• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.208-215
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• 2007

The significant drawback of the permanent magnet linear synchronous motor (PMLSM) is force ripples, which are generated by the distortion of the stator flux linkage distributions, cogging forces caused by the interaction of the permanent magnet and the iron core and the end effects. This will deteriorate the performance of the drive system in high precision applications. The PMLSM and its parasitic effects are analyzed and modeled using the complex state-variable approach. To minimize the force ripple and realize the high precision control, the components of force ripples are extracted first and then compensated by injecting the instantaneous current to counteract the force ripples. And this method of the PMLSM system is realized by the field oriented control method. In order to verify the validity of this proposed method, the system simulations are carried out and the results are analyzed. The effectiveness of the proposed force ripples reduction method can be seen according to the comparison between the compensation and non-compensation cases.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.993-996
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• 2000

A brushless linear motor is suitable for a high-accuracy servo mechanism. It is also suitable for operation with higher speed and precision. Since it does not involve some sort of mechanical coupling, linear driving force can be applied directly. Basic models including magetomotive force and electromotive forces are introduced and simplified. Both conventional PID and fuzzy controllers are implemented and performance results using those controllers are compared. Along with better simulated performance observed using fuzzy controller, further fabrication is to be included with various empirical results. Several system operational characteristics have been observed. Typical nonlinearities as friction, cogging and torque or thrust ripple that might deteriorate system performance would be tackled using presumably effective method such as neural network based learning controller.

• Journal of Magnetics
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• v.16 no.3
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• pp.288-293
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• 2011

Generally, the discontinuous armature permanent magnet linear synchronous motor (PM-LSM) is composed by the stator block (accelerator, re-accelerator, and decelerator) and the free running section. However, the stationary discontinuous armature design involves the velocity variation of the mover during drive when the armature's non-installation part changes over to installation part as a result of the outlet edge of the armature. Therefore, we considered deforming the shape of the outlet edge at the armature and apply skew on the permanent magnet by displacing the two magnet segments of each pole. This paper presents the results of a three-dimensional (3-D) numerical analysis with a finite element method (FEM) of the force exerted by the outlet edge.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.18-20
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• 1999

In the industrial field the necessity of the linear motion is increasing. We selected a moving magnet coreless type LDM, which have the advantages, such as long stoke, brushless, no cogging force. Actually, the design is accomplished using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In the course of design we have estimated airgap flux density and thrust.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.21-22
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• 2009

본 논문에서는 Phase Set Shift (PSS)를 이용한 영구자석형 선형 전동기에서의 코깅력의 저감에 대해 기술한다. Phase Set Shift는 코깅력의 주기성을 이용하여 코깅력을 저감하는 방법으로 각 phase set이 갖는 코깅력을 위상차이를 주어 서로의 코깅력을 상쇄하여 총 코깅력을 저감하는 방법이다. 선형 전동기의 코깅력의 해석을 위해서 유한요소법을 이용하였으며 코깅력의 주기성에 대한 연구를 위해 푸리에 급수를 이용하였다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1147-1149
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• 2005

Time switch is widely used to reduce the energy loss by selecting the duration of daily-based operating pattern for the electrical apparatus. Driving force of the time switch is the single-phase step motor which has the starting torque due to the asymmetrical airgap. Cogging and total torque of the tapered-airgap motor is analyzed by finite element method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.949-954
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• 2011

This paper presents a comparative study on motor characteristics with specific consideration of radial vibration force in interior permanent magnet synchronous motors (IPMSM) according to pole/slot combinations. Three IPMSM models, 16-pole/15-slot design, 16-pole/18-slot design and 16-pole/24-slot design are built, in which 16-pole/15-slot and 16-pole/18-slot designs provide high winding factor and 16-pole/24-slot design is known as a general pole/slot combination. By coupling finite element analysis (FEA) with equivalent circuit method, motor characteristics, back electro-motive force (Back-EMF), inductances, cogging torque, etc. as well as machine output performances are analyzed and compared. The radial vibration force (RVF) distribution in air gap causing stator vibration and noise is interested. It is expected that this study help with appropriate choice of pole/slot combination in IPMSM design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.987-994
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• 2016

In this paper, we present a comparative analysis of surface-mounted permanent magnet synchronous motors (SPMSM) and interior permanent magnet synchronous motors (IPMSM). First, we use 2D finite element analysis (FEA) to analyze models satisfying the same rated conditions according to the torque-speed curve characteristics, which are determined from the operating conditions. Next, we manufacture an SPMSM and IPMSM having good performances from an electromagnetic perspective based on analysis results, namely the cogging torque, torque ripple, and efficiency. We analyze both of the manufactured machines when they are connected back-to-back and when they are used as a motor and a generator, respectively. The motor is driven by a commercial inverter and the generator is connected to a three-phase resistance load bank. Finally, based on experimental results, which include the total harmonic distortion (THD) of the back electro-motive force (EMF), cogging torque, efficiency, and mass, we determine the motor that is most suitable under requirements.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.5
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• pp.405-413
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• 2015

This paper presents the motion accuracy simulation considering loads such as workpiece weight, cutting force, cogging force of a linear motor, and force caused by misalignment and runout error of a ballscrew in linear motion units. The transfer function method is basically utilized to estimate 5-DOF motion errors, together with the equilibrium equations of force and moment on the table. The transfer function method is modified in order to consider clearance changed according to the loads in the double sided hydrostatic/aerostatic bearings. Then, the analytic model for predicting the 5-DOF motion errors is proposed with the modified transfer function method. Motion errors were simulated under different loading conditions in the linear motion units using hydrostatic, aerostatic, and linear motion bearings, respectively. And the proposed analytic model was verified by comparing the estimated and measured motion errors.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.952-957
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• 2015

Recently, the interior permanent magnet (IPM) motors for electric vehicle (EV) traction motor are being extensively researched because of its high energy density and high efficiency. The traction motor for EV requires high power and high efficiency at the wide driving region. Therefore, it is essential to fully consider the characteristics of the motor from low speed to high-speed driving regions. Especially, when the motor is driven at high speed, a significant centrifugal force is applied to the rotor. Thus, the rotor must be stably structured and be fully endured at the critical speed. In this paper, aims to examine the characteristics of the IPM motor by adjusting the width of air-barrier according to the permanent magnet position which is critical in designing an IPM motor for EV traction motors and to conduct a centrifugal force analysis for grasping mechanical safety.