Calculation and Analysis of Transient and Sub-Transient Processes in Homopolar Inductor Machine

Homopolar inductor machine (HIM) belongs to the electrical excitation synchronous machine (EESM), but compared with the conventional wound-field synchronous machine (WFSM), it has static field winding and static armature winding, whose rotor is solid structure without any winding or permanent magnetic on it. In this paper, it is found that an obvious difference of the transient and sub-transient (T&ST) characteristics between HIM and WFSM due to the special three-dimensional homopolar magnetic structure of HIM. Firstly, in this paper, before analyzing the T&ST processes, it is necessary to sort, derive and develop the steady-state parameter formulae of HIM. Secondly, for the transient process, the variables are calculated, the special transient characteristics are explained and the reasons are revealed. Thirdly, the subtransient processes caused by the eddy currents in HIM are discussed qualitatively, whose parameters calculation method is the same as that of the transient process and not be repeated.