• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.375-379
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• 1990

A microprocessor-based multi-function switchgear for the protection, measurement and control of the power system is presented. For the extraction of the RMS values of the fundamental components of current and voltage signals, a simple digital filter based on cross-correlation of the distorted signal with even and odd heptagonal waves is used. The frequency response of this filter is almost identical to that of the filter based on the discrete fourier transform, while its computational requirement is far less. For the time delay element relaying, a new log-table based relaying algorithm is suggested. The suggested use of the heptagonal wave cross-correlation digital filter algorithm and a new relaying algorithm reduce the computational needs so drastically that all functions of the switchgear can be implemented on the microprocessor system. Real time testing of the implemented daboratory prototype show good practical response under different operating conditions.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.615-619
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• 2000

This paper presents an implementation of digital motion control system of Surface Permanent-Magnet Synchronous Motor(SPMSM) vector drives with a direct torque control(DTC) using the 16bit DSP TMS320F240 The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent control for motors which can be yield enhanced operation fewer system components lower system cost increased efficiency and high performance The system presented are stator flux and torque observer of stator flux feedback model that inputs are current and voltage sensing of motor terminal and angle for a low speed operating area two hysteresis band controllers an optimal switching look-up table and IGBT voltage source inverter by using fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 1.0Kw purposed servo drive SPMSM.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2741-2743
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• 2005

In this paper, Elevator is designed for real time security & management. Security & Management System is designed for wireless communication between an Elevator and an manager, between Elevation and an manager. Also, to have remote control capability, embedded system platform with TCP/IP techniques are applied to process control system with independent open structure for the precise data transmission and without constraint of operating system. Security and Management system is designed to solve problem of network port by Bluetooth module. Moved recording, unworked table, life of device and replacement time of device are made database, database is applied to Fuzzy Rule for pre-detection unworked Elevator. Security & Management system is designed safety and convenience for customers using Elevator as well as rapidly treatment with unworked Elevator.

• KIEAE Journal
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• v.3 no.1
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• pp.21-29
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• 2003

Scale model measurements should be conducted under an actual sky or in a simulated sky where conditions can be held constant. A number of successful attempts have been made to develop artificial sky domes with man-made sun emulators. With reference to formerly-developed examples, sky simulator facility has recently been activated in oder to provide desirable sky conditions for teaching and studies. The structure is a 6m-diameter dome and promises to set various condition for energy related and lighting research activities. The sky dome is also equipped a heliodon, the tilt table, to facilitate additive direct sun impact under clear skies. Shading studies, using scale models with the heliodon, reveal how a building's design blocks or permits light's passage to the interior; solar access studies, and tests of the reflection and transmittance characteristics of new daylighting technologies. The design and construction specification and the initial operating experience with a building configuration are reported.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.79-84
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• 2000

This paper presents an implementation of digital position control system for an induction motor vector drives by a direct torque control(DTC) using the 16bit DSP TMS320 F240. The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent controller for motors which can be yield enhanced operation, fewer system components, lower system cost, increased efficiency and high performance. The system presented are stator flux and torque observer using current model that inputs are current sensing of motor terminal and rotor angle for a low speed operating area, two hysteresis controller, optimal switching look-up table, and IGBT voltage source inverter by fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 2.2Kw general purposed induction motor.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.277-280
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• 2001

This paper presents a speed sensorless implementation of digital speed control system of Surface Permanent-Magnet Synchronous Motor(SPMSM) drives with a direct torque control(DTC). The system presented are stator flux and torque observer of stator flux feedback control model that inputs are current and voltage sensing of motor terminal with estimated rotor angle for a low speed operating area, two hysteresis band controllers, an optimal switching look-up table, rotor speed estimator, and IGBT voltage source inverter by using fully integrated control software. The developed speed sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0Kw purposed servo drive SPMSM.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.77-83
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• 2012

In this paper, an optimal solution to the harmonic reduction problem in a cascaded multilevel inverter with non-equal DC sources using a genetic algorithm (GA) is presented. Switching angles are generated for different values of modulation index by the proposed algorithm, considering minimum voltage total harmonic distortion (THD) whereas selected harmonics are controlled within the allowable limits at all desired modulation indices including the point of discontinuity. Results are stored as a look-up table to be used to control the inverter for a certain operating point. The computed angles are used in a simulated circuit in Matlab\Simulink to validate the results.