Improvement of stator insulation system for 24, 36 and 72 slots HV generators based on SNOPT method

Geometric properties of insulation layers in stator slot of HV generator such as semiconductive coatings, groundwall insulation, phase-phase insulation as well as turn and the strand insulation are major design consideration for insulation system of HV generators. In addition, electrical conductivity, thermal conductivity, heat capacity and electrical permittivity of these insulation layers have an important role on decreasing electrical field tensions. Obtaining of optimum value for these parameters leads to achieve less electrical field tensions and more uniform electrical field distribution across them. A very powerful method presented to optimization is SNOPT (generalpurpose system for large-scale nonlinearly constrained optimization) which is coupled with Finite Element Method (FEM). These processes of optimization have been done according the proposed optimization algorithm. In this algorithm the technical constraints have been considered. This paper describes the process used to perform improvement analysis of stator slot's insulation for 24, 36 and 72 slots generators with respect to objective function and constraints.