Study On The Excitation Field Of Superconducting Generator With3-D Finite Element Method

Superconducting generator have an advantage in material saving and high efficiency operation aspect. The volume, weight, performance and cost are decided by electromagnetic design of field winding and structure of superconducting generator. Therefore, it is necessary to study the electromagnetic design theory of superconducting generator and structure optimization of field winding elaborately.Firstly, the3-D finite element model of superconducting generators is built. The magnetomotive force waveform is optimized by changing runway number and turns of different runway; the space flux density waveform is optimized by changing superconducting materials, bending radiuses of field winding and thicknesses of magnetic shielding; at same time, the reasonable field winding structure and superconducting material are confirmed by studying magnetic field near superconducting materials, especially the vertical magnetic field which can cause the superconducting materials lose superconductivity. Finally, the no-load electromotive force waveform and its harmonic analysis are calculated by2-D finite element method.The conclusions are derived that it will be reasonable when bending radiuses of field winding and thicknesses of magnetic shielding are separately38mm and50mm; the structure of field winding adopted four runways. The no-load electromotive force waveform and its harmonic content fulfill the design requirement.