• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.763-765
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• 2000

Detent force is produced in a permanent magnet linear machine. It is generally an undesired effect that contributes to the output ripple of machine, vibration and noise. This paper analyzes detent force in a Permanent Magnet Linear Synchronous Motor (PMLSM) by using various detent force minimization techniques. A two-dimensional Finite Element Method(FEM) is used to predict detent forces due to structural factors and non-linearity. And moving node technique for the drawing models is used to reduce modeling time and efforts.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.165-170
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• 2013

This paper presents the iron loss prediction of rotating electric machines taking account of the vector hysteretic properties of electrical steel sheet. The E&S vector hysteresis model is adopted to describe the vector hysteretic properties of a non-oriented electrical steel sheet, and incorporated into finite element analysis (FEA) for magnetic field analysis and iron loss prediction. A permanent magnet synchronous generator is taken as a numerical model, and the analyzed magnetic field distribution and predicted iron loss by using the proposed method is compared with those from a conventional method which employs an empirical iron loss formula with FEA based on a non-linear B-H curve. Through the comparison the effectiveness of the presented method for the iron loss prediction of the rotating machine is verified.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.68-80
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• 2007

This paper covers switched reluctance generator (SRG) and its comparison with induction and synchronous machines for distributed generation. The SRG is simple in design, robust in construction, and fault tolerant in operation; it can also withstand very high temperatures. However, the performance and cost of the SRG power electronics driver are highly affected by the topology and design of the converter. IGBT and MOSFET based converters are not suitable for very high power applications. This paper presents thyristor-based resonant converters which are superior candidates for very high power applications. Operations of the converters are analyzed and their characteristics and dynamics are determined in terms of the system parameters. The resonant converters are capable of handling high currents and voltages; these converters are highly efficient and reliable as well. Therefore, they are suitable for high power applications in the range of 1MW or larger for distributed generation.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.11
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• pp.749-756
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• 2000

Detent force develops generally undesirable effect that contributes to the output ripple of machine, vibration and noise. This paper proposes detent force minimization techniques for a Permanent Magnet Linear Synchronous Motor (PMLSM). In addition, thrust according to each minimization technique is estimated to observe the change of machine performance. A two-dimensional Finite Element Method is used to predict detent force and thrust due to structural factors and non-linearity. And moving node technique for geometric models is proposed to reduce modeling time and efforts.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1136-1140
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• 2010

Esterel is an imperative synchronous language and its formal semantic based on finite state machine makes it easy to perform program analyses using automata. In this paper, we propose a syntax-driven automata generation rule. Because our rule intuitively expresses syntactic structure, it is very useful for other program analyses.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.141-143
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• 2005

A permanent magnet synchronous motor motor for high-speed drive was developed based on an analytical method. Especially. rated speed and torque according to switching scheme are offered. A prototype machine was also fabricated and tested to confirm the design. Preliminarily obtained experimental data using the prototype machine shows the validity of the design.

• Progress in Superconductivity and Cryogenics
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• v.11 no.2
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• pp.33-36
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• 2009

A 1 MW class HTS (High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of neon thermo siphonmechanism and the stator (armature) coil is cooled by water through hollow copper conductor. This paper also describes evaluation of some electrical parameters from performance test results of our motor, which was conducted at steady state in generator mode and motor mode. Open and short circuit tests were conducted in generator mode while a 1.1 MW rated induction machine was rotating the HTS machine. Electrical parameters such as mutual inductance and synchronous inductance are deduced from these tests. Load test was done upto rating torque during motor mode and efficiency was measured at each load torque.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.175-177
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• 1999

This paper presents a prototype of visualization MMI of the Power System Phenomenon, specially synchronous machine dynamics and frequency deviations of power system for KEPCO's Enhanced Power System Simulator(KEPS)[1]. And some visualization designs of the Power System Phenomenons such as voltage stability, transient stability, SSR, Line overflow, and voltage deviations are presented. The prototype MMI has included the animations & 3D graphics presentations for synchronous machine rotor deviations and frequency deviations. So, a user can intuitively acquire the basic concepts of the power system oscillations. Finally, it will be scheduled to development of the various visualization MMI of the power system phenomenons for development and installation of KEPS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.182-182
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• 2003

• Journal of Power Electronics
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• v.2 no.3
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• pp.220-229
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• 2002

In this paper, maximum efficiency operation of two types of permanent magnet synchronous motor drives, namely; surface type permanent magnet synchronous machine (SPMSM) and interior type permanent magnet synchronous motor(IPMSM), are investigated. The efficiency of both drives is maximized by minimizing copper and iron losses. Loss minimization is implemented using flux weakening. A neural network controller (NNC) is designed for each drive, to achieve loss minimization at difffrent speeds and load torque values. Data for training the NNC are obtained through off-line simulations of SPMSM and IPMSM at difffrent operating conditions. Accuracy and fast response of each NNC is proved by applying sudden changes in speed and load and tracking the UC output. The drives'efHciency obtained by flux weakening is compared with the efficiency obtained when setting the d-axis current component to zero, while varying the angle of advance "$\vartheta$" of the PWM inverter supplying the PMSM drive. Equal efficiencies are obtained at diffErent values of $\vartheta$, derived to be function of speed and load torque. A NN is also designed, and trained to vary $\vartheta$ following the derived control law. The accuracy and fast response of the NN controller is also proved.so proved.