• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1440-1443
• /
• 1997

The optimal residual generator based on parity relation approach for the fault detection and isolation of a arge diesel engine actuator position servo system is presented. The closed-loop residual generator is designed to have robustness against modeling errors and noise. Main purpose of the fault detection and isolation system in the process is to detect and isolate two important faults, i.e., actuatro fault and fault of speed sensor, that, if not detected and compensated, degrade the overall control system performance. Simulation results are give to show the practical applicability of the fault detecrtion and isloation scherme.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.95-98
• /
• 2006

This paper proposes high speed SRM drive system for blower with a new 4-level inverter and precise excitation position generator. For the high speed blower, a proper inverter and control method are proposed and the output characteristics are analyzed. In order to get a fast build-up and demagnetization of excitation a current, 4-level inverter system is proposed. The proposed 4-level inverter has additional charge capacitor, power switch and diode in the conventional asymmetric converter. The charged high voltage is supplied to the phase winding for fast current build-up, and demagnetization current is charged to additional capacitor of 4-level inverter. In addition, a precise excitation position generator can reduce turn-on and turn-off angle error according to sampling period of digital control system. The proposed high speed SRM drive system is verified by computer simulation and experimental result.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.139-142
• /
• 2006

This paper describes a new method using random modulated strategies for switched reluctance machines. The proposed method is combined random turn-on, turn-off angle technique and random pulse width modulation technique. The purpose of this proposed method is to decrease harmonic spectrum, and thus reduce the emitted acoustical noise. A random generator is generated by linear congruential generator (LCG) using random pulse position (RPP) scheme. Simulation results show that the harmonic intensity of proposed method is better than that of conventional method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제55권7호
• /
• pp.337-345
• /
• 2006

This paper proposes a high speed SRM drive system for blower application with a new 4-level inverter and precise excitation position generator. For a high speed blower, a proper inverter and control method are proposed and the output characteristics are analyzed. In order to get a fast build-up and demagnetization of excitation current, a 4-level inverter system is proposed. The proposed 4-level inverter has additional charge capacitor, power switch and diode in the conventional asymmetric converter. The charged high voltage is supplied to the phase winding for fast current build-up, and demagnetization current is charged to additional capacitor of the 4-level inverter. In addition, a precise excitation position generator can reduce turn-on and turn-off angle error according to sampling period of digital control system. The proposed high speed SRM drive system is verified by computer simulation and experimental results.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1999년도 춘계학술대회 논문집
• /
• pp.163-169
• /
• 1999

Residual stresses causing stress corrosion cracking (SCC) of thin-walled steam generator U tubes were investigated. The residual stresses were measured by hole drilling methods, and the applied stresses resulting from the internal pressure and the temperature gradient in the steam generator were estimated theoretically. In U-bent regions, the residual stresses at extrados were induced with compressive stress(-), and its maximum value reached -319MPa in axial direction at $\phi$= $0^{\circ}$ in position. Maximum tensile residual stress of 170MPa was found to be at the flank side at position of $\phi$= $90^{\circ}$, i.e., at apex region. Hoop stress due to the pressure and temperature differences between primary and secondary side were analyzed to be 76 MPa and 45 MPa, respectively.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.110-113
• /
• 2005

This paper proposes high speed SRM drive system for blower with a new 4-level inverter and precise excitation position generator. For the high speed blower, a proper 12/8 SRM is designed and analyzed. In order to get a fast build-up and demagnetization of excitation a current, now 4-level inverter system is proposed. The proposed 4-level inverter has additional charge capacitor, power switch and diode in the conventional asymmetric converter. The charged high voltage is supplied to the phase winding for fast current build-up, and demagnetization current is charged to additional capacitor of 4-level inverter. In addition, a precise excitation position generator can reduce turn-on and turn-off angle error according to sampling period of digital control system. The proposed high speed SRM drive system is verified by computer simulation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1622-1624
• /
• 1987

In general, pseudo noise generator(PNG) used for PLR System consists of linear feedback shift register. Based on a W.F. representation of shift registers, a method for analyzing operational characters & sequence of PNG are studied. PNG is characterized by the time-recursive equation & PNG sequence is analyzed by the output state variable equation. Methods studied in this paper are illustrated by appropriate example.

• 한국정밀공학회지
• /
• 제18권12호
• /
• pp.137-144
• /
• 2001

The major movement blocks of the container are the range between the apron and the designation points on yard in container terminals. The yard tractor drived by operator takes charge of it's movement in conventional container terminals. In automated container terminal, AGV(automatic guided vehicle) takes charge of a yard tractor's role and information of navigation path are ordered from upper control system. The automated container terminal facilities must have the docking system that guides landing zinc to execute high speed travelling and precision positioning. This paper describes the new docking method with the rotating LSB(laser slit beam) generator and two pair of photo receiver. The LSB generator is installed on the fixed ground and the photo receiver is implemented on the moving vehicle such as AGV. The proposed docking system is implemented to confirm it's function and accuracy. The accuracy of measured moving position is represented in ±5mm at 1 data sampling.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.1161-1164
• /
• 2002

The position information of the rotor are required while the SRG(Switched Reluctance Generator) is drived. The position information is generally provided by shaft encoder or resolver. But it is weak in the dusty, high temperator and EMI environment. Therefore, It is required for the sensor to be eliminated from SRG. In this paper, a estimation algorithm for the rotor position of the SRG is introducted and a constant DC-link voltage is controled by PID controller. The estimation algorithm is imple--mened by using the instantaneous flux profile, and the initial position is estimated by injecting high frequency pulse voltage. It is proved that the rotor position is esti--mated very well by the exeriments.

• 한국가스학회지
• /
• 제16권1호
• /
• pp.1-7
• /
• 2012

복합 화력발전소 배열회수보일러에서의 입구 덕트 확관 형상 변화에 따른 전열관군 전단에서의 유동 균일화 특성을 유동수치해석을 통하여 분석하였다. 배열회수보일러의 입구는 가스터빈 후류의 출구에 해당하고 가스터빈 후류는 강한 선회 및 난류 유동이다. 본 연구에서 배열회수 보일러 입구 유동 경계조건은 가스터빈을 통과한 출구 유동 해석 결과를 이용하여 수행하였다. 배열회수보일러의 전열관군 전단에서의 유동 균일화 특성이 배열회수 보일러의 효율에 직결되므로 입구 덕트 확관 변곡점의 위치 변화에 따라 유동 균일화 특성을 파악함으로써 배열회수 보일러의 형상 최적화의 기반을 마련하는 것을 목적으로 하였다. 본 연구로부터 배열회수 보일러 확관의 변곡점의 위치가 기준 형상에서 낮은 위치에서 전열관군 전단에서 최적의 유동 균일화가 이루어짐을 알았다.