The Study And Preparation Of The Material Used In Stress Cone Of The HV Cable Accessories

The power system fault is mostly caused by the cable system. Usually, it begins from the cable joint and cable end. So it is to say that the structure design and appropriate material chose of the cable terminal is rather important in the using of the cables. It determines the security of the power system. This paper discusses the electrical field and thermal field of the cable system in different kind of situations. Meanwhile, we try on manufacturing the right kind of material used in strain cone of cable accessories. Finally we get the following results:In the simulation and design of the cable terminal, we applied the ANSYS multi-physics module, electrostatic module and electric conductive module to get the following result:The resistance of the material decides the electric field distribution in DC situation, when it is below10~8Ω·m, the non-uniform coefficient is under a reasonable value of1.3. By the other hand, the dielectric constant value determines the electric field distribution in AC situation, and the non-uniform coefficient is smaller when the dielectric constant is between10and50. The ampacity of cable is affected heavily by the thermal conductivity of the surrounding material. In the other word, the larger the thermal conductive is, the quicker the heat dissipating, so that the cable system will be more reliable.In order to manufacture of the strain cone material in the cable terminal, we mixed Silicone rubber with different nano-BaTiO3, nano-A1203, conductive carbon black and SiO2. Finally we get composite materials with different electrical and thermal performance. Also we researched the mixing process and dosage of materials in use and found the right way to manufacture the material in need. Through the test results we can find that the increase of BaTiO3and A12O3will lead to a rise in permittivity constant, and the BaTiO3shows to be more effective. Otherwise, when use Al2O3inclusively, the thermal conductivity of the material get obviously improved. Though carbon black can improve the permittivity constant, but it will lead to rise in the dielectric loss in consequence. Each one of the three fillers can improve the mechanical properties of the material in low filling level. When the filling percent is larger than45singly or the mixed filler of the three fillers is larger than60, the mechanical properties will reduce largely. Then we designed a orthogonal test in considering of the earlier results, manufactured the composite material and analyzed its dielectric constant thermal conductivity parameters. Choosing right levels of fillers in the orthogonal test, we got the improved silicone rubber with permittivity constant of80, conductivity of1.9×105S/m and thermal conductivity of0.25W/m-K. Though the analysis of the data and its variance of each index, calculated the influence level of each filler and chose the optimum scheme.