Extended model of interior permanent magnet synchronous motors to include harmonics in d-and q- axes flux linkages

Conventional model for interior permanent magnet synchronous motor (IPMSM) utilizes only the fundamental component of flux linkages in the abc reference frame that means the flux linkages in d- and q- axes are constant quantities with rotor position. An extended analytical model of IPMSM is presented in this paper that incorporates the fundamental as well as the harmonics of flux linkages. The harmonics in d-and q- axes flux linkages are addressed here to enhance the conventional model and to have a better representation of the torque transients in an IPMSM. The analytical model is first validated through finite element analysis (FEA) by separating individual flux linkages using frozen permeability and then studied for the saturation and cross-magnetization under varying conditions of permanent magnet flux, d- and q- axes currents. Furthermore, the extended model is verified with test results of flux linkage and torque transients from two different motor types belonging to concentrated and distributed winding.