• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.898-899
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• 2015

This paper present a transient experiment to verify the performance of limited angle torque motor(LATM) designed using electromagnetic transient analysis. LATM requires access to the transitional state to the torque performance evaluation. Because LATM moves the rotor using a magnetic torque generated by the interaction of the permanent magnet and the armature winding. A separate control is not applied, it is switched on at the same time under the conditions that the current applied to the armature winding. It was compared to the transient analysis of the experimental data of LATM for the verification of approach method in the transitional state.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.138-143
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• 1999

A new control method for the precision robust position control of a brushless DC(BLDC) motor for direct drive m motor(BLDDM) system using the asymptotically stable adaptive load torque observer is presented. A precision position c control is obtained for the BLDD motor system appro성mately linearized using the fieldlongrightarroworientation method. Many of t these motor systems have BLDD motor to obtain no backlashes. On the other hand, it has disadvantages such as the h high cost and more complex controller caused by the nonlinear characteristics. And the load torque disturbance is d directly affected to a motor shaft. To r밍ect this problem, stability analysis is calTied out using Lyapunov stability t theorem. Using this results, the stability is proved and load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent CUlTent having the fast response.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.51-56
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• 2013

With the active development of hybrid electric vehicle (HEV), the application of interior permanent magnet synchronous motor (IPMSM) has been expanded. As wide driving region of IPMSM for electric vehicle (EV) traction motor is required, many studies are conducted to improve characteristics of a motor in both low and high-speed driving regions. A motor in high-speed driving region generates (produces) large stress to the rotor. Thus, the rotor needs to be designed considering the mechanical safety. Therefore, in this paper, we conducted stress analysis and electromagnetic analysis to determine the centerpost's distance which is considered important during the design of IPMSM for EV traction motor in order to secure mechanical safety and satisfy specifications of output requirement.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1132-1134
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• 2005

This paper presents a design strategy of Slotless type BLDC motor using the space harmonic field method. The distribution of Back emf and torque are considered by movement of the Permanent Magnet and armature current. The result of magnetic field distribution, back-emf, and torque are in agreement with FEM.

• 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 Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.144-149
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• 2007

Behaviour of a thread joint of a rocket motor case show complex structural characteristics. Pre-torque must be applied to the threads to prevent the loosening of the interface from the additional pressure load. During the pressurization of the rocket motor case, the jointing face may be opened if the pre-torque were not set properly or the structure may be failed if the local concentrated stress exceeds the strength of the material. In this paper, the structural behaviour of a thread joint of a rocket motor case were analyzed by the finite element method and the results were compared to the experimental ones. A method to set a pre-torque for a thread joint were proposed to ensure the structural safety.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.86-88
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• 2007

By reason of variation magnetic field, cogging torque is generated. Cogging torque of Spoke type motor is bigger than other type permanent magnet motor. So, this paper presents a design notch on stator and variation rotor shape to reduce cogging torque of Spoke Type motor. Through Fourier formulation of magnetic field on air gap, we found position of notch. The validity of the proposed design is confirmed with FEM analysis method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1846-1857
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• 2011

This paper deals with design and analysis of surface-mounted PM (SPM) motor for compressor of air-conditioning system for electric vehicle applications according to slot/pole combination. First, required torque-speed curve characteristics are determined from operating conditions of the compressor. Restricted conditions such as motor size limit and current density are also determined. And then, under same rated and restricted conditions, twelve models which have different slot/pole combinations each other are designed for various pole arc/pitch ratio using simple equations and 2-d finite element (FE) analyses. Designed models are analyzed and compared in terms of back-emf THD, cogging torque, torque ripple, power losses, efficiency, etc. On the basis of analysis results, it is found that the motor with a 6-pole PM rotor and a 27-slot stator has most outstanding performances in electromagnetic aspects. Finally, through the mechanical modal analysis and demagnetization analysis, it is concluded that the determined motor is most suitable for the compressor of air-conditioning system for electric vehicles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.955-964
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• 2011

In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.3
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• pp.135-142
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• 2004

In this paper, the magnetic circuit characteristics and the current/torque analysis of a Spoke Type permanent magnet motor have been researched, compared with the SPM Type motor. In the magnetic circuit analysis, the characteristic of air-gap flux density has been analyzed according to the variation of the number of pole and the ratio of magnet height to arc length using finite element method and circuit equations. Moreover, the electromagnetic and the reluctance torque have been analyzed by the current profile, which is obtained from the variation of turn-on angle, and these informative data has been utilized for the overall characteristics of the Spoke Type BLDC motor.