Design Modification in Single-Tooth Winding Double-Stator Switched Reluctance Motor for Torque Ripple Mitigation

Tripurari Das Gupta,R K Saket,Kalpana Chaudhary,Irfan Khan,Eklas Hossain,Rajvikram Madurai Elavarasan

doi:10.1109/access.2021.3052828

Abstract

Double-stator switched reluctance motors (DSSRMs) with single-tooth winding topology possesses high torque density when compared to conventional switched reluctance motors (SRMs). However, their inherent high torque ripple is still an issue for industrial applications. In SRMs, the torque shared by the outgoing phase reduces significantly in the commutation region. However, at the same time, the incoming phase does not achieve sufficient torque generation. This results in a high torque ripple in this region. In this paper, several design procedures are discussed to improve the performance of the radial flux DSSRM with single-tooth winding topology. Firstly, the pole arc equations of stator pole and rotor segments for the higher difference between aligned and unaligned inductance are derived for high output torque and based on this, the selection of the number of stator slots/rotor segments is discussed. Furthermore, the influence of winding polarities on the core loss and output torque of DSSRM is discussed. Finally, the design modification in rotor structure is proposed with an angular shift in the alternate rotor segments in the direction of rotation to mitigate the torque ripple. To investigate the effectiveness of the proposed design modification, a finite-element model of a 3-phase 12/10/12 pole radial flux DSSRM is developed in ANSYS/MAXWELL software, and simulation results are presented. It is observed that a 40% reduction in the torque ripple is achieved in the case of the proposed motor. The proposed design modification improves the torque generating capability of the incoming phase in the commutation region, which reduces the torque dip in this region and subsequently reduces the torque ripple.

Highlights

In the growing demand of high-performance electrical machines (EMs), permanent magnet (PM) machines currently prevail as a primary choice because of their high torque/power density and high efficiency [1]–[3]
Tavg = 2 Nph Ip Bg k diameter of rotor (Dr) l where Dr = (Dri+Dro)/2 is the average diameter of the rotor, l is the axial length of the motor and k = (1 − Lu/La) which can be calculated by finite-element method (FEM) based simulation results
Considering the above constraints the values of βexc, βaux and βr are as follows: βexc = βpr − βso βaux = 2βps − βpr − βso and βr = βpr − βso During the design of Double-stator switched reluctance motors (DSSRMs), the height of stator yoke hys and pole height of inner and outer stator can be calculated by FEM base simulation study in such a way that maximum flux density in different parts of the machine should be within Bmax

Summary

INTRODUCTION

In the growing demand of high-performance electrical machines (EMs), permanent magnet (PM) machines currently prevail as a primary choice because of their high torque/power density and high efficiency [1]–[3]. B. SINGLE-TOOTH WINDING DSSRM TOPOLOGY DSSRMs have higher torque/power density as compared to conventional SRMs because of better utilization of machine volume with the insertion of the segmented rotor and secondary stator. Where Dr = (Dri+Dro)/2 is the average diameter of the rotor, l is the axial length of the motor and k = (1 − Lu/La) which can be calculated by FEM based simulation results It is seen in Eq (8) that for a given MMF and magnetic loading Bg, the average torque depends on the average diameter of rotor (Dr ), axial length (l) of motor and the aligned and unaligned inductances of the phase windings. During the design procedure, the proper selection of these parameters is essential to obtain the higher output torque

SIZING PROCEDURE

INFLUENCE OF WINDING POLARITY ON DSSRM PERFORMANCE

TORQUE RIPPLE REDUCTION THROUGH ROTOR SEGMENTS SHIFT

Findings

VIII. CONCLUSION