• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.85-88
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• 2007

This paper describes various FTTH topology such as FTTH-R, Hybrid-FTTH etc. Especially, we focus on GW-PON based Hybrid-FTTH topology. Furthermore, the optical link technology and the features of the developed GW-PON system were explained in detail.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권3호
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• pp.312-319
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• 2012

The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

• 전기학회논문지
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• 제58권11호
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• pp.2200-2208
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• 2009

This paper presents a novel single converter and single inverter (1Con-1Inv) topology for photovoltaic (PV)-fuel cell (FC) hybrid system and a new control scheme for the PV-FC hybrid system is then proposed. The new topology and the unique algorithm can minimize volume and production cost of the hybrid system. Moreover, system efficiency can improve due to reduction of losses of hardware components and other control factors are well regulated using just 1Con-1Inv with the help of the proposed control algorithm. The validity of proposed algorithm is verified both computer simulation using PSIM and Matlab/Simulink program and experimental with 700W of PV and 600W of FC system.

• 전자공학회논문지
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• 제53권4호
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• pp.27-34
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• 2016

철도 차량은 일렬로 연결되는 구조적 특수성이 있으므로 네트워크 토폴로지를 구성하는 경우에서도 이를 고려하여야 한다. 또한 차량 내의 장치 간 연결에서의 토폴로지와 차량 간 연결에서의 토폴로지를 구분하여야 한다. 차량 간 연결에 있어서 기존의 링, 스타, 데이지체인, 버스 등의 토폴로지 대신 이를 조합한 하이브리드 토폴로지가 제안되었다. 이는 일렬로 연결된 철도 차량을 적절한 수의 그룹으로 묶고 그룹 내에서는 스타 네트워크 토폴로지로 구성하고 그룹 간 연결은 데이지체인 네트워크 토폴로지로 구성하는 방식이다. 이를 통해 하이브리드 토폴로지는 스타 토폴로지에 비해 차량 간 연결에 필요한 케이블의 수를 절감하고도 적절한 전송 속도를 유지할 수 있다. 하이브리드 토폴로지는 스타와 데이지 체인 두 가지 토폴로지를 절충하는 방식이므로 각각의 장점을 잘 활용할 수 있도록 그룹 내 차량의 수를 적절히 선정하는 것이 중요하다. 본 논문에서는 철도차량에서 최적의 하이브리드 네트워크 토폴로지를 구하는 것을 목적으로 한다. 이를 위해 차량 별로 데이터 생성 크기와 생성 주기가 동일하다는 가정 하에 차량 간 연결에서의 최대 케이블 수와 전송 속도에 대하여 각각 가중치를 별도로 두고 가중치 별로 전체 차량 수에 따른 최적의 그룹 내 차량의 수를 도출한다.

• Steel and Composite Structures
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• 제21권6호
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• pp.1389-1410
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• 2016

This paper proposes a hybrid of topological derivative-based level set method (LSM) and isogeometric analysis (IGA) for structural topology optimization. In topology optimization a significant drawback of the conventional LSM is that it cannot create new holes in the design domain. In this study, the topological derivative approach is used to create new holes in appropriate places of the design domain, and alleviate the strong dependency of the optimal topology on the initial design. Furthermore, the values of the gradient vector in Hamilton-Jacobi equation in the conventional LSM are replaced with a Delta function. In the topology optimization procedure IGA based on Non-Uniform Rational B-Spline (NURBS) functions is utilized to overcome the drawbacks in the conventional finite element method (FEM) based topology optimization approaches. Several numerical examples are provided to confirm the computational efficiency and robustness of the proposed method in comparison with derivative-based LSM and FEM.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1311-1318
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• 2015

This paper introduces a novel topology and an effective control strategy for a shunt hybrid power filter (SHPF) to simultaneously compensate harmonic currents and reactive power. The proposed SHPF topology is composed of an LC passive filter tuned to the 7^th harmonic frequency and a small-rated active filter connected in parallel with the inductor L_pf of the LC passive filter. Together with the SHPF topology, we also propose a control strategy, which consists of a proportional-integral (PI) controller for DC-link voltage regulation and a PI plus repetitive current controller, in order to compensate both the harmonic current and the reactive power without the need for additional hardware. Thanks to the effectiveness of the proposed control scheme, the supply current is sufficiently compensated to be sinusoidal and in-phase with the supply voltage, regardless of the distorted and phase lagging of the load current. The effectiveness of the proposed SHPF topology and control strategy is verified by simulated and experimental results.

• 한국공간구조학회논문집
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• 제21권2호
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• pp.89-97
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• 2021

This paper describes an adaptive hybrid evolutionary firefly algorithm for a topology optimization of truss structures. The truss topology optimization problems begins with a ground structure which is composed of all possible nodes and members. The optimization process aims to find the optimum layout of the truss members. The hybrid metaheuristics are then used to minimize the objective functions subjected to static or dynamic constraints. Several numerical examples are examined for the validity of the present method. The performance results are compared with those of other metaheuristic algorithms.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.485-486
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• 2016

This paper proposes a new hybrid five-level voltage-source inverter topology, based on the conventional five-level active neutral-point-clamped topology (5L-ANPC), where the lower number of switching devices is required, resulting in saving the cost. The operating principle and control method of the proposed topology is described. The comparison of THD, power losses, loss distribution, and cost of components are evaluated among the proposed topology, the 5L-ANPC and 5L-DCI (diode-clamped inverters) topology.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권9호
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• pp.498-502
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• 1999

Harmonics and the reactive power related problems in the supply and demand side are increasing with the proliferation of nonlinear loads such as power converters in industrial applications. Filtering options such as passive, active and hybrid filters are countermeasures against these problems. In this study, a novel hybrid active filter topology with a new approach to enhance the system performance is presented. In this study, a novel hybrid active filter topology with a new approach to enhance the system performance is presented. The proposed topology comprised a parallel inverter and a hybrid active filter. It improves the system efficiency and reduces VA ratings, hence, overall filtering cost. The system operation, control and experimental verification on three phase rectifier and/or capacitor loads are presented.

• 전자공학회논문지
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• 제54권6호
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• pp.106-113
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• 2017

본 논문에서는 자율주행형 다관절 차량용 제어 시스템 구축 시 장치 간 네트워크로 이더넷 기반의 Train Communication Network(TCN)를 적용할 경우 적합한 네트워크 토폴로지를 제안하고 실험을 통하여 그 결과를 측정하여 검증한다. 케이블 수, 포트 수 등 구조적인 제한조건과 네트워크 응답시간, 최대 전송량 등 성능적인 제한조건을 고려하여 네트워크 토폴로지를 제안한다. 스타 토폴로지, 데이지체인 토폴로지, 그리고 이들을 절충한 하이브리드 토폴로지를 각각 적용하여 비교하며 본 논문에서는 특히 하이브리드 토폴로지의 적절한 구성을 위해 그룹으로 묶이는 노드 수를 구한다. 적절하게 노드의 그룹이 구성된 하이브리드 토폴로지는 본 논문에서 최적 토폴로지로 제안하는 구조이다. 먼저 시뮬레이션을 통해 각각의 토폴로지 구성 시의 네트워크 성능에 대한 예상치를 도출하며 이 후 실제 장치를 연결하여 네트워크를 구현한다. 다양한 네트워크 성능 측정 프로그램을 이용하여 각 토폴로지에서의 성능을 측정하고 비교를 통해 제안한 방안의 우수성을 기술한다.