High direct voltage compound cable annex
Technical field
The utility model relates to a kind of high direct voltage compound cable annex.
Background technology
In the direct current high voltage cable field, need supporting electric cable accessories.Because direct current high voltage cable belongs to nonstandard product, China does not have the national standard of dc high-voltage cable fittings.In the engineering field, generally adopt the ac cable annex of equal electric pressure to replace the direct current cables annex, surpass the high-voltage alternating electric cable accessories cost height of 60kV, install complicated.Because the requirement of withstand voltage of direct current cables is lower than the ac cable annex requirement of ad eundem, and how indoors to use; So the direct current cables annex to the requirement of creep distance less than the ac cable height.This patent utilizes this characteristic of direct current cables annex, makes high direct voltage compound cable annex, can effectively reduce direct current cables annex cost and installation work-hour.
In the cable two ends make, the semiconductor layer of cable end piece need be separated with insulating barrier, the Electric Field Distribution of cable inside is even, but the axial electric field of the exposed insulating barrier of the semiconductor layer cut-off part outside insulating barrier is strong especially, and axial stress is concentrated especially in other words; Axial stress is too concentrated and can be destroyed cable insulation.
The utility model content
The purpose of this utility model provides a kind of high direct voltage compound cable annex, utilizes the stress cone of voltage levels to combine with the cable cover(ing) of 10kV electric cable accessories the inside, makes high direct voltage compound cable annex.
The technical solution of the utility model is as follows:
A kind of high direct voltage compound cable annex, include direct current high voltage cable, it is characterized in that: the front and rear sections of described high-tension cable is coated with cable cover(ing) and stress cone respectively, the end of described high-tension cable stretches out outside the described stress cone, and the front end of described high-tension cable is connected with binding post and draws.
Described high direct voltage compound cable annex is characterized in that: described high-tension cable includes semiconductor layer and insulation screen from inside to outside successively.
The primary structure of electric cable accessories is made up of two parts: stress cone and insulation cluster parachute.The function of stress cone is to improve the Electric Field Distribution of insulation screen, reduces axial stress; The insulation cluster parachute is the surperficial creep distance that increases cable end piece, to increase the dielectric voltage withstand grade, particularly wants to guarantee that cable still can operate as normal when the rainy day.Stress cone is connected as a whole in manufacturing process with the insulation cluster parachute.
For direct current high voltage cable, during particularly indoor use, cable end piece do not have a rainwater influence, do not need the cluster parachute that insulate.So direct current high voltage cable can adopt the electric cable accessories of stress cone and 10kV cable cover(ing) mixing manufacture.Utilize stress cone to reduce the axial stress of cable end piece, make it to satisfy cable operate as normal demand, cable insulation stretches out stress cone, and the length of specifically stretching out will satisfy the demand of real work voltage.In order to protect the cable insulation that exposes stress cone, prevent to be scratched or destroy by foreign matter, adopt the sleeve pipe of 10kV electric cable accessories to wrap up this partial insulative layer.The compound cable annex of Zhi Zuoing has the function of conventional ac cable annex like this: reduce the axial stress of high-tension cable end, satisfy the insulation creep distance requirement on cable end piece surface.
The beneficial effects of the utility model:
The utility model can effectively solve the axial stress concentration problem, extends by the cut-off part with insulation screen, and it is horn-like that zero potential is formed, improved the Electric Field Distribution of insulation screen, reduce the possibility that corona produces, reduced the destruction of insulating, guaranteed the service life of cable.
Description of drawings
Fig. 1 is the utility model structural representation.
Embodiment
Referring to Fig. 1, a kind of high direct voltage compound cable annex includes direct current high voltage cable 1, and the front and rear sections of high-tension cable 1 is coated with cable cover(ing) 2 and stress cone 3 respectively, the end of high-tension cable 1 stretches out outside the stress cone 2, and the front end of high-tension cable 1 is connected with binding post 4 and draws.
High-tension cable 1 includes copper core conductor 5, insulating barrier 6 and semiconductor layer 7 from inside to outside successively.
Electric pressure and the stress cone of the identical electric pressure of size Selection and the cable cover(ing) of 10kV electric cable accessories the inside according to direct current high voltage cable, then according to the manufacture method of normal cable annex to anticipating that the cable two ends carry out that electric cable accessories makes, comprising: cable jacket is peeled off, the peeling off of the peeling off of armouring and metal screen layer, cable insulation outer semiconductor layer, insulating barrier is carried out clean.The length of cable insulation will be determined according to the requirement of surface insulation creep distance.Then according to the working specification of electric cable accessories producer according to stress cone; According to the length of the cable insulation that exposes, the 10kV cable jacket is installed again; The binding post of cable is installed at last.Allow minim gap between 10kV cable jacket and the stress cone, this does not influence the useful life of cable, because the electric field stress specific stress awl place of gap location is low.