Torque Ripple Reduction of a Salient-Pole Permanent Magnet Synchronous Machine With an Advanced Step-Skewed Rotor Design

Abstract

In this paper, a salient-pole permanent magnet synchronous machine (SPPMSM) is introduced to high-speed trains, taking advantage of its high utilization of the reluctance torque from the unbalanced reactance. Torque characteristics, such as average torque and torque ripple, are rather important and should be carefully concerned during the optimal design of the SPPMSM. Both the eccentric air-gap and the advanced step-skewed rotor (ASSR) design are developed and implemented to reduce the torque ripple for comfort and safety issues. Compared to the conventional step-skewed rotor (CSSR), the ASSR takes advantage of the high utilization of permanent magnets (PMs), which are axial continuous assembled, and the easier manufacture with a single rotor lamination model, which is asymmetrically designed with pole shoes skewed by individual skewing angles. No skewing arrangement is applied to the rotor yoke and the PM chambers. The impacts of the eccentric air-gap and the ASSR on the torque characteristics are comprehensively investigated by finite element analysis. The results show that the proposed technique can significantly reduce the torque ripple with a slight expense of the average torque. Based on the optimal eccentric design, experiments of the SPPMSM with the non-skewed rotor, CSSR, and ASSR under various conditions are carried out to validate the estimated results. INDEX TERMS Eccentricity design, permanent magnet synchronous machine, step-skewed rotor, torque ripple.

Harmonic Order Analysis of Cogging Torque for Interior Permanent Magnet Synchronous Motor Considering Manufacturing Disturbances

“…The design specifications for 3 skew models are show 3 by assembling the prototypes of stator and rotor in Table 2. The skew design for the cogging torque reduction was introduced in Section 1; v ous skew design methods are generally applied to the EPS motor [5][6][7][8]. The skew mo for the 3D and prototype of IPMSM are shown in Table 2, with the design specificatio Table 1.…”

“…The design specifications for 3 skew models are shown in T 3 by assembling the prototypes of stator and rotor in Table 2. The skew design for the cogging torque reduction was introduced in Section 1; various skew design methods are generally applied to the EPS motor [5][6][7][8]. The skew models for the 3D and prototype of IPMSM are shown in Table 2, with the design specification of Table 1.…”

“…In the skew design, continuous and step skew are generally applied to the stator and rotor, respectively [5,6]. Chen proposed an uneven step skew design for the rotor of IPMSM [7]. Wang proposed a skewed magnet design by inserting magnet into the slot opening of stator for outer rotor type motor [8].…”

A Review of Torque Ripple Reduction Design Methods for Radial Flux PM Motors

“…As shown in Figure 1, there are plenty of possible approaches to reduce torque ripple by geometry optimization [1,[12][13][14][15][16][17][18][19][20][21][23][24][25][26][27][28][29][30][31][32]35,38,40,43,44,46,47,. However, all those approaches aim to reduce torque ripple by minimizing cogging torque or back EMFrelated issues.…”

Designing of an Enhanced Fuzzy Logic Controller of an Interior Permanent Magnet Synchronous Generator under Variable Wind Speed

“…Existing globally, wind energy has been highly approved by governments, leading to wind farm development’s growth [ 10 ]. More effective models of diminished ripple reduction for PMSGs have been largely investigated in the previous decades [ 11 ]. Rotor step-skewing with sinusoidal profiling of the rotor surface is the typical and prominent technique.…”