JP2000343985A - Method and device for detecting abraision of trolley wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make abraision contact and a trouble of a detector discriminated. SOLUTION: In this method, a signal voltage is impressed between a trolley wire main body 3 of a trolley wire 2 built-in with a sensing wire 4 and one end of the sensing wire 4 to detect a current flowing to an abraision point 8 via the sensing wire 4 at the time of abraision contact. In this method, an impedance 6 is provided in the one end of the sensing wire 4 to limit the current flowing to the abraision point 8, and the presence of a trouble current resulting from a cause other than the abraision contact is determined when a current exceeding the current limited by the impedance 6 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting wear of a trolley wire having a built-in detection wire, and more particularly, to a method of detecting wear of a trolley wire capable of distinguishing a contact between abrasion and a failure of a detection device. It concerns the device.

[0002]

2. Description of the Related Art A conventional technique for detecting wear of a trolley wire having a built-in detection wire will be described with reference to FIG. The trolley wire 2 indicated by a circle is one in which a single detection wire 4 insulated from the trolley wire main body 3 is provided inside the trolley wire main body 3. A trolley power supply 7 is connected to the start end of the trolley wire body 3. In the detection device 21 provided at the start end of the trolley wire 2, a signal voltage source 5 is provided between the trolley wire main body 3 and the detection wire 4.
Is inserted. The end of the detection line 4 is open.

When the trolley wire 2 is worn to the position where the detection wire 4 is built in at a point 8 between the start end and the end, the insulation coating of the detection wire 4 is broken, and the trolley wire main body 3 and the detection wire 4 are detected at the wear point 8. The line 4 comes into contact via the contact resistance (resistance value Rc). At this time, a detection current I of the following equation flows through the detection line 4.

[0004]

(Equation 1)

[0005] Here, Rt: resistance value per unit length of the trolley wire main body Rk: resistance value per unit length of the detection wire X: distance from the detection device to the wear point.

When such a detection current I flows,
It is determined that there is wear. Also, Rc << Rk.X, Rt.
If X << Rk · X,

[0007]

(Equation 2)

The distance X from the detection device 5 to the wear point 8 can be detected from the value of the detection current I.

A conventional technique for detecting wear of a trolley wire including a plurality of detection wires will be described with reference to FIG. The trolley wire 2 shown by a circle is provided with two detection wires 4 and 4 ′ which are insulated from the trolley wire main body 3 inside the trolley wire main body 3. A trolley power supply 7 is connected to the start end of the trolley wire body 3. In the detecting device 31 provided at the starting end of the trolley wire 2, the trolley wire main body 3 and the two detection wires 4, 4 '
And the signal voltage source 5 is inserted. Detection line 4,
The ends of 4 'are shorted together.

At the wear point 8, the trolley wire 2 is worn to the position where the detection wires 4 and 4 'are built in, the insulation coating of one of the detection wires 4' is broken, and the trolley wire main body 3 comes into contact with the detection wire 4 '. And At this time, the resistance value of the resistance of the trolley wire main body 3 from the detection device 31 to the wear point 8 is Rt · X. The resistance value of the contact resistance between the trolley wire body 3 and the detection wire 4 is Rc, the resistance value of the resistance from the detecting device 31 of the contacting detection line 4 'to the wear point 8 is R2, and the detection line 4 of the non-contacting one. The resistance value of the resistance from the detection device 31 to the wear point 8 (via the terminal portion) is R1.

The detection currents I1 and I2 flow through both the detection lines. The relational expression of these current value and resistance value is

[0012]

(Equation 3)

## EQU1 ##

This equation does not depend on the contact resistance value Rc and the resistance value Rt per unit length of the trolley wire body 3.

Assuming that both the detection lines 4, 4 'are uniform, the resistance value per unit length of the detection lines 4, 4' is Rk, and the total length of the trolley wire 2 is L,

[0016]

(Equation 4)

## EQU1 ##

From these relations,

[0019]

(Equation 5)

The distance X from the detecting device 61 to the wear point 9 can be detected from the ratio of the detected currents I1 and I2.

[0021]

In the prior art, at the wear point 8, the trolley wire 2 is worn down to the built-in position of the detection wires 4 and 4 ', and the insulation coating of the detection wires 4 and 4' is broken, so that a current is applied to the detection wire. Is flowing, the current is detected to determine wear contact. However, when a failure occurs in the detection device 1, the current flowing at the failure point may be detected. The current due to an internal failure of the detection device 1 and the detection device 1
Cannot be distinguished from the current due to abrasion contact in the vicinity of.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a trolley wire wear detecting method and a trolley wire wear detecting method capable of distinguishing a wear contact from a failure of a detecting device.

[0023]

In order to achieve the above object, a method according to the present invention comprises applying a signal voltage between a trolley wire body of a trolley wire having a built-in sensing wire and one end of the sensing wire. In a trolley wire wear detection method for detecting a current flowing to a wear point via the detection line at the time of wear contact, an impedance for limiting a current flowing to a wear point is provided at one end of the detection line, and the impedance is limited by the impedance. When a current exceeding the current is detected, it is determined that the fault current is not caused by abrasion contact.

Further, the apparatus of the present invention is provided with a signal voltage source for applying a signal voltage between a trolley wire main body of a trolley wire having a built-in detection wire and one end of the detection wire, and connecting the detection wire at the time of abrasion contact. In a trolley wire wear detection device provided with a current detection unit that detects a current flowing to a wear point via a wire, an impedance for limiting a current flowing to a wear point is provided at one end of the detection wire, and a current limited by the impedance is provided. When a current exceeding the current is detected, a determination unit is provided for determining that the failure current is not caused by abrasion contact.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, the detection device 1 according to the present invention is provided at the beginning (power application section) of a trolley wire 2 indicated by a circle. The trolley wire 2 is provided with a single detection wire 4 insulated from the trolley wire main body 3 inside the trolley wire main body 3. A signal voltage source 5 for applying a signal voltage between the trolley wire main body 3 and the detection wire 4 is provided in the detection device 1. Further, inside the detection device 1, an internal wiring for guiding a signal voltage to the detection line 4 is provided. A current detector (not shown) for detecting a current flowing from the signal voltage source 5 is provided in the internal wiring or the signal voltage source 5.

According to the present invention, the impedance limiting the current flowing to the wear point (fault detection impedance; resistance R
d) 6 is inserted between the start end of the detection line 4 and the internal wiring of the detection device 1. Further, in the present invention, a determination unit (not shown) is provided for determining whether the current detected by the current detection unit is a detection current due to wear contact or a detection current due to a failure based on the current value.

The end of the detection line 4 is open. A trolley power supply 7 is connected to a start end of the trolley wire main body 3.

When the trolley wire 2 is worn to the built-in position of the detection wire 4 at a certain point 8 between the start end and the end, the insulation coating of the detection wire 4 is broken, and the trolley wire main body 3 and the detection wire 4 are detected at the wear point 8. The line 4 comes into contact via the contact resistance (resistance value Rc). At this time, the detection current I3 of the following equation is applied from the signal voltage source 5 to the wear point 8 via the internal wiring and the detection line 4.
Flows, and is detected by a current detection unit (not shown).

[0030]

(Equation 6)

Here, Rt: resistance value per unit length of the trolley wire main body Rk: resistance value per unit length of the detection wire X: distance from the detection device to the wear point.

Even if the trolley wire 2 is not in abrasion contact (when the trolley wire is normal), if the internal wiring is in electrical contact with the trolley wire main body 3 at the failure point 9 in the detecting device 1, the signal voltage A detection current I4 of the following equation flows from the source 5 to the fault point 9 via the internal wiring, and is detected by a current detection unit (not shown).

[0033]

(Equation 7)

Here, Rb is a contact resistance value at a failure point.

When the trolley wire 2 makes abrasion contact at the near end of the detection device 1, that is, when the total resistance value (Rt.X + Rk.X + Rc) of the detection current loop when X is small, and when the detection device 1 fails, Between the contact resistance value Rb

[0036]

(Equation 8)

The following relationship may be satisfied. For this reason, in the related art, it is not possible to distinguish between the wear contact and the failure of the detection device.

In the present invention, since the failure detection impedance 6 is provided, the total resistance value of the detection current loop at the time of abrasion contact is Rt ・ X + Rk ・ X + Rc + Rd. Here, if Rd >> Rb, I4 >> I3 always holds even if X is small. That is, the contact resistance value R at the failure point
A failure detection impedance 6 having a resistance value Rd sufficiently larger than b is used, and a determination unit (not shown) determines that the current is a failure current if the magnitude of the detected current exceeds the current limited by the failure detection impedance 6. Keep it. Thereby, it is possible to distinguish between the wear contact and the failure of the detection device 1.

In the above embodiment, the present invention is applied to the trolley wire 2 having one detection line. However, the present invention can of course be applied to the trolley wire 2 having a plurality of detection lines.

[0040]

The present invention exhibits the following excellent effects.

(1) Since the impedance for limiting the current at the time of wear contact is provided, it is possible to distinguish between the wear contact of the trolley wire 2 and the failure of the detection device 1 by comparing the magnitude of the detected current.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a trolley wire wear detecting device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional trolley wire wear detecting device.

FIG. 3 is a circuit diagram of a conventional trolley wire wear detecting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detection apparatus 2 Trolley wire 3 Trolley wire main body 4 Detection wire 5 Signal voltage source 6 Fault detection impedance

Claims (2)

[Claims] A signal voltage is applied between a trolley wire main body of a trolley wire having a built-in detection wire and one end of the detection wire, and a current flowing to a wear point via the detection wire at the time of wear contact is provided. In the trolley wire wear detection method for detecting, an impedance for limiting a current flowing to a wear point is provided at one end of the detection wire, and when a current exceeding the current limited by the impedance is detected, a fault current not due to wear contact is detected. A trolley wire wear detection method, characterized in that: 2. A signal voltage source for applying a signal voltage between a trolley wire body of a trolley wire having a built-in detection wire and one end of the detection wire. In a trolley wire wear detection device provided with a current detection unit that detects a flowing current, an impedance that limits a current flowing to a wear point is provided at one end of the detection wire, and a current that exceeds a current limited by the impedance is detected. A trolley wire abrasion detecting device, characterized in that a deciding unit for determining a fault current that is not caused by abrasion contact is provided.