JP2008180657A - Method and program for estimating vibration life of aerial electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and program for estimating vibration lifetime of an aerial electric wire, capable of estimating the lifetime due to the vibration fatigue of the aerial electric wire mounted to an electric wire gripping section of a discharge clamp. <P>SOLUTION: The vibration frequency of the electric wire is calculated, based on the distance between poles and the relaxation rate of the aerial electric wire, the wind speed generating frequency is calculated based on the wind direction angle and turbulence of the wind, and the wind speed generating frequency is converted into a stress-generating frequency (S102). The stress generated for each wind speed is determined for the stress-generating frequency, the repetition number, until the wire of the aerial electric wire is disconnected is calculated, based on the vibration frequency (S106-S108). The occurrence time of the disconnection, due to vibration fatigue in the electric wire gripping section of the discharge clamp of the aerial electric wire, is predicted from the repetition number (S110). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration life estimation method and a vibration life estimation program for an overhead wire that predicts that an overhead wire attached to a wire gripping portion of a discharge clamp will cause vibration fatigue and break.

  For example, in a high-voltage 6600V high-voltage overhead electric wire line, a discharge clamp having a lever portion is widely used as a member of a wire support portion of a distribution facility. In the discharge clamp, the insulation of the wire insulation is destroyed by lightning, etc., and the continuation arc concentrates on the insulation breakdown point, and in order to prevent the wire from being damaged or blown, the insulation coating is stripped off. It is provided in order to discharge the current to the ground from the electric wire gripping portion that grips the conductor portion where the conductor is exposed.

  The electric wire gripping portion of the discharge clamp directly grips an aerial wire (hereinafter referred to as an electric wire) from which the insulator has been peeled and the conductor is exposed. On the other hand, since the electric wire and the discharge clamp vibrate due to the wind, the bending stress due to the repeated vibration concentrates on the electric wire gripping portion. When vibration is applied to the electric wire gripping portion for a long time, the conductor at the part where the insulator is peeled may be deteriorated over time such as damage, and if left untreated, it may break and break. In particular, if the route of the distribution line is close to the local environment, such as urban areas, densely populated houses, school roads, and important trunk roads, if the cable falls or drops due to disconnection, electric shock or property damage may occur. May cause accidents.

  Therefore, it is desired to diagnose an abnormality of the electric wire in the electric wire gripping portion of the discharge clamp and prevent an electric shock accident and a property damage accident by preventing the electric wire from dropping or drooping due to disconnection.

As a method of diagnosing abnormalities in the electric wire gripping part of the discharge clamp, there is a method of estimating the vibration-resistant life of the electric wire. A strain gauge is attached to a predetermined part of the electric wire, etc. Is obtained in advance and recorded as a master curve, the dynamic strain amplitude of the electric wire to be predicted is detected with a strain gauge, and the dynamic strain amplitude and master curve obtained by this strain gauge are obtained. A vibration-resistant life prediction method that collates and predicts the vibration-resistant life of an electric wire is known (for example, see Patent Document 1).
JP 2003-185551 A

  However, according to the conventional anti-vibration life prediction method, since the data is only the dynamic strain amplitude of the electric wire, the weather condition (wind condition) related to wind such as outdoor wind force, wind direction, wind speed, etc. is exposed under non-constant conditions. There is a problem that the life of a vibrating wire cannot be estimated.

  An object of the present invention is to provide a vibration life estimation method and program for an overhead electric wire capable of estimating the lifetime due to vibration fatigue of the overhead wire attached to the electric wire gripping portion of the discharge clamp.

  In order to achieve the above object, the present invention calculates a wind speed generation frequency based on a wind condition in a region where an overhead electric wire subject to life estimation exists, and converts the wind speed generation frequency into a stress generation frequency. And a second step of calculating a vibration frequency of the overhead wire based on the overhead wire condition of the overhead wire, and a repetition until the strands of the overhead wire are broken based on the stress occurrence frequency and the vibration frequency. A third step of calculating the number of times, and a fourth step of predicting the occurrence time of disconnection due to vibration fatigue in the wire gripping portion of the discharge clamp of the overhead wire from the number of repetitions. A vibration life estimation method is provided.

  In order to achieve the above object, the present invention calculates a wind speed generation frequency based on a wind condition in a region where an overhead electric wire subject to life estimation exists, and converts the wind speed generation frequency into a stress generation frequency. Calculating the number of repetitions until the wire of the overhead wire is broken based on the stress generation frequency and the vibration frequency of the overhead wire by the wind condition processing unit. An overhead electric wire vibration life estimation program for functioning as an arithmetic unit for predicting and calculating the occurrence timing of disconnection due to vibration fatigue in the electric wire gripping portion of the electric discharge clamp of the overhead electric wire from the number of times.

  According to the vibration life estimation method and the vibration life estimation program of the overhead electric wire of the present invention, it is possible to estimate the life due to vibration fatigue of the overhead electric wire attached to the electric wire gripping portion of the discharge clamp.

(Configuration of vibration life estimation system)
FIG. 1 is a schematic configuration diagram showing a vibration life estimation system according to an embodiment of the present invention.
The vibration life estimation system 10 includes a vibration life estimation device 1 that performs vibration life estimation processing, a database unit 2 that is used for vibration life estimation processing by the vibration dynamic life estimation device 1, and a database unit via a communication line 8. 2 and a host computer 3 connected to 2.

  For example, the vibration life estimation apparatus 1 can be a personal computer or a dedicated apparatus.

  The database unit 2 includes a storage unit such as a non-volatile memory and a hard disk drive that store data on the stress generated at each wind speed, data on an S (stress) -N (number of repetitions) curve, and the like.

  The host computer 3 is configured using, for example, a personal computer.

  The vibration life estimation apparatus 1 includes an input unit 4 used when an operator performs various inputs, an arithmetic processing unit 5 connected to the input unit 4, and a display 6 connected to the arithmetic processing unit 5. Has been.

  The input unit 4 includes input devices such as a keyboard and a mouse.

  The arithmetic processing unit 5 includes a non-volatile memory storing a program for executing a vibration life estimation process, a storage unit 51 such as a hard disk drive, a CPU 52 for executing processing according to the program stored in the storage unit 51, and its peripheral circuits Etc. are provided.

  The display 6 is configured using, for example, a liquid crystal display.

(Interface screen)
FIG. 2 is a diagram illustrating an interface screen displayed on the display of the vibration life estimation apparatus when the vibration life estimation process is executed.

  The interface screen 7 includes an estimated area column 71, an electric wire type input column 72, an end column 73, a data setting column 74, an overhead line condition input / life estimation result display column 75, an area display column 76, and the like.

  The data setting column 74 includes a utility pole input column 74a, a wind turbulence input column 74b, a main direction (wind direction angle) input column 74c, and the like.

  The overhead line condition input / life estimation result display field 75 includes a sag rate input field 75a, an estimated life display field 75b, a span length input field 75c, a disconnection level display field 75d, and the like.

  The input to the above input fields is performed, for example, by an operator manually operating the input unit 4 to input.

(Operation of vibration life estimation system)
FIG. 3 is a flowchart showing processing of the arithmetic processing unit shown in FIG.

  FIG. 4 is a characteristic diagram showing the wind speed occurrence frequency.

  FIG. 5 is a characteristic diagram of “generated stress—assumed wind speed” read as a database in step S103 of FIG.

  FIG. 6 is a characteristic diagram of “repetitive strain−repetition count” used for calculating the number of disconnections.

  FIG. 7 is a characteristic diagram of allowable stress read as a database in step S107 of FIG.

  The operation of the vibration life estimation system according to the embodiment of the present invention will be described below with reference to FIGS.

  First, the operator operates the input unit 4 and clicks the “estimated area” column 71 in FIG. 2 to specify the area where the utility pole for which the lifetime is to be estimated exists. Here, as shown in FIG. 2, “Nasu area” is selected as the assumed area and is displayed in the area display column 76.

  Furthermore, as the overhead wire conditions necessary for the calculation, input the wire type, span length (distance between poles), sag rate, wire unit weight, wire ground height, wind condition (wind direction, wind turbulence), etc. Input from the unit 4 (S101). From the above conditions, the following relationship can be grasped.

(1) Electric wire type, wind direction → lateral runout, wind pressure load (2) span length, sag rate → electric wire vibration frequency between utility poles, changes in generated stress (3) wind turbulence → wind fluctuation numerical value (4) Weight per unit of wire → Wind pressure load, amount of side deflection of the wire

  The arithmetic processing unit 5 calculates the overhead wire condition process, that is, the tension and the vibration frequency based on the condition (2) above, and statistically calculates the wind condition condition process, that is, the wind speed occurrence frequency based on the above (3). In order to evaluate the wind speed generation frequency distribution as shown in FIG. 4 from the weather data (for example, AMeDAS data) for the past several years (for example, 10 years), weibull (Weibull) ) Calculate scale factor (C) shape factor (k) of distribution. In the case of FIG. 4, it can be seen that the generation frequency of the wind speed is concentrated at about 3 m / s. A process of converting the scale factor (C) and the shape factor (k) obtained as described above into the generated stress with respect to the wind speed is executed (S102).

  In order for a wire to break due to vibration fatigue, when stress exceeding the allowable stress occurs in the wire, the number of repetitions accumulates, causing breakage and breakage. The generated stress changes moment by moment as the wind pressure load changes depending on the wind speed. The magnitude of the generated stress for each wind speed is obtained based on the experimental data and the generated stress at the wire gripping portion of the discharge clamp for each wind speed. In addition, by calculating the frequency of occurrence of the stress on the actual line, the total number of times the stress has been generated over a certain period can be determined, so the frequency of stress generated by wind vibration is converted from the frequency of wind speed. ing.

  Next, the arithmetic processing unit 5 is connected to the database unit 2 via the host computer 3 and acquires data on the generated stress (strain) for each wind speed (S103). As shown in FIG. 5, the generated stress is, based on experimental data, the stress generated in the electric wire gripping part of the discharge clamp to which the electric wire is attached, for example, at an interval of 2 m / s for 0 to 40 m / s, and a sag rate of 1 The relationship of “generated stress-wind speed” is obtained in advance for every 1% for ˜8%. This data is necessary because the stress increases or decreases depending on the sag rate, and the stress with respect to the wind speed changes. Note that “attachable” in the present specification indicates a state in which members are fixed without causing surface contact and loosening or gaps.

  Next, the arithmetic processing unit 5 calculates an allowable stress (fatigue limit stress) from the tension / Goodman diagram (S104), and obtains an allowable stress characteristic diagram shown in FIG. As the breakage of the wire of the electric wire proceeds, since the shared stress of the remaining wire increases, the allowable stress decreases and the frequency of occurrence of stress increases. The allowable stress of the electric wire material is calculated by calculating the cumulative stress when the allowable stress decreases because the individual wire load sharing the overhead wire tension changes due to the breakage of the wire.

  Next, based on the vibration frequency calculated in step S102 and the vibration fatigue characteristics stored in the database unit 2 (the SN curve which is the master curve shown in FIG. 6), the strand breaks and breaks. The number of times of vibration (number of repetitions) is calculated (S105).

  The number of breaks in which the wires are subjected to vibration fatigue due to repeated bending stress is calculated by the following equation (1). The number of breaks due to stress (repetitive strain) is obtained from the fatigue test of the wires shown in FIG. Since it can be determined from the curve, the total number of vibrations at a certain stress is the number of disconnections. The characteristics shown in FIG. 6 are created by conducting a factory test on the relationship of the number of breaks n corresponding to the generated strain ε, and obtaining the relationship of εi = f (ni), and are stored in the database unit 2 as a database.

（但し、ｎｉは、歪εｉが作用した回数、Ｎｉは、Ｓ−Ｎ曲線上のｉに対応するｎ値である。）

(Where ni is the number of times the strain εi has been applied, and Ni is the n value corresponding to i on the SN curve.)

  The number of times until the wire of the electric wire breaks due to repeated vibrations can be determined from the fatigue limit stress diagram, so the number of breaks at a certain stress can be obtained. Therefore, by calculating the number of vibrations in a certain period, the ratio of the stress to the total number of vibrations can be obtained from the stress frequency calculated from the wind speed frequency. From this, by accumulating the total number of occurrences of different stresses depending on the wind speed, it is possible to obtain the number of times until breaking and breaking.

  As the wire breakage progresses, the load shared by the uncut strands increases, and the breakage of the strands may progress at an accelerated rate. Therefore, the number of vibrations that result in disconnection is calculated for each wire size and the number of strands, and the disconnection years are calculated based on this result.

  First, the number of strands (x) for each wire size is input (for example, 240 SQ: x = 1), and this is used as a parameter (S106), and the allowable strain that changes due to strand breakage is read from the database unit 2 ( S107), from the vibration frequency obtained in step S102 and the repetitive stress of the allowable stress characteristic shown in FIG. 7 obtained in step S104, the number of vibrations until the number of wires x breaks and breaks is calculated. (S108). This calculation is sequentially performed for the number of strands x, x−1,..., 1 by the loop of steps S107 to S109, and is repeated until x = 0 is determined in step S109.

  The number of vibrations of all stresses by the above calculation is counted only when a stress exceeding the fatigue limit stress (allowable stress) of the material is generated. From the total number of times that the cumulative number of occurrences of the stress reaches disconnection on the SN curve stored in the database unit 2, the number of years of disconnection due to vibration fatigue (the number of years from the time of the facility of the wire) is calculated (S110). . In addition, by determining the number of wire breaks that differ depending on the type of electric wire, the initial stage, middle stage, and danger stage of the occurrence of disconnection are obtained.

  The disconnection years calculated in step S110 are displayed in the estimated life display column 75b of the interface screen 7 shown in FIG. 2 by the arithmetic processing unit 5 (S111). Further, in the disconnection level display column 75d, a display corresponding to the disconnection dose of the strands (one or two strands are disconnected, half of the strands are disconnected, all the strands are disconnected, etc.) is displayed.

(Effect of embodiment)
According to the above-described embodiment, the wind speed occurrence frequency is calculated based on several years of weather data, the wind speed occurrence frequency is converted into the stress occurrence frequency, and the vibration frequency obtained from the stress occurrence frequency and the overhead condition of the track The number of repetitions (vibration frequency) of the relevant part is calculated based on the above, and the life until the wire breaks and breaks is estimated from the accumulated result. The life due to vibration fatigue of the overhead electric wire attached to the part can be estimated.

(Example 1)
Next, examples of the present invention will be described.
First, on the actual track, the height of the power pole, the slackness of the electric wire, the span length, and the wind direction are measured, and these values are stored in the storage unit 51 of the vibration life estimation apparatus 1 and the life estimation of the processing content shown in FIG. The verification was performed using the results of calculation input to the software and the results of the dismantling investigation after removing the wires from the actual track.

  For example, when the span length is about 35 m and the wire is wired with a slack of about 5.0% with respect to the span length, and the wind turbulence at the location is calculated and input from the measured data, When the number of years until the wire breaks was calculated from the number of years from the start of the facility using the life estimation software, it was found that the error was about two years and was consistent with the survey results of the removed wires. This is a calculation result with a short life of about two years from the result of the dismantling investigation of the removed electric wire, and is a prediction result on the strict side in terms of track operation.

  Therefore, according to the present embodiment, it becomes possible to predict the disconnection timing of the electric wire from the vibration fatigue generated when the electric wire vibrates due to the wind hitting the electric wire gripping portion of the discharge clamp to which the electric wire is attached. It is possible to obtain a guideline for the wire replacement / inspection cycle for facility maintenance management of facilities, and even if the wire breaks due to vibration fatigue, personal injury due to electric shock due to dropping or sagging, facility damage, house Damage or the like can be prevented in advance.

[Other embodiments]
The present invention is not limited to the above embodiments, and various modifications can be made without departing from or changing the technical idea of the present invention.

It is a schematic structure figure showing a vibration life presumption system concerning an embodiment of the invention. It is a figure which shows the interface screen displayed on the display of a measuring device at the time of execution of a vibration life estimation process. It is a flowchart which shows the process of the arithmetic processing part shown in FIG. It is a characteristic view which shows a wind speed generation frequency. FIG. 4 is a “generated stress—assumed wind speed” characteristic diagram read as a database in step S103 of FIG. 3. It is a "repetitive strain-repetition number" characteristic view used for calculation of the number of breaks. FIG. 4 is a characteristic diagram of allowable stress read as a database in step S107 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vibration life estimation apparatus, 2 ... Database part, 3 ... Host computer, 4 ... Input part, 5 ... Operation processing part, 6 ... Display, 7 ... Interface screen, 8 ... Communication line, 10 ... Vibration life estimation system, 51 ... Storage section, 52 ... CPU, 71 ... Estimated area column, 72 ... Electric wire type input column, 73 ... End column, 74 ... Data setting column, 74a ... Electric pole input column, 74b ... Wind turbulence input column, 74c ... Main direction input Field 75 ... overhead wire condition input / life estimation result display field, 75a ... sag rate input field, 75b ... estimated life display field, 75c ... span length input field, 75d ... disconnection level display field, 76 ... area display field

Claims (5)

A first step of calculating a wind speed generation frequency based on a wind condition in a region where an overhead electric wire subject to life estimation exists, and converting the wind speed generation frequency into a stress generation frequency;
A second step of calculating a vibration frequency of the overhead electric wire based on an overhead wire condition of the overhead electric wire;
A third step of calculating the number of repetitions until the wire of the overhead wire reaches breakage based on the stress generation frequency and the vibration frequency;
And a fourth step of predicting the occurrence time of disconnection due to vibration fatigue in the electric wire gripping portion of the discharge clamp of the overhead electric wire from the number of repetitions.   2. The method for estimating a vibration life of an overhead electric wire according to claim 1, wherein the first step uses a wind direction angle and wind turbulence as the wind condition.   The method for estimating the vibration life of an overhead electric wire according to claim 1, wherein the fourth step calculates the number of years from the time of the facility until the breakage of the electric wire as the occurrence time of the vibration fatigue disconnection. Computer
A wind speed condition processing unit that calculates the wind speed occurrence frequency based on the wind condition condition of the region where the overhead wire to be estimated for life exists, and converts the wind speed occurrence frequency into a stress occurrence frequency, and
Based on the stress generation frequency by the wind condition processing unit and the vibration frequency of the overhead wire, the number of repetitions until the wire of the overhead wire is broken is calculated, and the discharge clamp of the overhead wire is calculated from the number of repetitions. A vibration life estimation program for an overhead electric wire to function as a calculation unit that predicts and calculates the occurrence time of disconnection due to vibration fatigue in the wire gripping portion.   The said operation part calculates the said vibration frequency based on the overhead wire conditions of the said overhead wire, The vibration lifetime estimation program of the overhead wire of Claim 4 characterized by the above-mentioned.

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