Research Of Stress Cone Based On HTS Cable Terminal

ABSTRACT:HTS cable terminal is the most important component of HTS cable system which is used to connect the HTS cable and the conventional cable accessory. The inner characteristic of HTS cable terminal is the temperature field presents staircase distribution, and the electric field is distorted. In the HTS cable terminal, the roles of the stress cone are improving the distribution of electric field and increase the electric insulating strength. And the insulating material of stress cone should be able to endure low temperature. This project centers on the study of the stress cone of HTS cable terminal. The equivalent circuit model of stress-cone is constructed and the structural parameters of35kV stress-cone have been designed optimally. The different electric field distribution with different structure of stress cone has been analyzed and compared. The prototype of stress cone is complete and has been put to the test at last.Firstly, the mathematical model of stress cone is constructed. This model has been proposed which is based on the dielectric constant of materials, stress-cone’s plate length etc. We found the relationship between the capacitance of stress cone and structural parameters, found the relationship between the sag voltage of each layer and structural parameters, analyze the structure of the stress cone’s influence on electromagnetism parameter and obtain the distribution curve.Secondly, optimization of stress cone’s parameters realized and the electric field is analyzed. Based on the design principle of PSO algorithm and equal voltage, equal capacitance, we construct the objective function, constraint condition and obtain the parameters in batch which is suitable for stress cone. Verify these parameters according to the analysis of the electric field. And simulating the inner electric field and the magnetic field of stress cone is to verify these parameters and optimization algorithm feasibility.Finally, the prototype of stress cone is designed and has been put to the test. On the basis of selecting a suitable low-temperature insulating material and the processing equipment, we applied the winding type technology, designed and processed several prototypes of35kVclass stress cone. The electrical insulation test has been made on these prototypes. The lightning impulse voltage test verifies the insulation performance of the stress cone and the capacitor voltage test verifies the equal capacitance and voltage design of stress cone. The study and designing of35kV class condenser-type stress cone are the further spread of low temperature high voltage insulation, the key technology of the medium voltage class of HTS cable terminal and the foundation for the research of medium voltage class of HTS cable terminal.