Performance Analysis of Aluminum- and Copper-Rotor Induction Generators Considering Skin and Thermal Effects

Recent progress in wind-power generation has led to the use of grid-connected and self-excited induction generators (SEIGs). Aluminum has been the common conductor material for squirrel-cage induction machines for a long time, largely because of low cost and ease of manufacturing. Recent developments in materials engineering have brought forth copper-rotor induction machines with promising results. In these machines, skin effect as well as temperature effect on the machine equivalent-circuit parameters during operation are expected to play an important role in the evaluation of induction-machine performance. In this paper, a qualitative performance analysis of aluminum- and copper-rotor SEIGs considering the skin and thermal effects has been presented theoretically and experimentally.