Totally enclosed air to air cooled (TEAAC) generator with IC6A1A6 (as per IEC 60034-6) cooling is a widely accepted generator cooling solution for squirrel cage induction generators (SCIG) used in wind power generation, where the generator has two cooling systems, internal and external. The internal cooling is a closed loop system, where a shaft mounted mechanical fan helps in recirculating air inside the generator, and transfers the heat from the generator into an air-to-air heat exchanger. The external cooling system is a separate ventilation system creating airflow from the nacelle through the heat exchanger and removing the heat outside the nacelle with the help of an electrical fan mounted near the non-drive end of the generator. Cooling improvement of generator and bearing windings for performance enhancement is a well known research topic in turbo-generation as well as wind energy. Various winding design effort has been made in past for efficient generator cooling for turbogenerator as well as for wind turbine generator. With the increasing demand of power output, winding and bearing temperature class reaching its limit. Challenge is to come up with a solution for improving the performance of generator in terms of reducing temperature experienced by windings and at the same time reducing the cost. Detailed testing has been done on a test turbine to compare results obtained from open ventilated solution IC3A1 (as per IEC60034-6) and IC6A1A6 cooling for the squirrel cage induction generator. Paper presents advantages in case of using IC3A1 cooling where temperature of windings reduced substantially in comparison with IC6A1A6 cooling. To avoid contamination led windings and bearings hotspots, presented IC3A1 cooling configuration uses a unique design with inlet duct, filters, outlet duct and wire mesh.

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