KR20110035244A - Method for transmission line parameter measument of electric railway - Google Patents

Abstract

PURPOSE: A method for measuring a rail parameter of an electric railway is provided to reflect a real railway integer value to railway construction. CONSTITUTION: Fourteen conductors are classified into five conductor groups(S10). All conductor groups are short-circuited so that a closed circuit is formed on an electricity sectioning post(S11). Voltages and currents of different combinations of conductive terminals are measured in an electric railway substation to calculate impedance(S12~S14). A railway integer measuring device is an open circuit(S21). Voltages and currents of different combinations of the conductive terminals are measured in the electric railway substation to calculate admittance(S22~S24).

Description

Method for transmission line parameter measument of electric railway

The present invention relates to a method for measuring the line constant of a tram line, and more particularly, to a method for measuring the line constant of a tram line that can measure each line constant for a group of five conductors constituting a tram line system in an actual system. It is about.

In general, the power system is always pressurized and exposed to the external environment, so that there is a possibility that a failure occurs due to a change in temperature, humidity, wind, etc., as well as contact with foreign matter, external shock, etc. In particular, the power system for electric railway As power loads continue to be stressed due to rapid load changes at all times, they are operating in harsher conditions than general power facilities.

Therefore, it is impossible to fundamentally eliminate the occurrence of the failure, but it is necessary to quickly detect and recover the failure point and to quickly eliminate the failure while limiting the failure range to the minimum.

Therefore, it is necessary to calculate the exact fault point by the distance relay or the fault point expression device installed in the substation, and for this purpose, the impedance from the reference point to the fault point by the distance relay or fault point expression device installed in the substation or feed station SP. Since the distance to the fault point is calculated by dividing the impedance value per unit distance by calculating (R + jX), it is necessary to secure the correct impedance value for detecting the correct fault point or for the correct operation of the protective relay.

However, the railway tramway system is a complex system composed of several conductors, and the impedance of the tramline increases linearly in proportion to the distance, whereas a protection line connection line or a single winding transformer is installed in the middle of the feeder line. There is a characteristic that does not increase linearly proportionally.

 In order to understand the various phenomena appearing in the railway tramline system, the line constant values of the tramline composed of impedance and admittance must be given. In order to obtain these values, the measurement of the track constant values of the railway tramline system must be preceded.

In the past, track constants could not be measured for conductors of an electric railway system, and various phenomena were analyzed using the predicted values. The predicted value is difficult to calculate because the impedance value varies depending on the installation method and the location of the feeder, tramline, rail, and protection line, and the predicted value does not reflect the actual line constant value. There is a problem that does not occur.

Accordingly, an object of the present invention is to divide the conductors constituting the tram line system into a group of five conductors and to measure the track constants of the five conductor groups in the actual system to increase the measured line constants in a nonlinear curve form. It is to provide a method for measuring the line constant of the tram line.

In order to achieve the above-described object of the present invention, a method for measuring a line constant of a tramline according to the present invention is a method for measuring a line constant of a tramline composed of a plurality of conductors, and after classifying the connected conductors into equipotential conductors, Dividing into conductor groups; Equalizing the conductor group separated in the above step by the equivalent modeling method, characterized in that consisting of the step of measuring the line constant.

In this case, the step of classifying the equipotential conductor and then divided into a predetermined group of conductors, the ascending feeder to the first conductor group, the ascending feeder to the second conductor group, the ascending tram line and the ascending ramp, the third conductor group, the descending tramline and the descending The rough wire is divided into a fourth conductor group, a rail, a work protection line, and a ground line by a fifth conductor group.

In the measuring of the line constant, voltage and current are measured by applying voltage and current between tram line conductors, and an impedance and an admittance between lines are derived based on the measured voltage-current relationship. It is characterized by measuring the line constant of each conductor group.

Here, in order to derive the impedance, a short circuit is formed by shorting all conductor groups in the feed section for the train line circuit in the train substation and the feed section, and the voltage- for different combinations of conductor terminals in the train substation stage. It is characterized by measuring the current.

In addition, in order to derive the admittance, all the conductor groups are opened in the feeder section for the train line circuits of the train substation and the feeder section, forming an open circuit, and voltages for different combinations of conductor terminals in the train substation stage. It is characterized by measuring the current.

According to the method for measuring the railway constant of the tram line as described above, it is possible to confirm that the actual track constant is increased in a nonlinear curve form by measuring the track constant of the 5 conductor group in the actual system, and accordingly, when the tram line is constructed, There is an effect that can reflect an integer value.

In addition, the method for measuring the line constant of the tram line of the present invention has an effect that can be applied to the voltage drop analysis and electric current of the electric railway system, harmonic analysis, energy storage system application analysis, AC train supply system analysis.

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 modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention.

1 is a view showing the geometrical structure of a railway tramway system applied to an embodiment of the present invention, Figure 2 is a flow chart illustrating a method for measuring the line constant of the tramline according to an embodiment of the present invention.

Referring to FIG. 1, the railway tramline system is composed of 14 conductors, but since the tramline and the runway are connected by a dropper and the up and down rails, overhead protection lines, and ground lines are connected in common, the conductors may be represented by five conductor groups. have.

In other words, if you look closely at the railway tramway system, the number of tracks is complicated, but some conductors are short-circuited and can be treated as a single conductor electrically. More specifically, the tramline and the rough line are connected by equalization lines or droppers. And up and down rail, up and down overhead protective line, up and down ground wire is jointly grounded together, it can be seen as a group of electrical conductors.

Thus, the first conductor group is an ascending feeder line (1), the second conductor group is an ascending feeder line (2), the third conductor group is an ascending chariot line (4) and an ascending jogline (3), and the fourth conductor group is an ascending tank line (6) and It consists of the down-column line (5) and the fifth conductor group is co-grounded by rails (7, 8, 9, 10), overhead protection lines (11, 12), and ground lines (13, 14). However, although the number of conductors may vary depending on the earthwork section, bridge section, and tunnel section, the entire conductor group is composed of five conductor groups.

As described above, since the conductors are short-circuited in any section, the line constant of the five conductor group cannot be measured, and the line constant is composed of impedance and admittance.

Referring to the method of measuring the line constant of the tram line with reference to FIG. 2, the tramline line constant measuring device for measuring the line constant of the railway tramline may measure voltage and current to measure the line constant of the line section. It includes a power analysis function and a calculation function to calculate a line constant.

Such a tram line constant measuring device divides 14 conductors that constitute the tram line system into 5 conductor groups as shown in FIG. 1 (S10), and the tram line circuit between the train substation and the feed section In the feed section, all the conductor groups are short-circuited to form a closed circuit. (S11)

In addition, voltage and current are applied to each conductor group, and impedance is derived by measuring voltage and current for different combinations of conductor terminals in a train substation stage. (S12 to S14)

On the other hand, the railway line track constant measuring device is configured to open all the conductor groups in the feed section to the train line circuit between the train substation and the feed section to form an open circuit (S21).

After that, voltage and current are applied to each conductor group, and the admittance is derived by measuring the voltage and current for different combinations of conductor terminals in the train substation stage. (S22 to S24)

In this way, the tramline line constant measuring apparatus may measure the line constant composed of impedance and admittance, and as a result, the measured impedance and admittance may increase in a nonlinear curve form (S30).

Hereinafter, a process of deriving an impedance and an admittance among the line constant measurement methods of the tram line according to the embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

3 is a circuit diagram for measuring impedance of a train substation and a parallel feeder section according to an embodiment of the present invention, Figure 4 is a line for measuring the line admittance between the train substation and feed section section according to an embodiment of the present invention 5 is a diagram showing the relationship between the Y connection and the Δ connection of the line admittance according to the embodiment of the present invention, and FIG. 6 is a T-type equivalent circuit for obtaining a magnetic admittance according to the embodiment of the present invention. Is a graph showing the Y connection of FIG. 7 is a graph showing the predicted impedance magnitude of the equivalent model of the five conductor group according to the embodiment of the present invention, and FIG. 8 is the equivalent of the five conductor group according to the embodiment of the present invention. FIG. 9 is a graph showing the measured impedance of the model, FIG. 9 is a graph showing the predicted admittance size of the equivalent model of the five-conductor group according to an embodiment of the present invention, and FIG. 10 is an embodiment of the present invention. It is a graph showing the measured admittance size of the equivalent model of the five conductor group according to.

  First, in order to measure the line constant of five conductor groups in a real system section, the tram line constant measuring apparatus may be obtained by measuring the voltage and current between the tram line conductors to derive the impedance and admittance.

A) magnetic and mutual impedance

As shown in FIG. 3, a closed circuit is formed by shorting all groups of conductors in a feed section, and a current impedance and a voltage drop relationship of a tramline circuit diagram are represented by 25 impedance matrix elements as shown in Equation (1).

Due to the symmetrical structure of the tramline, the mutual impedance in symmetry in Equation 1 shows symmetry, so the required matrix elements are nine. Equation 1 is expressed by Equation 2 by these nine matrix elements.

To derive each impedance matrix element, voltage-current is measured for a total of six different combinations of conductor terminals in the substation stage shown in FIG.

① When the current (I) is applied to the T1-T2 terminal and the voltage (V) is measured, it is expressed as Equation (3).

  ② When the current (I) is applied to the T1-R terminal and the voltage (V) is measured, it is as shown in equation (4).

  ③ When the current (I) is applied to the T1-F1 terminal and the voltage (V) is measured, it is expressed by Equation 5.

④ When the current (I) is applied to the T1-F2 terminal and the voltage (V) is measured, it is expressed by Equation 6.

(Reference) The equations in the terminals T2-R, T2-F1, and T2-F2 are linearly dependent on equations (4), (5) and (6).

⑤ When the current (I) is applied to the R-F1 terminal and the voltage (V) is measured, it is as shown in Equation (7).

(Reference) Equation at R-F2 terminal has a linear dependency relation with Equation (7).

⑥ When the current (I) is applied to the F1-F2 terminal and the voltage (V) is measured, it is as shown in Equation (8).

(Reference) Equation at COMMON (T1, T2) -R, R-COMMON (F1, F2), COMMON (T1, T2)-COMMON (F1, F2) terminals is linearly dependent on Equations 7, 8. .

By doing so, the tramline constant measuring device derives the impedance by the voltage-current relationship respectively measured for different combinations of conductor terminals in the train substation stage.

B) line admittance

As shown in FIG. 4, the open circuit is formed by opening all the conductor groups in the feed section, so that the magnetic impedance, mutual impedance, and line admittance of each conductor group can be represented by a T-type equivalent circuit.

However, the line admittance is a Δ connection, which is very complicated to find. Therefore, from Fig. 4, the Δ connection is converted to the Y connection to obtain the magnetic admittance, and then, the inverse admittance is obtained through the Y-Δ conversion relationship.

The relationship between the line admittance Y connection and the Δ connection is as shown in FIG. 5.

a) circuit equation for the Y connection

As shown in FIG. 5, when the current relationship is applied when KCL is applied to the Y connection, Equation 9 is obtained.

When the last equation of Equation 9 is summarized as Vn and substituted into the remaining equation of Equation 9, Equation 10 is obtained.

①

①

②

③

④

b) circuit equation for the Δ connection

The circuit equation is also established for the? Connection shown in FIG.

The circuit equation of the Y connection is compared with the circuit equation of the Δ connection to derive the admittance between the lines of the Δ connection as shown in Equation 12.

In order to convert the Δ connection to the Y connection to obtain the magnetic admittance, converting the T-type equivalent circuit Δ connection to the Y connection is as shown in FIG. 6, and when the T-type equivalent circuit Y connection is expressed in a matrix relationship, Equation 13 is obtained.

c) Derivation of line admittance from the voltage and current relationship

In order to derive the line admittance matrix element from the voltage-current relationship, the voltage-current measurement of the tram line is performed.

  ① When the voltage (V) is applied to the T1-T2 terminals and the current (I) is measured, Equation 14 is obtained.

(2) Applying the voltage (V) to the T1-R terminal, and measuring the current (I) is as shown in equation (15).

③ When the voltage (V) is applied to the T1-F1 terminal and the current (I) is measured, it is expressed by Equation 16 below.

  ④ When the voltage (V) is applied to the T1-F2 terminal and the current (I) is measured, it is expressed by Equation 17.

  ⑤ When the voltage (V) is applied to the R-F1 terminal and the current (I) is measured, Equation 18 is obtained.

⑥ When voltage (V) is applied to F1-F2 terminal and current (I) is measured, it is expressed by Equation 19.

By doing so, the tramline constant measuring device measures voltage-current for different combinations of conductor terminals in the train substation stage, and derives an admittance by each measured voltage-current relationship.

As such, when verifying the 5-conductor group track constant of the railway tramline system for the actual system section, the predicted line constant and the calculated line constant calculated by varying the frequency from 60 Hz to 3000 Hz are compared.

7 and 8 show the magnitudes of the predicted impedance and the measured impedance for the actual system of the railway tramline system, and the magnitudes of the predicted admittance and the measured admittance are shown in FIGS. 9 and 10, respectively.

As shown in FIGS. 6 to 8, the predicted impedance and admittance increase linearly, but the impedance and admittance measured in FIGS. 7 and 9 increase in a nonlinear curve form, and the predicted line constant and measured calculation It can be seen that there is a big difference in the value of one line constant.

In other words, the change of the value according to the frequency of the actual measurement and the prediction is the same, but there is a big difference in the value. As the frequency increases, the reactance value of the line affects the curve graph instead of the linear graph proportional to the frequency as in the prediction calculation. Because it appears.

As described above, in the method for measuring the line constant of the tram line according to the embodiment of the present invention, there is a big difference between the measured line constant and the predicted line constant value according to the frequency, and the impedance and admittance value according to the frequency increases as the frequency increases. Relative trends in the values of conductors are also rarely the same as measured and predicted.

Such a method for measuring the line constant of the tram line of the present invention can be applied to voltage drop analysis, electric current distribution, harmonic analysis, and AC train supply system protection of an electric railway system.

Although described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

The present invention relates to a method for measuring the line constant of the tram line, and more specifically, it can be seen that the measured line constant increases in a nonlinear curve form by measuring the line constant of the 5 conductor group in the actual system. It can reflect the actual line constant value during construction, and it can be applied to the voltage drop analysis of electric railway system, the electric current of electric train line, the harmonic analysis, the application of energy storage system, the analysis of AC train supply system.

1 is a view showing the geometrical structure of a railway tramway system applied to an embodiment of the present invention,

2 is a flowchart illustrating a method for measuring a line constant of a tram line according to an embodiment of the present invention;

3 is a circuit diagram for measuring impedance of a train substation and a parallel feeder section according to an embodiment of the present invention;

4 is a circuit diagram for measuring the line admittance between the train substation and the feed section section according to an embodiment of the present invention,

5 is a view showing the relationship between the Y connection and △ connection of the line admittance according to an embodiment of the present invention,

6 is a diagram illustrating a Y connection of a T-type equivalent circuit for obtaining magnetic admittance according to an embodiment of the present invention;

7 is a graph showing the predicted impedance of the equivalent model of the five conductor group according to an embodiment of the present invention,

8 is a graph showing the measured impedance of the equivalent model of the five conductor group according to an embodiment of the present invention,

9 is a graph showing the predicted admittance size of the equivalent model of the five conductor group according to an embodiment of the present invention;

10 is a graph showing the measured admittance size of the equivalent model of the five conductor group according to an embodiment of the present invention.

Claims (5)

In the method of measuring the line constant of a tram line composed of a plurality of conductors, Classifying the connected conductors into equipotential conductors and then classifying the conductors into predetermined conductor groups; Equivalent to the conductor group divided in the step by the equivalent modeling method after the track constant measuring method comprising the step of measuring the line constant. The method of claim 1, After dividing the equipotential conductor into a predetermined group of conductors, the ascending feeder is the first conductor group, the descending feeder is the second conductor group, the ascending tram line and the ascending tramp line, the third conductor group, the descending tram line and the descending tram line. A method for measuring the line constant of a tramline, comprising dividing the fourth conductor group, the rail, the overhead protective line, and the ground wire into the fifth conductor group. The method of claim 1, Measuring the line constant, Measuring voltage and current by applying voltage and current between train line conductors, deriving impedance and line admittance from each measured voltage-current relationship, and measuring the line constant of each conductor group in the actual system section. Line constant measuring method of a tram line characterized by the above-mentioned. The method of claim 3, In order to derive the impedance, a short circuit is formed by shorting all conductor groups in a feeder division for a train line circuit in a train substation and a feed section, and a voltage-current is applied to a different combination of conductor terminals in a train substation stage. A method for measuring the line constant of a tramway, characterized in that for measuring. The method of claim 3, In order to derive the admittance, an open circuit is formed by opening all the conductor groups in the feed section for the train line circuit in the train substation and the feed section, and the voltage-current for different combinations of conductor terminals in the train substation stage. Line constant measurement method of the tram line, characterized in that for measuring.

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