• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.173-174
• /
• 2016

This paper proposes a comparison of Voltage Oriented Control (VOC) and Direct Power Control (DPC) under command mode transition for PMSG Wind Turbines (WT). Based on a neutral point clamped three level back to back type Voltage Source Converter (VSC), proposed control scheme automatically control the generated output power to satisfy a grid requirement from the hierarchical wind farm controller. Automatic command mode transition based on the dc-link voltage error provides a command mode changing between grid command and MPPT mode. It is confirmed through PLECS simulations in Matlab. Simulation result shows that proposed control scheme of VOC and DPC achieves a much shorter transient time of generated output power than the conventional control scheme of MPPT with optimal torque control and VOC under a step response. The proposed control scheme makes it possible to provide a good dynamic performance for PMSG wind turbines in order to generate a high quality output power.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.11a
• /
• pp.295-299
• /
• 2007

This paper presents the photovoltaic(PV) water pumping system with a maximum power point tracking(MPPT). The wale- pumping system uses a variable speed single phase induction motor(SPIM) driven a centrifugal pimp by field oriented control(FOC) inverter. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The duty cycle directly relate with a flux producing current control($i_{ds}$). The FOC inverter uses a current control voltage source inverter(CC-VSI). The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage ($V_{dq}$), current($I_{dq}$), speed of motor and torque.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2110-2112
• /
• 1997

The induction motor drive for the spindle of machining center is required to do not only a constant torque operation in low speed region(below base rpm), but also a constant power operation in high speed region(beyond base rpm). Also, control voltage shortage due to high speed operation must be overcome. The vector controlled inverter system with input 3 phase pwm converter is designed for that kind of condition. We experimented the performance of the inverter system with spindle motor made by Hyosung industries co.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.6
• /
• pp.1060-1068
• /
• 2002

Compound continuously variable transmission(CVT) mechanisms are proposed, which can offer a backward mode, a geared neutral, an underdrive mode and an overdrive mode. They are composed of a 2K-H I type differential gear unit, a V-belt type continuously variable unit(CVU), a few friction clutches and gears, and not required of a starting device as a torque converter. Compound CVT mechanisms developed here present two distinct operating modes which are a power circulation mode and a power split mode. The transition of two modes takes place at the particular CVU speed ratio. For these CVT mechanisms, performance analysis related to speed ratio, power ratio and efficiency are executed and proven by experimental studies.

• Journal of the korean Society of Automotive Engineers
• /
• v.7 no.3
• /
• pp.11-18
• /
• 1985

세계경제가 만성적으로 저미한 상태에서, 전세계적으로 자동차 생산도 크게 성장하기를 바랄 수 없는 상황이 계속 되고 있다. 한편, 승용차의 기술면에서는, 배기가스 규제대응기술의 개발이 일 단락되고, 석유사정도 일단은 안정상태를 유지하고 있는 가운데, 자동차 본래의 기능 및 유용성을 높이기위한 기술개발에 힘을 기울여 왔다. 승용차의 구동방식에 대해서도 FF(Front Engine, Front Drive)방식이 세계적인 추세이고, 더욱이 4WD(사윤구동차)의 보급이 주목되고 있다. 또 이지 드라이브(Easy Drive)화에의 움직임도 강하여 AT(Automatic Transmission, 자동변속기)가 부착된 자동차의 비율이 검증하고 있으며, 유체토오크 컨버어터(Fluid Torque Converter)와 유 성치차장치(Planetary gear)식의 변속 장치를 조합한 AT는 전자제어기술에 의한 정확한 제어로 그 완성도가 더욱더 높아지고 있다. 또 종래로부터 새로운 AT로서의 기술동향이 주목되고 있 었든 CVT(무단변속기)도 실용화 기술의 개발이 진척되어 일부 양산화 모델의 발표도 있으며, CVT가 AT중에서 그위치를 크게 차지하게 될 날도 머지않은 것으로 생각된다. 이하 근년 관심이 높아지고 있는 4WD 및 AT를 중심으로 승용차의 구동방식과 그 기구의 동향을 해설하기로 한다.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.55-58
• /
• 2005

풍력발전기에 있어서 보호 및 제어 시스템은 그 효율, 성능, 안전 및 수명까지도 영향을 미칠 수 있는 중요한 구성요소이다 따라서 제어 시스템은 풍력발전기의 최대 효율 및 가동률을 확보하여야 하며 풍력발전기에 문제가 발생할 경우 즉시 가동을 정지할 수 있도록 안전성을 확보할 수 있도록 설계되어야 한다. 본 연구에서는 "750kw급 Gearless형 풍력발전시스템 개발" 과제의 일환으로 수행되었던 풍력발전기용 제어시스템의 설계 및 제작 과정과 상용제품으로서의 본 제어 시스템을 소개하고자 한다.

• KEPCO Journal on Electric Power and Energy
• /
• v.5 no.4
• /
• pp.343-347
• /
• 2019

When referring to weight, volume, and efficiency, a SuperConducting Synchronous Generator (SCSG) is definitely superior to conventional generators as a large-scale wind power generation system. The SCSG is connected to a full power converter that transmits the energy from the SCSG to the power grid. To reduce the current stress and system cost, the SCSG which has nine-phase armature windings with three converters is used. This paper deals with a comparative analysis of 10 MW superconducting wind power generators with three-phase and nine-phase armature windings. The stator windings of SCSGs are of various types. Using the finite element method, SCSGs are analyzed and compared in terms of the weight and volume of SCSGs, the total length of the superconducting wire, harmonics, torque performance, and efficiency. The analyzed results will be effectively utilized to design large-scale superconducting generators for wind power generation systems.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.7
• /
• pp.916-923
• /
• 2014

This paper proposes a low-cost switched-mode rectifier (SMR) for a small-scale wind turbine with a permanent magnet synchronous generator (PMSG) system. Also, a sensorless Fuzzy MPPT control is realized by the proposed system. In the PMSG system with the SMR, the synchronous impedance can be replaced as the input inductor of a boost converter. Moreover, the sensorless MPPT control using the Fuzzy technique is carried out by the duty-ratio regulation of the SMR. The relation between the generating power and the duty-ratio is ruled by the chain rule. The wind turbine model is implemented by the squirrel cage induction motor and generated the variable torque when the generator speed is varied. To verify the performance of the proposed system, simulation and experimental results are executed.

• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.1206-1210
• /
• 1992

To satisfy the requirements of a stable speed control, comfortable ride and precise landing in the high-speed elevator. The induction motor driving elevator is controlled by inverter using vector control method which calculates optimum torque to apply to the Induction motor. This paper describes the control system of high-speed elevator that consists of the voltage-type PWM converter with an unity input power factor and sinusoidal input current and the voltage-type PWM inverter with a precise speed control and sinusoidal output current. The test results of actual elevator are presented.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.60 no.3
• /
• pp.144-149
• /
• 2011

Currently, switched reluctance motors are studied to increase energy efficient. The switched reluctance motor is possible to control higher speed and torque than the induction motors and composition is simple. Current and rotor speed are considered to install the switched reluctance motor. In this paper, Simulink model of the switched reluctance motor is suggested and the adaptive controller is applied to the model for the speed control. Asymmetry converter including the IGBT is concerned with real-time control and the speed of switched reluctance motor is controlled by installing adaptive controller.