A survey of state-of-the-art methods to compute rotor eddy-current losses in synchronous permanent magnet machines

A major concern in the design of permanent magnet machines is the possible overheating of permanent magnets and their consequent demagnetization. One of the heating sources is the occurrence of eddy currents produced by air-gap space harmonics. In the attempt to avoid the computational burden of 3D time-stepping Finite Element Analysis, a wide variety of analytical or semi-analytical methods have been reported in the literature for rotor eddy current prediction. This paper critically surveys the most recent cutting-edge methods to determine rotor eddy-current losses in synchronous permanent-magnet machines, highlighting the frontiers and potentials of the main current lines of inquiry.