Design and Analysis of a New Symmetrical Three-phase Doubly Salient Electro-magnetic Generator

Aiming at the asymmetry of each phase of the conventional doubly salient electro-magnetic generator (DSEG), this paper proposes a symmetrical design method. A 24/16-pole three-phase DSEG with long pitch excitation winding is designed. Each excitation element is wound across four stator poles so as to make the magnetic flux path of each phase consistent. And the number of each phase rotor pole obtuse angles sliding in (out) and that sharp angles sliding in (out) are the same. While realizing the three-phase symmetry of DSEG, the adoption of the pole shoes design to avoid the asymmetric contact becomes unnecessary. Then the electromagnetic characteristics of the traditional and the proposed symmetrical DSEG are simulated and compared by finite element method (FEM). The results show that each phase of the proposed DSEG is symmetrical and has good power generation performance, which solves the problems of large voltage fluctuation and phase current asymmetry in the operation of traditional DSEG power generation, and verifies the correctness of the design method and theoretical analysis in this paper.