Comparative Analysis of Distributed Winding and Fractional Slot Winding on High Power Synchronous Hydro-Generators

This paper aims to present the possibility to adopt on high power synchronous hydro-generators of the fractional slot winding structure instead of the classical distributed winding. The fractional slot machine can be obtained by using the concentric coils on the stator teeth that offer copper economy and constructive simplicity. One comparative analysis is presented in this paper which evaluates the physical construction and electrical performance of these two structures: distributed winding with Z=72 slots and 6 rotor poles and fractional slot machine with Z=9 slots and 2p=6 rotor poles.