Electrical,Thermal and Mechanical Simulation Study of Buffer Layer Design of Smooth Aluminum Sheathed High Voltage XLPE Cables
Smooth aluminum sheathed cable can effectively avoid the defects of the buffer layer of corrugated aluminum sheathed cable,but the optimal parameters of its buffer layer structure design are not clear in China.Through calculations,experimental verification and formula correction of insulation expansion,this paper studies the insulation expansion and gap design.It also analyzes the electric field distribution with and without air gap by establishing a simulation model,as well as the effects of different buffer layer thickness on the cable temperature and the thermal stress distribution.By establishing a simplified structure of the cable four-point bending simulation model,the paper studies the distribution of its mechanical stress under the action of gravity.The results show that combining gravity,insulation expansion and other factors,the size of the negative gap between the buffer layer and the aluminum sheath of 220 kV 1 200 mm2 smooth aluminum sheathed cable is recommended to be designed as 1.3～1.6 mm.In the design of the buffer layer of the smooth aluminum sheathed cable,the thickness of the buffer layer should be reduced as much as possible to meet the thermal expansion of the insulation,to improve the cable current-carrying capacity,to avoid the aluminum sheath to withstand excessive thermal stresses.
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维普
