even in this case, monitoring is not always performed, and it is very troublesome because a load cell must be attached and measured at the time of each inspection.
In addition, since the test line for inspection is purposely installed, the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an insulator life monitoring apparatus capable of constantly monitoring the deterioration state of an insulator and displaying the deterioration state. It is in.

[0005]

In order to achieve the above object, according to the present invention, fluctuation of an insulator detected by a detecting means is provided.
The detected value as the number of repetitions for each load
For each load that is stored in advance in
Comparison of the number of times of destruction repetition with the set comparison value
And integrate the repetition ratio, or
Take the sum, and calculate the result
Notify fatigue status by comparing against values
The gist is that it was done.

[0006]

According to the above arrangement, the fatigue of the insulator is always accurate.
(Deterioration) state can be confirmed, and the insulator has a special margin
There is no need to design.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the insulator life monitoring apparatus of the present invention is applied to a tension insulator will be described below with reference to FIGS.

As shown in FIG. 1, a tension insulator 5 is connected and supported to a mounting plate 2 of a support arm 1 of a tower body via a tower side fitting 4 by a support pin (not shown). Tensile insulator 5
A power transmission line (not shown) is erected and supported on the power application side end via a wire side connection fitting 6 and a compression clamp 7. The load cell 3 serving as monitoring means is mounted and fixed on the tower-side connection fitting 4. The load cell 3 is a strain gauge type pressure sensor in which a strain gauge is bonded to an internal strain body,
The stress applied to the connection fitting 4 is converted into a voltage value corresponding to the change in the stress. Here, the strain body of the load cell 3 is brought into contact with the connection fitting 4 in order to detect a change in stress of the connection fitting 4. Each tension insulator 5 and the connection fitting 4 are pulled by the transmission line via the compression clamp 7, and the stress applied to each tension insulator 5 and the stress applied to the connection fitting 4 are substantially equalized. Therefore, if the stress of the connection fitting 4 is detected, the stress applied to each tension insulator 5 can be detected.
The load cell 3 outputs a detection signal to a life monitoring device main body 15 disposed in a substation on the ground side via a cable 16.

Next, the electrical configuration of the main part of the insulator life monitoring apparatus according to the present embodiment will be described with reference to the block diagram of FIG. Hereinafter, the electrical configuration is provided in the apparatus main body 15. A central processing unit (CPU) 20 as a comparing means for controlling the life monitoring device of the tension insulator 5 has a read-only memory (ROM) as a memory in which various control programs and a comparison value serving as a reference of the fatigue degree of the insulator are stored in advance. 21 are connected.

The comparison values stored in the ROM 21 are set based on the graph of the SN curve shown in FIG. In the SN curve, which is a characteristic diagram of the tensile load of the insulator, the parameter is an average load, the vertical axis is the load (load amplitude), and the horizontal axis is the fatigue count (repetition count). The tension insulator 5 of this embodiment has an average load of 8800 kgf and is shown as an SN curve as shown in FIG. The SN curve of this embodiment will be described in more detail with reference to FIG. For example, FIG.
At point P, since the load amplitude is ± 2250 kgf, the number N of destruction repetitions at this amplitude is 10 ⁵ . That is, the insulator 5 more than 10 ⁵ times if cyclic loading of ± 2250Kgf in theory becomes causing fatigue fracture. Similarly, at point Q in FIG.
Since it is 1250 kgf, the number N of destruction repetitions at this amplitude is 10 ⁶ . Further, at the point R, the SN curve becomes horizontal (fatigue limit), and if it is less than the fatigue limit theoretically, it becomes a region that does not break even if there is infinite repetition.

In this embodiment, the average load is 8800 k
The number of times of destruction repetition N based on the SN curve at the time of gf
Is calculated. However, in the ROM 21, SN curves corresponding to various average loads based on past experimental data are stored.
By selecting the average load corresponding to the tension insulator 5 installed by the above operation, an SN curve using the average load as a parameter is selected. Therefore, if the tensile strength insulator 5 has a different average load, the number N of times of destruction at a certain load amplitude naturally differs.

Further, a simple repeated load is not applied to the tension insulator 5, but the load should be a variable load in which the magnitude of the load changes randomly. That is, it is necessary to calculate the fatigue life on the assumption that the load fluctuates in an actual transmission line. In this embodiment, Miner's law of linear damage is used as this calculation means. As shown in FIG. 4, in the SN curve with an average load of 8800 kgf, it is assumed that a certain load amplitude is Δa _{1 and the} number of times of repeated fracture is N ₁ .
Also, when the load amplitude is Δa ₂ ,
_Let it be ₂ . If the number of substantial repetitions at the load amplitude Δa ₁ is n _{1 and the} number of substantial repetitions at the load amplitude Δa ₂ is n ₂ , the ratio of the number of repetitions n ₁ / N ₁ and n ₂ / When the sum with N ₂ reaches 1, it is assumed that destruction occurs theoretically.

An equation satisfying this condition is expressed as follows.

[0014]

(Equation 1)

In this embodiment, the load amplitude Δa is set for each SN curve.
Is divided into eight bands a to h, and a unique number of times of destruction repetition Ni, which is a comparison value, is given to each band. The CPU20 is the data of the real quality repeat count that will be output from the load cell 3 is integrated by counting the n every eight bands to h, to calculate the number of repetition ratio ni / Ni, the sum of the number of repetitions ratio ni / Ni Is determined to have reached 1.

The CPU 20 is connected to a random access memory (RAM) 22 as a buffer for temporarily storing a signal output from the load cell 3. Also CPU
A determination circuit 24 is connected to the input side of the signal line 20 via an input / output interface 23. The load cell 3 is connected to the determination circuit 24 via an amplifier 25. The determination circuit 24 includes a plurality of operational amplifiers, and
And outputs data to the CPU 20 by comparing and determining the voltages detected in accordance with the eight bands a to h. Amplifier 25 boosts the voltage detected by load cell 3 to a predetermined voltage.

A display device 28 and an operation unit 29 are connected to an output side of the CPU 20 via an input / output interface 27. The display device 28 is a CPU 2 serving as a display control unit.
The data content output by the control of 0 is displayed on the display. The displayed contents include, for example, the average load on the tension insulator 5 in the monitoring state and the SN curve. The number N of destruction repetitions, the number n of substantial repetitions, the repetition ratio n / N, and the repetition ratio n for each of the bands a to h
/ N. The operation unit 29 has a key operation unit for selecting memory contents of the ROM 21 and changing a display mode.

Next, the operation of the apparatus for monitoring the life of an insulator configured as described above will be described. For example, ± 1000 to 1250 kgf included in the band c in the tension insulator 5 of this embodiment.
It is assumed that load amplitude is applied and signal data is output from the load cell 3. In this case, as shown in FIG.
At f or less, the fatigue limit is not exceeded, so no matter how much stress is applied, no fatigue fracture occurs. However, for example, ± 2
When a load amplitude of 250 kgf is applied, the CPU 20 counts the load amplitude based on the signal data output from the load cell 3 and determines that it is included in the band e. Since the number of times of destruction repetition of band e is 10 ⁵ , the ratio of the number of repetitions of band e is (n + 1) /
10 ⁵ (n is the actual number of repetitions in band e up to that point). Each time the load amplitude is applied, the load cell 3 outputs a signal to the CPU 20. The CPU 20 monitors this, counts each of the bands a to h, calculates by the above formula, displays it on the display, and notifies the worker of the fatigue state. I do. The fatigue state is, for example, each band a to h
The determination is made by visually recognizing the repetition ratio n / N and the total sum thereof. In this case, the CPU 20 sets the time of theoretical fatigue failure to 1
Assuming that the repetition ratio n / N of each of the bands a to h is set to 00%, the calculation is converted to a percentage display, and the result is always displayed on the display, for example, "Hirodo 60%". Good.

As described above, in the present embodiment, the stress of the tension insulator 5 is always detected by the load cell 3, and the CPU 20 compares this with the comparison value to notify the fatigue state. For this reason, the tension insulator 5 can always be monitored,
Therefore, it is not necessary to design in consideration of the tolerance as in the related art. In addition, since the test can be performed on a commercial line, there is no need to provide a test line, and the cost is reduced. Further, it is not necessary to go around the route for checking the fatigue state, and the deterioration time can be determined more accurately.

It should be noted that the present invention is not limited to the above embodiment, and may be configured as follows without departing from the spirit of the invention. In the above embodiment, it was assumed that destruction would theoretically occur when the sum of the number of repetitions was 1. However, this value is corrected in the range of a multiplier of 0.3 to 3.0 because experimental data is actually considered. It is also possible to do. For example, it can be changed as follows.

[0021]

(Equation 2)

In the above embodiment, the load amplitude range is divided into bands a to h. However, the load amplitude range may be divided more finely. Further, in the above embodiment, the load cell 3 is used as the detecting means, but it is free to use another type of sensor. In addition, the present invention can be applied to suspension insulators other than the tension insulator 5, and can be freely modified and implemented without departing from the gist thereof.

[0023]

As described in detail above , according to the present invention ,
Deterioration status can be checked accurately at all times.
There is no need to design insulators.

[Brief description of the drawings]

FIG. 1 is a side view of a tension insulator device equipped with an insulator life monitoring device of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the same embodiment.

FIG. 3 is a graph illustrating the relationship between stress and the number of fatigues in the SN curve of the same example.

FIG. 4 is a graph illustrating a case of a fluctuating load in the SN curve of the same example.

[Description of Signs] 3 ... Load cell as detection means, 5 ... Tension insulator, insulator
21 ... ROM as memory

Claims (1)

(57) [Claims] 1. A fluctuation of an insulator detected by a detecting means.
The detected value as the number of repetitions for each load
For each load that is stored in advance and serves as a criterion for determining the degree of fatigue of insulators
The number of times of destruction repetition is compared with the set comparison value,
Integrate the repetition rate ratio or sum the repetition rate ratio
And calculate the result to a specific value corresponding to destruction.
To notify the fatigue status by comparing
The insulator of life monitoring equipment.