• Journal of Korea Society of Industrial Information Systems
• /
• v.18 no.5
• /
• pp.81-92
• /
• 2013

The satellite includes many release mechanisms such as solar array deployment, antenna deployment, cover to protect contamination in scientific equipment, pyro value of the propulsion subsytem, and bypass device in Li-Ion cell module. A drive the initiators is a critical to the successful mission because the initiators of release mechanism driving by the pyrotechnic circuit is operated in single short. The pyrotechnic circuit has to provide switching network for safety. A typical switching network has defect consisting of high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit is required some form of power conditioning to reduce the peak power demanded from the bus if the initiators are to be fired from the main bus. This paper design a pyrotechnic circuit synchronized to the fire-command to activate the fire switch to overcome use high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit provides a current limited widow pulse for fire current synchronized to the fire-command to insure that fire switch will only carry the current but never switch it. The current limited widow pulse for fire current can be possible to use low current rating and light mass switch in switching network. The current limit function in the pyrotechnic circuit reduces supply voltage to initiator and provides the effect of power conditioning function to reduce peak bus power. The pyrotechnic circuit to apply satellite development on geostationary orbit is verified the function by test in development model.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.2
• /
• pp.143-148
• /
• 2014

Conventional wireless power transfer methods based on coupled magnetic fields need a complex winding structure on the surface of the energy transfer and shows poor efficiency near metal objects due to the eddy current effect. In this study, to mitigate these problems, we investigate an electric field-coupled power transmission system, which is less prone to metal object problems and EMI. Because of the fundamental physical limit in the size of link capacitances, a half-bridge converter with an impedance matching transformer is proposed and the design procedure is derived to provide a soft-switching scheme. Hardware implementation shows that the proposed scheme with a pair of 10cm by 10cm copper plate can power a 1.4W USB FAN in a separation of 0.2mm by using insulating paper when driven by 227 kHz gate pulse.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.1
• /
• pp.57-63
• /
• 2012

In this paper, a switch sizing method is proposed in order to prevent the cross-regulation in the TM type SIDO DC-DC buck converter. In TM type SIDO DC-DC buck converter, a DCM operation is required. In the DCM operation, the inductor peak current is larger than that in the CCM. Because of the larger inductor peak current and the added switch resistance, the voltage drop is increased, resulting in possible cross-regulation. To solve this problem, the switch resistance must be considered in sizing the switch. To simplify the calculation of the resistance, the inductor current was replaced by the average load current. Using the proposed method, TM type SIDO DC-DC buck converter for camera module was designed to provide two independent supply voltage(2.8 V and 1.8 V). The designed circuit was fabricated in a standard $0.35{\mu}m$ CMOS process. At a switching frequency of 1 MHz and a load current of 200 mA, a power effciency of 80.7% was achieved.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.513-514
• /
• 2016

본 논문에서는 스위칭 셀 구조의 직접형 PWM ac-ac 컨버터를 이용한 새로운 단상 무효전력 보상 장치를 제안한다. 제안한 보상기는 최근에 개발된 가변 임피던스 개념을 이용한 무효전력 보상기에서 발전된 형태이다. 기존 보상기에는 시스템 신뢰성에 심각한 악영향을 주는 커뮤테이션 문제가 존재하는데 제안한 보상기에서는 스위칭셀 구조와 결합인덕터로 구성된 ac-ac 컨버터를 사용하여서 커뮤테이션 문제를 해결하였다. 이로인해 기존 시스템에 비해 스위칭 신호 구현이 매우 간편하고 RC 스너버가 필요하지 않으며 결과적으로 매우 신뢰성이 높은 시스템을 구현할 수 있다. 간략화 된 단상시스템을 구축하여 실험을 통해 성능을 검증하였다.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.259-261
• /
• 1996

In this paper, active input filter for power factor correction(PFC) circuit employing ripple arrent and voltage cancellation is proposed to reduce filter's size and cost, and to make filter design easy. Switching ripple current and voltage can be sensed through the secondary windings of filter inductor. Single stage passive filter can achieve high order filter characteristics by using active ripple current and voltage cancellation technique. Conventional high order passive filter and its problems are suggested. Analysis of active filter and design procedure are detailed. Simulation result is presented to verify high order filter characteristics of proposed scheme.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.56 no.2
• /
• pp.90-98
• /
• 2007

More and All-Electric Aircraft (AEA) carry many loads with varied functions. In particular, there may be large pulsed loads with short duty ratio, which can affect the normal operation of other loads. In this paper, a bi-directional converter with inductive storage is used as a voltage bus conditioner (VBC) to mitigate voltage transients on the bus. In addition, the constant frequency hysteresis control technique for a VBC is presented. A simple and fast prediction of the hysteresis band-width is implemented by the phase-lock loop control, keeping constant switching frequency. This technique offers the excellent dynamic response in load or parameter variation. The control performance is illustrated by simulated results with the SABER package, The proposed hysteresis control results in the shortest and the smallest excursions.

• Journal of Power Electronics
• /
• v.1 no.1
• /
• pp.26-35
• /
• 2001

In most inverter/converter applications SVPWM method is a preferred approach since it shows good characteristics in linear modulation range and waveform quality. In this paper, we propose a new carrier based SVPWM method for multi-level system, First, we survey the conventional carrier based SVPWM method, and investigate the problem of the conventional one for the multi-level system with the focus on the switching frequency harmonic flux trajectories. Finally, we propose a new carrier based SVPWM method that can reduce harmonic distortion. Simulation and experimental results are given for verification of the proposed SVPWM method.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.2 no.3
• /
• pp.1-10
• /
• 1997

3-레벨 ZVS PWM DC/DC 컨버터는 풀브리지 ZVS PWM DC/DC 컨버터와 같은 동작 특성을 가지면서 입력전압의 반을 스위칭 소자의 차단전압으로 갖기 때문에 높은 입력을 갖는 DC-DC 변환시스템에 적합한 구조라 할 것이다. 그러나 부유 인덕턴스의 영향으로 인한 내외측 소자간의 차단전압 불균형의 문제와 경부하에서 영전압 스위칭 동작을 하지 못하므로 부하범위가 작다는 문제점을 가지고 있다. 이와 같은 문제점들은 시스템의 신뢰도를 낮추며, 경부하로 갈수록 효율을 떨어뜨리게 된다. 철도 차량과 같은 고압, 대용량의 시스템에서 이러한 문제들은 더욱 두드러 진다. 본 논문에서는 내외측 소자간의 차단전압 불균형의 문제를 없애며, 무부하에서 전부하까지 모든 부하 영역에서 영전압 스위칭 동작을 할 수 있는 새로운 3-레벨 ZVS PWM DC/DC 컨버터를 제시한다. 제안한 회로의 동작 특성과 타당성을 시뮬레이션 및 실험 결과를 통하여 입증한다.

• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.100-102
• /
• 2007

본 논문에서는 태양광발전용 소프트 스위칭 부스트 컨버터를 제안하였다. 900W급 어레이 태양전지를 사용하였고, 제안된 컨버터가 최대 전력점에서 발전을 하도록 P&O방식의 MPPT 알고리즘을 적용하였다.[1] 제안된 컨버터의 스위칭 소자 시비율은 MPPT 알고리즘의 수행결과에 따라 제어되며, 그 결과 컨버터에서 태양전지 출력전압(132~260V)을 입력받아 380Vdc로 승압한다. 소프트웨어를 활용하여 태양전지 구성과 MPPT 알고리즘 구현하였고 제안된 컨버터를 시뮬레이션 하였다.

• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.118-120
• /
• 2007

일반적인 AC/DC변환 장치는 안정화된 직류 전원을 얻기 위해 대용량의 커패시터와 고속의 전력용 반도체 스위칭 소자를 사용한다. 하지만, 이러한 소자의 사용으로 인해 입력측의 고조파 손실 및 역률 저하의 문제점을 갖게 되고 고속 스위칭에 따른 스위칭 손실에 의한 효율이 저하되는 문제점을 갖게 된다. 따라서 본 논문에서는 역률개선이 가능하고 스위칭 손실이 저감되는 ZVS 방식을 이용한 새로운 형태의 역률개선용 소프트스위칭 방식의 부스트 컨버터를 제안한다.