Modern testing technology for insulation system development of global VPIed large motors

This paper introduces some modern testing technology used to develop and improve the insulation systems of global vacuum and pressure impregnated high voltage large motors. With the market trend toward reduced frame sizes and more cost-competitive motors growing rapidly, there is increasing pressure to reduce insulation thickness. This in turn leads to the need for increased dielectric strength for the insulation system. In order to ensure the proper selection of new materials and processes, and to ensure the quality and reliability of newly developed insulation systems, an effective testing system must be developed. This system must be used to evaluate the prospective insulation systems. In the last few fears, extensive tests have been conducted by the TECO-Westinghouse Motor Company to develop a comprehensive and modern test system. This system has been used successfully to evaluate different new materials and systems and to set the quality criteria for motor manufacturing processes. In this paper, an overview of a modern testing system and some sample results is presented.