• Journal of Institute of Control, Robotics and Systems
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• v.22 no.5
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• pp.315-319
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• 2016

This paper proposes a simple adaptive sliding mode control algorithm for controlling a permanent magnet synchronous generator (PMSG) of a MW-class direct-driven wind turbine system. The proposed adaptive sliding mode controller does not require accurate knowledge of the PMSG parameter or turbine torque values. The proposed controller can accurately track the reference angular speed computed by the maximum power point tracking(MPPT) algorithm. Finally, this paper gives Matlab/Simulink simulation results to verify the practicality and effectiveness of the proposed adaptive sliding mode controller.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.55-57
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• 2007

A Power control and Distribution Unit (PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU for the small Low Earth Orbit (LEO) Satellite applications. The main constitutes of the PCDU are the battery interface module, solar array regulators with maximum power point tracking (MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation, power distribution modules of unregulated and regulated primary bus, and instrument power distribution modules.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.109-116
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• 2005

Wind power and photovoltaic(PV) systems are getting into the spotlight as substitute energy. But problem is happened stability by speed change of wind and the power output of the sun's ray. The power output amount according to velocity of wind power system. System breakdown can happen at change of sudden velocity, typhoon and night. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The operation of automatic tail safety controller verified by manual test. PV system is a energy change system by temperature of sun's ray and cell. Maximum power point tracking(MPPT) is used in PV systems to maximize the photovoltaic array output power. In existed PV system is low output and changeable DC voltage for boost and filtering the buck-boost converter use. But, this paper established deformed DC-DC converter. Changed Buck-boost converter's unlined output current to line output current using DC-DC converter. This is effect that reduce ripple of output current. Proved through an output waveform comparison experiment. Finally, tail safety brake controller is established to wind turbine system for stability elevation and DC-DC converter is established on PV system for stability output.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.3
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• pp.201-210
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• 2014

In this paper, dc-link voltage control of a grid-connected QZSI is presented. Since the input current of the ZSI is discontinuous, a capacity with relatively large capacitance should be connected to the output of the PV array in order to reduce the current ripple. Due to the presence of the impedance network inductor in series with the PV array, the QZSI can achieve continuous input current flow. Several dc-link voltage control methods are compared and the method for power quality improvement is also presented. The performance of the proposed method is verified through both simulation and experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.283-287
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• 2005

In this paper, one general approach is proposed for the design of power system that can be applicable for next generation LEO satellite application. The power system consists of solar panels, battery, and power control and distribution unit(PCDU). The PCDU contains solar array modules, battery interface modules, low-voltage power distribution modules, high-voltage distribution modules, heater power distribution modules, on-board computer interface modules, and internal DC/DC converter modules. The PCDU plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. We review the functional schemes of the main constitutes of the PCDU such as the battery interface module, the auxiliary supply module, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, spacecraft unit power distribution modules, and instrument power distribution module.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.287-288
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• 2011

주택 혹 산업용, 공공건물용으로 상용화 되어 있는 스트링 어레이 중앙 인버터 방식은 고압의 DC 배선으로 인한 안전문제, 고가의 고압 DC 차단기의 설치 및 과전압보호기 등으로 가격이 상승하게 되고 설치 시에도 패널간 균일 성능을 보장해야하고 스트링 상에 놓여 있는 패널 일부가 불량이거나 그림자가 져서 발전이 미비할 경우 전체 시스템 발전이 정지하거나 발전량이 미비해지는 문제가 생기므로 항상 최적의 상태로 운전할 수 없다. 그래서 이러한 태양광 발전 방식의 문제점을 해결하기 위해 각 모듈마다 마이크로 인버터를 장착하여 각각 패널마다 분산적인 MPPT(Maximum Power Point Tracking) 를 수행할 수 있고 DC 배선이 없기 때문에 시스템 설치비용을 획기적으로 절감할 수 있으며 안정성 문제도 중앙 인버터 방식보다 획기적으로 향상된다. 패널 또는 인버터 고장 시 전체 시스템의 차단 없이 교체가 가능 하여 시스템의 설비 이용률을 최대로 할 수 있다. 이러한 패널에 쓰이는 마이크로 인버터를 PSIM으로 구현하여 DLL로 통해 디지털 제어로 구현을 하고 시뮬레이션으로 통해 시스템의 효능을 알아보았다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.49-52
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• 2007

In this paper, we proposed a design photovoltaic generation systems with SEPIC-Flyback converter. The SEPIC-Flyback converter is operated to SEPIC converter the state turn-on of the switch and the state turn-off the switch is operated Flyback converter. Therefore application rate of the core increases and voltage stress of switch and transformer decreases with active clamp operation. Also we performed MPPT(Maximum Power Point Tracking) control for efficient working of Photovoltaic Dower generation system.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.293-296
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• 2007

본 논문에서는 UPS 기능을 갖는 단상 태양광 발전 시스템을 제안하였다. 제안하는 시스템은 태양광 어레이 (photovoltaic array)에서 최대전력을 얻기 위해 MPPT (maximum power point tracking)를 수행하는 컨버터, 계통전원 상태나 태양광 발전량에 상관없이 부하에 정현파 전압을 공급하는 인버터, 태양광 어레이에서 발전된 잉여전력을 계통으로 전달하거나 부하에 필요한 전력을 dc bus로 공급하는 인버터, 정전시 dc bus에 전력을 공급하는 양방향 컨버터 (bidirectional converter)로 구성된다. 제안하는 시스템은 발전된 전력을 계통으로 전달할 뿐만 아니라, UPS (uninterruptible power supply)기능도 수행하는 시스템으로 계통전압이 불안정하거나 정전시에도 부하에 안정적이고 깨끗한 전압을 항상 공급할 수 있다. 각각의 인버터, 컨버터, 및 양방향 컨버터는 dc bus를 공유하며, dc bus의 전압에 따라 동작상태가 결정이 된다. dc bus중심의 제어는 dc bus전압을 안정적으로 유지시키며, 부하에 걸리는 전압의 변동을 최소로 하고 시스템의 디자인 및 제어를 단순화한다. 모든 알고리즘과 제어기를 하나의 마이크로 컨트롤러로 구현하였고 제안된 시스템의 우수성을 실험을 통해 검증하였다.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.346-348
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• 2001

In this paper a wind power simulator is designed and implemented. This simulator realize the torque of wind blade by DC motor. And squirrel-cage induction machine is used as generator and controlled to achieve the maximum power point tracking(MPPT) algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.4
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• pp.297-304
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• 2013

This paper presents a improved control technique to overcome disadvantage when the inductor current of boost converter in PV system becomes DCM(Discontinuous Conduction Mode) due to the low insolation. MPPT(Maximum Power Point Tracking) output reference voltage could not be exactly followed by conventional dual-loop PI control method used typically because of the error between the actual current and measured current. Therefore, in this paper, Hybrid controller that changes the control method in DCM and CCM(Continuous Conduction Mode), and single state feedback controller are used to compensate that problem. The proposed control technique was verified by simulation using PSIM 9.0 and experiments.