JPH07128374A - Method for detecting rail-earth voltage and rail leak current for dc electric railway - Google Patents

Abstract

PURPOSE:To make it possible to the rail-earth voltage and the rail leak current of a DC electric railway comprising a single conducting section or a plurality of transforming stations and electric railcars through simulation. CONSTITUTION:A position where an electric railcar or a transforming station is present is represented by a node 1 to n+1. The rail-earth voltage Vk+1 at each node is determined from an equivalent circuit of equivalent ground conductances bk, bk+1. of right and left half-conducting sections, a conduction current Ik+1, and rail resistance (r). The rail leak current is then determined for the right and left half-conducting sections based on the rail-earth voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a rail ground voltage and a rail leakage current in a DC feeding system using a rail as a return line.

[0002]

2. Description of the Related Art In an aerial single-track electric railway, a traveling rail is used as a return line. Since the ground resistance (leakage resistance) of this rail is 0.1 to 100 Ω / Km, part of the current flowing through the rail is It diverts to the earth. Electrolytic corrosion occurs on rails and dog nails at the part where this leakage current flows out from the rails.

[0003] Grasping the amount of electrolytic corrosion is an important issue in the planning of the feeding system and the rail maintenance and inspection plan. Also,
The rail leakage current related to electrolytic corrosion has an influence on the geomagnetic disturbance for the geomagnetic observation, and it is required to detect the rail leakage current.

On the other hand, the rail leakage current is related to the rail-to-ground voltage, and the detection of the rail-to-ground voltage is also a necessary condition.

Conventionally, in a feeder system for exchanging electric power between a plurality of substations and a plurality of electric trains (including regenerative vehicles) with a rail as a return line, each node when the substation and electric trains are node points The method of calculating and analyzing the voltage and current distributions at points is described in, for example, Technical Report of the Institute of Electrical Engineers of Japan (Part 2) No. 296, “Current State and Ideal State of Feeding System Including Regenerative Vehicle”, No. 18
See pages 20 to 20 in detail.

On the other hand, with respect to the method for detecting and analyzing the rail earth-to-ground voltage and the rail leakage current, a method for obtaining under a specific condition that a single train exists between a single energization section and two substations, for example, new edition, electrolytic corrosion・ Soil Corrosion Handbook, P61
~ P75.

This analysis method will be described with reference to FIG.
This figure is a gradient diagram of the rail-to-ground voltage V in a single conduction section, where the conduction section length is L (Km), the distance from the voltage zero point to any rail point is x (Km), and the rail conduction current is Where I (A) is the rail leakage resistance is ω (Ω · Km) and the rail resistance is r (Ω), the absolute value of the rail-to-ground voltage V in a single conduction section is expressed by the following equation (1). To be done.

[0008]

[Equation 5] | V | = r · I · L / 2 (1) If the minute leakage current in the minute section dx is dI _L , the leakage current I _{L of the} entire single conduction section is It is represented by the formula 2).

[0009]

[Equation 6]

[0010]

Conventionally, in a DC feeding system using a rail as a return line, when electric power is exchanged between a plurality of substations and a plurality of trains (including regenerative vehicles), A method for obtaining the voltage and current distribution on the feeder side at the corresponding position has been established.

However, the rail side has not been studied at all under the above operating conditions, and the rail-to-ground voltage when one substation and one substation are operating or one substation exists between two substations The leakage current is only being analyzed.

Therefore, in the case where there are a plurality of substations and a plurality of trains that are the actual feeding system, the method for detecting the rail-ground voltage and the rail leakage current is only by actual measurement, which requires a lot of manpower and time. Need. In addition, there is no way to actually measure the plan of the feeder system, and accurate data cannot be obtained by using past data.

An object of the present invention is to provide a detection method for enabling a simulation to detect rail-to-ground voltage and rail leakage current of a DC electric railway having a single energizing section or a plurality of substations and a plurality of trains. Especially.

[0014]

In order to solve the above-mentioned problems, the present invention uses a rail as a return line and one substation or one substation.
In a DC feeding system for exchanging power between a single regenerative train and a single train, and having a rail other than the energized section during single section energization, on the rail where the substation and the train exist A node point is set to each position, and a node point N ₁ for supplying current and a node point N ₂ for supplying current and a known feeder current I ₁ obtained by feeder circuit analysis between the infinite ground and respectively. A negative current source −I ₁ and a positive current source I ₂ opposite to the load inflow current −I ₂ , and the node point N
Equivalent ground conductance b = L / 2ω based on equivalent rail leakage resistance ω of rail length L / 2 for each half-energized section between ₁ and N _2.
When energization interval outside rail length of each node point _{N 1, N 2 L 1,} L 2
Equivalent ground conductance c ₁ = L ₁ / ω, c ₂ = L ₂ / ω based on the equivalent rail leakage resistance ω of both node points N ₁ and N ₂
A determinant expressing an equivalent circuit having a rail resistance a = rL based on the equivalent resistance r between the circuit elements and expressing the characteristics of the equivalent circuit.

[0015]

[Equation 7]

Y ₁₁ : Sum of admittance components connected to node N ₁ Y ₁₂ : Negative value of admittance component connected between nodes N ₁ and N ₂ Y ₂₁ : Connected between nodes N ₂ and N _1. Negative value of admittance component Y ₂₂ : Rail-to-ground voltages V ₁ and V ₂ at the node points N ₁ and N ₂ are calculated from the sum of admittance components connected to the node N ₂ , and the rail-to-ground voltage and the above-mentioned equivalent ground. From the conductance

[0017]

[Equation 8]

According to the above, the rail leakage currents I _LL and I _LR in each half-energized section are obtained.

Further, according to the present invention, the rail-to-ground voltage V
It is characterized in that the rail total leakage current or the total inflow current A and the section length S thereof are obtained according to the positive / negative and the magnitude of ₁ and V ₂ .

Further, according to the present invention, a rail is used as a return line, power is exchanged between a plurality of substations and a plurality of trains including a regenerative train, and a plurality of sections other than the current-carrying section are energized during energization. In the DC feeding system, the node points N _{1 to} N _n are respectively provided at the positions on the rail where the substation and the train exist.
For each of the node points and the ground at infinity, and current sources I _{1 to} I _{n + 1 in the} opposite direction to the known feeder currents obtained by feeder circuit analysis and the node points N ₁ to equivalent ground conductance b ₁ ~b _n based on the left and right equivalent rails leakage resistance in each half energization interval of n _n, equivalent ground-based equivalent rail leakage resistance ω across node point n _1, n _n-conducting time zone outside rails The rail resistance a based on the conductances c ₁ and c ₂ and the equivalent resistance r between the nodes at the node points N _{1 to} N _n.
And ₁ ~a _n set an equivalent circuit of the circuit elements, a matrix equation representing the characteristic of the equivalent circuit

[0021]

[Equation 9]

Y _jk (j ≠ k): Negative value of the admittance component connected to the nodes j and k Y _jk (j = k): Each node point from the sum of all the admittance components connected to the node j The rail-to-ground voltages V _{1 to} V _n of N _{1 to} N _n are obtained, and the node points N _k and N _{k + 1 are} calculated from the rail-to-ground voltages V _{1 to} V _n and the equivalent ground conductance of the node points.
The rail leakage currents I _LLk and I _LRk in the left and right half-energized section _viewed from (k = 1 to n) are _calculated by the following equations.

[0023]

[Equation 10]

It is characterized by being obtained from

Further, according to the present invention, the rail ground voltage V
It is characterized in that the rail total leakage current or the total inflow current A and the section length S thereof are obtained according to the positive / negative and the magnitude of _{1 to} V _n .

[0026]

FIG. 1 shows an actual circuit (a) and its equivalent circuit (b) for obtaining the rail-ground voltage in a single energizing section.
In the feeder circuit, as shown in (a) of the figure, current I is supplied from the current source at point A, which is a substation or regenerative vehicle, to the train at point B through the feeder, and the running rail to be retraced is fed to this rail. It is assumed that the current I flows in the direction shown.

The equivalent circuit at this time is, as shown in (b), the rail-to-ground voltage V between the starting point A and the ending point B at which the distance L is reached.
₁ , V ₂ reverse the current direction of the current source so as to match the direction of the current flowing in the running rail, and make the ground conductance b, c ₁ , c ₂ between the rail and the infinite ground and the current I of the rail. Required based on

Here, the ground conductances b, c ₁ , c ₂
Represents the area between the following rail sections and ground.

B: Equivalent ground conductance L / 2ω (Ω) in the half-energized section c ₁ : Left equivalent ground conductance L _1/2 outside the energized section
ω (Ω) c _2: the right equivalent outside the energization period ground conductance L _2/2
ω (Ω) L ₁ : Left rail length outside energization section (Km) L ₂ : Right rail length outside energization section (Km) ω: Equivalent rail leakage resistance (Ω · Km) Also, between start end A and end B The resistance value a of the rail is expressed as a product r · L of the equivalent rail resistance r (Ω / Km) and the distance L. The equivalent rail resistance means the resistance when the rail current flows through the right rail and the left rail of the rail in half, and is regarded as one rail equivalently by combining them.

From the above equivalent circuit, the rail-to-ground voltages V ₁ and V _{2 at} the starting point A and the ending point B can be expressed by the following equations by solving the equation (3).

[0031]

[Equation 11]

When the distances L ₁ and L ₂ outside the section are set to zero in the above equation, the rail-to-ground voltages V ₁ and V ₂ are obtained as the following values, respectively.

[0033]

[Equation 12]

The rail-to-ground voltages V ₁ and V ₂ coincide with the analysis result (1) in the conventional single energization section. Also,
When L ₁ = ∞ and L ₂ = 0, V ₁ = 0 and V ₂ ≉rLI, which is the same as the conventional one.

Next, the rail leakage current in the single energizing section will be described. FIG. 2 shows a graph for obtaining the rail leakage current in a single energization section. In the same figure, the horizontal axis is shown by the conductance corresponding to the distance L, and the vertical axis is shown by the rail ground voltage V.

In the figure, the equivalent ground conductance (Ω ⁻¹ ) due to the rail leakage resistance ω (Ω · Km) in the semi-energized section becomes L / 2ω, and the leakage current from the rail to the ground in the left half section. Corresponds to the area of the region A, and the leakage current in the right half section corresponds to the area of the region B.

Therefore, the rail leakage current I _{LL in the} left half section and the rail leakage current I _LR in the right half section are linear functions having a rail-to-ground voltage gradient for each section.

[0038]

[Equation 13]

Y: Rail-to-ground voltage x: distance is integrated over each half-energized section to obtain the following.

[0040]

[Equation 14]

The inflow section length, the leakage section length, the total inflow current, and the total leakage current are shown in the following table according to the positive / negative and the magnitude of the rail-to-ground voltages V ₁ , V ₂ .

[0042]

[Table 1]

Next, an equivalent circuit in a system for exchanging electric power between a plurality of substations and a plurality of trains (including regenerative cars) is as follows:
The circuit shown in FIG. 3 is a development of the equivalent circuit of FIG.

In the figure, substations and trains are designated as node points 1 to n + 1, and distances L _{1 to} L _n (K
m), an equivalent ground conductance b _{1 to} b _n (= L _k / 2ω _k ) in a half section between each node point, a known current source I _{1 to In n + 1 at} each node point, a left side outside the energization section, and There are equivalent ground conductances c ₁ and c ₂ on the right side.

If there is a grounding object such as a vehicle depot that branches off from the line, the grounding resistance is expressed as including the equivalent grounding conductance.

In the equivalent circuit of FIG. 3, the rail-to-ground voltages V _{1 to} V _{n + 1} at the respective node points are the same as the method for obtaining the rail-to-ground voltages V ₁ and V ₂ in the single section energization of FIG. Similarly, it can be obtained for each section.

Here, since the energizing currents I _{1 to} I _{n + 1} are originally synthesized by exchanging currents between a plurality of substations and trains or between trains and trains, the values are It becomes a pair of current sources having the same and opposite signs, and can be decomposed into a circuit equivalent to the single conduction section in FIG.

Therefore, from the "superposition principle", the voltages V _{1 to} V _{n + 1} at the respective node points are the same as the combination of the voltages at the respective node points obtained in the single conduction section. This becomes the determinant of the above equation (5), and the solution is obtained as the rail ground voltage at the node.

Next, the rail leakage current in the equivalent circuit of FIG. 3 is obtained in the same manner as the rail leakage current in the single conduction section obtained from the graph shown in FIG.

To obtain the rail leakage current, if the distance L _k between the node point k and the node point k + 1, the rail leakage resistance ω _k between them, and the voltages V _k and V _{k + 1} at the node points k and k + 1 are given, The rail leakage current I _{LLk in the} left half section and the rail leakage current I _{LRk in the} right half section between the node points k and k + 1 are respectively expressed by the following equations.

[0051]

[Equation 15]

Further, the inflow section length, the leak section length, the total inflow current, and the total leakage current are shown in the following table according to the positive / negative and the magnitude of the rail-ground voltages V _k , V _{k + 1} .

[0053]

[Table 2]

From the above, according to the present invention, the position where the substation or train exists is taken as the node point, and the equivalent ground conductance of the rails in the left and right half-energized sections is provided between each node point and the ground at infinity. An equivalent circuit in which there is a conducting current and rail resistance between nodes, and by setting known circuit constants such as conducting section distance and equivalent rail leakage resistance, rail-to-ground voltage and rail leakage in a single conducting section and multiple conducting sections. The current or inflow current is detected for each node point.

[0055]

FIG. 4 is a flow chart for obtaining a rail ground voltage and a rail leakage current or an inflow current in a plurality of conducting sections according to an embodiment of the present invention. The setting or reading (S1) of the known circuit constant is performed by the equivalent rail resistance r (Ω · Km) and the equivalent rail leakage resistance ω (Ω · K) of the target line.
m) is read as setting or data.

In the train position detection (S2), each train position is obtained at each time in accordance with the train schedule in the system operation, and the train position and the known substation position are set as node points, and between each node point (energized section ) Distance L _{1 to} L
Calculation of _n (Km) and the rail length of the left and right half sections of the energization section and the equivalent rail leakage resistance ω to the equivalent ground conductance b ₁
˜b _n (Ω ⁻¹ ) is calculated.

The energizing current setting (S3) is carried out by applying the energizing currents I _{1 to} I _{n + 1} (A) known to each train to each node point based on the driving conditions (slope traveling, regenerative traveling) at the train position of each node point. Set as a current source.

[0058] Setting of circuit constants (S4), the constant c ₁ between the node points and node _{points, c 2, b 1 ~bn,} rL 1 ~rL
Set _n .

[0059] Rail ground voltage operation (S5), said from the value obtained in step S1 to S4 (5) rail across ground voltages V ₁ for each node point in accordance with formula ~V _n + 1 (V)
Ask for.

The rail leakage current calculation (S6) is performed as the rail leakage currents I _LLk and I _LRk for each node point from the equation (6) from the rail ground voltage obtained in step S5, and further according to Table 2. The total leakage (inflow) current A and its section length S are obtained.

In the calculation result output (S7), the calculation up to the rail ground voltage and the rail leakage current is obtained for each time, and the totalized result for each day is output as a detected value.

[0062]

As described above, according to the present invention, a position where a train or a substation exists is a node point, and an equivalent rail equivalent ground conductance, a conducting current and a rail resistance in a half-energized section between the node points. Since the rail ground voltage and the rail leakage current or inflow current at each node point are obtained from the circuit, the rail ground voltage, rail leakage current or inflow current depending on the train position (node point) is calculated using a processing device such as a computer. Can be easily obtained by simulation.

In particular, the rail-to-ground voltage at each rail position in a system having a plurality of trains and a plurality of substations,
It is applied to the detection of rail leakage current or inflow current to facilitate its calculation.

The detection of the rail earth voltage, the rail leakage current or the inflow current facilitates the quantitative examination at the planning stage of the system and the calculation of the annual electric erosion amount of the rail of the existing system.

[Brief description of drawings]

FIG. 1 is an actual circuit in a single conduction section and a rail-to-ground voltage equivalent circuit.

FIG. 2 is a rail leakage current graph in a single energized section.

FIG. 3 is a rail-to-ground voltage equivalent circuit for a plurality of conducting sections.

FIG. 4 is a flowchart of an embodiment.

FIG. 5 is a rail-to-ground voltage gradient in a single conduction section.

Claims (4)

[Claims] 1. A substation or 1 with a rail as a return line
In a DC feeding system for exchanging electric power between one regenerative train and one train, and having a rail other than the energized section during energization of a single section, on the rail where the substation and the train exist Positions are set to node points, respectively, and a known feeder current I ₁ and a feeder current I ₁ obtained by feeder circuit analysis between a node point N ₁ supplying current and a node point N ₂ supplying current Load inflow current-I ₂
Of the opposite negative current source −I ₁ and positive current source I ₂ and the equivalent rail conductance based on the equivalent rail leakage resistance ω of each half-conduction section rail length L / 2 between the node points N ₁ and N _2. b
= L / 2ω and the equivalent ground conductance c ₁ = L ₁ / ω, c ₂ = L ₂ / based on the equivalent rail leakage resistance ω of the outer rail lengths L ₁ and L _{2 at} the node points N ₁ and N ₂ and the rail resistance a = rL based on the equivalent resistance r between both node points N ₁ and N _2.
An equivalent circuit having circuit elements of and is set, and a determinant representing the characteristics of the equivalent circuit Y ₁₁ : Sum of admittance components connected to node N ₁ Y ₁₂ : Negative value of admittance component connected between nodes N ₁ and N ₂ Y ₂₁ : Of admittance component connected between nodes N ₂ and N ₁ Negative value Y ₂₂ : Rail-to-ground voltages V ₁ and V ₂ at the node points N ₁ and N ₂ are calculated from the sum of admittance components connected to the node N ₂ , and the following is calculated from the rail-to-ground voltage and the equivalent ground conductance. Expression [2] Rail leakage currents I _LL and I _{LL in} each semi-energized section
_A method for detecting rail-to-ground voltage / rail leakage current in a single energizing section of a DC feeding system, which is characterized by obtaining _LR . 2. The rail earth according to claim 1, wherein the rail total leakage current or the total inflow current A and the section length S thereof are determined according to the positive / negative and the magnitude of the rail earth-to-earth voltages V ₁ , V _2. Inter-voltage / rail leakage current detection method. 3. A DC feeding system for energizing a plurality of sections in which a rail is used as a return line, electric power is transferred between a plurality of substations and a plurality of trains including a regenerative train, and rails exist in addition to the energizing section. In the above, a known feeder line is obtained by setting node points N _{1 to} N _n at positions on the rail where the substation and the train exist, respectively, and calculating by feeder circuit analysis between each node point and the ground at infinity. Current source I in the opposite direction to the current
₁ ~I n + ₁ and the respective equivalent ground conductance b ₁ ~b _n based on the equivalent rail leakage resistance in the semi-conducting time zone left of each node point N ₁ to N _n, across the node point N _1, N _n The equivalent ground conductances c ₁ and c ₂ based on the equivalent rail leakage resistance ω of the rail outside the energization section and the rail resistances a _{1 to} a _n based on the equivalent resistance r between the nodes at the node points N _{1 to} N _n are circuited. An equivalent circuit as an element is set, and a determinant expressing the characteristics of the equivalent circuit Y _jk (j ≠ k): Negative value of admittance component connected to node j and node Y Y _jk (j = k): Each node point N ₁ ~ from the sum of all admittance components connected to node j The rail-to-ground voltages V _{1 to} V _n of N _n are obtained, and the node points N _k and N _{k + 1} (k = 1 to ₁ ) are calculated from the rail-to-ground voltages V _{1 to} V _n and the equivalent ground conductance of the node points. n)
Rail leakage currents I _LLk , I in the left and right half-energized sections
_LRk is given by the following equation [4] A method for detecting rail-to-ground voltage / rail leakage current in multiple energizing sections of a DC feeding system, which is obtained from 4. The rail ground according to claim 3, wherein the rail total leakage current or the total inflow current A and the section length S thereof are determined according to the positive / negative and the magnitude of the rail ground voltage V _{1 to} V _n. Inter-voltage / rail leakage current detection method.