• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.4
• /
• pp.465-471
• /
• 2014

This paper proposes a new switching algorithm for an active clamp snubber to improve the efficiency of a module integrated converter system. This system uses an active clamp method for the snubber circuit for the efficiency and reliability of the system. However, the active clamp snubber circuit has the disadvantage that system efficiency is decreased by switch operating time because of heat loss in resonance between the snubber capacitor and leakage inductance. To address this, this paper proposes a new switching algorithm. The proposed algorithm is a technique to reduce power consumption by reducing the resonance of the snubber switch operation time. Also, the snubber switch is operated at zero voltage switching by turning on the snubber switch before main switch turn-off. Simulation and experimental results are presented to show the validity of the proposed new active clamp control algorithm.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.9
• /
• pp.1209-1218
• /
• 1995

In this paper, we develope an ATM switch simulator in order to evaluate the HAN/B-ISDN ATM switch currently being developed by ETRI. It models the basic cell switching functions of the target ATM switch with priority control and multicasting features and it also supports such various traffic models as random or bursty traffic, balanced or unbalanced traffic, multicast traffic models. Using this simulator, we can evaluate the performances of the ATM switch in terms of various performance indices, i.e. cell delay, cell loss probability, etc., and this simulator can be utilized in the system parameter tunings such as the common buffer size and address buffer size.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.52 no.4
• /
• pp.205-211
• /
• 2003

In this paper we propose a disturbance design method to test a system's stability. It is shown that the time maximum disturbance is represented in bang-bang and state feedback form. To maximize the time severity index, the value of disturbance is determined by the associated switch curve. The original switch curve is vulnerable to model uncertainties and takes much calculation time. We propose an improved method to approximate the original switch curve. This reduces the computational time and implements sufficiently to test the stable system. Simulation results show how the approximate switch curve can be used to stress a system by driving it to oscillation along the maximum limit cycle.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.8
• /
• pp.1356-1361
• /
• 2008

A switched reluctance generator(SRG) has simple magnetic structure, and needs simple power electronic driving circuit. But, a SRG are no windings or permanent magnets on the rotor, and there are concentrated windings placed around each salient pole on the stator. Because of the characteristics of time-sharing excitation, the control of SRG is very flexible. And there are several parameters for controlling SRG, such as switch turn-on angle, switch turn-off angle, and exciting voltage and controlling mode, all these will affect the generation greatly. A SRG has positive torque at increasing inductance region and negative torque at decreasing inductance region. In this paper, we studied characteristics about the switch turn-on and off angles according to switch method for constant output voltage of the fixed speed SRG. It is the acoustic noise and torque ripple characteristics. Characteristics for a switch angle and method are presented by experiment using a 50W SRG with 12/8 poles.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.5
• /
• pp.57-64
• /
• 2015

This paper proposes a new switching algorithm for an controllable clamp snubber to improve the efficiency of a fly-back converter system. This system uses an controllable clamp method for the snubber circuit for the efficiency and reliability of the system. However, the active clamp snubber circuit has the disadvantage that system efficiency is decreased by switch operating time because of heat loss in resonance between the snubber capacitor and leakage inductance. To address this, this paper proposes a new switching algorithm. The proposed algorithm is a technique to reduce power consumption by reducing the resonance of the snubber switch operation time. Also, the snubber switch is operated at zero voltage switching by turning on the snubber switch before main switch turn-off. Experimental results are presented to show the validity of the proposed controllable clamp control algorithm.

• Annual Conference of KIPS
• /
• 2011.11a
• /
• pp.703-705
• /
• 2011

내부 네트워크의 IP관리를 위해 많은 네트워크 관리 방안 및 솔루션들이 기 구축되어 운영 중이고, 이를 위해 내부 네트워크에 연결된 모든 단말에 특정 Agent를 설치하여 IP를 관리하고 있어 단말(PC, IPT전화기 등)의 OS에 따른 기종별 Agent의 호환문제 및 단말에 기 설치 운영중인 응용프로그램과의 충돌문제가 발생한다. 본 연구에서는 이러한 네트워크 IP관리를 위해 Agent가 필요 없는 네트워크 관리 방식을 제안한다. 네트워크 Switch장비 Firmware의 포트차단 설정을 이용한 기법으로 Agent의 설치없이 Switch장비의 Firmware를 이용하여 네트워크의 접근제어가 가능함을 제안한다. 이를 위하여 인가되지 않은 IP를 Switch장비의 Firmware로 차단하여 네트워크의 접근제어가 가능함을 증명하였다.

• ETRI Journal
• /
• v.31 no.5
• /
• pp.593-597
• /
• 2009

In this paper, we present a spatial perturbation method to control the optical patterns in semiconductor microresonators in the far-field configuration. We propose a fast all-optical switch which operates at a low light level. The switching beam controls the behavior of output beams with strong intensities. The method has been applied successfully to different optical patterns such as rolls, squares, and hexagons.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1987.04a
• /
• pp.79-81
• /
• 1987

The traffic characteristicsof digitalswich network depend on the structure blocking probability, path searching method and etc. This paper presents the study of TDX-1 swicth network traffic capacity by considering some decisive factors such as call processing software, switch network structrure and control schme Conclusively the study shows that the switch network of TDX-1 can handle approximately up to 1650 Erlang.

• ETRI Journal
• /
• v.31 no.3
• /
• pp.298-303
• /
• 2009

A single-switch parallel resonant converter for induction heating is implemented. The circuit consists of an input LC-filter, a bridge rectifier, and a controlled power switch. The switch operates in soft commutation mode and serves as a high frequency generator. The output power is controlled via the switching frequency. A steady state analysis of the converter operation is presented. A closed-loop circuit model is also presented, and the experimental results are compared with the simulation results.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.265-268
• /
• 1998

This paper presents a soft-switching average current control PWM high power factor boost converter. Conventional boost ZVT-PWM converter has a disadvantage of hard-switching for auxiliary switch at turn-off. A soft switched auxiliary switch is proposed to achieve a high performance ZVT-PWM boost rectifier. The simulation and experimental results show that soft switching operation can be maintained for wide line and load range, which in turn improves the converter performance in terms of efficiency, switching noise and circuit reliability.