KR101031595B1 - Power transmission character evaluation system using small scale and mathod for thereof - Google Patents

Abstract

PURPOSE: A power transmission property evaluation system using a downscaled model and method for the same are provided to reduce the period and cost required for implementing the evaluating process of an electric environmental failure in a direct current power transmission line. CONSTITUTION: Small scale power transmission lines(31, 32) geometrically downscale a real power transmission line. A pole(10) supports the downscaled power transmission line. A varying unit(20) is in connection with the pole and vertically moves the downscaled power transmission line. A sensor(60) measures the electric field strength and the ion current density of the ground. A calculating unit(100) calculates the radius of a real power transmission line and the height of the real power transmission line with respect to the ground.

Description

System and method for evaluating transmission line characteristics using scaled model {POWER TRANSMISSION CHARACTER EVALUATION SYSTEM USING SMALL SCALE AND MATHOD FOR THEREOF}

The present invention relates to a transmission line characteristic evaluation system and method using a reduced model.

Conventionally, in order to evaluate the electrical environmental disturbance of a transmission line, the electrical environmental disturbance of a overhead transmission line is evaluated using the measuring apparatus, such as a corona gauge, or using the actual scale test line.

However, since the corona gauge measures the corona discharge using a low voltage and corresponds to the corona discharge phenomenon generated in the actual line, there are many errors in the practical application. That is, the generation characteristics of ions vary depending on the polarity of the DC overhead transmission line, but if a corona gauge or the like is used, there is a problem that the measurement error for such environmental influence is very large.

In order to solve the above problems, the electric environment disturbance of the AC or DC overhead transmission line is evaluated using the actual scale experimental test line. The use of a real scale experimental test line has the advantage of accurately measuring the electrical environmental effects such as corona discharge. However, when using the actual scale experimental test line, expensive facilities are required, and it takes a lot of time and expense when experimenting while replacing various conductor methods (for example, 2, 4, 6 conductor type power transmission). There is this.

An object of the present invention is to provide a transmission line environmental evaluation system and method capable of evaluating the electrical environmental disturbances of a direct current overhead transmission line.

An object of the present invention is to provide a transmission line environmental evaluation system and method capable of evaluating the electrical environmental disturbance of a hybrid overhead transmission line operated in the same tower and direct current voltage.

According to an aspect of the present invention, a transmission line characteristic evaluation method using a reduction model of a transmission line, the method comprising: (a) applying a voltage to a reduction transmission line; (b) measuring electric field strength and ion current density generated on the ground by the voltage applied to the reduced transmission line; (c) determining an optimum value of the electric field strength and ion current density for each of the reduced transmission line shapes; And (d) it can provide a transmission line characteristic evaluation method using a reduced model comprising the step of converting the environmental disturbance value of the actual transmission line through the electric field strength and ion current density.

According to another aspect of the present invention, the evaluation system for evaluating the electrical environment characteristics of the actual transmission line by using the reduced model of the transmission line, comprising: at least one reduced transmission line geometrically reduced the actual transmission line; A support for supporting the reduced power transmission line; Variable means connected to said support and moving said reduced transmission line up and down; A power supply unit applying a voltage to the reduced transmission line; A sensor unit for measuring electric field strength and ion current density generated on the ground by the voltage applied to the reduced transmission line; And a calculation unit calculating a radius of the actual transmission line and a height of the ground by using a reduction factor using the measured electric field strength and ion current density, and the radius, height, and applied voltage of the transmission line. Can be provided.

According to an embodiment of the present invention, there is an advantage that the electrical environment failure of the overhead transmission line can be evaluated in a short period of time, low cost through a scale model.

In addition, according to an embodiment of the present invention, there is an advantage that can be evaluated in the electrical environment of the AC, DC, AC and DC hybrid overhead transmission line.

In addition, according to an embodiment of the present invention, there is an advantage that the electrical environment failure evaluation for various conductor methods of the transmission line can be made at low cost.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

1 is a view schematically showing a transmission line reduction model according to an embodiment of the present invention.

Referring to FIG. 1, reduced transmission lines 31 and 32 and a support 10 are included.

Specifically, the support 10 is fixedly supported on both sides of the reduced power transmission line (31, 32). At this time, the variable transmission line (31, 32) may further include a variable means for varying the distance between the ground.

The variable means 20 are attached to both struts 10. The variable means 20 fixes the reduced power transmission lines 31 and 32. In this case, the variable means 20 is capable of adjusting the height in a state in which the reduced power transmission lines 31 and 32 are fixed, or in a state in which the reduced power transmission lines 31 and 32 are unfixed.

In the embodiment of the present invention, the length of the strut is 1.2m, the variable means 20 is adjustable from 1.2m to 1.2m or more from the ground, but is not limited to this, the variable means is variable within the length of the strut 10 Can be.

The reduced transmission lines 31 and 32 calculate the actual transmission lines through reduction factors. In this case, the reduction coefficients of the reduction transmission lines 31 and 32 are the one-dimensional geometric reduction coefficient K _L , the reduction coefficient K _v for the applied voltage, the reduction coefficient of the surface electric field strength K _e , and the reduction of the charge density. The coefficient K _ρ , the reduction factor K _j of the ion current density, and the reduction factor K _c of the corona current can be calculated.

First, the one-dimensional geometrical reduction factor K _L is expressed as in Equation 1.

[Equation 1]

Where r represents the conductor radius, h represents the height from the ground, and S represents the spacing between the conductors.

The reduction factor K _v with respect to the applied voltage is expressed by Equation 2.

[Equation 2]

Where V represents the volume. The reduction factor (K _v ) for the applied voltage is the volume (V _reduction ) of the _reduced transmission line divided by the volume (V _actual ) of the actual transmission line.

Since the influence of ions by corona discharge does not affect the earth surface in the ultra high voltage AC transmission line, it is assumed that the relationship between the applied voltage and the surface electric field strength has no corona discharge regardless of whether or not corona is generated. Thus, the reduction coefficient (K _e) of the field strength of the surface of the transmission line can be expressed as Equation (3).

&Quot; (3) "

In Equation 3, E represents the electric field strength of the earth's surface, h represents a height with the earth's surface, and V represents a volume. At this time, in Equation 3 above, it is assumed that there is no relationship between the electric field strength of the ground surface and the corona discharge in the reduction factor of the ultra-high voltage AC transmission line, but in the case of the ultra-high voltage DC power transmission, the effect on the ion effect should be considered.

That is, in the case of the direct-current power transmission line reduction coefficient (K _e) is less than a corona discharge threshold voltage that the corona discharge does not occur, but the conditions, such as alternating current transmission line in the corona discharge threshold voltage above which the corona discharge takes effect on the ion impact Should be taken into account. In addition, the charge density at the ground must also be considered.

Equation 4 is related to the charge density on the earth's surface.

&Quot; (4) "

In Equation 4, ε represents permittivity, E represents surface electric field strength, A represents cross-sectional area, and Vsms volume. Therefore, the reduction factor K _ρ of the charge density may be expressed as in Equation 5.

[Equation 5]

From Equation 5, the reduction coefficient K _j of the surface ion current density J can be expressed as Equation 6.

&Quot; (6) "

In Equation (6), (K _j ) is a reduction factor of ion mobility, but the mobility of the actual transmission line and the reduction model are not the same, but when the same conditions such as weather conditions are the same, the mobility of ions is the same. The equation 6 can be satisfied as K _k = 1.

The corona current (I _c ) can be expressed as the product of the ion current density at ground level by the closed area (A). Therefore, the reduction coefficient K _c of the corona current may be expressed by Equation 7 below.

[Equation 7]

2 is a flowchart sequentially illustrating a method of evaluating ion current generation characteristics among electrical environment characteristics using a transmission line reduction model of the present invention, and FIG. 3 is a block diagram illustrating a system for measuring ion current generation using a transmission line reduction model. It is also.

2 and 3, the method for evaluating ion current generation characteristics according to the present invention includes applying power to a reduced transmission line (S100), and electric field strength and ions generated from the ground by the power applied to the reduced transmission line. Measuring the current density (S200), determining the optimum value for each of the reduced transmission line shape (S300) and converting the environmental disturbance value of the actual transmission line (S400).

Specifically, in the step S100 of applying power to the reduced transmission line, the power supply unit 50 applies AC power or DC power to the reduced transmission line. At this time, the voltage of the AC power or DC power is applied to a voltage capable of measuring the ion current density or a voltage mainly used for transmission in an actual transmission line. In the embodiment of the present invention 50kV and 60kV were applied.

Next, measuring the electric field strength and the ion current density generated in the ground by the power applied to the reduced transmission line (S200) measures the ion current density of the ground through the sensor unit 60. At this time, the electric field strength of the ground surface is measured using the sensor unit 60.

Next, determining the optimum value for each of the reduced transmission line shape (S300) is the distance between the ground and the reduced transmission line (31, 32) using the variable means 20 for varying the reduced transmission line (31, 32). Adjust the to measure the electric field strength and ion current density of the ground. At this time, the electric field strength and ion current density between the two reduced power transmission lines 31 and 32 are measured while varying the distances of the two reduced power transmission lines 31 and 32.

At this time, the electric field strength and the ion current density on the ground can be measured while varying the distance between the reduced transmission lines 31 and 32 and the ground according to the conductor method of the reduced transmission line.

Next, the step (S400) of converting the environmental disturbance value of the actual transmission line is calculated using Equations 1 to 7 described above.

For example, simulation was performed by applying ± 35KV to a model in which a bipolar ± 500KV actual transmission line was geometrically reduced to 1/30, and the surface magnetic field strength was 10kV / m and the surface ion current density was 100μA / When measured in m ² , the surface electric field strength and ion current density on the actual bipolar ± 500 kV line can be obtained from the reduction factor. Voltage reduction factor, K = 35kV / 500kV to 0.07 since the electric field intensity reduction factor (K _e) is a _{K e = 0.07 / 0.03 = 2.1} .

Therefore, the electric field strength E in the actual power transmission line is 4.76 KV / m by equation (3). Since the ion current density reduction coefficient K _j becomes 132.3 with Kj = 0.07 ² /0.03 ³ according to Equation 6, the surface ion current density of the actual transmission line becomes 0.75 uA / m ² by Equation 6.

4 is a result of measuring ion current density between reduced transmission lines, and is an example of applying a DC voltage of 50 kV and 60 kV. 5 is a result of measuring the ion current density according to the distance between the reduced transmission line and the ground, and is an example of applying a DC voltage of 50 kV and 60 kV.

For example, it can be seen that the ion current density in the ground after applying 50 kV and 60 kV DC voltages is very low when the distance between the reduced transmission line and the ground is 0.7 m or more. The measured values can be used to calculate the minimum distance between the actual transmission line and the ground using the reduction factor.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a view schematically showing a transmission line reduction model according to an embodiment of the present invention.

2 is a flowchart sequentially illustrating a method for evaluating ion current generation characteristics among electrical environment characteristics using the transmission line reduction model of the present invention.

3 is a block diagram showing an ion current generation measurement system using a transmission line reduction model.

Figure 4 is a graph of the result of measuring the ion current density between the reduced transmission line.

5 is a graph of the result of measuring the ion current density according to the distance between the reduced transmission line and the ground;

<Brief Description of Drawings>

10: prop

20: variable means

31, 32: reduced transmission line

40: track fixing means

50: power supply

60: sensor

100: calculation unit

Claims (8)

In the transmission line characteristics evaluation method using the reduced model of the transmission line, (a) applying a voltage to the reduced transmission line; (b) measuring electric field strength and ion current density generated on the ground by the power applied to the reduced transmission line; (c) determining an optimum value of the electric field strength and ion current density for each of the reduced transmission line shapes; And (d) a method for evaluating transmission line characteristics using a scaled down model comprising converting the environmental disturbance value of an actual transmission line through the electric field strength and the ion current density. The method of claim 1, Step (c) is And measuring the ion current density while varying the distance between the reduced transmission line and the ground. The method of claim 1, Step (c) is And measuring the ion current density while varying a distance between the reduced power transmission line and another reduced power transmission line adjacent thereto. 4. The method according to any one of claims 1 to 3, Step (d) is The transmission line characteristic evaluation method using the reduction model, characterized in that for converting the radius of the actual transmission line, the height with respect to the ground and the distance between the transmission line through the geometric reduction coefficient of the reduced transmission line. The method of claim 4, wherein Step (d) is A voltage input to the reduced transmission line, a radius of the reduced transmission line, the measured electric field strength and an ion current density value, Using the relationship between geometric reduction factor (K _L ), applied voltage reduction factor (K _v ), electric field reduction factor (K _e ), charge density reduction factor (K _ρ ) and ion current density reduction factor (K _j ) A method for evaluating transmission line characteristics using a scaled down model characterized by calculating an environmental disturbance of a transmission line. Where the geometric reduction factor (K _L )

Calculated by the formula, the applied voltage reduction factor (K _v )

Calculated by the formula, the field strength reduction factor (K _e )

Calculated by the formula, and the charge density reduction coefficient (K _ρ ) is

Calculated by the equation, the ion current density reduction coefficient (K _j )

Where r is the conductor radius, h is the distance to the ground, S is the distance between the transmission lines, V is the applied voltage, ρ is the charge density, A is the cross-sectional area, ε is the dielectric constant, J is the ion current density, K _k Is the mobility reduction factor of ions) In the evaluation system for evaluating the electrical environment characteristics of the actual transmission line using a scale model of the transmission line, At least one reduced transmission line in which the actual transmission line is geometrically reduced; A support for supporting the reduced power transmission line; Variable means connected to said support and moving said reduced transmission line up and down; A power supply unit applying a voltage to the reduced transmission line; A sensor unit for measuring electric field strength and ion current density generated on the ground by the voltage applied to the reduced transmission line; And And a calculation unit configured to calculate the radius of the actual transmission line and the height of the ground by applying a reduction factor to the measured electric field strength and ion current density and the radius, height, and applied voltage of the transmission line. The method of claim 6, The power supply unit Transmission line characteristic evaluation system, characterized in that any one of the AC voltage, DC voltage and cross-flow hybrid voltage. The method of claim 6, The reduction factor is Geometrical reduction factor (K _L ), applied voltage reduction factor (K _v ), electric field strength reduction factor (K _e ), charge density reduction factor (K _ρ ) and ion current density reduction factor (K _j ) Transmission line characteristic evaluation system. Where the geometric reduction factor (K _L )

Calculated by the formula, the applied voltage reduction factor (K _v )

Calculated by the formula, the field strength reduction factor (K _e )

Calculated by the formula, and the charge density reduction coefficient (K _ρ ) is

Calculated by the equation, the ion current density reduction coefficient (K _j )

Where r is the conductor radius, h is the distance to the ground, S is the distance between the transmission lines, V is the applied voltage, ρ is the charge density, A is the cross-sectional area, ε is the dielectric constant, J is the ion current density, K _k Is the mobility reduction factor of ions)

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