JP5551974B2 - Elastic support method and elastic support device for partial model of transmission line - Google Patents

Description

  The present invention relates to an elastic support method and an elastic support device for a transmission line partial model. More specifically, the present invention is suitable for application to the support of a transmission line portion model used for, for example, vibration analysis of an overhead transmission line based on a wind tunnel experiment or used as a snow landing sampler in an outdoor icing snow experiment. The present invention relates to a model elastic support method and an elastic support device.

  Aerodynamic vibration may occur due to snow and ice adhering to overhead power transmission lines in winter. Such aerodynamic vibration is called galloping. The galloping phenomenon in overhead power transmission lines during icing and snowing is very large in amplitude due to torsion and horizontal vibration in addition to vertical vibration. And when galloping reaches a large amplitude, it leads to short circuit and damage to insulators and steel towers due to contact between wires in different phases, so various researches such as investigation of occurrence conditions, examination of countermeasure methods, development of countermeasure products, etc. (Non-patent Document 1). As methods for elucidating the occurrence conditions and response characteristics of galloping in the transmission line, the following three methods are performed.

1) Observation under natural icing snow or simulated icing snow on actual scale transmission line Observe using actual aerial transmission line and observation test line to understand galloping response characteristics and verify the effectiveness of countermeasure products Etc. are being implemented. In the observation test line, there are a method of observing icing snow shape and transmission line response under weather conditions that actually icy and snowing in winter, and a method of observing with artificial simulated icing snow shape attached. (For example, Non-Patent Document 2).

2) Response analysis by numerical calculation based on the measurement result of the aerodynamic coefficient of the cross section of the icing snow transmission line As an attempt to formulate the occurrence of galloping, the aerodynamic force acting on a vibrating object at that moment Den Hartog's conditional formula formulated using quasi-stationary theory is assumed to be equal to the stationary aerodynamic force generated when the wind acts on a stationary object at a relative angle of attack and relative wind speed. This is to determine the possibility of occurrence of galloping from the cross-sectional shape using the steady aerodynamic coefficient obtained by wind tunnel experiments or the like. On the other hand, Den Hartog's conditional expression determines whether the cross-sectional shape is aerodynamically unstable (in other words, galloping can occur). To estimate the galloping response amplitude, An analysis that takes into account the structural characteristics of the wire is required. Therefore, a finite element method analysis program (referred to as CAFSS) that takes into account the geometric nonlinearity of transmission lines has been developed, and analysis of galloping time history responses under various conditions has been carried out (for example, non-patent literature). 3).

3) Estimation based on results of free vibration experiments in wind tunnels using partial models of icing snow transmission lines Various free vibration experiments have been carried out by applying wind to partial models that model icing snow transmission lines. For example, a galloping response is measured by elastically supporting a partial model of a 4-conductor transmission line during icing snow in the wind tunnel with two degrees of freedom in the vertical and torsional directions, or a single-conductor icing snow transmission line model in the wind tunnel. The response is measured with elastic support. In these measurement results, it is said that the response characteristic can be substantially evaluated using the quasi-stationary aerodynamic force. However, due to device limitations, the galloping measured in these experiments is such that the double amplitude in the vertical and horizontal directions is about 10-20 [cm], and the double amplitude in the torsion direction is about 10 [deg.]. Limited to a small amplitude range. However, in galloping in actual transmission lines, it is said that the double amplitude in the vertical and horizontal directions reaches several meters, and the double amplitude in the torsional direction becomes very large. Therefore, an experiment that enables large-amplitude vibration with three degrees of freedom in the vertical, horizontal, and torsional directions by supporting a partial model of a four-conductor transmission line with wires from two points separated in the span direction has been conducted. (For example, nonpatent literature 4).

Research Committee on Galloping Phenomenon and Analysis Technology for Overhead Transmission Lines: Galloping Phenomenon Analysis Technology for Overhead Transmission Lines, IEEJ Technical Report, No. 844, 2001 Takeshi Okuma et al .: Galloping observation results on the Mogami test line, AEW technique, No. 26, pp.67-76, 1997 Mikio Shimizu et al .: Geometrically nonlinear analysis of galloping of transmission lines, Journal of Structural Engineering, Vol.44A, pp.951-960, 1998 Mikio Shimizu et al .: Elucidation of galloping phenomenon of four-ice and single-conductor transmission lines on ice and snow (Part 1) -Reproduction experiment of galloping in a wind tunnel of a partial model-

  However, although the galloping phenomenon in the real scale power transmission line has been confirmed in the above 1) observation on the real scale power transmission line, the data necessary for grasping the phenomenon when the galloping has occurred (for example, wind speed in the span) It is very difficult to acquire all of the distribution, ice-covered snow shape distribution, response amplitude, response mode, etc. Further, input conditions such as wind direction and wind speed, and the shape of icing snow cannot be arbitrarily adjusted. In addition, large-scale construction is required each time the galloping phenomenon is observed by changing the overhead wire form and countermeasure products. As described above, when observations on actual scale transmission lines can capture actual icing and snow phenomena and galloping phenomena on actual scale transmission lines, the types of overhead lines, types of countermeasures, and weather conditions have changed. In order to examine the difference in response characteristics in detail, there is a problem that much time and cost are required. For this reason, it is hard to say that it is versatile.

  Further, in the response analysis by the above-mentioned 2) numerical calculation, generally, the aerodynamic force that is an input condition in the galloping analysis is input by using a quasi-stationary theory as a stationary aerodynamic coefficient measured by a wind tunnel experiment or numerical calculation. . However, in transmission line galloping, torsional vibrations occur in addition to reaching large amplitude vibrations, and it has been the subject of discussion whether aerodynamics can be evaluated with quasi-stationary aerodynamics. And in the 4-conductor transmission line at the time of icing snow, the aerodynamic force is unsteady in the moment during large amplitude vertical vibration and the lift and moment during large amplitude torsional vibration. It has become clear that it cannot be expressed exactly (for example, Yoshiro Kimura et al .: Characteristics of unsteady aerodynamic forces acting on a four-conductor transmission line with icing snow during large-amplitude excitation, Journal of Structural Engineering, Vol.46A, pp. .1055-1062, 2000). As described above, in response analysis by numerical calculation, it is easy to set various conditions, but the application range of aerodynamic force formulation using quasi-stationary theory and the estimation accuracy of galloping response obtained by numerical calculation, etc. There is a problem that needs to be verified in comparison with response characteristics obtained from observations and experiments. For this reason, it is hard to say that it is versatile.

  In addition, in the above 3) free vibration test using a wind tunnel, large amplitude with 3 degrees of freedom of vertical, horizontal and torsion by supporting the partial model of the above-mentioned 4-conductor transmission line with wires from two points separated in the span direction. In the experiment that enabled vibration, although the vertical and horizontal double amplitude was about 50 [cm], and the torsional double amplitude was about 100 [deg.], The actual transmission line It is not possible to reproduce a low frequency corresponding to the condition in. In this way, in a free vibration test using a wind tunnel, the response characteristics can be measured after easily adjusting any structural characteristics, wind direction, wind speed, turbulence intensity, and the shape of icing snow. In experiments for galloping, it is necessary to conduct experiments with a very large amplitude and a very low frequency with respect to the size of the model (conductor diameter, etc.) compared to experiments for aerodynamic phenomena of other structures. Therefore, there is a problem that it is difficult to perform an experiment that reproduces an actual phenomenon even if a similarity rule is used, and the experiment method itself needs to be devised. For this reason, it is hard to say that it is versatile.

  Based on the above background, if wind tunnel experiments and outdoor icing snow experiments that can simulate the structural characteristics of actual transmission lines can be carried out, various conditions (for example, structural characteristics, wind direction, wind speed, etc.) It is possible to clarify the occurrence conditions and response characteristics of galloping under the input conditions of ( Furthermore, it becomes possible to clarify the applicability range of the aerodynamic evaluation using the quasi-stationary theory and the estimation accuracy of the galloping response obtained by numerical calculation.

  Therefore, the present invention has an object to provide an elastic support method and an elastic support device for a transmission line partial model that can vibrate the transmission line partial model with a large amplitude and a low frequency in wind tunnel experiments, outdoor icing snow experiments, and the like. And

  In order to achieve such an object, the elastic support method for a transmission line partial model according to claim 1 is characterized in that a transmission line partial model having a conductor portion and a pair of opposed end plates attached to both ends of the conductor portion, A pair of elastic members attached to one of the pair of end plates and supported at one of a pair of support bases disposed on both sides of the power transmission line partial model with the other end facing each of the pair of end plates The suspension member is suspended and elastically supported, and at least one of the pair of elastic suspension members is constituted by a plurality of linear elastic members, and the radial support position of the elastic member is changed and the circumferential direction is changed. The other end of the elastic suspension member is supported by the support base via a position adjustment mechanism that changes the support position of the support.

  In addition, the elastic support device for a transmission line partial model according to claim 6 is provided on each of the transmission line partial model having a conductor portion and a pair of opposing end plates attached to both ends of the conductor portion, and the pair of end plates. A pair of support bases arranged opposite to each other on both sides of the transmission line partial model, and one end is attached to one of the pair of end plates and the other end is supported by one of the pair of support bases. A pair of elastic suspension members that are elastically supported by suspending the partial model, and at least one of the pair of elastic suspension members is composed of a plurality of linear elastic members and is attached to a support base. The other end of the elastic suspension member is supported by the support base through a position adjusting mechanism that changes the radial support position of the elastic member and changes the circumferential support position.

  Therefore, according to the elastic support method and the elastic support device for these power transmission line partial models, the radial support position of the elastic member is changed by the position adjustment mechanism attached to the support base, and the fixed point intervals of the plurality of elastic members are increased. Since it can be changed as appropriate, the frequency in the torsional direction of the transmission line partial model can be easily adjusted according to the experimental conditions and the like. In addition, since the flexural rigidity can be adjusted by selecting a member to be used as an elastic member, it is possible to easily adjust the frequency in the vertical direction and torsional direction of the transmission line partial model according to experimental conditions and the like. it can. Furthermore, the horizontal frequency of the power transmission line partial model can be adjusted by adjusting the sag of the elastic support of the power transmission line partial model by the elastic suspension member.

  According to a second aspect of the present invention, in the elastic support method for a power transmission line partial model according to the first aspect, a position adjusting mechanism is provided on the end plate of the power transmission line partial model to change the radial attachment position of the elastic member. I am doing so. According to a seventh aspect of the present invention, in the elastic support device for a power transmission line partial model according to the sixth aspect, the end plate of the power transmission line partial model includes a position adjusting mechanism for changing a radial attachment position of the elastic member. I am doing so. In this case, by changing the radial support position of the elastic member by the position adjusting mechanism provided on the end plate of the power transmission line partial model, and changing the fixed point interval of the plurality of elastic members, the transmission line portion The frequency in the torsional direction of the model can be adjusted.

  According to a third aspect of the present invention, in the elastic support method for a power transmission line partial model according to the first aspect, a tension adjusting mechanism for changing the tension of the elastic member for each elastic member is provided on the support base. . According to an eighth aspect of the present invention, in the elastic support device for a power transmission line partial model according to the sixth aspect, the support base includes a tension adjusting mechanism that changes the tension of the elastic member for each elastic member. . In this case, since the support base is provided with a tension adjustment mechanism, the sag of the elastic support of the transmission line partial model can be changed as appropriate, so that the horizontal frequency of the transmission line partial model is used as an experimental condition. In addition, it can be easily adjusted each time.

  According to a fourth aspect of the present invention, in the elastic support method for the transmission line partial model according to the first aspect, the vertical frequency of the transmission line partial model is changed by changing the rigidity of the elastic member. Yes. In this case, the frequency in the vertical direction of the transmission line partial model can be easily adjusted each time according to the experimental conditions and the like.

According to a fifth aspect of the present invention, in the elastic support method for the transmission line partial model according to the first aspect, the vertical frequency f _y , the horizontal frequency f _z , and the torsional vibration of the transmission line partial model. It has a number f _theta as each represented by formula. In this case, each frequency in each direction of the transmission line partial model can be adjusted and set so as to meet the experimental conditions.

  According to the elastic support method and the elastic support device for the transmission line partial model according to claims 1 and 6, the frequency in the vertical direction, horizontal direction, and twist direction of the transmission line partial model can be easily adjusted according to the experimental conditions. Because it can be adjusted, the transmission line model can be vibrated with large amplitude and low frequency in wind tunnel experiments and outdoor icing snow experiments, and the usefulness of data obtained by wind tunnel experiments and outdoor icing snow experiments etc. It is possible to improve the reliability and to easily adjust the support device for the transmission line partial model, thereby reducing the labor and improving the versatility. In addition, by installing a device according to the present invention in an area where icing and snowing occurs outdoors using a partial model simulating the conductor shape of an overhead power transmission line, the actual icing and snowing phenomenon can be reproduced and the actual landing Since the experiment of the galloping phenomenon under the reproduction condition of the ice and snow can be conducted, useful data can be provided for the analysis of the icing snow phenomenon itself and the relationship between the icing snow phenomenon and the galloping phenomenon.

  According to the elastic support method and the elastic support device for the transmission line partial model according to claims 2 and 7, the frequency in the torsional direction of the transmission line partial model can be adjusted. By appropriately adjusting the frequency of the transmission line partial model, it is possible to improve the usefulness and reliability of data obtained by wind tunnel experiments, outdoor icing snow experiments, and the like.

  According to the elastic support method and the elastic support device for the transmission line partial model according to claims 3 and 8, the horizontal frequency of the transmission line partial model can be easily adjusted according to the experimental conditions and the like. In addition, it is possible to easily adjust the support device for the transmission line partial model in wind tunnel experiments and outdoor ice / snow experiments, thereby reducing the labor and improving versatility.

  According to the elastic support method and the elastic support device of the power transmission line partial model according to claim 4, the vertical frequency of the power transmission line partial model can be easily adjusted according to the experimental conditions and the like. It becomes possible to easily adjust the support device for the transmission line partial model in an experiment or an outdoor icy and snow experiment, thereby reducing the labor and improving the versatility.

  According to the elastic support method and the elastic support device of the power transmission line partial model according to claim 5, each frequency of each direction of the power transmission line partial model can be adjusted and set so as to meet the experimental conditions. In addition, it is possible to easily set the specifications of the supporting device for the transmission line partial model in accordance with various experimental conditions in wind tunnel experiments and outdoor ice / snow experiments, etc., thereby reducing the effort and improving the versatility.

It is a general | schematic perspective view which shows an example of embodiment of the elastic support apparatus of the power transmission line partial model of this invention. It is a schematic diagram which shows an example of the position adjustment mechanism of the elastic support apparatus of the power transmission line partial model of this invention. It is a schematic diagram which shows an example of the tension adjustment mechanism of the elastic support apparatus of the power transmission line partial model of this invention. It is a figure explaining the definition of the parameter in connection with the equation of motion showing the structural characteristic of the transmission line partial model of Example 1. It is a figure explaining the definition of the parameter in connection with the equation of motion showing the structural characteristic of the transmission line partial model of Example 1. It is a figure which shows the analysis result of the frequency characteristic with respect to the double amplitude of Example 1. FIG. It is a figure which shows the detailed dimension of the end plate of Example 3. FIG. It is a figure explaining the definition of an amplitude and a period in the time history waveform of Example 3. It is a figure which shows the vertical displacement waveform after giving the initial displacement to the perpendicular direction of Example 3. FIG. It is a figure which shows the free vibration experiment result and analysis result of the frequency characteristic with respect to the double amplitude of Example 3. It is a figure which shows the free vibration experiment result and analysis result of the frequency characteristic with respect to the double amplitude of Example 3. It is a figure which shows the waveform after giving the initial displacement to the horizontal direction of Example 3. FIG.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  FIG. 1 to FIG. 3 show an example of an embodiment of an elastic support method and an elastic support device for a power transmission line partial model of the present invention. In the present embodiment, a case where an actual size partial model of a four-conductor power transmission line (hereinafter referred to as a power transmission line partial model) is supported will be described as an example.

  Specifically, in the power transmission line partial model 10 of the present embodiment, the four conductor portions 11,..., 11 are parallel to each other in the axial direction, and the arrangement of the end portions 11 a of each conductor portion 11 is square. The both ends 11a and 11a are arranged and fixed by a pair of end plates 12 and 12 facing each other. Here, in the following description, it is defined that the axial direction of the transmission line partial model 10 is the same as the axial direction of each conductor portion 11.

  If the transmission line partial model 10 simulates the response of an actual transmission line in, for example, a wind tunnel experiment or an outdoor icing snow experiment, the conductor shape, the conductor interval, the mass, and the mass moment of inertia are those of the actual transmission line. Is configured to be equivalent to Specifically, for example, the interval between the conductor portions 11 (in this embodiment, in other words, the length of one side of the square formed by the positions of the end portions 11a of the four conductor portions 11) is the actual transmission. It is conceivable that it is set to about 40 [cm] as with the electric wire.

  On the other hand, the length of the conductor portion 11 of the power transmission line partial model 10 is not limited to a specific length. For example, the power transmission line partial model assumed from the scale of the wind tunnel test facility and the size of the power transmission line partial model 10. The length is set to an appropriate length in consideration of the overall size of the elastic support device 1. Specifically, for example, the length of the conductor portion 11 is set to about 100 [cm].

  Moreover, as the conductor part 11, what cut | disconnected the pipe which simulated the shape of the actual conductor, and the steel core aluminum strand wire actually used as a conductor is used. Further, when conducting an experiment on a power transmission line during icing snow, a model of icing snow simulating the shape of icing snow may be manufactured and the model may be attached to the conductor 11. A conductor model that reproduces the shape of the ice and snow condition may be manufactured and used as the conductor portion 11.

  In order to fix each conductor part 11 in a predetermined positional relationship, a pair of opposed end plates 12 attached to both ends 11a and 11a of the conductor part 11 are generally two air currents when performing a wind tunnel experiment. In order to ensure dimensionality, it is formed in a thin circular flat plate shape. In addition, when it is not necessary to positively ensure the two-dimensionality of the airflow, for example, an annular shape may be used. Further, the shape of the end plate 12 is not limited to a circle, and may be a regular polygon. In the following description, the surface of the end plate 12 on the conductor portion 11 side is referred to as an inner surface, and the opposite surface is referred to as an outer surface.

  Each conductor portion 11 may be fixedly attached to the end plate 12, or may be attached so as to be rotated by an arbitrary angle and then fixed. When it is attached so as to be rotatable about the shaft, it is possible to adjust the development angle of the icing snow shape in an arbitrary direction for each conductor portion 11. In addition, since each conductor portion 11 can be individually attached to and detached from the end plate 12 and an arbitrary conductor portion can be removed, a model having a different icing snow shape for each conductor portion (for example, after a multiconductor). Experiments such as reducing the shape of the icy snow on the flow side) are also possible.

  Further, in order to make the mass and the mass moment of inertia of the entire transmission line partial model 10 the same as the actual overhead transmission line, a weight for mass adjustment may be appropriately attached to, for example, the outer surface of the end plate 12.

  Further, for example, a position measurement mark may be attached to the outer surface of the end plate 12 in order to measure the behavior of the transmission line partial model 10 during a wind tunnel experiment or the like. Then, the position of the mark may be measured by visual observation or image analysis to calculate the displacement of the transmission line partial model 10 in the vertical direction, horizontal direction, and twist direction. For example, four image tracing markers of different colors are attached at equal intervals at positions near the outer edge of the end plate 12, and a video camera is installed at the lower part of the support base 4, and images taken by the video camera are displayed on the computer. The displacement in the vertical direction, the horizontal direction, and the torsional direction is calculated by analyzing the image after taking in the image. Specifically, in the captured video, by specifying the region to be analyzed (ie, the range of pixels) and the color to be extracted (ie, the range of RGB values) in each frame, It is conceivable to calculate coordinate values.

  And the elastic support method of the power transmission line partial model of this invention is the power transmission line partial model 10 which has a pair of opposing end plates 12 and 12 attached to the both ends of the conductor part 11 and this conductor part 11, and one end is a pair. Of the pair of support bases 4, 4 attached to one of the end plates 12, 12 and having the other end opposed to the pair of end plates 12, 12 on both sides of the transmission line partial model 10. A pair of elastic suspension members 2 and 2 supported by one of the two are suspended and elastically supported, and each of the pair of elastic suspension members 2 and 2 is constituted by a plurality of linear elastic members 2a. The other end of the elastic suspension member 2 is supported by the support base 4 via a position adjustment mechanism 3 that changes the support position in the radial direction of the member 2a and changes the support position in the circumferential direction.

  The elastic support method for the transmission line partial model is realized as an elastic support device for the transmission line partial model of the present invention. The elastic support device 1 of the power transmission line partial model of the present invention includes a power transmission line partial model 10 having a conductor portion 11 and a pair of opposed end plates 12 and 12 attached to both ends of the conductor portion 11, and a pair of end plates. 12 and 12, a pair of support bases 4 and 4 disposed on both sides of the transmission line partial model 10, and one end is attached to one of the pair of end plates 12 and 12, and the other end is a pair. A pair of elastic suspension members 2, 2 that are supported by one of the support bases 4, 4 and elastically support the power transmission line partial model 10 by aerial, and the pair of elastic suspension members 2, 2. Each of these comprises a plurality of linear elastic members 2a, and is attached to a support base 4 via a position adjusting mechanism 3 that changes the radial support position of the elastic member 2a and changes the circumferential support position. The other end of the elastic suspension member 2 is the support base 4. It is to be supported.

  In this embodiment, four linear (in other words, string-like) elastic members 2 a constituting the elastic suspension member 2 are attached to the outer surface of each end plate 12 of the power transmission line partial model 10. In addition, the linear (string-like) elastic member 2a which comprises the elastic suspension member 2 is not restricted to four. Further, the number of elastic members 2 a may be different on both sides of the power transmission line partial model 10. Specifically, for example, in addition to four on both sides as in this embodiment, two or three on both sides may be used, one on two and the other on three, or one on one. The book may be two or three on the other side. That is, it is only necessary that at least one of the pair of elastic suspension members 2 and 2 on both sides of the power transmission line partial model 10 is constituted by a plurality of linear elastic members 2a.

  The elastic member 2a preferably has a rigidity that is as constant as possible with respect to elongation (in other words, linearity is maintained). In addition, as the elastic member 2a, an elastic suspension member 2 having a sufficient strength to support the power transmission line partial model 10 is used. Specifically, for example, a string member made of urethane rubber, nitrile rubber, or natural rubber and having a round cross-sectional shape of about 3 mm in diameter is used.

  The two support bases 4, 4 are arranged on both sides of the transmission line partial model 10 in the axial direction so as to be separated from the transmission line partial model 10. The support base 4 of this embodiment is comprised as a rectangular parallelepiped frame structure. In FIG. 1, only the bottom rectangular frame 4 a and the front rectangular frame 4 b having the same bottom side as the bottom rectangular frame 4 a among the rectangular frame structures constituting the support base 4 are shown.

  And the horizontal member 4c is attached to the front part rectangular frame 4b of the support stand 4, and the position adjustment mechanism 3 is attached to the said horizontal member 4c so that the end plate 12 of both ends of the power transmission line partial model 10 may be opposed.

  As shown in FIG. 2, the position adjustment mechanism 3 has a circular flat plate-shaped main body 3a, and is attached to the horizontal member 4c by a center bolt 3c that passes through the center of the main body 3a. In addition, the shape of the main body 3a is not limited to a circle, and may be a polygon.

  The main body 3a of the position adjusting mechanism 3 includes a radial position adjusting mechanism for adjusting the attachment / fixing position of each elastic member 2a constituting the elastic hanging member 2 in the radial direction. Four slits 3b are formed. The four radial slits 3b,..., 3b are formed at the positions of the sides of the cross centered on the central bolt 3c of the main body 3a, in other words, the directions of the adjacent slits are shifted by 90 °.

  In the present embodiment, the number of the radial slits 3b is four because the number of the elastic members 2a constituting the elastic suspension member 2 is four, that is, at least as many as the number of the elastic members 2a are formed. The Therefore, for example, when there are three elastic members 2a, the directions of adjacent slits may be shifted by 120 ° to form three radial slits 3b, and when there are two elastic members 2a. Alternatively, two radial slits 3b may be formed on a straight line passing through the center bolt 3c.

  One slider 5 is attached to each of the radial slits 3b of the position adjusting mechanism 3 as a component of the radial position adjusting mechanism. The slider 5 has fixing bolts 5b and 5b on both sides in a direction orthogonal to the longitudinal direction of the radial slit 3b (that is, the radial direction of the main body 3a).

  The position adjusting mechanism 3 has the radial slit 3b, and when the bolts 5b and 5b are loosened, the position adjusting mechanism 3 has a longitudinal direction of the radial slit 3b (that is, the radial direction of the main body 3a; double arrow 3f in FIG. 2). ), And when bolts 5b and 5b are tightened, they are fixed so that they cannot slide.

  The slider 5 is further provided with a through hole 5a at the center position. And the elastic member 2a penetrates the said through-hole 5a. Each elastic member 2a is supported by the support 4 via the slider 5 (in other words, locked to the slider 5).

  Here, each slider 5 that locks the elastic member 2a and positions the fixing point of the elastic member 2a is on the circumference centered on the central bolt 3c, that is, at a position separated from the central bolt 3c by the same distance. Arranged and fixed. For this reason, in this embodiment, the scale 3h is attached | subjected to the both sides of the longitudinal direction of the radial direction slit 3b.

  The body 3a of the position adjusting mechanism 3 further includes two circumferential slits 3d that constitute a circumferential position adjusting mechanism for adjusting the attaching / fixing position of each elastic member 2a end in the circumferential direction. Is done. The two circumferential slits 3d, 3d are formed to face each other at a position near the outer edge of the main body 3a as having a length of a quarter of one circumference in the circumferential direction. And the peripheral volt | bolt 3e which penetrates the circumferential direction slit 3d and is fitted by the horizontal member 4c of the support stand 4 is provided. The circumferential slit 3d functions as a guide when the main body 3a rotates, and also functions as a guide allowing rotation of 90 degrees or more so that the main body 3a can be set at an arbitrary angle. Any shape may be used, and for example, it may have a length exceeding a quarter of one round in the circumferential direction. Further, the number of circumferential slits 3d may be one.

  The position adjusting mechanism 3 has a circumferential slit 3d so that the main body 3a can rotate around the central bolt 3c (arrow 3g in FIG. 2) when the central bolt 3c and the peripheral bolts 3e and 3e are loosened. At the same time, when these bolts 3c, 3e, 3e are tightened, they are fixed so as not to rotate.

  In the initial state of attaching the position adjusting mechanism 3 to the horizontal member 4c of the support base 4, for example, each radial slit 3b,..., 3b forms an angle of 45 degrees with respect to the horizontal member 4c, and two circumferential directions The slits 3d and 3d face each other horizontally (in other words, left and right). However, the initial state (posture) of attachment of the position adjustment mechanism 3 is not limited to this, and is adjusted as appropriate so that it can be set to a desired angle according to the contents of the experiment.

  The elastic support device 1 of the power transmission line partial model of the present embodiment further includes a tension adjusting mechanism 6. The tension adjusting mechanism 6 is for individually adjusting the tension of each elastic member 2a. As shown in FIG. 3, the tension adjusting mechanism 6 includes a pulley 6 a and a weight 6 b and is provided on the support base 4. And the elastic member 2a which penetrated the through-hole 5a of the slider 5 attached to the position adjustment mechanism 3 is put on the pulley 6a. Then, a weight 6b is attached to the distal end portion (in other words, the lower end portion) of the elastic member 2a that passes through the pulley 6a and hangs downward.

  In FIG. 3, only two sets of the pulley 6a and the weight 6b are displayed. However, in this embodiment, the number of the elastic members 2a constituting the elastic suspension member 2 is four, so that one support is provided. The table 4 is provided with four sets of pulleys 6a and weights 6b. That is, the same number of pulleys 6a and weights 6b as the number of elastic members 2a are provided.

  By adjusting the weight of the weight 6b of the tension adjusting mechanism 6, the tension of each elastic member 2a is individually adjusted. The elastic member 2a penetrates the slider 5 in a state in which the tension of each elastic member 2a and the three components of the angle of the transmission line partial model 10 (that is, the horizontal angle, the inclination angle, and the elevation angle) are ensured according to the contents of the experiment. The elastic member 2a is fixed to the slider 5 by sandwiching both sides of the portion with a fixing jig. Thereby, it becomes possible to elastically support the power transmission line partial model 10 in a state in which an arbitrary tension and an arbitrary posture of each elastic member 2a are set in accordance with the contents of the experiment.

  With the above-described configuration, the power transmission line partial model 10 is elastically supported by the elastic suspension member 2 between the support bases 4 and 4 that are disposed to face each other on both sides in the axial direction. The elastic member 2 a constituting the elastic suspension member 2 can be adjusted in tension so that the support position (locking position) can be adjusted by the position adjusting mechanism 3 and the tension adjusting mechanism 6 can adjust the tension. In this way, it is supported by the support base 4.

  For example, the mounting position of the horizontal member 4c to the front rectangular frame 4b of the support base 4 can be changed, and the height of the position adjusting mechanism 3 is changed in accordance with the slackness of the elastic support of the power transmission line partial model 10. The height of the support point of the power transmission line partial model 10 may be adjusted.

  According to the elastic support method and the elastic support device of the power transmission line partial model of the present invention having the above configuration, the radial support positions and the circumferential support positions of the plurality of elastic members 2a are changed, or the plurality of elastic members The tension of 2a can be adjusted for each elastic member 2a.

  As a result, the transmission line partial model 10 can be vibrated with a large amplitude with three degrees of freedom in the vertical direction, the horizontal direction, and the torsional direction. In addition, the elastic member 2a, which is a string member that exhibits elastic behavior (in other words, low rigidity), is vibrated at a low frequency equivalent to that of an actual power transmission line by using it long in the axial direction of the power transmission line partial model 10. Is possible. And it becomes possible to adjust and set each vibration characteristic of each direction of a power transmission line partial model so that it may meet experimental conditions.

  Specifically, in the present invention, the support point of the elastic member 2 a constituting the elastic suspension member 2 by the support base 4 is the radial slit 3 b and the slider 5 as the radial position adjustment mechanism of the position adjustment mechanism 3 and the circumference. It is adjusted to an arbitrary position (in other words, the angle and interval of the support points are adjusted to an arbitrary position) and fixed at an arbitrary position by the circumferential slit 3d as the directional position adjusting mechanism.

  Then, by adjusting the angle of the support point (fixed point) of the elastic suspension member 2 constituted by the elastic member 2a by the position adjustment mechanism 3, the axis in the axial direction of the power transmission line partial model 10 is set as the rotation center. The installation angle can be adjusted. In the experiment using the wind tunnel, the wind is generally blowing in the horizontal direction. According to the present invention, the position adjustment mechanism 3 is rotated to rotate the transmission line partial model 10. The elevation angle with respect to the wind can be adjusted, and arbitrary blowing and blowing angles can be set.

  Further, by adjusting the distance between the support points (fixed points) of the elastic member 2a constituting the elastic suspension member 2 by the position adjusting mechanism 3, the frequency in the torsional direction of the transmission line partial model 10 can be adjusted. It is.

  Further, the horizontal frequency is adjusted by adjusting the slackness of the elastic support of the power transmission line partial model 10 (in other words, the tension of the elastic member 2a constituting the elastic suspension member 2) by the tension adjusting mechanism 6. In addition, by adjusting the flexural rigidity of the elastic member 2a constituting the elastic suspension member 2, it is possible to adjust the frequency in the vertical direction and the twist direction of the transmission line partial model 10.

  Therefore, in order to simulate the response of actual transmission lines in wind tunnel experiments and outdoor icing and snow experiments, it is necessary to make the frequency characteristics equivalent to the actual transmission lines in addition to the conductor shape, conductor spacing, mass, and mass moment of inertia. However, in the present invention, by combining the above-described configurations and mechanisms, the respective frequencies in the vertical direction, the horizontal direction, and the torsional direction can be adjusted to the target values. Thereby, the frequency characteristic in the situation where various overhead wire forms or countermeasure products are attached can be reproduced, and the difference in galloping response characteristics due to these differences can be examined.

  According to the elastic supporting method and the elastic supporting device of the transmission line partial model of the present invention having the above-described configuration, the experiment is performed in an area where icing snow is outdoors using the partial model simulating the conductor shape of the overhead transmission line. By installing the device, it is possible to reproduce the actual icing snow phenomenon and to analyze the galloping phenomenon under the actual icing snow condition.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the partial model 10 of the four-conductor transmission line having the four conductor portions 11 is taken as an example of the transmission line partial model supported by the elastic support method and the elastic support device of the transmission line partial model of the present invention. However, the types of transmission lines that can be targeted by the present invention are not limited to four-conductor transmission lines, and may be single-conductor transmission lines or 2 to 8-conductor transmission lines.

  In the above-described embodiment, the radial position adjustment mechanism of the position adjustment mechanism 3 is configured to include the radial slit 3b and the slider 5, but the configuration of the radial position adjustment mechanism is not limited to this. In addition, it is possible to adjust the distance between the fixing points of the elastic members 2a by moving the support positions of the elastic members 2a constituting the elastic suspension member 2 in the radial direction (that is, the radial direction) with respect to the center of the support positions. Any configuration may be used.

  In the above-described embodiment, the circumferential position adjustment mechanism of the position adjustment mechanism 3 is configured to have the circumferential slit 3d. However, the configuration of the circumferential position adjustment mechanism is not limited to this, and is elastic. Any configuration may be used as long as the support positions (fixed points) of the elastic members 2a constituting the suspension member 2 can be adjusted in the circumferential direction by rotating with respect to the centers of these support positions.

  Further, the end plate 12 of the power transmission line partial model 10 may be provided with a mechanism for adjusting the attachment position of each elastic member 2a to the end plate 12 in the radial direction. In this case, the transmission line can also be adjusted by moving the attachment position of each elastic member 2a to the end plate 12 in the radial direction with respect to the axis of the transmission line partial model 10 to adjust the fixed point interval of each elastic member 2a. The frequency in the torsional direction of the partial model 10 can be adjusted.

  In the above-described embodiment, the tension adjustment mechanism 3 is configured by the pulley 6a and the weight 6b. However, the configuration of the tension adjustment mechanism is not limited to this, and the elastic suspension member 2 is configured. Any configuration may be used as long as the tension of the elastic member 2a to be adjusted is adjustable. Specifically, for example, a tensioner may be adjusted by winding the elastic member 2a so as to include a winder instead of the weight 6b. In the present invention, the tension adjusting mechanism 3 is not an essential configuration. In the present invention, the horizontal frequency of the transmission line partial model 10 is adjusted by adjusting the slackness of the elastic support of the transmission line partial model 10 by the elastic suspension member 2 without the tension adjusting mechanism 3. Is possible.

  An embodiment in which the elastic support method of the power transmission line partial model and the adjustment method of the frequency in each direction of the power transmission line partial model in the elastic support device according to the present invention will be described with reference to FIGS. The configuration of the elastic support method and the elastic support device of the power transmission line partial model of this example is the same as that described in the above embodiment. In FIG. 4, only two elastic members 2a are displayed per side. This is because the horizontal positions of the elastic members 2a overlap each other, and the elastic member 2a actually hits one side. There are four.

  The following were used as parameters related to the equation of motion representing the structural characteristics of the transmission line partial model 10 when no wind was applied. The definition of each parameter is shown in FIGS. The fixing of the elastic member on the power transmission line partial model side refers to the attachment of each elastic member 2a to the outer surface of the end plate 12 of the power transmission line partial model 10, and the fixing of the elastic member on the support base side. Is a support point (fixed point) of each elastic member 2 a by the position adjusting mechanism 3 and the slider 5.

l: Length of conductor [m]
m: Mass of the transmission line partial model [kg]
I: Mass moment of inertia [kgm ² ] of the transmission line partial model
B _r : Elastic member fixed radius on the transmission line partial model side [m]
_Dr : elastic member fixing radius on the support base side [m]
α _B ,: Elastic member fixing angle on the transmission line partial model side [rad.]
α _D : Elastic member fixing angle on the support base side [rad.]
L: Distance between the support base and the transmission line partial model [m]
H: Sag of elastic support of transmission line partial model [m]
T: tension of elastic member [N]
E: Young's modulus of elastic member [N / m ² ]
A: Cross-sectional area of elastic member [m ² ]

Point D ₁ , point D ₂ , point D ₃ , and point D ₄ in FIG. 5A are the positions of the support points (fixed points) of the four elastic members 2 a locked by the sliders 5. ₀ is the position of the center bolt 3c of the position adjusting mechanism 3 and the center of the circumference where each slider 5 is arranged. Further, point B ₁ , point B ₂ , point B ₃ , and point B ₄ in (b) are attachment points of the four elastic members 2 a to the end plate 12, and point B ₀ is the four elastic members 2 a. This is the center of the attachment point to the end plate 12. The slackness H of the elastic support of the transmission line partial model is a distance between the point D ₀ in FIG. 5A and the point B ₀ in FIG. 5B.

In this embodiment, a total of eight uniform / homogeneous elastic members 2a on each side are fixed with equal tension, and the fixing point interval between the four elastic members 2a is equal on the support base 4 side. D, the state where the transmission line partial model 10 is fixed at an equal interval B was considered. Note that holds the relationship of Equation 1-1 between the equally spaced D and the elastic hanging member fixed radius D _r of the fixed point in the support base 4 side, and equally spaced B fixed point in the transmission line part model 10 side relationship equations 1-2 between the elastic hanging member fixed radius B _r holds. In the following examination, it is assumed that the mass of the elastic member 2a can be ignored.

Paying attention to the four elastic members 2a on the left side in FIG. 4, by considering the center of the support point (fixed point) on the support table 4 side (ie, point D ₀ ) as the origin, the elastic member 2a on the support table 4 side. The fixed points D _{1 to} D ₄ and the fixed points B _{1 to} B ₄ of the elastic member 2a on the transmission line partial model 10 side are represented by the following coordinates.

At this time, the lengths L ^* _{10 to} L ^* ₄₀ of the elastic member 2a between the respective fixed points are expressed as Equation 3.

If the Young's modulus E and the cross-sectional area A of the elastic member 2a are constant regardless of the elongation, the original length L _i0 (where i = 1, 2, 3, 4) of the elastic member 2a It is expressed as 4.

Here, if the transmission line partial model 10 is displaced from the balanced position in the vertical direction, the horizontal direction, and the torsional direction, the lengths L _{1 to} L ₄ of the respective elastic members 2a are derived in the same manner as in Equation 3 and It is expressed as follows.

However, the displacement of each direction of the transmission line partial model 10 is defined as follows according to the coordinate system shown in FIG.
y: Vertical displacement from the balance position [m]
z: Horizontal displacement from balanced position [m]
θ: Torsional displacement from the balance position [rad.]

  The transmission line partial model 10 is premised on that no rotational displacement (specifically, rolling displacement and yawing displacement) in the span direction (that is, the axial direction; the x-axis direction shown in FIG. 4) occurs.

Here, the Lagrangian equation of motion when non-conservative force such as damping force is not taken into consideration is expressed as Equation 6.
Where T is the kinetic energy of the transmission line partial model,
U _k : potential energy due to the elastic member of the transmission line partial model,
U _g : Potential energy due to gravity of the transmission line partial model,
q: displacement in a certain direction (specifically, any one of y, z, and θ)
Respectively.

Here, the kinetic energy T of the power transmission line partial model 10 is expressed as Equation 7.

Further, the potential energy U _k due to the elastic member 2 a of the power transmission line partial model 10 is expressed as Equation 8.

Further, the potential energy U _g due to gravity of the power transmission line partial model 10 is expressed by Equation 9 using the gravitational acceleration g.

By substituting Equations 7-9 into Equation 6, the equation of motion in the vertical direction is as in Equation 10, the equation of motion in the horizontal direction is as in Equation 11, and the equation of motion in the torsional direction is as in Equation 12. expressed.
<Equation of vertical motion>
<Equation of horizontal motion>
<Equation of motion in twist direction>

  Subsequently, using the equations of motion represented by Equations 10 to 12, the change in the frequency characteristics of the transmission line partial model in the elastic support apparatus and the elastic support device of the present invention when each parameter is changed It was investigated.

Specifically, the specifications shown in Table 1 are used as the basic case, the elastic member fixing point interval D on the support base side, the flexural rigidity EA of the elastic member, the slackness H of the elastic support of the transmission line partial model, and the elastic member fixing angle. The frequency characteristics when α _D (= α _B ) was changed were compared. In Table 1, the elastic member 2a is described as a rubber string.

  Since Equations 10 to 12 are equations including a nonlinear term with respect to each displacement, it was considered that the frequency characteristics differ depending on the response amplitude. For this reason, the steady response waveform of the time history after giving different initial displacement was calculated | required using numerical formulas 10-12 which do not consider attenuation | damping, and the dominant frequency in each amplitude was read by carrying out the spectrum analysis of the said waveform. In this example, a time history response analysis was performed using a fourth-order Runge-Kutta method.

First, the equations of motion of Equations 10-12 were modified and expressed as Equation 13. In addition, since the attenuation terms are not taken into consideration in Expressions 10 to 12, the velocity terms are not included in the equations of motion in the vertical direction, the horizontal direction, and the torsion direction. For this reason, the right side of each expression of Expression 13 is a function of only the displacement term.

Equation 13 can be displayed as a matrix like Equation 14.

When the fourth-order Runge-Kutta method is used, the response of the i-th step is expressed as Equation 15 using the response of the (i-1) -th step (where i is a natural number).
Where X _{0 is} the initial value for the analysis,
h: Time step [second]
Respectively.

In order to obtain the frequency characteristics of each degree of freedom at different amplitudes, the initial value X ₀ was used including only components in the respective directions as shown below.
When obtaining the frequency characteristics in the vertical direction: X ₀ = [y ₀ 0 0 0 0 0] ^T
When obtaining frequency characteristics in the horizontal direction: X ₀ = [0 z ₀ 0 0 0 0] ^T
When obtaining the frequency characteristics in the torsional direction: X ₀ = [0 0 θ ₀ 0 0 0] ^T

As y ₀ and z ₀ , 0.01, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50 [m] are given, and as θ ₀ , 0.1, 25, 50, 75, 100, 125, 150 [deg. ] Was given.

  When the Runge-Kutta method is used, the time increment h is set to 0.01 seconds, the calculation is performed in 50000 steps (that is, 500 seconds), the spectrum is analyzed using the waveform in the direction in which the initial displacement is given, and the peak value is calculated. The frequency taken was read.

The results shown in FIG. 6 were obtained for the frequency characteristics with respect to the double amplitude when each parameter was changed from the basic case. FIG. 6A shows the frequency characteristics when only the support base side elastic member fixing point interval D is changed from the basic case to 0.200 and 0.600 [m], and FIG. 6B shows the flexural rigidity of the elastic member. The frequency characteristics when only EA is changed to 49.0, 196.0 [N] from the basic case are shown. In (c), only the slackness H of the elastic support of the transmission line partial model is 1.400, 1.800 [from the basic case. m] shows the frequency characteristics when changed, and (d) shows the vibration when only the elastic member fixing angle (α _B = α _D ) is changed from the basic case to 30.0, 45.0 [deg.]. Number characteristics are shown.

  As shown in FIG. 6, it was confirmed that the frequency characteristic has a dependence characteristic on the amplitude. In particular, the characteristic is remarkable in the frequency in the torsional direction, and it has been confirmed that the frequency decreases as the amplitude increases. On the other hand, the frequency in the vertical and horizontal directions is almost constant with respect to the amplitude, but when the amplitude is increased, the frequency tends to be slightly lower in the vertical direction and slightly higher in the horizontal direction. Was confirmed.

  From the result shown in FIG. 6A, it is confirmed that if only the elastic member fixing point interval D on the support base side is changed, the frequency in the torsional direction is changed, although the frequency in the vertical and horizontal directions is not changed. It was done. From this, it was confirmed that the frequency in the torsional direction can be lowered by reducing the elastic member fixing point interval D on the support base side.

  Further, from the results shown in FIG. 6B, it is confirmed that when only the flexural rigidity EA of the elastic member is changed, the frequency in the horizontal direction and the frequency in the torsional direction are changed although the horizontal frequency does not change much. It was. From this, it was confirmed that the vibration frequency in the vertical direction and the torsional direction can be increased by increasing the flexural rigidity EA of the elastic member.

  Further, from the results shown in FIG. 6C, it was confirmed that the frequency in the vertical direction, the horizontal direction, and the torsional direction changes when only the elastic support slack H of the transmission line partial model is changed. The change is noticeable in the horizontal frequency, and from this, by increasing the sag H of the elastic support of the transmission line partial model (in other words, decreasing the tension T of the elastic member), It has been confirmed that the frequency of can be lowered.

Further, from the result shown in FIG. 6 (d), even if only the fixing angle (α _B = α _D ) of the elastic member 2a constituting the elastic suspension member 2 is changed, the frequency in the vertical, horizontal, and twist directions is It was confirmed that there was no change. This tendency is the same when D = 0.200 [m], and it was confirmed that the fixed angle (α _B = α _D ) of the elastic suspension member 2 (elastic member 2a) does not affect the frequency characteristics. . And in the response characteristics of aerodynamic phenomena such as galloping, the influence of the elevation angle of the cross section is very large. However, the fixed angle of the elastic suspension member (elastic member) in the configuration of the present invention hardly affects the frequency characteristics. According to the present invention, the position adjustment mechanism 3 adjusts the installation angle of the transmission line partial model to a target value, and then obtains desired data by performing highly reproducible experiments without affecting the structural characteristics of the model. And the usefulness of being able to perform analysis was confirmed.

  Next, description will be made on the method of elastic support of the power transmission line partial model of the present invention and the guidance of the line form representing the structural characteristics of the power transmission line partial model in the elastic support device. In addition, the structure of the elastic support method of the power transmission line partial model of this example and the elastic support device is the same as that described in the above-described embodiments and examples.

In Expressions 10 to 12 of Example 1 described above, assuming that each displacement is a minute displacement, the fixed angle α _D = α of the elastic suspension member 2 (elastic member 2a) on each of the support base side and the transmission line partial model side is assumed. By simplifying _B = 0, the equation for linearizing the equation of motion in the vertical direction is as shown in Equation 16, the equation for linearizing the equation of motion in the horizontal direction as shown in Equation 17, and the equation of motion in the torsional direction is linear. The converted equations are expressed as in Equation 18.
<Vertical direction line format>
<Horizontal line format>
<Twist direction line type>

However, L _d , L _u , and H _d are as in Expression 19.

Further, the tension T is expressed by Equation 20 from the static balance condition.

By performing eigenvalue analysis using Equations 16 to 18, the frequency in each direction at a minute amplitude can be calculated. It was confirmed that the result corresponds to the value obtained by reading the dominant frequency by performing time history response analysis by giving the smallest possible value as the initial displacement X ₀ using Equations 10 to 12.

  In addition, in Formulas 16 to 18, when the elastic member fixing point intervals on the support base side and the transmission line partial model side are the same (that is, D = B), the vertical direction, horizontal direction, and twist direction equations are Since displacement terms other than the respective directions are not included, it was confirmed that the vibrations in the vertical direction, the horizontal direction, and the torsional direction are independent from each other within a minute amplitude range.

  On the other hand, when the distance between the elastic member fixing points on the support base side and the transmission line partial model side is different (that is, D ≠ B), the mutual displacement terms are included in the equations of motion in the horizontal direction and the torsional direction. Therefore, the horizontal direction and the torsional direction vibrate structurally. It has also been reported that the structural interaction between the horizontal direction and the torsional direction plays a very important role in the aerodynamic instability phenomenon, and this effect is also fully examined when conducting wind tunnel experiments. Confirmed that there is a need to do.

Further, when Formula 21 is satisfied, the vertical frequency f _y , the horizontal frequency f _z , and the torsional frequency f _θ are expressed by Formula 22, respectively.

However, the length L _{g of} the elastic suspension member 2 (elastic member 2 a) and the rotation radius R around the x-axis of the power transmission line partial model 10 are expressed by Equation 23.

From Equation 22, the frequency characteristic of the horizontal frequency f _z is determined by the slackness H of the elastic support. From this, the horizontal frequency f _z can be adjusted by adjusting the tension T of the elastic member. confirmed. Frequency f _y of the vertical direction because there is a term included in addition to the flexural rigidity EA elastic hanging member, is confirmed to be able to adjust the frequency f _y in the vertical direction by changing the rigidity of the elastic hanging member It was. Further, the vibration frequency f _theta twist sense it was confirmed that can be adjusted by changing the fixing position B _r of the elastic member in addition to these. These characteristics were confirmed to be consistent with the characteristics confirmed in Example 1.

In addition, when the elastic member fixing point interval D on the support base is different from the elastic member fixing point interval B on the transmission line partial model side, the frequency at each minute amplitude is obtained by eigenvalue analysis using Equations 16 to 18. The frequency f _y in the vertical direction and the frequency f _{z in the} horizontal direction are not much different from the values calculated by Equation 22, but the frequency f _{θ in the} torsional direction is as large as the value calculated by Equation 22. change.

  Subsequently, in order to confirm the structural characteristics of the transmission line partial model of the transmission line partial model of the present invention and the elastic support apparatus, an initial displacement is given to the transmission line partial model in the absence of wind and the free vibration waveform An example of an experiment in which measurement is performed will be described with reference to FIGS. The configuration of the elastic support method and the elastic support device of the power transmission line partial model of this example is the same as that described in the above-described embodiment and examples.

In the present embodiment, the frequency characteristics obtained by performing the experiment for changing the fixed point interval D and the fixed angle α _D on the support base 4 side of the elastic member 2a were compared with the analysis result of the above-described first embodiment.

In this example, an experiment simulating an actual steel core aluminum stranded wire with four conductors in actual size is assumed, and the conductor spacing, mass, and moment of inertia are the same as those in an actual steel core aluminum stranded wire. An electric wire partial model 10 was produced. A transmission line partial model 10 having a length l of the conductor portion of 1.000 [m] and a mass m and a mass moment of inertia I shown in Table 2 was manufactured. The mass m and the mass moment of inertia I were adjusted so as to be equal to the values shown in Table 2 including the end plate 12 and the fixing member of the elastic member 2a attached to the end plate 12.

  In this embodiment, since the purpose is to understand only the structural characteristics when there is no wind, it is not necessary to simulate the conductor shape, so the conductor portion 11 was made of a pipe (diameter 28.0 [mm]). Further, the end plate 12 is composed of only a frame (specifically, an annular frame). Detailed dimensions of the end plate 12 are shown in FIG.

In this embodiment, in all measurement cases, in addition to the model specifications shown in Table 2, the fixed point interval L between the support 4 and the transmission line partial model 10 and the elastic member fixed point interval on the transmission line partial model side. The experiment was conducted with B and the weight for tension adjustment (in other words, tension) set to the same value. Table 3 shows these common experimental specifications. In this embodiment, urethane rubber having a circular cross-sectional shape with a diameter of 3 [mm] is used as the elastic member 2a (in this embodiment, the elastic member is also referred to as a rubber string).

In this example, the experiment was performed while changing the fixed point interval D and the fixed angle α _D of the rubber cord on the support base 4 side. Table 4 shows a measurement case (Case) in this example. In the measurement cases (Case 1 and 4) having a fixed angle on the support base side of 0.0 [deg.], The rubber cords are fixed after adjusting the tension of the rubber cords, while the Case 2 of the other measurement cases is fixed. , 3 and Cases 5 and 6, the position adjustment mechanism 3 was rotated from the state where the support base side fixing angle of Case 1 and Case 4 was 0.0 [deg.] And the rubber cord was fixed, and the respective fixing angles were set.

  In this embodiment, the transmission line partial model 10 is freely vibrated by pulling the transmission line partial model 10 by human power and then giving an initial displacement in each of the vertical, horizontal, and twist directions, and then gently releasing the hand. . At this time, the initial displacement was given so as not to cause displacement other than the target direction as much as possible.

  Then, the vibration of the transmission line partial model 10 was photographed on a mini DV tape at a sampling frequency of 29.97 [Hz] using a digital video camera recorder. It should be noted that four image trace markers of blue, red, yellow, and green were attached in advance at equal intervals at positions near the outer edge of the end plate 12 of the transmission line partial model 10. In order to make it easier to identify these markers when shooting, a black curtain was placed behind the model.

  Then, after taking the captured video in the AVI format (DV codec format, number of recorded pixels: 640 × 480 dots) to a personal computer, Math Works in order to calculate the coordinates of the markers attached to the outer surface of the end plate 12 -Image tracing was performed using a program produced on MATLAB.

  In this embodiment, a pixel group satisfying the condition is extracted by designating a region to be analyzed (that is, a range of pixels) and a color to be extracted (that is, a range of RGB values) for each image. Conditions were set for each marker, and the center coordinates of the extracted plurality of pixel groups were used as the marker positions. Thereafter, the vertical displacement, the horizontal displacement, and the torsional displacement from the balanced position of the transmission line partial model 10 were calculated based on the positional relationship of the four markers.

Moreover, about the displacement of the direction which gave the initial displacement among the obtained displacements, after applying a 3 Hz low-pass filter, as shown in FIG. 8, the maximum value and the minimum value of each wave are obtained, and from each of them, the half wave is obtained. The period T _i (where i = 1, 2, 3,...) Was read. The frequency f _i was calculated using Equation 24.
(Equation 24) f _i = 1 / T _i (where i = 1, 2, 3,...)

  FIG. 9 shows a vertical displacement waveform obtained by image tracing the behavior of the power transmission line partial model 10 after the initial displacement is given in the vertical direction in Case1. FIG. 9 also shows the maximum and minimum values in each wave.

  From the results shown in FIG. 9, it was confirmed that the traced waveform was smoothly damped and oscillated. Moreover, the frequency characteristic in each amplitude was read from the result shown in FIG. Similar smooth attenuation waveforms were obtained when initial displacement was applied in other directions and in other measurement cases, and the frequency characteristics were read for each.

  The change characteristics of the frequency with respect to the double amplitude of each displacement obtained for each measurement case are shown in FIGS. 10A and 10B. Moreover, in FIG. 10A and FIG. 10B, the frequency characteristic in each amplitude calculated | required analytically using Numerical formula 10-12 was also shown with the experimental result. In the present embodiment, as described in the first embodiment, the frequency characteristics for each double amplitude are calculated by performing spectrum analysis on the time history response waveform after the initial displacement is applied in each direction. The analysis was performed assuming that the flexural rigidity EA of the rubber string was 98.0 [N].

  From the results shown in FIGS. 10A and 10B, according to the elastic supporting method and the elastic supporting device for the transmission line partial model of the present invention, the vertical amplitude and the horizontal direction are about double amplitude 1-2 [m], and the double amplitude is twisted. It was confirmed that vibrations of 180 [deg.] Or more can be reproduced, and vibrations with a low frequency of 0.5 [Hz] or less can be reproduced.

  It is possible to reproduce a larger vertical amplitude by adjusting the height of the position adjustment mechanism 3 (specifically, the elastic member fixing portion) of the support base 4. By taking a longer distance L from the partial model 10, it is possible to reproduce vibrations with a larger amplitude and lower frequency.

  From the results shown in FIG. 10A and FIG. 10B, the experimental results and the analysis results almost coincide, and the frequency characteristic of the power transmission line partial model in the power transmission line partial model and the elastic support device of the present invention is as follows. It was confirmed that it was able to express correctly by numerical formulas 10-12.

  Moreover, the result shown in FIG. 11 as a part of the waveform after giving the initial displacement in the horizontal direction in Case 1 and Case 4 was obtained. From the results shown in FIG. 11 (a), in Case 1 where the distances D and B between the support base 4 and the transmission line partial model 10 are equal, vibrations in directions other than horizontal are hardly generated. confirmed. On the other hand, from the result shown in FIG. 11 (b), in Case 4 in which the distances D and B between the rubber strap fixing points on the support base 4 side and the transmission line partial model 10 side are different, the vibration in the torsional direction is accompanied by the vibration in the horizontal direction. It was confirmed that this occurred. Moreover, about this phenomenon, the same characteristic was seen also by the time history response analysis using Numerical formulas 10-12.

  The structural coupling between the horizontal direction and the twist direction may play a very important role in the occurrence of galloping. For this reason, when conducting a wind tunnel experiment, not only the frequency characteristics but also the difference in response characteristics when the distances D and B between the fixed points of the rubber straps on the support base 4 side and the transmission line partial model 10 side are changed. It has been confirmed that more useful data can be collected in wind tunnel experiments for vibration analysis of overhead power transmission lines.

DESCRIPTION OF SYMBOLS 1 Elastic support apparatus 2 Elastic suspension member 2a Elastic member 3 Position adjustment mechanism 4 Support stand 5 Slider 10 Power transmission line partial model 11 Conductor part 12 End plate

Claims (8)

  A power transmission line partial model having a conductor portion and a pair of opposing end plates attached to both ends of the conductor portion, one end being attached to one of the pair of end plates and the other end being a pair of the end plates. A pair of elastic suspension members that are suspended and elastically supported by a pair of elastic suspension members that are supported by one of a pair of support bases arranged on both sides of the transmission line partial model so as to face each other, and the pair of elastic suspension members At least one of the elastic suspension members is configured by a plurality of linear elastic members, and the elastic suspension members are arranged via a position adjusting mechanism that changes the radial support positions of the elastic members and changes the circumferential support positions. An elastic support method for a transmission line partial model, wherein the other end is supported by the support base.   The elastic support method for a power transmission line partial model according to claim 1, wherein a position adjusting mechanism for changing a radial attachment position of the elastic member is provided on the end plate.   The elastic support method for a power transmission line partial model according to claim 1, wherein a tension adjusting mechanism for changing the tension of the elastic member for each elastic member is provided on the support base.   The elastic support method for a power transmission line partial model according to claim 1, wherein the vertical frequency of the power transmission line partial model is changed by changing the rigidity of the elastic member. The elasticity of the transmission line partial model according to claim 1, wherein the vertical frequency f _y , the horizontal frequency f _z , and the torsional frequency f _θ of the transmission line partial model are expressed by Formula 1. Support method.
Where m: mass of the transmission line partial model [kg],
I: Mass moment of inertia [kgm ² ] of the transmission line partial model,
B _r : elastic member fixed radius [m] on the transmission line partial model side,
L: Distance [m] between the support base and the transmission line partial model,
H: slackness of elastic support of transmission line partial model [m],
T: tension of elastic member [N],
E: Young's modulus of elastic member [N / m ² ],
A: Cross-sectional area of elastic member [m ² ],
g: Gravity acceleration [m / s ² ], respectively.   A power transmission line partial model having a conductor part and a pair of opposed end plates attached to both ends of the conductor part, and a pair of power lines arranged on both sides of the power transmission line partial model facing each of the pair of end plates And a pair of elastic members, one end of which is attached to one of the pair of end plates and the other end of which is supported by one of the pair of support bases, and which elastically supports the power transmission line model. A suspension member, and at least one of the pair of elastic suspension members is composed of a plurality of linear elastic members, and is attached to the support base to change the radial support position of the elastic members. An elastic support device for a power transmission line partial model, wherein the other end of the elastic suspension member is supported by the support base via a position adjusting mechanism that changes the circumferential support position.   The said end plate is equipped with the position adjustment mechanism which changes the attachment position of the radial direction of the said elastic member, The elastic support apparatus of the power transmission line partial model of Claim 6 characterized by the above-mentioned.   The said support stand is equipped with the tension adjustment mechanism which changes the tension | tensile_strength of the said elastic member for every said elastic member, The elastic support apparatus of the power transmission line partial model of Claim 6 characterized by the above-mentioned.