Size reduction of permanent magnet generators for wind turbines with higher energy density permanent magnets

Abstract

Permanent magnet generators' (PMGs) dimensions scale with rated power due the sizing law for PMGs, which necessitates increased rotor volume to provide additional torque, preventing use of PMGs in large scale wind turbines. The use of higher energy density permanent magnets may offset the need to scale dimensions to achieve higher input torque. The properties of a permanent magnet necessary to achieve 25% reduction in dimensions in a 10MW wind turbine were calculated. A 29% increase in torque as a result of a 34% increase in the energy product of the permanent magnet is demonstrated.