Traction current and traction backflow composite channel

Abstract

The utility model relates to a traction current and traction backflow composite channel which comprises a traction current channel composed of a plurality of metal wires. The traction backflow channel is composed of a plurality of metal wires, the traction backflow channel is evenly arranged on the periphery of the traction current channel, and the current direction of the traction current channel is opposite to that of the traction backflow channel; the insulating layer is arranged between the traction backflow channel and the traction current channel, uniformly coats the outer surface of the traction current channel and is uniformly attached to the inner surface of the traction backflow channel; according to the utility model, the anode cable and the cathode cable are integrated in the composite channel, and the advantages that the current directions of the anode cable and the cathode cable are opposite and the distance is short are utilized, so that the electromagnetic induction of the anode cable and the cathode cable can offset each other, and the electromagnetic induction influence range is greatly reduced; and the electromagnetic influence of the traction network on surrounding electrical equipment is fundamentally reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a combined channel for traction current and traction return current. Background Art

[0002] At present, the common power supply methods for electrified railways are direct power supply with a return line (DN power supply) and autotransformer power supply (AT power supply). Under these two power supply methods, a negative cable is used to introduce the traction return current into the substation, and a positive cable is used to transmit the traction current to the catenary. The structures of the negative cable and the positive cable are exactly the same. As relatively independent individuals, in some special scenarios, both the positive and negative cables will have an electromagnetic impact on adjacent high-voltage cables, causing the induced voltage of the metal layer of the high-voltage cable to exceed the design reference. In severe cases, it will lead to a short circuit of the metal layer to the ground, causing electrical faults.

[0003] The electrified railway uses single-phase alternating current to supply power to the traction network. The traction network is an asymmetric power supply loop composed of the catenary, rails, the earth, and the return line, which will inevitably generate an electromagnetic field around it, thus affecting the surrounding electrical equipment. At present, there are mainly two methods to solve the problem. One is to strengthen the shielding measures for the affected equipment or relocate it out of the affected area. The other is to take measures to suppress interference in the power supply. However, these measures are costly and have a wide impact range, and they cannot effectively reduce the electromagnetic impact of the traction network on the surrounding electrical equipment fundamentally. Summary of the Utility Model

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the problem that the positive and negative cables, as relatively independent individuals, have a large electromagnetic impact on the surrounding electrical equipment in the prior art. Furthermore, a combined channel for traction current and traction return current is provided. By integrating the positive cable and the negative cable into a combined channel and taking advantage of the fact that the current directions of the positive cable and the negative cable are opposite and the distance between them is close, the electromagnetic induction of the positive cable and the negative cable can not only cancel each other out, but also greatly reduce the electromagnetic induction influence range, fundamentally reducing the electromagnetic impact of the traction network on the surrounding electrical equipment.

[0005] To solve the above technical problem, the utility model provides a combined channel for traction current and traction return current, including

[0006] A traction current channel, which is composed of multiple metal wires;

[0007] A traction return current channel, which is composed of multiple metal wires. The traction return current channel is uniformly arranged around the traction current channel, and the current directions of the traction current channel and the traction return current channel are opposite;

[0008] An insulating layer is provided between the traction return current channel and the traction current channel. The insulating layer uniformly coats the outer surface of the traction current channel and uniformly adheres to the inner surface of the traction return current channel.

[0009] In an embodiment of the present invention, an inner shielding layer is further included between the insulating layer and the traction current channel. The inner shielding layer uniformly coats the outer surface of the traction current channel and uniformly adheres to the inner surface of the insulating layer.

[0010] In an embodiment of the present invention, an outer shielding layer is further included between the insulating layer and the traction return current channel. The outer shielding layer uniformly coats the outer surface of the insulating layer and uniformly adheres to the inner surface of the traction return current channel.

[0011] In an embodiment of the present invention, the inner shielding layer is composed of a semi-conductive inner shielding material, and the outer shielding layer is composed of a semi-conductive outer shielding material.

[0012] In an embodiment of the present invention, a protective layer is further included between the outer shielding layer and the traction return current channel. The protective layer uniformly coats the outer surface of the outer shielding layer and uniformly adheres to the inner surface of the traction return current channel.

[0013] In an embodiment of the present invention, the protective layer is provided as a semi-conductive water-resistant tape.

[0014] In an embodiment of the present invention, the traction return current channel includes a first traction return current channel and a second traction return current channel. The second traction return current channel uniformly coats the outer surface of the first traction return current channel.

[0015] In an embodiment of the present invention, a first auxiliary layer and a second auxiliary layer are further included. The first auxiliary layer and the second auxiliary layer are made of metal or semi-conductive tape. The first auxiliary layer is located between the first traction return current channel and the second traction return current channel, and the second auxiliary layer uniformly coats the outer surface of the second traction return current channel.

[0016] In an embodiment of the present invention, the insulating layer is composed of a cross-linked polyethylene insulating material.

[0017] In an embodiment of the present invention, the total cross-sectional area of the multiple metal wires of the traction current channel is equal to the total cross-sectional area of the multiple metal wires of the traction return current channel.

[0018] The above technical solution of the present invention has the following advantages compared with the prior art:

[0019] The combined channel for traction current and traction return current described in the present utility model integrates a traction current channel and a traction return current channel within the combined channel. It not only realizes the functions of power supply to and return of the catenary, but also confines the electromagnetic induction of the traction current channel and the traction return current channel within a small range, reducing the impact on surrounding electrical equipment. After integrating the traction current channel and the traction return current channel into one combined channel, due to the opposite current directions of the traction return current channel and the traction current channel, the mutual cancellation effect of their electromagnetic induction is greatly enhanced, improving the problem of the large electromagnetic influence of the original positive and negative cables on surrounding electrical equipment. Integrating the traction current channel and the traction return current channel into one combined channel also improves the laying efficiency and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present utility model easier to be clearly understood, the following further elaborates on the present utility model in detail according to the specific embodiments of the present utility model in conjunction with the drawings.

[0021] Figure 1 It is a schematic structural diagram of the front sectional view of the combined channel for traction current and traction return current described in the present utility model;

[0022] Figure 2 is Figure 1 a schematic structural diagram of the side sectional view of the combined channel for traction current and traction return current shown;

[0023] Figure 3 is Figure 1 a partial enlarged view of the A position of the combined channel for traction current and traction return current shown;

[0024] Explanation of the reference numerals in the drawings: 1. Traction current channel; 2. Inner shielding layer; 3. Insulating layer; 4. Outer shielding layer; 5. Protective layer; 6. Traction return current channel; 61. First traction return current channel; 62. Second traction return current channel; 7. Auxiliary layer; 71. First auxiliary layer; 72. Second auxiliary layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following further illustrates the present utility model in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present utility model and be able to implement it, but the embodiments cited do not limit the present utility model.

[0026] Embodiment

[0027] Referring to Figure 1 and 2 shown, in an embodiment of the present utility model, a combined channel for traction current and traction return current is disclosed, which is used on an electrified railway for transmitting traction current and return current from a substation to the catenary of the electrified railway. The combined channel includes

[0028] The traction current channel 1 is formed by stranding or bundling multiple metal wires. One end of the traction current channel 1 is connected to the low-voltage side of the transformer in the substation, and the other end is connected to the online disconnecting switch, for delivering the traction current from the substation to the catenary; the metal wire is preferably a round copper conductor;

[0029] The traction return current channel 6 is composed of multiple metal wires. The metal wire is preferably an electrically conductive round copper wire. The traction return current channel 6 is uniformly arranged around the traction current channel 1. One end of the traction return current channel 6 is connected to the rail, and the other end is connected to the neutral point of the transformer, for conducting the traction return current gathered from the track, the return wire and the earth back to the substation; in use, the current directions of the traction current channel 1 and the traction return current channel 6 are opposite, so that the electromagnetic fields generated by the traction return current channel 6 and the traction current channel 1 can cancel each other out, greatly reducing the electromagnetic influence of the composite channel on the electrical equipment in the surrounding environment. For example, the arrow directions in Figure 2 indicate the current flow directions;

[0030] The insulating layer 3 is arranged between the traction return current channel 6 and the traction current channel 1 for insulating the two to prevent short circuits; further, the insulating layer 3 uniformly coats the outer surface of the traction current channel 1 for tightly combining the multiple conductive metal wires of the traction current channel 1; and uniformly adheres to the inner surface of the traction return current channel 6.

[0031] In an embodiment of the present invention, as shown in Figure 1 a figure, there is also an inner shielding layer 2 located between the insulating layer 3 and the traction current channel 1. The thickness of the inner shielding layer 2 is less than the thickness of the insulating layer 3. The inner shielding layer 2 uniformly coats the outer surface of the traction current channel 1 and uniformly adheres to the inner surface of the insulating layer 3. The inner shielding layer 2 is used to eliminate the increase in the electric field strength caused by the unevenness of the surface of the traction current channel 1.

[0032] In an embodiment of the present invention, as shown in Figure 1 a figure, there is also an outer shielding layer 4 located between the insulating layer 3 and the traction return current channel 6. The thickness of the outer shielding layer 4 is less than the thickness of the insulating layer 3. The outer shielding layer 4 uniformly coats the outer surface of the insulating layer 3 and uniformly adheres to the inner surface of the traction return current channel 6; the outer shielding layer 4 is used to uniformly insulate the electric field on the outer surface of the insulating layer 3 and at the same time protect the insulating layer from damage.

[0033] In an embodiment of the present invention, as shown in Figure 1 a figure, the inner shielding layer 2 is composed of a semi-conductive inner shielding material, and the outer shielding layer 4 is composed of a semi-conductive outer shielding material. Both the semi-conductive outer shielding material and the semi-conductive inner shielding material can improve the electric field distribution of the composite channel, make the electric field distribution more uniform, and avoid local electric field distortion.

[0034] In one embodiment of the present utility model, referring to Figure 1 as shown, it further includes a protective layer 5 located between the outer shielding layer 4 and the traction return channel 6. The protective layer 5 uniformly wraps the outer surface of the outer shielding layer 4 and uniformly adheres to the inner surface of the traction return channel 6. The protective layer 5 is used to prevent moisture and other liquids from penetrating into the composite channel, reducing the risk of electric leakage, and at the same time protecting the outer shielding layer 4 from damage.

[0035] In one embodiment of the present utility model, the protective layer 5 is arranged as a semiconductive moisture-resistant tape, and the semiconductive moisture-resistant tape is in contact with the traction return channel 6 to keep the two at the same potential.

[0036] In one embodiment of the present utility model, referring to Figure 3 as shown, in order to ensure the uniform outer diameter of the traction return channel 6, the traction return channel 6 includes a first traction return channel 61 and a second traction return channel 62. The second traction return channel 62 uniformly wraps the outer surface of the first traction return channel 61. In the technological process, a first layer of metal wire is evenly wound around the outer surface of the protective layer 5 to form the first traction return channel 61, and then a second layer of metal wire is wound around the outer surface of the first layer of metal wire to form the second traction return channel 62.

[0037] In one embodiment of the present utility model, referring to Figure 3 as shown, it further includes a first auxiliary layer 71 and a second auxiliary layer 72. The first auxiliary layer 71 is located between the first traction return channel 61 and the second traction return channel 62. The first auxiliary layer 71 wraps the outer surface of the first traction return channel 61 to improve the structural stability of the first traction return channel 61; the second auxiliary layer 72 uniformly wraps the outer surface of the second traction return channel 62, and the second auxiliary layer 72 is used to improve the structural stability of the second traction return channel 62; further, the first auxiliary layer 71 and the second auxiliary layer 72 are made of metal or semiconductive tape and are used to form a conductive whole with the traction return channel 6.

[0038] In one embodiment of the present utility model, the insulating layer 3 is composed of cross-linked polyethylene insulating material.

[0039] In one embodiment of the present utility model, the total cross-sectional area of the multiple metal wires of the traction current channel 1 is equal to the total cross-sectional area of the multiple metal wires of the traction return channel 6, which makes the current paths of the traction current channel 1 and the traction return channel 6 more symmetrical, thereby reducing the influence of the electromagnetic field on surrounding devices.

[0040] The working principle of the traction current and traction return composite channel of the present utility model is:

[0041] At one end of the composite channel, the traction current channel 1 is connected to the low-voltage side of the substation transformer, and the traction return channel 6 is connected to the neutral point of the transformer. At the other end of the composite channel, the traction current channel 1 is connected to the online disconnector, and the traction return channel 6 is connected to the rail. During power supply, the traction current of the substation is conducted from the traction current channel 1 to the catenary to achieve power supply. Finally, the traction return current collected from the track, the return line and the ground is conducted back to the substation through the traction return channel 6. Since the traction return channel 6 and the traction current channel 1 are integrated in the composite channel, the electromagnetic induction between the two is limited within a small range, and the impact on surrounding electrical equipment is small. Moreover, the currents in the traction return channel 6 and the traction current channel 1 are opposite, which greatly enhances the mutual cancellation effect of the electromagnetic induction between the two, further reducing the electromagnetic impact on surrounding electrical equipment.

[0042] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present utility model.

Claims

1. A combined channel for traction current and traction return current, characterized in that Including, A traction current channel, which is composed of multiple metal wires; A traction return current channel, which is composed of multiple metal wires. The traction return current channel is uniformly arranged around the traction current channel, and the current directions of the traction current channel and the traction return current channel are opposite; An insulating layer, which is arranged between the traction return current channel and the traction current channel. The insulating layer uniformly coats the outer surface of the traction current channel and uniformly adheres to the inner surface of the traction return current channel.

2. The composite channel for traction current and traction return current according to claim 1, wherein It further includes an inner shielding layer located between the insulating layer and the traction current channel. The inner shielding layer uniformly coats the outer surface of the traction current channel and uniformly adheres to the inner surface of the insulating layer.

3. A combined channel for traction current and traction return current according to claim 2, wherein It further includes an outer shielding layer located between the insulating layer and the traction return current channel. The outer shielding layer uniformly coats the outer surface of the insulating layer and uniformly adheres to the inner surface of the traction return current channel.

4. The composite channel for traction current and traction return current according to claim 3, wherein, The inner shielding layer is composed of a semi-conductive inner shielding material, and the outer shielding layer is composed of a semi-conductive outer shielding material.

5. A combined channel for traction current and traction return current according to claim 3, characterized in that, It further includes a protective layer located between the outer shielding layer and the traction return current channel. The protective layer uniformly coats the outer surface of the outer shielding layer and uniformly adheres to the inner surface of the traction return current channel.

6. The composite channel for traction current and traction return current according to claim 5, characterized in that, The protective layer is set as a semi-conductive water-resistant tape.

7. A combined channel for traction current and traction return current according to claim 1, characterized in that The traction return current channel includes a first traction return current channel and a second traction return current channel. The second traction return current channel uniformly coats the outer surface of the first traction return current channel.

8. A combined channel for traction current and traction return current according to claim 7, characterized in that, It further includes a first auxiliary layer and a second auxiliary layer. The first auxiliary layer and the second auxiliary layer are made of metal or semi-conductive tape. The first auxiliary layer is located between the first traction return current channel and the second traction return current channel, and the second auxiliary layer uniformly coats the outer surface of the second traction return current channel.

9. A combined channel for traction current and traction return current according to claim 1, wherein The insulating layer is composed of a cross-linked polyethylene insulating material.

10. A combined channel for traction current and traction return current according to claim 1, characterized in that, The sum of the cross-sectional areas of the multiple metal wires of the traction current channel is equal to the sum of the cross-sectional areas of the multiple metal wires of the traction return current channel.

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