• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1391-1396
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• 2009

The direct drive motor used in a precision motion rotate at about 1/10 speed and high torque comparing with general rotary motor. Excessive heating of the coils cause an exacerbating the heat problems and reducing the performance of motor. Because the rotation speed of the rotor and surrounding air is low, the motor can not be inefficiently cooled, the thermal analysis in the motor is very important. As the variations of rotation speed and torque, the temperature of several parts is measured and the features of the heat transfer is analyzed and improved.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.193-199
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• 2011

The next generation domestic high speed railway system is a power distributed type and uses vector control method for motor speed control. Nowadays, inverter driven induction motor system is widely used. However, recently PMSM drives are deeply considered as a alternative candidate instead of an induction motor driven system due to their advantages in efficiency, noise reduction and maintenance. The next-generation high-speed train is composed of 2 converter units, 4 inverter units, and 4 Traction Motor units. Each motor is connected to the inverter directly. In this paper, the effects of IPMSM parameter variation to the system operation characteristics of the multi inverter driven high speed train system are investigated. The parallel connected inverter input-output characteristics are analyzed to the parameter mismatches of the IPMSM in 1C1M control using Matlab/Simulink, then the reliability of the simulation results are verified through experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.4
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• pp.152-160
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• 1999

A high speed motor has been generating a lot of attention due to its performance-more light, thin, short, compact than ordinary motors. But they have low efficiency with high frequency power source because of the iron losses which may produce too much heat as well as the copper losses occurred in the rotor windings. The Halbach array can generate the strong magnetic field systems without additional magnetic materials, therefore the iron losses can be removed. In this paper, the Halbach array is applied to the field system for the high speed motor, and three dimensional FEM is used to analyze the field of the Halbach array considering with the leakage flux. The measured values of flux density are also compared with the FEM analysis. And the magnetic characteristics of the Halbach array field system are compared with those of the conventional field systems such as slot-iron type, PM-iron type. Consequently, it is confirmed that the Halbach array field system is more suitable to the high speed motor because it has high flux density, sinusoidal flux distribution than others.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.187-193
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• 1998

An inverter-driven induction motor is used as the traction motor for a high speed drive system that required safty, reliability and performance and so on. rotor bar and end ring of the traction motor are the electrical equipments which form the conductive close loop and then induce current by interaction wi th the current of stator. the materials selection of rotor bar and end ring are seriously considered in the aspects of electrical and mechanical specification and Motor slip relation to inverter. Particularly motor slip guarantee the safty and reliability of induction motor. this paper show the material selection and the determining of slip in the design of traction motor for high speed train by analyzing the specifications of material being used currently.

• Journal of Power Electronics
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• v.1 no.1
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• pp.19-25
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• 2001

A high speed, three phase, 12/8 pole, 225 kW switched reluctance motor (SRM) has been designed and analyzed. A circuital approach has been used to find the geometry, windings parameters and electromagnetic loading. Then, the 3D finite element method (FEM) has been used to calculate the static torque more accurately and optimize the design. The efficiency of the designed SRM is almost constant over wide range of speed and its phase current is less sensitive to the speed than that of an induction motor of the same rating. Recommendations for manufacturers and users are given.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.216-218
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• 2006

The paper is proposed high performance control of induction motor drive with adaptive fuzzy logic controller(AFLC). Also, this paper is proposed speed control of induction motor using AFLC and estimation of speed using artificial neural network(ANN) controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The error between the desired state variable and the actual one is back-propagated to adjust the rotor speed, so that the actual state variable will coincide with the desired one. The proposed control algorithm is applied to induction motor drive system controlled AFLC and ANN controller. And this paper is proposed the results to verify the effectiveness of the AFLC and ANN controller.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.8
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• pp.426-430
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• 1999

In this paper, a speed sensorless algorithm for a high-speed induction motor is proposed. The proposed algorithm simply estimates rotor speed by integrating the deviation between the command current value of a controller and the real current value of the motor. To estimate rotor speed without a speed sensor, a fuzzy speed controller and a neural network speed estimator are applied. Computer simulation and implementation of the proposed system is described.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.306-310
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• 2010

On account of small size and light weight, a high-speed machine is regarded as a key technology for many future applications of drive systems. In high-speed applications, permanent magnet synchronous motors have a number of merits such as high efficiency and high power density. Therefore, they are suitable for driving the air-blower of a fuel cell electric vehicle (FCEV) where space and energy savings are critical. Particularly, a surface-mounted permanent magnet synchronous motor (SPMSM) of them is mainly used as a high-speed machine. However, the motor has a fatal flaw due to a retaining can to maintain the mechanical integrity of a rotor assembly. The can results in the increase of magnetic air-gap length in the SPMSM. Thus, in this paper, an interior permanent magnet synchronous motor (IPMSM) is applied in order to drive the air-blower of FCEV instead of the SPMSM, and the experimental results of two models are compared to verify the capability of the IPMSM for high-speed applications.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.2
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• pp.121-126
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• 2008

This paper analyzes the losses of a Steinmetz connection three-phase induction motor which is supplied by a single-phase source. The T-type equivalent circuit which is taken no-load losses into account is used to determine phase converter capacitive reactances at starting and rated speed by using the condition of the minimum voltage unbalance. The starting and the operating capacitor are replaced at the slip of the same voltage unbalance factor points which are depicted using two capacitive reactances. The operation characteristics are investigated by comparing with those of three-phase balanced operation to find the feasibility of single-phase operation. To analyze the losses of this motor, the output power decrease factor(OPDF), the loss ratio(LR), the no load loss ratio(NLLR), the copper loss ratio(CLR), the stator copper loss ratio(SCLR), and the rotor copper loss ratio(RCLR) are defined and simulated in the whole slip range. The simulated results show that OPDF is maintained almost uniformly, LR is low at low speed and high at high speed, CLR is higher !ban NLLR, but CLR varies concavely and NLLR varies convexly at high speed, SCLR is low at low speed and high at high speed, but SCLR varies convexly at high speed, and RCLR is nearly opposite to SCLR.

• The KSFM Journal of Fluid Machinery
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• v.4 no.1 s.10
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• pp.14-21
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• 2001

In a small centrifugal compressor system, a high-speed motor needs to be developed to drive impellers directly. Heat is generated by both electrical heating due to copper coil resistance and aerodynamic heating in the gap between the rotor and stator in a high-speed motor. Removal of the heat is essential to the design of such motors since most magnetic materials are brittle and can be easily fractured by the heat. In the present study the cooling flow fields and temperature distributions are analyzed by using computational fluid dynamics simulation for a high-speed motor which has air cooling system as well as water cooling system. In the analysis, a conjugate heat transfer problem is solved by considering both convective heat transfer in the cooling system and conduction heat transfer in solid parts. Based on design drawings of a motor, air cooling system and water cooling system are analyzed to obtain temperature field and thus to check the coiling system performance. Also the cooling performance are studied for various flow rates of cooling air and water at the inlets.