Ew Insulation Technology Impacts Generator Design

1. Abstract
The performance of an electrical rotating machine is defined by many material, component and design parameters. Some of them like core diameter, active length, cooling medium etc. strongly influence the power output but also have a big impact on material, manufacturing and operational costs.
With quite simple modifications in the design of the stator winding, mainly altering copper cross section and groundwall insulation thickness, and utilising the mica insulation tape with the latest technology, a substantial change in either performance or machine size, without a big increase in costs, can be achieved.
Such a material change combined with small design changes can boost up the performance of indirect cooled generators and motors up to 20 % compared to state of the art design. This is valid not only for new generators, but also for generators already in operation with a proper Rewind.
On the other hand it is also feasible, especially for new Hydro generator projects, to reduce the machine size dimensions compared to standard design with equal power output. Therefore material and manufacturing costs can be reduced significantly. Only the material saving of the active part can be up to 10 %.