• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1258-1260
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• 2005

Superconducting synchronous motors and generators have the field coil composed of superconductor with almost zero resistance at superconducting state. Therefore, co or loss at the conventional field coil is eliminated and the superconducting machine gets higher efficiency. The armature coil of the superconducting machine is composed of cower wire and supported by non-magnetic material such as FRP(Fiber Reinforced Plastic). Although a fully-superconducting machine with superconducting armature coil has been researched, it was not developed toward industrial application because of AC transporting loss and difficulty in construction of the cooling structure and so on. This paper contains the design procedure of a 1 MW superconducting synchronous motor using high-temperature superconductor only for the field coil. Especially, the armature coil is designed by water-cooling in order to dissipate Joule heat easily. Moreover, 3-dimensional electromagnetic design is conducted to get a proper design result and reduce design errors from 2-dimensional approach.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.169-171
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• 2007

We studied the partial discharge detecting by sensing electromagnetic wave emitted from the partial discharge source in the HV Rotating Machine with the new prototype patch antenna sensor. In this study, we design new type of patch antenna based on microstrip technology and make many experiments of elaine testing compare with the existing HFCT and EM probe on stator winding of HV generator in the laboratory. This paper will mention comparison of experimental results based on the three kinds of sensors.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1980-1990
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• 2017

A study on the multi-objective optimization of Interior Permanent-Magnet Synchronous Motors (IPMSMs) with 2, 3, 4 and 5 flux barriers per magnetic pole, based on Genetic Algorithm (GA) is presented by considering the aspect of irreversible demagnetization. Applying the 2004 Toyota Prius single-layer IPMSM as the reference machine, the asymmetrical two-, three-, four- and five-layer rotor models with the same amount of Permanent-Magnets (PMs) is presented to improve the torque characteristics, i.e., reducing the torque pulsation and increasing the average torque. A reduction of the torque pulsations is achieved by adopting different and asymmetrical flux barrier geometries in each magnetic pole of the rotor topology. The demagnetization performance in the PMs is considered as well as the motor performance; and analyzed by using finite element method (FEM) for verification of the optimal solutions.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.12
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• pp.1218-1229
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• 1991

The time optimal position control design can be repeatedly taken from the initial state of a dynamic system to a desired one as fast as possible in the industrial drives. In this case, an induction machine parameters will vary due to temperature, frequency, and saturation effects. In particular, the rotor resistance changes critically with temperature and frequency. These changes affect the command values of the stator current components and slip speed. There is a mismatch between the commanded variables and actual ones of the induction motor drive, and this situation leads to coupling of the vector controller from the plant, i.e. the induction motor . Consequences of such a coupling include the initiation of oscillations of the rotor flux and unsuitable switching of electromagnetic torque for the induction motor servo drive. Therefore, this paper describes a rotor resistance parameter compensating method for the induction motor, And the validity of the proposed design method is confirmed by simulation studies and experiment results.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.826-827
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• 2011

The selection of optimum parameters in electromagnetic design usually requires optimization of multimodal, non linear functions. This leads to extensive calculations which pose a huge inconvenience in the design process. This paper proposes a novel algorithm for dealing efficiently with this issue. Through the use of contour line concept coupled with Kriging, the algorithm finds out all the peaks in the problem domain with as few function calls as possible. The proposed algorithm is applied to the magnet shape optimization of an axial flux permanent magnet synchronous machine and the cogging torque was reduced to 79.8% of the initial one.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.10-12
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• 1998

Pumping liquid metal in nuclear power plant application by conventional centrifugal pumps pose difficulties such as bearing wear out at high temperatures and leak proof sealing of the liquid metal. MHD machine is obtained by replacing solid conducting secondary of conventional motors with ionized gas or liquid metal. It is used for reactor cooling pump because of construction simplicity, perfect sealing and easy operation/maintenance MHD pump is complicated because it includes electromagnetic and hydrodynamic phenomena. The principle of MHD Pumps is described in this paper. We design small laboratory size Flat Linear Induction Pump(FLIP) for transferring sodium.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.219-221
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• 1996

A reluctance motor is a electric machine in which torque is produced by the tendency of its movable part to move to a position where the inductance of the excited winding is maximized. This means physical fact that the energy stored in the field tend to be minimized as the energy stored in the field is converted the mechanical work. In this paper, we have studied the characteristics of the electromagnetic energy conversion about SRM which have 6 stator and 4 rotor poles with 3 phase. In addition we design the fundamental model of SRM with requirements(e.g. power, speed) and simulate with PC-SRD.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.274-281
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• 2012

This paper discusses the issues associated with the design of high speed machines for applications with a wide constant-power region requirement. Using described multi-domain design environments which put equal weight on the electromagnetic, thermal and mechanical considerations, the suitability and power density achievable using Induction Machines (IM) and Permanent Magnet Synchronous Machines (PMSM) are compared.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2135-2144
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• 2007

This paper presents system design of the slotless double-side Permanent Magnet Linear Synchronous Machine system (PMLSM) through magnetic field analysis and dynamic modeling. In our analysis, 2-D analytical treatments based on the magnetic vector potential were adopted to predict magnetic field with space harmonics by PM mover magnetization and stator winding current. From these, the design parameters such as inductance, Back-emf, and thrust are estimated. And, the electrical dynamic modeling including synchronous speed is completed by calculation of a DC link voltage in effort to obtain the accurate mechanical power from Space Vector Pulse Width Modulation(SVPWM). Therefore, the system design of PMLSM is performed from estimation of design parameters according to PM size and coil turns in magnetic field and from calculation of a DC link voltage to satisfy base speed and base thrust represented as the maximum output power in dynamic modeling. The estimated values from the analysis are verified by the finite element method and experimental results.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.1
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• pp.39-44
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• 2019

A high-temperature superconducting(HTS) generators have been actively studied because of its advantages of weight, size, and efficiency. A large-scale superconducting wind power generator becomes a very low-speed high-torque rotating machine. In these machines, high electromagnetic force and torque are important issued. Two generators connected in series on one shaft design are one of the solution to overcome the high torque problem. In this paper, the authors design and analyze a 15 MW class HTS generator. The 15 MW HTS generator is confirmed in terms of magnetic field distribution and torque performance using a 3D finite element method. As a result, the designed generators generates less torque than a conventional generator. The designed 15 MW superconducting generator will be effectively utilized in the construction of the large-scale wind power generation system.