Finite length effects study in massive iron rotors using 3D electromagnetic field computation

The 3D effects in rotating electrical machines can be investigated by analytical methods. However strong assumptions are necessary to obtain a solution. Less assumptions are required with electromagnetic field computation. We study here in this paper the closure of eddy current in massive iron rotors with some 3D computation programs using different formulations. Each one can be used depending on the frequency of the field harmonics represented. Also some formulas are tested to include the 3D effects in 2D computation