JPS60116534A - Feeding device for dc type electric railway - Google Patents

Abstract

PURPOSE:To reduce a leakage current flowing between rails and the ground as well as to prevent a buried metal body from electric erosion, by installing a DC power source feeding an electric current in a direction of negating the current flowing in the rails via a suction return current feeder line. CONSTITUTION:When DC power is fed to an electric car 7 from DC substations 1a and 1b, electric current IA, IB flow in an electric-car line and rails 3. Hereat, each voltage of variable DC power sources 4a and 4b is regulated, and each of these currents IA' and IB' is made to flow in a direction of negating these currents IA and IB flowing in the rails 3 via an insulated wire 6 whereby the current flowing in the rails 3 between connecting points A and 5a as well as B and 5b is set down to zero. Therefore, a section, where the current flows in the rails 3, comes to only the section connecting a position of the electric car 7 and these connecting points A and B so that a leakage current flowing from the rails 3 to the ground and vice versa is remarkably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a power supply device for an electric railway, and in particular to a power supply device for a six-direct current electric railway that limits leakage current flowing from the rails to the ground.
related to construction equipment.

(Prior Art and Problems) In general, a DC electric railway supply system connects the positive output end of a DC substation to the overhead contact line, connects the negative output end to the rail, and connects the DC substation's DC A system has been adopted in which electricity is supplied to electric cars running under the overhead contact lines. In the power supply device, the current that flows when power is supplied to the electric car flows from the positive output end of the substation to the negative output end of the substation via the overhead contact line, the electric car, and the rail. When current flows through the rails, this leakage current between the rails and the ground can cause electrolytic corrosion to the buried metal objects near the rails, and if there is a geomagnetic observatory nearby, this leakage current can cause electrical corrosion to the buried metal objects near the rails. This is undesirable as it may cause problems. In order to reduce this leakage direct current, conventional methods have been used to shorten the distance between installed substations. However, this method has the drawback of increasing the number of substations, resulting in a huge construction cost.

(Object of the Invention) The present invention was made in view of the above points, and provides a DC type regional air railway power supply device that can significantly reduce leakage current flowing from the rail to the ground side or from the ground to the rail side. is intended to provide.

(Summary of the Invention) The present invention is configured by connecting a small-scale DC power supply with a maximum output voltage of about 100μ to a rail, and arranging a suction return current line in parallel, and connecting the DC power supply to the rail. One special mission is to prevent leakage current from flowing from the rail to the ground side or from the ground to the rail side by supplying current through the suction return current line in a direction that cancels the current flowing through the rail. .

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 1, la and lb are DC substations located adjacent to each other. The positive output ends of these substations 1a and lb are both connected to the overhead contact line 2, and the negative output ends are both connected to the rail 3. Both 4a and 4b are DC power supplies, for example, variable DC power supplies with a maximum output voltage of about 100V and an output voltage adjustment function. The positive side output end of this variable DC' power supply 4a is connected to the common connection point 5a between the food storage area 1a and the rail 3, and the negative side output end is connected to a suction return current line, such as an insulated electric wire, installed in parallel with the rail. 6. The positive output end of the variable DC power supply 4b is connected to the common connection point 5b between the substation 1b and the rail 3, and the negative output end is connected to the insulated wire 6. Reference numeral 7 denotes an electric car, and DC power is supplied to the electric car 7 from the surface current transformers da and jb, respectively. A predetermined position on the rail 3, for example, points A and B where the rail' (5) is at its maximum are both connected to the insulated wire 6.

Next, the operation of the apparatus configured as above will be explained.

A predetermined DC power is supplied to the electric car 7 currently located at the illustrated position below the overhead contact line 2 from DC substations la and lb. At this time, from the positive output end of the DC substation 1a to the overhead contact line 2.
'A current flows through the electric car 7 and the rail 3 to the negative output terminal of the substation 1a as shown by the arrow, and
From the positive output end of the DC substation 1-b to the overhead contact line 2. 'A gorge flows through the air wheel 7 and the rail 3 to the negative output end of the substation 1b as shown by the arrow. Here, the output voltage of the variable DC power supply 4a is adjusted, and from the positive output end of the power supply 4a to the connection point 5a, the rail 3. Connected to the negative output terminal of the power source 4a via the connection point A and the insulated m wire 6.
’ to flow. Similarly, the output voltage of the variable DC power supply 4b is adjusted, and the output voltage is adjusted from the positive output end of the power supply 4b to the connection point 5.
b. Rail 3. A current is passed through the connection point B and the insulated wire 6 to the negative output terminal of the power source 4b. At this time, the output voltage of the variable power supply 4a is adjusted by W so that the value of the current factor A becomes the same value as the current factor A, and the
If the output voltage of the variable power supply 4b is adjusted so that the value of ' than the current is equal to the value of 'RL current melting', the current flowing in the rail in the section connecting the connection point 5a and the connection point A and the connection point 5b can be adjusted.
The current flowing in the rail in the section connecting point B and B becomes zero. For this reason, the current flowing through the electric car 7 flows from the positive output end of the DC plexus 1a to the α lane 2. Electric car7. Connection point A
, Insulated N6. Flows to the negative side output terminal of the substation 1a via the variable direct current source 4a and the connection point 5a, and
From the positive output end of the DC substation 1b to the sleep lane 2. Electric car7.
Connection point B, insulation' is wire 6. It flows to the negative output terminal of the substation b via the variable DC source 4b and the connection point 5b.

As a result, the only sections where current flows through the rail 3 are the section connecting the illustrated electric vehicle 7's location and the connection point A, and the section connecting the illustrated electric vehicle 7's location and the connection point B.
Leakage current flowing from the rail 3 to the ground side or from the ground to the rail 3 side is significantly reduced.

Even if the electric car 7 is located at a position 14t other than the position 1d shown in the figure, the same operation as described above will occur.

The variable DC power supplies 4a and 4b are not limited to being connected to the connection points 5a and 5k, but are connected to the connection point A as shown in FIG.

It may be connected to B. The difference in FIG. 2 from FIG. 1 is that the negative output end of the variable DC power supply 4a is connected to the contact α point A, and the positive output end is connected to the insulated electrolytic 6. The negative output end of the DC' power source 4b is connected to the connection point B, and the positive output end is connected to the insulated wire 6, and the connection points 5a, 5
b is also connected to the insulated wire 6, and other parts are the same as in FIG. 1. In the case of the device shown in FIG. 2, the current generator A is also adjusted to cancel the currents I, IB by adjusting the output voltages of the variable DC power supplies 4a and 4b.

If currents A' and B' of the same value as 8 are passed, the leakage current of the rail can be reduced in the same way as described above.

(Effects) As described above, according to the present invention, a power supply device for a DC-type α-air railway is constructed by connecting the positive output end of a DC substation to a train track and connecting the negative output end to a rail. Here,
On the rail in the section connecting one suction return (IF) line installed parallel to the rail, the point where the negative output end of the substation is connected to the rail, and a point a certain distance from this connection point. , since it is equipped with a direct current that supplies current through the sink return current line in the direction of canceling the current flowing through the rail,
Leakage current flowing from the rail to the ground side or from the ground to the rail side can be significantly reduced. Therefore, it is possible to prevent electrolytic corrosion from occurring on all the buried rails near the rail, and it is also possible to significantly reduce the negative impact on geomagnetic observation. Further, the DC power supply may be small-scale with a maximum output voltage of about 100 V, and may be stationary maintenance-free equipment, so the entire device can be simplified and the cost can be reduced. In particular, costs can be significantly reduced compared to the conventional method of shortening the installation interval of substations.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the invention, and FIG. 2 is a circuit diagram showing another embodiment of the invention. la, lb... blood flow substation, 2 medium overhead contact line, 3... rail, 4a, 4b river variable direct current source, 6... insulated wire, 7...
・・'Direct car.

Claims (1)

[Claims] In a power supply system for a DC electric railway, the positive 111tl output end of a DC substation is connected to the overhead contact line, and the negative output end is connected to the rail. In a direction that cancels the current flowing through the rail in the section connecting the streamline and the point where the negative output end of the rail is connected to the eclipse and a point a predetermined distance tF from this connection point, A power supply device for a DC electric railway, comprising: a DC power source that supplies current through the suction return current line.