Comparison of High Pole Number Ultra-Low Speed Generator Designs Using Slotted and Air-Gap Windings

Optimization of a 3‐kWaxial flux permanent magnet generator with variable air gap

“…When the literature on AF generators is examined, different AF topologies such as funnel, toroidal, single side, double side, and multi‐side, can be seen as main machine types 2,3,26,27 . Although the RF machines were invented much before AF, indeed RF topology has many demerits such as complicated production and maintenance, high weight and core losses, length, and high temperatures in operation 2,7,24,28 .…”

Electromagnetic analysis of a wind turbine magnetic gearbox

“…However, the torque density of a DD‐PM generator is thermally limited (by current) and, therefore, a PM generator does not normally achieve torque densities >50 Nm/L [7, 8]. For this reason, DD‐PM generators become very large when scaled up in size and their low torque density results in the need for a massive quantity of rare‐earth magnet material being used [9, 10]. The increased size of the drivetrain results in a significantly higher installation cost and, therefore, the system is then less cost‐competitive when compared with more traditional non‐renewable energy sources or with the DFIG [11].…”

Analysis of a Novel Stator Construction Employing Steel Wire in Place of Laminations

“…HERE are many applications that require electrical machines with large air gap diameters. Examples include certain designs of wind turbine generators [1]- [4], wave energy converter [5]- [6], tidal stream turbines employing rim generators [7]- [12], and marine propulsion motors [13]- [14]. These machines typically employ Permanent Magnets (PM) with a high pole numbers and thin corebacks.…”