• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
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• pp.27-29
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• 2004

This paper presents improved teaching and learning Gill for easily analysis tool of load flow of power system. This GUI includes not only contingency analysis function, but also calculating power loss from transmission line flow. The Gill is friendly for study for power system operation and control because picture provide a better visualizing of relationships between input parameters and effect than a tabula type result. This Gill enables topology and the output data of load flow for line outages to be shown on same picture page. Users can input the system data for power flow on the the picture and can easily see the the result diagram of bus voltage, bus power, line flow. It is also observe the effects of different types of variation of tap, shunt capacitor, loads level, line outages. Proposed Gill has been studied on the Ward-Hale 6-Bus system.

• 전기학회논문지
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• 제59권2호
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• pp.232-241
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• 2010

This paper describes the development of robust contingency analysis program for Korean Energy Management System. The important function of contingency analysis is to determine the bus/branch model for contingency, and to calculate the state of the power network based on the network model and topology output. In the proposed method, the bus/branch models for contingencies are determined exactly using a fast linked-list method based on the application common model database. To calculate the state of the power system included contingency, the full-decoupled powerflow approach, the partial powerflow method for contingencies and the proposed contingency screening algorithm are also used to contingency analysis. To verify the performance of the developed processor, we performed a file-based test using several structured input data and online test using the database which resides on memory. The results of these comprehensive tests showed that the developed processors can accurately calculate the power system contingency state from online data and can be applied to Korea Power Exchange system.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.399-402
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• 2006

This paper presents a new circuit topology of dc bus line switch-assisted half-bridge soft switching PWM inverter type dc-dc converter for arc welder. The proposed power converter is composed of typical voltage source half-bridge high frequency PWM inverter with a high frequency transformer link in addition to dc bus line side power semiconductor switching devices fer PWM control scheme and capacitive lossless snubbers. All the active power switches in the half-bridge arm and dc bus lines can achieve ZCS turn-on and ZVS turn-off commutation operation and consequently the total turn-off switching losses can be significantly reduced. As a result, a high switching frequency of using IGBTs can be actually selected more than about 20 kHz. The effectiveness of this new converter topology is proved for low voltage and large current dc-dc power supplies such as arc welder from a practical point of view.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.11-13
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• 2019

This paper proposes a novel high step-up non-isolated DC-DC converter, suitable for regulating dc bus in various inherent low voltage micro sources especially for photovoltaic (PV) and fuel cell sources. This novel high voltage Non-isolated Boost DC-DC converter topology is best replacement, where high voltage conversion ratio is required without the transformer and also need continuous input current. Since the proposed topology utilizes the stack-based structure, the voltage gain, and the efficiency are higher than other conventional non-isolated converters. Switches in this topology is easier to control since its control signal is grounding reference. Also, there is no need of extra gate driver and extra power supply for driver circuit, which reduces the cost and size of system. In order to show the feasibility and practicality of the proposed topology principle operation, steady state analysis and simulation result is presented and analyzed in detail. To verify the performance of proposed converter and theoretical analysis 360W laboratory prototype is implemented.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권6호
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• pp.745-753
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• 2016

This paper presents a fully synthesizable low power interconnect bus for millimeter-scale wireless sensor nodes. A segmented ring bus topology minimizes the required chip real estate with low input/output pad count for ultra-small form factors. By avoiding the conventional open drain-based solution, the bus can be fully synthesizable. Low power is achieved by obviating a need for local oscillators in member nodes. Also, aggressive power gating allows low-power standby mode with only 53 gates powered on. An integrated wakeup scheme is compatible with a power management unit that has nW standby mode. A 3-module system including the bus is fabricated in a 180 nm process. The entire system consumes 8 nW in standby mode, and the bus achieves 17.5 pJ/bit/chip.

• 전자공학회논문지
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• 제53권2호
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• pp.10-16
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• 2016

철도 차량 내 전자 장치 연결의 높은 안정성을 위해 제어망은 링크 장애 발생 시에도 장치의 계속된 연결을 지원할 수 있어야 한다. 본 논문은 철도 차량용 이더넷 기반 제어망에서 링 토폴로지 적용 시 링크 장애가 발생하면 노드 위치에 따라 급격한 전송 딜레이 변화가 발생함을 보인다. 이 문제를 해결하기 위해, 장치별 딜레이 증가를 감안한 포워딩 우선순위를 설정하는 기법과 백업용 버스 망을 두어 장애 발생 시 일부 노드를 선택적으로 버스 망으로 스위칭 시키는 토폴로지 스위칭 기법을 제안한다. 시뮬레이션을 통한 성능 평가에서, 포워딩 우선순위를 설정하는 기법은 큐잉 딜레이의 보상만 가능하여 제한된 효과를 얻는 반면, 토폴로지 스위칭 기법은 링크 수에 따른 딜레이 증가 측면에 대해 충분한 성능 개선이 있음을 보인다. 또한, 토폴로지 스위칭 기법의 딜레이 성능과 패킷 손실율은 버스 망에 연결된 노드 수에 영향을 받는 것을 보인다.

• 전기학회논문지P
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• 제58권2호
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• pp.116-121
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• 2009

Distributed power systems (DPSs) has been widely used various industrial/military applications due to their various advantages. Furthermore, the "All electric" concept, in conjunction with DC DPS, appears to be more advanced and mature in the AEV(All-Electric Vehicular) industry. Generally, AEV carry many loads with varied functions. However, there may be large pulsed loads with short duty ratios which can affect the normal operation of other loads. In this paper, a converter with spilt capacitors and a simple adaptive controller is proposed as a active damping device to mitigate the voltage transients on the bus. The proposed converter allows the smaller capacitive storage. In addition, the proposed control approach has the advantage of requiring only one sensor and performing both the functions of mitigating the voltage bus transients and maintaining the level of energy stored. The control algorithm has been implemented on a TMS320F2812 Digital Signal Processor (DSP). Simulation and experimental results are presented which verify the proposed control principle and demonstrate the practicality of the circuit topology.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1147-1149
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• 1992

A novel 3$\phi$ ZVS PWM VSI topology employing a simple dc bus subcircuit that provides soft switching commutations is proposed in this paper. The main advantage of the proposed inverter commutation schem is that the dc bus subcircuit is activated only when required, that is, when dictated by the respective PWM. Detailed analysis is provided and simmulation results are presented to verify the principles of operation of the proposed inverter schem.

• 조명전기설비학회논문지
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• 제25권3호
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• pp.40-49
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• 2011

This paper presents novel circuit topology of half-bridge soft-switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed, half-bridge high frequency PWM inverter with a high frequency planar transformer link PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode-equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC bus lines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, high switching frequency IGBTs can actually be selected in the frequency range of 40[kHz] under the principle of soft-switching. The performance evaluations of the experimental setup are illustrated practically.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.168-172
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• 2003

This paper presents a non-electrical isolated Prototype of N+X redundant UPS with two-quadrant converter. Proposed topology has multi-functions of battery charge and discharge regulation, operates with a near unity input power factor, compensates unbalanced voltage on U bus capacitors, and regenerates the circulating active power among the inverters into battery or grid. And furthermore, this system adopts a novel wireless parallel operation algorithm of N+X redundant UPS system with no control interconnections. Simulation and experiment results are provided in this paper to prove the validity of proposed topology and wireless control algorithm.