A △ wiring method for T-connected power supply of cable lines

Abstract

The present invention relates to the field of high-voltage power distribution network power supply. A delta wiring method for T-connected power supply in a cable line is provided, wherein a three-phase high-voltage power supply is connected to a first user via two cables, one for backup and one for use, and a second user is located along the two cables. When the second user needs to be connected to the three-phase high-voltage power supply, a suitable construction point is selected based on the original cable laying method and the distance between the second user and the three-phase high-voltage power supply and the first user, and the second user is connected to the two cables, one for backup and one for use. The beneficial effects of the present invention are: while meeting the conditions for T-connected power supply, minimal equipment investment is adopted, the wiring is ensured to be simple, easy to implement, and significant in efficiency.

Description

Technical Field

[0001] The present invention relates to the field of high-voltage power distribution network power supply. Background Art

[0002] For high-voltage distribution network power supply lines, most of them currently use cables for power supply. For power supply branches with larger currents, one circuit is generally powered by two or more cables in parallel (one for backup and one for use).

[0003] When power supply is needed near the high-voltage cable laying path, due to the high-voltage cable manufacturing process and the characteristics of the high-voltage electric field distribution, the high-voltage cable cannot be directly connected using the T-connection method like the low-voltage cable (that is, directly connecting the cable after removing the cable sheath in the middle). The general method is: cut the original cable and connect it to the cable connection box in the middle (such as Figure 2 shown).

[0004] Because the original cable was laid in a straight line with no margin, the cable length was insufficient when it was cut and connected to the docking box. Therefore, two cable docking boxes were required, each connected by cables of the same specification. The additional equipment and materials required included two cable docking boxes, two cables of the same specification, and eight sets of cable terminals, resulting in a large investment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: how to realize low-cost power supply to users who need power supply near the high-voltage cable laying path.

[0006] The technical solution adopted by the present invention is: a △ wiring method for T-connected power supply of cable lines, in which a three-phase high-voltage power supply is connected to a first user through two cables, one for backup and one for use, and a second user is located along the two cables, one for backup and one for use. When the second user needs to be connected to the three-phase high-voltage power supply, a suitable construction point is selected based on the original cable laying method and the distance between the second user and the three-phase high-voltage power supply and the first user, and the second user is connected to the two cables, one for backup and one for use.

[0007] A suitable construction site refers to a location with low construction difficulty.

[0008] Connecting the second user to two cables, one for backup and one for use, means that the second user is far away from the three-phase high-voltage power supply and the first user. When the cable needs to be disconnected, the same type of connecting cable is used to connect the two ends of the disconnected cable and the second user. When the second user is far away from the three-phase high-voltage power supply or the first user, the connecting cable is used to directly connect the second user and the three-phase high-voltage power supply or the first user that is close to the second user.

[0009] The beneficial effects of the present invention are: under the condition of meeting the T-connection power supply, the minimum equipment investment is adopted, the wiring is ensured to be simple, easy to implement, and the benefits are significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a wiring diagram of the present invention;

[0011] Figure 2 It is a prior art connection diagram;

[0012] Figure 3 This is the wiring diagram when the distance between the second user and the three-phase high-voltage power supply is small;

[0013] Figure 4 This is the wiring diagram when the distance between the first user and the three-phase high-voltage power supply is small;

[0014] Figure 5 This is a schematic diagram of the four connection methods of A / B / C / D;

[0015] Among them, 1. three-phase high-voltage power supply, 2. first user, 3. second user, 4. spare cable, 5. working cable, 61. first connecting cable, 62. second connecting cable, 71. first cable docking box, 72. second cable docking box. DETAILED DESCRIPTION

[0016] Example 1

[0017] Clarify the original cable path: determine the exact cable location based on markers (drawings), cable line path detectors, etc.

[0018] Determine the connection plan for the access cables and power cables required by new users.

[0019] If the original cable was laid using methods such as direct burial or a simple cable trench that make it difficult to extract, or if re-installation is challenging, plan A can be selected based on the site conditions. Select suitable locations (close to each other) for the new and old cable joints, forming a triangle (power source, primary user, secondary user).

[0020] If the original cable was laid using a less complex method, such as a cable tunnel or a convenient cable trench, construction can proceed using a less complex method based on site conditions. Depending on the site conditions, you can choose to replace the cable on one side and reroute the original cable to the other side. If the second user is close to the power source, you can choose Option B: replace the power-to-second user cable and reroute one of the original cables to a liaison cable between the first and second users, forming a triangle. If the second user is close to the first user, you can choose Option C: replace the first-to-second user cable and reroute one of the original cables to the second user, forming a triangle.

[0021] In special cases, plan D can be selected, in which a cable is cut to a selected size, enough for one side, and a new cable is added to the other end to form a triangle.

[0022] After the cable is laid, repair the holes in the cable trench and cable tunnel and make sure they are waterproof. Mark the newly laid cables with stakes and take measures to prevent water ingress and external damage to the newly built intermediate cable heads.

[0023] The cable installation standard test is passed and connected to the switch cabinet.

[0024] After power is supplied and put into operation, the temperature of the connection points and cable heads (including measurable intermediate heads) is measured and verified.

Claims

1. A cable line T-connection power supply method, wherein a three-phase high-voltage power supply is connected to a first user via two cables, one backup and one use, and a second user is located along the two cables, characterized in that: When the second user needs to be connected to a three-phase high-voltage power supply, a suitable construction point is selected according to the laying method of the original cable and the distance between the second user and the three-phase high-voltage power supply and the first user, and the second user is connected to two cables, one for backup and one for use; a suitable construction point refers to a location with low construction difficulty; connecting the second user to two cables, one for backup and one for use, means that the second user is far away from the three-phase high-voltage power supply and the first user. When the cable needs to be disconnected, the same type of connecting cable is used to connect the two ends of the disconnected cable and the second user to form a triangle. When the second user is close to the three-phase high-voltage power supply or the first user, the connecting cable is used to directly connect the second user and the three-phase high-voltage power supply or the first user close to the second user. Specifically: when the second user is close to the power supply side, the power supply to the second user cable is replaced, and one of the original cables is changed to a communication cable between the first user and the second user to form a triangle. When the second user is close to the first user, the first user to the second user cable is replaced, and one of the original cables is transferred to the second user to form a triangle.

Images