• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.03a
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• pp.9-16
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• 1995

The thermal deformation of machine tool spindle influences the performance of the manufacturing systems for precision products. In this research thermal analysis of a high speed machine tool spindle with the rolling bearing and the built-in motor is carried out using Finite Difference Method. The thermal boundary conditions describing the hear generation in the bearing and built-in motor are considered in the simulation. And various convective boundary conditions are assumed with the empirical formula in the references. From the simulation results the characteristics of each element affecting the dynamic thermal behaviour of the machine tool spindle systems have been clarified. This model can be well applied to the future development of the high speed spindle systems.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.419-424
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• 2012

This paper presents a tubular reciprocating translational motion permanent magnet synchronous motor for percussive drilling applications for offshore oil & gas industry. The motor model and rock model are built up by doing force analysis of the motor and analyzing the physical procesof impact. The optimization of input voltage waveforms to maximize the rate of penetration is done by simulations. The simulation results show that the motor can be utilized in percussive drilling applications and achieve a very large impact force. Simulation results for optimization also show that second harmonic input voltage produces a higher rate of penetration than the sine wave and fourth harmonic input voltages.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.45-51
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• 2005

This paper presents a comparison of rotor position estimation of a switched reluctance motor(SRM) with built-in search coils by three methods. The search coil EMFs are not generated in the SRM with built-in search coils at standstill. So an initial rotor position estimation method is needed. In this paper squared euclidean distance, fuzzy logic and neural network methods we proposed for the estimation of initial rotor position. The simulated results of the three methods are compared. The simulated result of the squared euclidean distance method, which has the best performance, is supported by the experimental result.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1027-1028
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• 2007

In this paper, the variation of air-gap field intensity caused by the slot-opening in interior permanent magnet (IPM) motor is investigated, which is for predicting the instantaneous magnetic field more preciously in analytical method further. It is different with the approach of dealing the slot-opening effect on the air-gap field distribution with the "relative permeance" function in surface permanent magnet (SPM) motor. The prediction of the air-gap field in IPM motor is much more complex than SPM motor. In this study, an approximate estimation method is adopted based on analyzing the changing of flux path in both the IPM rotor part and stator part, and in additional an analytical function defined as "relative pole-arc" is built. The finite element method(FEM) is used for confirming the slot-opening effect on the field prediction.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.158-161
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• 2005

For low power motor control, there are increasing demands for compactness, cost effective and built in many functions. Hence Intelligent Power Module(IPM) is considered as an important technology in inverter-driven motor applications. Regarding BID-IPM(Built In DC/DC converter, Intelligent Power Module) newly developed to integrate NPT-IGBT, HVIC and Flyback converter in a compact package, this paper discussed design of BID-IPM and presented the experimental results by using signal source board and equivalent load test board.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.257-260
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• 1997

In this paper, the double inverted pendulum having a single actuator is built and the controller for the system is proposed. The lower link is hinged on the plate to free for rotation in the x-z plane. The upper link is connected to the lower link through a DC motor. The double inverted pendulum built can be kept upright posture by controlling the position of the upper link even though the proposed inverted pendulum has no actuator in lower hinge. The algorithm to control the inverted pendulum is consisted of a state feedback controller within a linearizable range and a fuzzy logic controller coupled with a feedback linearization control for the rest of the range. Concept of the virtual work is employed to drive the linearlized model for the state feedback controller. The feedback linearization controller drives a DC motor with the modified reference joint angle from the fuzzy controller which adjusts a upright posture of a proposed pendulum system. Finally, the experiments are conducted to show the validity of the proposed controller.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.441-446
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• 2001

This paper presents the thermal characteristics analysis of a high-speed HMC spindle system with angular contact ball bearings, built-in motor, oil-jet lubrication method, oil jacket cooling method, and so on. The spindle system is composed of the main spindle and sub-spindle which are mechanically connected by a flexible coupling. The spindles are supported by two front and rear bearings, and the built-in motor is located between the front and rear bearings of the sub-spindle. The thermal analysis model of spindle system is constructed by the finite element method, and the thermal characteristics in the design stage are estimated based on temperature distribution and heat flow under the various testing conditions related to material of bearing ball, spindle speed and coolant temperature.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1151-1153
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• 2003

In this paper, switching surge voltage distribution in stator windings of induction motor driven by IGBT PWM inverter is studied. To analyze the irregular voltage of stator winding, equivalent circuit model of inverter-cable-motor was proposed and high frequency parameter is computed by using finite element method (FEM). Electromagnetic transient program (EMTP) analysis of the whole system for induction motor and PWM inverter is proposed. In order to experiment, an induction motor, 380 [V], 50 [HP], with taps from one phase and a switching surge generator was built to consider the voltage distribution.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.485-486
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• 2015

This paper introduces the new 1200V $SPM^{(R)}$ (Smart Power Module), which is fully optimized and intelligent integrated IGBT inverter modules for up to 6kW motor drive applications. It utilizes newly developed NPT trench IGBT with the advanced STEALTHTM freewheeling diode, and built-in bootstrap diode. HVICs, multi-function LVIC, and built-in thermistor provide good reliable characteristics for the entire system. This module also takes technical advantage of DBC(Direct Bonded Copper) substrate for the better thermal performance. This paper provides an overall description of the newly developed 1200V/35A $SPM^{(R)}$ 2 product.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.255-257
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• 2007

In this paper, we develop a single wheeled robot that has one wheel to move. The single wheel robot is similar to a rolling disk relying on gyroscopic motions to balance. The Gyrobo consists of three actuators: a spin motor, a tilt motor and a drive motor. The spin motor spins a flywheel at high rate so that it provides the balancing stability to upright the robot. The tilt motor controls steering of the robot by gyroscopic effect. The drive motor make forward accelerated motion to the robot. We have built and tested the Gyrobo to turn and move forward.