• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.136-142
• /
• 2014

A major problem in Switched Reluctance Motor (SRM) is torque ripple, which causes undesirable acoustic noise and vibration. This work focuses on reducing the undesirable torque ripple in SRM by modifying stator and rotor geometry. This paper presents a comparative study on torque ripple minimization in SRM with modified pole shapes such as stator pole taper, stator pole face with non-uniform air gap and pole shoe attached to rotor pole. Further this paper presents a detailed sensitivity analysis of the effect of different geometrical parameters that alter the pole face shapes on the performance of SRM. The analysis is performed using finite-element method considering average torque and torque ripple as performance parameters. Based on the analysis, a design combining stator pole taper with non-uniform air gap is proposed to improve the torque characteristics of SRM. The dynamic characteristics of the proposed design are simulated and the results show satisfactory reduction in torque ripple.

• Proceedings of the KIEE Conference
• /
• 2006.10d
• /
• pp.59-61
• /
• 2006

The single phase switched reluctance motor(SRM) is simpler in control circuit because the number of switching devices is fewer than the poly phase SRM. The energy density per unit volume is very big because all stator poles are excited simultaneously by a single switching power source. But it must be provided a starting device on account of not being generated the starting torque at specific rotor positions. And also it has some demerits that have a torque ripple, noise and vibration because of being excited by switching pulse power source. Therefore, to make up for these demerits, it is realized many studies for the structure design used by computer and the operating methods by power electronics technique. In this paper, we'll present the comparison of the single phase SRM with the various rotor pole face types, as like stepped rotor pole face type and general rotor pole face type. For the torque characteristics analysis.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.5
• /
• pp.222-230
• /
• 2005

This paper deals with the reduction of cogging torque of a outer-rotor type BLDC motor mainly used for washing machines. The motor comprises permanent magnet outer-rotor and stator with coils and core. This structure inherently produces vibration and cogging torque because of uneven reluctance according to rotation of the rotor. Up to now, adopted a type of 24 magnet pole and 36 slot-stator. This generates high main torque but accompanies comparatively large cogging torque. This paper proposes a 32-pole 36-slot type motor which reduces cogging torque remarkably. The influence of cogging torque is varied according to pole-slot combinations. The characteristic of the motor was obtained by a two-dimensional finite element method coupled with a drive circuit. The performance of the proposed model is superior to that of the existing model because of the reduction of torque ripple and the improvement of back ernf wave form.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.2
• /
• pp.595-602
• /
• 2015

The rotor configuration of the brushless doubly fed induction generator (BDFIG) plays an important role in its performance. In order to make the magnetomotive force (MMF) space vector in one set rotor windings to couple both magnetic fields with different pole-pair and have low resistance and inductance, this paper presents a novel wound rotor type for BDFIG with low space harmonic contents. In accordance with the principles of slot MMF harmonics and unequal element coils, this novel rotor winding is designed to be composed of three-layer unequal-pitch unequal-turn coils. The optimal design process and rules are given in detail with an example. The performance of a 700kW 2/4 pole-pair prototype with the proposed wound rotor is analyzed by the finite element simulation and experimental test, which are also carried out to verify the effectiveness of the proposed wound rotor configuration.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.51 no.11
• /
• pp.612-615
• /
• 2002

The main advantages of Disk type Single-Phase Switched Reluctance Motor (DSPSRM) is the simple construction, rugged structure, low manufacturing cost and simple driving circuit. It is especially possible to make the short axial length of DSPSRM. Therefore, it is suitable to setup this motor in a narrow space. This paper presents the shape design to maximize the average torque of DSPSRM that is achieved by 3D Finite Element Method (3D FEM) considering the nonlinear of magnetic material. The characteristics of two different rotor shapes are compared. The design parameters, such as the rotor and stator pole arc, are selected to the parametric study. The effect of pole arc ratios on the torque performance is investigated. From these results, the optimal pole arc to produce the maximum torque is determined.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.274-276
• /
• 2009

This paper presents a rotor shape optimization of interior type permanent magnet (IPM) motor for cogging torque minimization and maximization of reluctance torque. In order to minimize the cogging torque, the optimal notches are put on the rotor pole face and the arc type pole face is applied. The variations of cogging torque and d-q axis inductions are analyzed by finite element method (FEM).

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.2
• /
• pp.309-314
• /
• 2011

Outer rotor type in-wheel switched reluctance motor for Welfare neighborhood electric vehicle is researched. In-wheel system is to drive the electric vehicle without mechanical transmission, shaft, differential gears or other mechanical system. To calculate drive power for each wheels, the elder's and disable's safety driving conditions are considered. The designed outer rotor SRM has a 6-stator and 8-rotor pole. The determined dimensions as well as the stator and rotor pole arc are simulated and tested with CAD and finite element analysis to verify the performance of the proposed motor.

• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.170-172
• /
• 2006

This paper proposes a design method by varying rotor pole shape to reduce cogging torque, torque ripple and harmonics of back emf in Spoke type brushless DC(BLDC) motor. In the process of design and analysis, Response surface method(RSM) and finite-element method(FEM) are employed to get the rotor geometry and verify the results of new pole shape.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.868-870
• /
• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) can be use axial direction magnetic flux and radial direction magnetic flux at the same time. Then, it has higher energy density per unit volume and can be lessened the shaft length of motor or exciting magnetic force. Additionally, it's durability is good because it is simple structure and driving device. Prototype of Salient pole rotor type single phase SRM was fabricated by using parameters of three phase SRM and 3D FEM analysis. Also, driving device was fabricated for prototype. Speed and torque characteristic was confirmed through the experiments, and flux linkage, which is important parameter of SRM for generating torque, was measured. The induction emf was calculated by using ideal inductance graph and current graph. Calculated emf and measured emf was compared for confirming loss of prototype in this paper.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.12
• /
• pp.158-162
• /
• 2002

In this paper, the usefulness of a three-dimensional forging simulation technique is verified through its application to process design in rotor pole forging. A simulator, AFDEX3D developed based on the rigid-plastic finite element method and hexahedral elements, is employed. The simulated results of an application example found in a precision forging company are compared with the actually forged ones in detail. It has been verified that the simulation results are in good agreement with the actual phenomena.