• 한국정보과학회논문지:시스템및이론
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• 제27권3호
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• pp.287-299
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• 2000

본 논문에서는 양방향 토러스 네트워크와 웜홀 라우팅을 사용하는 다중컴퓨터에 대해 멀티캐스트 통신방법을 트리방식, 경로방식, 그리고 두 방식을 조합한 하이브리드방식으로 분류하였다. 경로방식으로는 동적분할 멀티캐스트 라우팅 알고리즘을 제안하였으며, 하이브리드방식으로는 라우팅의 첫 단계로 트리방식을 사용하고 두 번째 단계로는 경로방식을 사용하는 멀티캐스트 라우팅 알고리즘을 제안하여 성능을 분석하였다. 세가지 멀티캐스트 라우팅 알고리즘간의 성능은 메세지 길이에 따른 평균 지연시간을 사용하여 비교하였다. 그리고 웜홀 라우팅에서 플릿 버퍼 크기의 변화에 따른 성능을 가상 컷-스루와 비교 하였으며, 경로방식의 알고리즘을 사용하여 버퍼 크기의 변화에 따른 지연시간을 기준으로 두 스위칭 방식의 성능관계를 분석하였다.

• Journal of Power Electronics
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• 제17권1호
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• pp.96-105
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• 2017

In this paper, a hybrid modular multilevel converter (MMC) topology with an improved nearest level modulation method is proposed for medium-voltage high-power applications. The arm of the proposed topology contains N series connected half-bridge submodules (HBSMs), one full-bridge submodule (FBSM) and an inductor. By exploiting the FBSM, half-level voltages are obtained in the arm voltages. Therefore, an output voltage with a 2N+1 level number can be generated. Moreover, the total level number of the inserted submodules (SMs) is a constant. Thus, there is no pulse voltage across the arm inductors, and the SM capacitor voltage is rated. With the proposed voltage balancing method, the capacitor voltage of the HBSM is twice the voltage of the FBSM, and each IGBT of the FBSM has a relatively low switching frequency and an equalized conduction loss. The capacitor voltage balancing methods of the two kinds of SMs are implemented independently. As a result, the switching frequency of the HBSM is not increased compared to the conventional MMC. In addition, according to a theoretical calculation of the total harmonic distortion of the electromotive force (EMF), the voltage quality with the presented method can be significantly enhanced when the SM number is relatively small. Simulation and experimental results obtained with a MMC-based inverter verify the validity of the developed method.

• Journal of Power Electronics
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• 제19권1호
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• pp.158-167
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• 2019

This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1986년도 추계학술발표회 논문집
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• pp.64-67
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• 1986

• 대한전기학회논문지
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• 제45권2호
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• pp.230-234
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• 1996

A new trenched Hybrid Schottky INjection Field Effect Transistor (HSINFET) is proposed and verified by 2-D semiconductor device simulation. The feature of the proposed structure is that the hybrid Schottky injector is implemented at the trench sidewall and p-n junction injector at the upper sidewall and bottom of a trench. Two-dimensional simulation has been performed to compare the new HSINFET with the SINFET, conventional HSINFET and lateral insulated gate bipolar transistor(LIGBT). The numerical results shows that the current handling capability of the proposed HSINFET is significantly increased without sacrificing turn-off characteristics. The proposed HSINFET exhibits higher latch-up current density and much faster switching speed than the lateral IGBT. The forward voltage drop of the proposed HSINFET is 0.4 V lower than that of the conventional HSINFET and the turn-off time of the trenched HSINFET is much smaller than that of LIGBT.

• International Journal of Control, Automation, and Systems
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• 제4권4호
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• pp.428-437
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• 2006

Many physical systems are hybrid in the sense that they have continuous behaviors and discrete phenomena. In control system with multiple models, switching strategy and stability of the closed-loop system under switching are very important issues. In this paper, a novel adaptive control scheme based on multiple parameter models is proposed to cope with a change in Parameters. Switching strategy guarantees the non-increase in the global control Lyapunov function if the estimation of Lyapunov function value converges. Least-square estimation is used to find the estimated value of the Lyapunov function. Switching and adaptation law guarantees the stability of closed-loop system in the sense of Lyapunov. Simulation results on anti-lock brake system are shown to verify the effectiveness of the proposed controller in view of a large change in system parameters.

• Journal of Power Electronics
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• 제10권6호
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• pp.784-791
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• 2010

In this paper, a resonant pulse power converter (RPPC) is proposed. The proposed RPPC transfers the pulse-shape power from a DC source to a load periodically. The RPPC consists of a resonant circuit and a resonant pulse converter driven by a self-switching circuit. Depending on the magnitude difference between the input and output voltages, the operations of the RPPC are divided into 4 modes; boost mode, hybrid mode, direct mode and cut-off mode, respectively. The main switch of the RPPC turns on in the ZCS condition and off in the ZVS condition spontaneously. The operational principles of a RPPC using the self-switching technique are analyzed and verified in experiments. An example of a RPPC application is demonstrated in the area of thermoelectric energy harvesting.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.818-819
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• 2011

본 논문은 가변자속 기능을 가지는 Flux Switching Permanent Magnet (FSPM) 전동기의 전 자기적 등가회로를 이용한 특성해석방법을 다룬다. 우선 가변자속 기능을 갖는 FSPM 전동기의 구조와 동작원리를 설명하였다. 다음으로 오버행을 고려한 2-D유한요소 해석 모델을 이용하여 역기전력, 인덕턴스를 구하였다. 마지막으로 등가회로 해석을 통해 가변자속 운전 시 FSPM 전동기의 특성해석을 실시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.514-518
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• 1988

The switching system and transport will be developed and serve as hybrid switching system and link respectively according to the needs of mixed voice and data service in ISDN era. This paper describes a theory of optimal band width allocation in multiplexing voice and nonvoice traffic, and analyzes traffic performances on a model network.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.193-196
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• 1996

A pneumatic cylinder has been used in the production facilities of various industries. However, it is difficult to achieve deciding the precise position of the piston rod, due to the nonlinear properties arising from the air compression and the friction. In recent years, the fuzzy control algorithm has been frequently applied to various kinds of systems on account of its simple algorithm, good adaptability to complex or nonlinear systems and so on. On the other hand, the PID or I-PD control has been used in many engineering fields because of the excellent performance. However, it is known that each one of them has disadvantages. In this paper, we propose a hybrid control which is strived to obtain the advantages of each other. It is shown that the proposed hybrid control performs better than the conventional I-PD control through the experimental results.