• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.153-155
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• 2000

This paper reveals some correlations between LDC voltage control method and the output of DGS, and also presents a method for determining the amounts of real, reactive Power of DGS for proper voltage regulation of power distribution system with LDC. Proposed method has been applied to a 22.9 kV class power distribution system, and those results show that the distribution system voltage profile is improved.

• 인터넷정보학회논문지
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• 제13권1호
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• pp.99-106
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• 2012

다수의 오브젝트로 구성된 반응형 시스템을 모델링 하거나 디자인하기 위해 외부의 입력 및 오브젝트들간의 상호작용을 분석하는 것은 중요하고 어려운 문제이다. 또한, 반응형 시스템이 요구 사항들을 모든 가능한 환경 하에서 올바르게 만족하는지를 확인하는 것은 많은 노력이 필요하다. 본 논문에서는 요구 사항들을 기존에 다양한 분야에서 사용되는 시나리오 명세 언어인 MSC(Message Sequence Chart)에 대해 구문 및 의미를 확장한 LSC(Live Sequence Chart)를 이용하여 반응형 시스템에 적합한 시나리오 기반 명세 모델을 만든다. 그리고 LTL Synthesis를 통해 각 오브젝트에 대하여 모든 요구 사항을 올바르게 만족하는 반응형 시스템 모델을 자동으로 생성한다. 마지막으로 생성된 반응형 시스템 모델로부터 의미적으로 동일한 코드로 변환하는 과정을 반복함으로써 전체 반응형 시스템을 개발하는 방법을 제안한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.269-272
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• 1988

This paper introduces a method to reduce the reactive power required by electronic converters. The instantaeous reactive power is calculated and compensated by the current controlled PWH voltage source converter connected parallel between the power lines and the converter. A high performance current control technique which is based on the current deviation vector is used for the PWM converter as compensator of reactive power. Accurate compensation of the reactive power and t control system ensuring fast response to the sudden change of loaf are attained. The converter structure and control scheme are discussed. Simulation of the system is performed.

• 제어로봇시스템학회논문지
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• 제18권1호
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• pp.28-34
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• 2012

Human generally uses three methods to keep balance. One of them is using reactive momentum such as swing an upper body or arms. In this study, we proposed a balancing controller for the reactive momentum method using an inverted pendulum. We simplified a human or a humanoid robot as a two-link inverted pendulum having two edges. In addition, we proposed a distinctive condition for controller transition. If a human is pushed, he has to change a balancing controller from using an ankle torque to using a reactive momentum or changing foot placement. When the balancing controller is changed from using an ankle torque to using a reactive momentum, it is required a proper timing to keep a stability and make smooth movement. In the experiment, the proposed controller and distinctive condition were verified.

• International Journal of Advanced Culture Technology
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• 제8권2호
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• pp.283-288
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• 2020

This study investigated the purification process of groundwater contaminated with zinc and arsenic using a permeable reactive barrier with a zero-valent iron/pumice mixture. We determined the removal rates of the contaminants for 30 days. In this study, column reactor filled with the zero-valent iron/pumice reactive mixture was used. Experimental results showed that the mixture exhibited an almost complete removal of the zinc and arsenic ions. Arsenic was removed via co-precipitation and adsorption processes while zinc ions were asorbed in active sites.The purification process of water from the metal ionscontinued for 30 days with constant hydraulic conductivity because of the enhanced porosity of the pumice and interparticle distance between the zero-valent iron and pumice. Contaminants removal rates and the remediation mechanism for each reactive system are described in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.484-487
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• 2003

With the restructuring of the electric power industry during the past decade, operation and control strategies have undergone a shift in paradigm. Certain activities that were earlier considered as part of the integrated electricity supply(such as voltage and frequency control) are now treated as separate services and often independently managed and accounted for. This paper examines the management of reactive power services in deregulated electricity markets around the world. From the review several diverse methods for handling reactive power within the deregulated market framework emerges. While in many of the markets, proper financial compensation mechanisms exist to compensate the providers for their service, some others continue to handle reactive power through regulatory frameworks and technical operation guidelines.

• 전기학회논문지
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• 제56권8호
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• pp.1343-1350
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• 2007

This paper describes the tests on the reactive power output limit and the Over-Excitation Limiter (OEL) dynamics of a generation unit. The suggested test methods on reactive limit can identify the allowable maximum/minimum reactive power at 100% rated MW in the steady-state unit operation condition. The on-line OEL test method can identify the time characteristics of OEL with the generation output at 50% of the rated MW. These methods are validated by applying to four Yang-Yang pumped storage units with 282 rated MVA each.

• 전기전자학회논문지
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• 제22권3호
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• pp.539-547
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• 2018

계통 연계형 인버터는 단독운전 조건에서 반드시 전력 공급을 차단해야 한다. 이러한 이유로 분산 발전 시스템은 단독운전을 검출 기능을 반드시 가지고 있어야 한다. 분산 발전용 인버터에 적용되는 일반적인 방법 중에는 Slip-Mode frequency Shift (SMS) 단독운전 검출 기법이 있다. SMS 기법은 계통 전압의 주파수에 따라 무효 전력을 공급하여 단독운전 조건에서 계통 주파수를 허용 범위 밖으로 이동시키는 방법이다. SMS 기법은 안정적으로 단독운전을 검출할 수 있으며, 계통 전류에 고주파를 인가하지 않는다는 장점이 있으나, 무효 전류를 인가하기 때문에 계통 역률이 나빠져서 전력 품질의 저하를 가져온다. 본 논문에서는 계통 전원이 연결되어 있는 정상 조건에서 전력 품질 저하가 없는 수정된 SMS 기법을 제안한다. 600W 단상 인버터 실험을 통해 제안된 방법의 유효성을 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.231-234
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• 1990

This paper shows real-time control technique of voltage-reactive power using the fuzzy theory. Here, major benefits of applying the fuzzy set theory as follow. First, heuristic knowledge of operator has been used in the operation and control of power system. Second, difficulties in traditional multi-objective numerical solution methods have been solved. Also, to achieve optimizing process on the voltage-reactive power control conventional search method have been used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.498-501
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• 1994

This paper presents a digital calculation method of instantaneous reactive power component for standby power supply(SPS) system. Reactive current is defined in time domain, calculated instantaneously by using a TMS320C25. The theoretical analysis is verified by the digital simulation and experimental results.