Study and design of low-speed direct-driven permanent magnet synchronous machines(PMSM) for fan used on power air cooling island

In this paper, based on the special requirements and rigor conditions of the power air cooling island motor for fan, a 115kW 67.9RPM 380V low-speed high-torque direct-driven PMSM with fractional-slot winding for fan used on power air cooling island was designed to state design feature and difficulties. For the air cooling island vertical motor for fan, due to space and weight restricted, cooling difficulties, larger axial force, electromagnetic calculation and cooling structure design, as well as the design of the bearing is the focus and difficulty. A new stator cooling structure design is studied by fluid and temperature field, and some measures on how to reduce stator temperature rise and enhance the capability of bearing and shafting are also propose. Finally, the prototype machine was developed and tested to validate the feasibility and correctness of design and analysis.