• Journal of Power Electronics
• /
• v.15 no.2
• /
• pp.319-326
• /
• 2015

In this paper, a cost-effective single switch multi-channel LED (light emitting diode) driver is proposed. While conventional LED drivers require as many non-isolated DC/DC converters as the number of LED channels, the proposed LED driver needs only one power switch and several balancing capacitors instead of expensive non-isolated DC/DC converters. Therefore, the proposed driver features a simpler structure, with a lower cost and a higher efficiency. Because its power switch can be turned off under the zero current switching condition, it has very desirable advantages such as improved electromagnetic interference characteristics and high efficiency. Moreover, it uses only a small number of DC blocking capacitors with no additional active devices for the current balancing of multi-channel LEDs. As a result, the proposed driver exhibits high reliability and is cost effective. To confirm the validity of the proposed driver, a theoretical analysis is performed, and design considerations and experimental results obtained from a prototype that is applicable to a 46" LED-TV are presented.

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.147-149
• /
• 1998

In this paper, zero voltage switched half bridge converter and an active-clamped, zero voltage switched forward converter equipped with self-driven synchronous rectifier is designed and investigated for high efficiency BC-DC converter. A synchronous rectifier is has a lower conduction power loss than shottky diode rectifier. The purpose of this paper is to investigate the effect of parasitic inductance in a synchronous rectifier of DC-DC converters and examine overall efficiency of zero voltage switched DC-DC converters.

• Proceedings of the KIPE Conference
• /
• 2016.11a
• /
• pp.61-62
• /
• 2016

It is the general trend that AC/DC power system topologies with various sources and loads. To control the AC/DC power system, different kind of control system are needed. This paper discusses the parallel operation of single-phase AC/DC converters using a proportional integral (PI) controller and a proportional resonant (PR) controller. The performance of PI and PR controller have been evaluated by simulation.

• Journal of Power Electronics
• /
• v.17 no.4
• /
• pp.1071-1087
• /
• 2017

This paper introduces a DC/AC converter, which can be connected in parallel with a diode rectifier for regenerative applications. The DC/AC converter is supposed to transmit regenerative energy to the power grid when a motor is braking. Isolation transformers are not needed in the topology, which can reduce the size and cost. An analysis of the zero-order current existing in the system is carried out. In addition, algorithms to minimize the zero-order current, control the power factor and keep the DC bus voltage stable are discussed. A 55kW industrial prototype is built to verify the proposed analysis and control strategies.

• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.370-371
• /
• 2011

This paper presents a control algorithm that minimizes the DC-link capacitance by decreasing the capacitor current. The capacitor current can be nullified by a feedback compensation term which is calculated from the power balance in the AC/DC converter. As a result, voltage variation in the DC-link is reduced further, which makes a large reduction in the size of DC-link capacitors which are expensive and have limitations in life time. Simulations are performed with two 80uF DC-link capacitors, which can be replaced by film capacitors.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.2 s.19
• /
• pp.45-48
• /
• 2007

The proposed method offers an improved DC/DC converter scheme to increase power density. It is based on half-bridge topology with newly introduced pulse-grouping control method, which helps to reduce the transformer size and the volume of semiconductor devices maintaining high efficiency. Test results with 85W(18.5V/4.6A) design shows that the measured efficiency is 93.5% with power density of $36W/in^3$.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.407-408
• /
• 2013

본 논문은 주파수 제어를 통한 인터리브드 DC-DC 컨버터의 입력 전류 리플 최소화 알고리즘을 제안한다. 제안하는 알고리즘은 시스템을 전류 불연속 모드에서 0.33 또는 0.67의 고정 듀티로 제어하여 입력전류 리플을 저감한다. 제안한 알고리즘을 3상 부스트 컨버터에 적용하고 그 타당성을 실험 및 시뮬레이션을 통해 검증한다.

• Proceedings of the KIPE Conference
• /
• 2019.11a
• /
• pp.138-139
• /
• 2019

본 논문은 입력 필터를 갖는 풀브리지 기반의 ISOP 모듈러 DC-DC 컨버터에서 각 모듈 간에 동일전력 분담을 위한 디커플링 제어기법을 제안한다. 이 제어기법은 PSIM 시뮬레이션을 통해 타당성이 검증되었다.

• Proceedings of the KIEE Conference
• /
• 1987.07a
• /
• pp.824-827
• /
• 1987

The miniturization of a DC-DC converter circuit in connection with the stability is investigated in this paper. As both the capacitance of the smoothing capacitor and the inductance of the reactor are reduced by raising the switching frequency, it is known that the stability of the buck converter declines with the switching frequency but the buck-boost converter has a nearly uniform stability. Furthermore, that in the frequency region above a certain switching frequency the buck-boost converter is suitable for the miniturization of circuit is cleared.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.227-228
• /
• 2017

본 논문에서는 모듈라 ESS에 사용되는 인터리브드 DC-DC 컨버터의 평균 모델을 이용하여 제어 시스템을 설계함으로써 기존 소신호 모델 기반 제어의 동작점이 변동하는 경우 과도 응답 특성이 저하되는 단점을 개선하고자 한다. 또한, PSIM 시뮬레이션과 실험을 통해 제시된 설계방법의 우수성을 실증하고자 한다.