CN203673026U - Misplaced partial discharge model for stress cone of 10kV-cable intermediate joint - Google Patents

Abstract

The purpose of this utility model is to provide a 10kV cable intermediate joint stress cone dislocation partial discharge model, which can directly make ordinary XLPE cables, and can truly reflect that the cable intermediate joint is exposed during the manufacturing, installation and operation process under the condition of ensuring safety. model. In order to solve the above-mentioned technical problems, the utility model 10kV cable intermediate joint stress cone dislocation partial discharge model includes two cables connected together, and the cables peel off the shielding layer, outer conductive layer, main insulating layer, and inner conductive layer layer by layer, The copper core is exposed; the outside of the stripped part of the cable is covered with a stress cone, and the fracture of the outer semiconducting layer of one cable protrudes from the stress cone by at least 5mm to form a dislocation. Compared with the existing technology, the utility model artificially makes a defective part inside the real cable intermediate joint, which can truly reflect the nature, characteristics and discharge of representative defects exposed during the manufacturing, installation and operation of the cable intermediate joint. mechanism.

Description

Partial discharge model of stress cone dislocation in 10kV cable intermediate joint

technical field

The utility model relates to the field of power systems, in particular to a stress cone dislocation partial discharge model of a 10kV cable intermediate joint. the

Background technique

XLPE cables are widely used in transmission lines due to their excellent performance. However, the length of cables is generally less than 1km, and cable intermediate joints are required for connection. Therefore, cable intermediate joints are an important part of power cables, but they are also frequent sites of transmission line accidents. , its reliability directly affects the security of the power supply system. During on-site installation, various defects may be introduced into the cable accessories due to improper operation, causing serious damage to the accessories. The partial discharge of the cable is closely related to its insulation condition, and the change of the partial discharge indicates that there may be defects in the cable insulation that may endanger the safe operation of the cable. the

In this regard, in order to address such problems, the best solution is to design a physical model for special research. At the same time, it is also convenient for the staff to practice problem-solving methods. the

At present, a lot of research has been done on the discharge characteristics of insulation defects in cable intermediate joints at home and abroad, but most of the research on the discharge characteristics of typical defects is not carried out on the actual cable joints, which is different from the real discharge characteristics in the joints. And if you really choose a section of defective cable, you can't guarantee the safety of this model. Therefore, how to more realistically simulate the stress cone dislocation partial discharge model of the 10kV cable intermediate joint under the premise of safety has become a difficult problem. the

Utility model content

The purpose of this utility model is to provide a 10kV cable intermediate joint stress cone dislocation partial discharge model, which is directly made of ordinary XLPE cables, and can truly reflect that the cable intermediate joint is exposed during the manufacturing, installation and operation process under the condition of ensuring safety. model. the

In order to solve the above technical problems, the utility model is achieved through the following technical solutions:

10kV cable intermediate joint stress cone dislocation partial discharge model, including two cables connected together, the cables peel off the shielding layer, outer conductive layer, main insulating layer, and inner conductive layer layer by layer to expose the copper core; the copper of the two cables The cores are connected by a crimping tube, the outer side of the copper core and the crimping tube is covered with a semi-conductive sheath, and the outside of the stripped part of the cable is covered with a stress cone, and the fracture of the outer semi-conductive layer of one cable extends out of the stress cone for at least 5mm forms a misalignment. the

Preferably, the semi-conductive sleeve layer is a semi-conductive tape. Such a structure is easier to wrap. the

Preferably, the semiconductive sheath layer is a semiconductive plastic sheath. The plastic sleeve is a special device, which is more convenient to use than semi-conductive tape, but it can only be used for one model. the

Preferably, the semi-conductive tape is wrapped from the shielding layer of one cable to the shielding layer of another cable. Such wrapping ensures that the least material is used to ensure the wrapping effect. the

Preferably, the junction of the main insulating layer and the surface of the main insulating layer are also coated with a Wacker silicone grease layer. WACKER's silicone grease layer can play a flame-retardant effect of high temperature resistance, and can also strengthen the bonding effect. the

Preferably, the fracture of the outer semiconducting layer of one of the cables protrudes 30 mm from the stress cone to form a dislocation. the

Preferably, the shielding layer, the outer conductive layer and the main insulating layer are distributed in steps. Such a structure is convenient to find the corresponding layer during the production process, and there is no error. the

Preferably, the exposed portions of the shielding layer, the outer conductive layer and the main insulating layer have the same length. This design is mainly for structural beauty. the

Compared with the prior art, the stress cone dislocation partial discharge model of the 10kV cable intermediate joint of the utility model is selected to artificially make a defective part inside the real cable intermediate joint, which can truly and safely reflect the manufacturing, installation and operation process of the cable intermediate joint The nature, characteristics and discharge mechanism of the representative defects exposed in the test can effectively extract the characteristic quantities of partial discharge of typical defects, and study the characteristic quantities of partial discharge formed by the dislocation of stress cones well. Physical basis. the

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the cable used in the stress cone dislocation partial discharge model of the 10kV cable intermediate joint of the utility model after it is pulled apart as required. the

Fig. 2 is a schematic diagram of the overall structure of the stress cone dislocation partial discharge model of the 10kV cable intermediate joint of the utility model. the

Detailed ways

10kV cable intermediate joint stress cone dislocation partial discharge model, including two cables 1 connected together, the cables 1 peel off the shielding layer 11, outer semiconducting layer 12, main insulating layer 13, inner conductive layer 14 layer by layer, exposing copper Core 2; the copper cores 2 of the two cables 1 are connected through a crimping tube 3, the outer side of the copper core 2 and the crimping tube 3 is covered with a semi-conductive sheath 4, and the outer side of the stripped part of the cable 1 is provided with a stress cone 5 , wherein the fracture of the outer semiconducting layer 12 of one cable 1 protrudes out of the stress cone by at least 5 mm to form a dislocation. the

The semiconductive sheath layer 4 is a semiconductive tape or a semiconductive plastic sheath. The semi-conductive tape is wrapped from the shielding layer of one cable 1 to the shielding layer 11 of the other cable 1 . The junction of the main insulating layer 13 and the surface of the main insulating layer 13 are also coated with a Wacker silicone grease layer. The fracture of the outer semiconducting layer 12 of one of the cables 1 protrudes 30 mm from the stress cone to form a dislocation. The shielding layer 11, the outer semiconducting layer 12, and the main insulating layer 13 are distributed in a ladder shape.

The exposed portions of the shielding layer 11 , the outer semiconducting layer 12 and the main insulating layer 13 have the same length. the

In the normal production process of the stress cone of the 10kV cable intermediate joint, the end of the stress cone 5 should be tightly crimped with the fracture of the outer semiconducting layer 12 of the cable. In order to ensure the installation quality, a certain margin is left in the relative position of the stress cone 5. However, if care is not taken, the fracture of one end of the outer semiconducting layer 12 protrudes from the tail of the stress cone 5, and electric field concentration will occur, and creepage phenomenon will occur at the interface, thereby causing partial discharge. The partial discharge generated by the dislocation defect of the stress cone of the cable intermediate joint is very large, and the damage to the internal insulation performance of the cable joint is serious. And the stress cone dislocation partial discharge model of the 10kV cable intermediate joint that the utility model makes, pass on 10kV alternating current, after a day and night, stop energizing, cut open stress cone 5 positions, just can see a place of apparent radius 1-5 centimeters or multiple scorch marks. Through the analysis of the short circuit situation, we can know the different consequences brought about by the misalignment of the stress cone 5 at different angles in different occasions. At the same time, it can also simulate damage conditions in rainy days or other harsh environments. The research process can be realized with only an AC power supply and a remote control switch and an open experimental field. Compared with other solutions in the prior art, it is economical and safe and reliable. the

When the utility model is made, the fracture of the outer semiconducting layer 12 protrudes out of the stress cone 25-35mm to form a dislocation to ensure that the partial discharge situation after the simulated conduction is large enough for easy observation, but also to ensure safety. If this distance is too small, it may take more than 2 weeks to detect internal scorching marks under the action of 10kV AC. However, if the distance is too large, electric sparks may appear directly, which will damage this section of the cable and cause danger at the same time. the

The above is only a specific embodiment of the utility model, but the technical characteristics of the utility model are not limited thereto, and any changes or modifications made by those skilled in the art within the scope of the utility model are all covered by the utility model. In the scope of the new patent. the

Claims (8)

1. 10kV cable intermediate joint stress cone dislocation partial discharge model, characterized in that it includes two cables (1) connected together, and the cables (1) peel off the shielding layer (11) and the outer semiconducting layer (12) layer by layer , the main insulating layer (13), the inner conductive layer (14), and expose the copper core (2); the copper cores (2) of the two cables (1) are connected by crimping tubes (3), and the copper cores (2) and The outer side of the crimping tube (3) is covered with a semiconductive sheath (4), and the outer side of the stripped part of the cable (1) is sheathed with a stress cone (5). The outer semiconductive layer (12) of one cable (1) is ) The fracture extends out of the stress cone by at least 5mm to form a dislocation. the 2. The stress cone dislocation partial discharge model of the 10kV cable intermediate joint according to claim 1, wherein the semiconductive sheath (4) is a semiconductive tape. the 3. The stress cone dislocation partial discharge model of the 10kV cable intermediate joint according to claim 1, characterized in that the semiconductive sheath (4) is a semiconductive plastic sheath. the 4. According to claim 2 said 10kV cable intermediate joint stress cone dislocation partial discharge model, it is characterized in that said semi-conductive adhesive tape is wrapped from the shielding layer of a cable (1) to the shielding layer of another cable (1) (11). the 5. according to the said 10kV cable intermediate joint stress cone dislocation partial discharge model of claim 1, it is characterized in that, the junction of the main insulating layer (13) and the surface of the main insulating layer (13) are also coated with Wacker silicone grease layer . the 6. The stress cone dislocation partial discharge model of the 10kV cable intermediate joint according to claim 1, wherein the fracture of the outer semiconducting layer (12) of one of the cables (1) protrudes out of the stress cone by 30mm to form a dislocation. the 7. According to claim 1-6 wherein any one of said 10kV cable intermediate joint stress cone dislocation partial discharge model, it is characterized in that, said shielding layer (11), outer semiconducting layer (12), main insulating layer (13) distributed in steps. the 8. according to claim 7 said 10kV cable intermediate joint stress cone dislocation partial discharge model, it is characterized in that, the exposed part length of described shielding layer (11), outer semiconductive layer (12), main insulating layer (13) is the same . the

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