Non-uniform air gap modeling and electromagnetic characteristics of a new six-phase doubly salient electro-magnetic generator

Abstract

The voltage harmonics of the six-phase doubly salient electro-magnetic generator (DSEG) are large, and the electromagnetic isolation is poor due to the mutual inductance of the armature winding. An optimization scheme for the stator non-uniform air gap structure is proposed. By establishing a non-uniform air gap angle function model, the analytical expression of the induced electromotive force in the non-uniform air gap structure is derived. Using finite element and mathematical model to verify that the stator tip is changed from circular arc to linear structure can increase power and reduce voltage high harmonics, improve the power quality of the generator. Based on the equivalent magnetic circuit, the influence of the winding method of the excitation winding on the mutual inductance of the armature winding is studied. When the field winding is wound interval every two stator poles, the mutual inductance is small. The electromagnetic properties of the new six-phase electric excitation double salient pole are analyzed by two-dimensional finite element analysis. The rationality of the proposed motor structure is verified by experiments.

Keywords

Voltage harmonic Stator non-uniform air gap doubly salient electro-magnetic generator

Get full access to this article

View all access options for this article.

References

Zhang

Wang

, Overview and design methodology of doubly salient brushless DC generators with stator-field winding, IET Electric Power Applications11(2) (2017), 197–211.

Chen

Wang

and Yan

, A doubly salient starter/generator with two-section twisted-rotor structure for potential future aerospace application, IEEE Trans. on Industrial Electronics59(9) (2012), 3588–3595.

Shi

Zhou

Wei

, Analysis of electromagnetic characteristics of five-phase electric excitation doubly salient generators with relative symmetry, Proceedings of the CSEE (10) (2016), 2800–2807.

Rusu

Pop

A.C.

and Szabo

, Study of winding arrangement and material quality effects on the core losses in high speed switched reluctance machines, in: InternationalConference on Engineering of Modern Electric Systems, IEEE, 2015.

Liu

Han

and Pei

, Optimization of permanent magnet motor air-gap flux density based on the non-uniform air gap 2013, in: International Conference on Mechatronic Sciences, Electric Engineering and Computer, IEEE, 2013.

Zhu

Z.Q.

Azar

and Ombach

, Influence of additional air gaps between stator segments on cogging torque of permanent-magnet machines having modular stators, IEEE Transactions on Magnetics48(6) (2012), 0–0.

Zhang

Dai

and Yan

, Investigation of hybrid excitation synchronous machines with axial auxiliary air-gaps and non-uniform air-gaps, IEEE Transactions on Industry Applications50(3) (2014), 1729–1737.

X.Z.

Feng

H.C.

Wang

X.D.

and Du

B.Y.

, Characteristics analysis of PM linear synchronous motor with non-uniform air-gap, in: 2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, 2015, pp. 199–200.

Islam

and Ortega

A.P.

, Practical Aspects of Implementing Skew Angle to Reduce Cogging Torque for the Mass-Production of Permanent Magnet Synchronous Motors, ICEMS, Sydney, 2017.

10.

Xia

Zhang

and Geng

, Analytical modeling analysis of surface mounted permanent magnet machines with skewed slots, IEEE Transactions on Magnetics51(5) (2015), 1–8.