Breaking the Ceiling of Motor Temperature Rise for Special Applications

The power density of electrical machines has increased manifold over the last century due to the immense progress made in material science, especially in the domain of electrical insulation systems (EIS). However, the experience of the industry, as well as academia, is very limited regarding the design and production of electrical machines with winding temperature rise beyond 240 °C due to the application threshold temperature of EISs. The present article discusses the design considerations for transcending this boundary imposed by the conventional polymer-based EIS. The rationale behind the choice of different materials suitable for continuous operation at 350 °C is discussed. The effect of temperature on different motor performances is also investigated. Breaking the ceiling of the temperature rise limit of the conventional polymer-based EIS will allow the use of higher current/power density and thereby reduce the consumption of critical and precious materials, thereby not only increase the system reliability which is crucial for nuclear, aerospace, medical, and transportation industries but also help the motor industry align better with green manufacturing practices.