• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.351-351
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• 2004

For greeting the era of ubiquitous network, data storage devices have been essentially attached to mobile data devices. As a result, the minimization of the storage device has arisen as major interests in the next generation data storage technology. So, there are many researches for the small form factor ODD. In this paper, we propose a pick up that consists of a linear VCM and 2-wire focusing actuator for a small form factor ODD. For the sake of checking performance of the coarse actuator, PID controller is designed. Experiment with controller and DSP board shows its propriety as a fine tracking actuator. And, 2-wire suspension actuator is designed in order to be contained in a coarse actuator and to satisfy the thickness of a PCMCIA type. Through the experiment of designed actuator, It verifies performance as a focusing actuator.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.479-483
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• 1997

In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.715-723
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• 2016

This paper proposes a design of optimal PI(D) controller for brushless DC (BLDC) motor speed control by the particle swarm optimization (PSO), one of the powerful metaheuristic optimization search techniques. The proposed control system is implemented on the TMS320F28335 DSP board interfacing to MATLAB/SIMULINK. With Back EMF detection, the proposed system is considered as a class of sensorless control. This scheme leads to the speed adjustment of the BLDC motor by PWM. In this work, the BLDC motor of 100 watt is conducted to investigate the control performance. As results, it was found that the speed response of BLDC motor can be regulated at the operating speed of 800 and 1200 rpm in both no load and full load conditions. Very satisfactory responses of the BLDC system can be successfully achieved by the proposed control structure and PSO-based design approach.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.440-444
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• 2008

The 7-phase BLDC motor is possible for higher efficiency per the unit area, high power and high speed due to the increasing number of phase. Also, it can be looking forward to reduce the current ripple at a point of commutation by the increasing number of phase. Thus, a study for applications of servo system, medical and military instruments is progressing about the BLDC motor is manufactured with multi-phase, currently. This paper is used the fuzzy logic control method for speed control of 7-phase BLDC motor and this is compared with the conventional PI controller using by simulation and experimental results for verification validity of the fuzzy logic controller in this system. The 7-phase BLDC motor and controller are modeled by PSIM6.0 software of PowerSim co. in simulation and we are experimented by the test board that is composed with TMS320VC33-150 DSP controller of Texas Instruments co. and FLEX EPF6016TC144-3 of ALTERA co.

• Journal of Power Electronics
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• v.8 no.4
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• pp.363-370
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• 2008

In this paper, three kinds of PWM strategies for a three-phase current-fed dc/dc converter are proposed and compared in terms of losses and voltage transfer ratio. Each PWM strategy is described graphically and their switching losses are analyzed. With the proposed PWM C strategy, one turn-off switching of each bridge switch is eliminated to reduce switching losses under the same switching frequency. In addition, RMS current through the bridge switches is lowered by using parallel connection between two bridge switches and thus, conduction losses of the switches are reduced. Further, copper losses of the transformer are decreased due to the reduced RMS current of each transformer's winding. Therefore, total losses are minimized and the efficiency of the converter is improved by using the proposed PWM C strategy. Digital signal processor (DSP: TI320LF2407) and a field-programmable gate array (FPGA: EPM7128) board are used to generate PWM patterns for three-phase bridge and clamp MOSFETs. A 500W prototype converter is built and its experimental results verify the validity of the proposed PWM strategies.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.135-136
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• 2006

A precise linear motion stage supported by magnetically preloaded air bearings is introduced where preloading magnetic actuators are combined with permanent magnets and coils to adjust air bearing clearance by controlling magnetic force actively. Each of the magnetic actuators has a permanent magnet generating nominal magnetic flux for required preload and a coil to perturb the magnetic force resulting adjustment of air-bearing clearance. The characteristics of porous aerostatic bearing are analyzed by numerical analysis, and analytic magnetic circuit model is driven for magnetic actuator to calculate nominal preload and variation of force due to current. A 1-axis linear stage motorized with a coreless linear motor and a linear encoder is built for verifying this design concept. With the active magnetic preloading actuators controlled with DSP board and PWM power amplifiers, the active on-line adjusting tests about the vertical, pitching and rolling motion were performed, and the result shows very good linearity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1061-1070
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• 2002

In this paper, we present a performance analysis of the smart antenna test-bed operating in a IS2000 1x through a test-bed that has been implemented on a DSP(TMS320C6711) board. The test-bed consists of a PC (for generating the RX data), beam-former(i.e., a stand-alone PCB for weight computation), and an interfacing module. The performance improvements compared to a normal base station system consisting of a single antenna are shown in terms the BER(bit error rate) in the wide-band CDMA channel.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.1
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• pp.18-27
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• 2002

This paper presents an implementation of digital high-performance speed sensorless control system of an induction motor drives with Direct Torque Control(DTC). The system consists of closed loop stator flux and torque observer, speed and torque estimators, two hysteresis controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP controller board. The stator flux observer is based on the combined current and voltage model with stator flux feedback adaptive control for wide speed range. The speed estimator is using the model reference adaptive system(MRAS) with rotor flux linkages for speed turning signal estimation. In order to prove the suggested speed sensorless control algorithm, and to obtain a high-dynamic robust adaptive performance, we have some simulations and actual experiments at low(20rpm) and high(1000rpm) speed areas. The developed speed sensorless system are shown a good speed control response characteristic, and high performance features using 2.2[kW] general purposed induction motor.

• Journal of Power Electronics
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• v.14 no.3
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• pp.507-518
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• 2014

This paper presents a new cascaded asymmetrical single phase multilevel converter with a lower number of power semiconductor switches and isolated DC sources. Therefore, the number of power electronic devices, converter losses, size, and cost are reduced. The proposed multilevel converter topology consists of two H-bridges connected in cascaded configuration. One H-bridge operates at a high frequency (high frequency inverter) and is capable of developing a two level output while the other H-bridge operates at the fundamental frequency (low frequency inverter) and is capable of developing a multilevel output. The addition of each power electronic switch to the low frequency inverter increases the number of levels by four. This paper also introduces a hybrid switching algorithm which uses very simple arithmetic and logical operations. The simplified hybrid switching algorithm is generalized for any number of levels. The proposed simplified switching algorithm is developed using a TMS320F2812 DSP board. The operation and performance of the proposed multilevel converter are verified by simulations using MATLAB/SIMULINK and experimental results.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.853-855
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• 1996

This paper describes the dissipation factor measuring techniques of insulating oil on the operating transformer by using digital signal processing. After applying voltage to the electrodes which is installed In a transformer, acquiring source voltage and current of electrodes and using cross-correlation techniques. we can check the dissipation factor of insulating oil. To Improve measuring accuracy and the speed of process, we use hardware such as TMS320C31 DSP board and analog filter and software such as cross-correlation techniques, rectangular window, and digital filtering techniques. We simulated the measuring accuracy and the degree of the noise effect of this new measuring techniques by using computer simulation, and compared the simplified measuring devices with schering bridge on degraded insulating oil. The result showed that this measuring technique can be used as diagnostic method on the pole transformers.