• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.12
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• pp.789-796
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• 2000

This paper deals with magnetic field and characteristic analysis for ring type slotless synchronous motors by using analytical method. Since magnetic air-gap in the slotless motors is much larger than mechanical air-gap, it is necessary to analyze the magnetic flux distribution at the whole magnetic airgap region. therefore, this paper analyzes the duplicated magnetic field derived by both Permanent Magnet(PM) and armature current and estimates the back electromotive force and torque characteristic by subdividing the conductor region. The analysis results are verified by comparing with Finite Element Analysis(FEA) results.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.793-798
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• 2011

Numerous methods are available for reducing the end-effect force of linear machines. Majority of these methods focus on redesigning the poles or slots. However, these methods require additional manufacturing cost and decrease the power density. The current paper introduces another approach to reduce the end-effect force. The new approach is a method of tuning the input phase current magnitudes individually. According to the proposed method, reduction of the end-effect force could be achieved without redesigning the poles/slots or attaching auxiliary poles/slots. The proposed method is especially applicable when the target motor is very expensive or will be used for a special mission, such as hauling army vehicles equipped with three single-phase inverters. The validity of the suggested method was exemplified by the finite element method with three-phase permanent-magnet linear synchronous motor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1486-1492
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• 2015

The following study carried out the characteristic analysis based on the magnet segment of Interior Permanent Magnet Synchronous Motor(IPMSM) for the urban railway vehicles. IPMSM affects the electromagnetic characteristics through the change in magnetic flux based on the rotor structure, and significantly influences the structural features through the change of pressure. Therefore, satisfied by the demanded traction force of the IPMSM, magnet segment derived three different model types. The 1-segment PM model consisted an undivided permanent magnet. The 2-Bridge model consisted a divided permanent magnet with the application of Bridge. The 3-Bridge model consisted additional dividing with one more Bridge applied. The electromagnetic characteristics of the three models were compared and analyzed along with the structural features regarding the scattering of permanent magnet based on strong centrifugal force from the rotation of the rotor at high speed. In conclusion, the final model with electromagnetic characteristics and structural features most suitable of IPMSM for the urban railway vehicles was derived, and the effectiveness was verified through the characteristic experiments after the production of the derived model.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.613_614
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• 2009

Electric power steering(EPS) has many attentions such as fuel consumption improvement, thus it has been widely adopted for automotive application in recent years. In the EPS system, torque vibrations are directly transferred through the steering wheel to the hands of the driver. Hence, the design of PM motors for the EPS should be performed in order to reduce torque ripples including cogging torque. In this paper, Surface mounted Permanent Magnet Synchronous Motor(SPMSM) is designed to reduce torque ripples and cogging torque at a same time for the EPS propulsion and the design results are verified with the experimental ones.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.139-141
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• 1999

This paper presents the design schemes for the improvement of force characteristics in Controlled permanent magnet linear synchronous motor (CPMLSM). The dependence of motor performance on various design schemes, such as the slot shapes, magnetizing patterns of PM and skewing, have been investigated in detail by using FEM and experiment. From this study, it is known that in the various design schemes, skewing is most efficient in the aspects of force characteristic, efficiency and force density.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.37-39
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• 2005

This paper is proposed maximum thrust design of slotted Permanent Magnet Linear Synchrous Motor (PMLSM) using surface harmonic method considering slot effect. The genetic algorithm is used for optimization. The objective functions are the maximum thrust and the minimum detent force. This time, design parameters are set as PM width, PM height and slot width.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.5
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• pp.18-28
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• 2009

To analyze influences under faults caused by a stator winding short and to evaluate an effectiveness of a diagnostic algorithm a faulty model for an inverter-driven permanent magnet synchronous motor is presented. Even though the conventional dq motor model obtained through the transformation of phase voltage model is widely used to analyze and control the motor, it can not be used in the analysis of a faulty motor since the 3-phase balanced condition is no longer hold under the fault caused by a stator winding short, and thus, it is very difficult to obtain motor input voltages from the pole voltage of an inverter. To overcome this problem, a faulty model for an inverter-driven permanent magnet synchronous motor is proposed by considering the line voltage of 3-phase variables. The effectiveness of the proposed faulty model is verified through comparative simulations and experiments using DSP TMS320F28335 and motor built to allow a partial short of inter-turn.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.245-247
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• 1992

We utilize as a processor TMS320C25 (Texas Instrument) in making a driver for a 4 pole PM synchronous servo motor. TMS320C25 has a 32bit ALU and a 16 bit hardware multiplier, and the maximum instruction execution rate is 10MIPS at 40MHz. We adopted a space vector modulation PWM method. An interesting point of this work is that PWM wave is generated by utilizing timer interrupts. Hence, in the rest of time the processor can take care of the other routine such as Park's coordinate transformation and the computation required in the feedback loops. Thus, it mates the hardware circuit very simple. Due to the decrease in the number of components, the motor drive system becomes more fault-tolerant and cost-optimized. Also, more flexibility is gained in changing the control parameters.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1051-1053
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• 2003

Flywheel Energy Storage System (FESS) consists of a high-speed flywheel with an integral motor/generator suspended on magnetic bearings and in an evacuated housing. Permanent magnet (PM) machines as the FESS motor/generator are a popular choice. since there are no excitation losses which mean substantial increase in the efficiency. In this paper, the basic design and the steady-state performances of a permanent magnet synchronous high speed motor/generator for FESS are presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.3
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• pp.243-254
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• 2014

It is essential to predict the coil temperature under over load and over speed conditions for reliability in high speed low torque surface mounted PM synchronous motors(SPM). In the present study, the losses and coil temperature are measured under rated condition and calculated under over speed and over load conditions in the three different motors with 35PN440, 25PN250 and 15HTH1000. The heat transfer modeling has been performed based on acquired losses and temperature. The difference of coil temperature between heat transfer modeling and experiment is less than 6.4% under no load, over speed and over load conditions. Subsequently, the coil temperature of the motor with 15HTH1000 is 84.4% of the coil temperature of the motor with 35PN440 when speed is 0.9 and load is 3.0. The output of motor with 15HTH1000 is 85.2% greater than the output of the motor with 35PN440 when the dimensionless coil temperature is 1.0.