• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1001_1002
• /
• 2009

본 논문은 태양광 PCS 발전 시스템을 위한 3KW 3상 인터리브드 부스트 컨버터의 동작과 제작을 위한 기반사항에 대해 서술하였으며, 컨버터의 희망 출력전압을 얻기 위한 제어부의 구성과 비례전류제어를 사용한 동작알고리즘을 포함해 실제 PCB 제작을 위해 선정한 부품 및 배치의 구성에 대해 다루었다. 제어부는 아날로그가 아닌 디지털 제어를 채택하여 컨버터 각 부의 센서를 통해 전류, 전압 값을 취득하고, 이를 DSP에서 처리하여, 기준값과 피드백 값과의 오차 보상을 위한 PWM 신호를 생성, 컨버터를 동작시킨다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1998.11a
• /
• pp.120-124
• /
• 1998

In this paper, new zero voltage and zero current switched PWM(Pulse Width Modulated) converters are suggested. The main and auxiliary switch of the converters satisfy soft switching conditions, which are zero voltage or zero current switching of the switches. The switching characteristics of the proposed converters are experimentally verified by boost typed converter, which has 250 kHz switching frequency. For the 250 kHz operation, turn on period of auxiliary switch is about 1/40 for switching period of 4 ${\mu}\textrm{s}$. Therefore, the conduction loss of auxiliary switch is reduced.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.1
• /
• pp.45-53
• /
• 2013

Fuel cell power system is one of the most promising energy source for the alternative energy because it has unique advantages such as high energy density, no power drop during operation, and feasible to make compact size. However, due to very low response time, fuel cell is difficult to correspond to drastic load changes and start-up operation. For solving these problem, fuel cell power system must include energy storage device such as Li-Poly battery or super capacitor. Therefore, bi-directional DC-DC converter must be required for this storage device and fuel cell-PCS control. This paper presents a design and modeling of the bi-directional DC/DC converter. Firstly, we present modeling the boost and buck mode of the bi-directional converter through both PWM switch model and state space averaging technique. Secondly, in order to minimize output ripple and transient response overshoot, we have two identical DC-DC converters interleaved and adopt two-loop voltage-current controller. The proposed bi-directional DC-DC converter's modeling method and control design have been verified with computer simulation and experimentation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.6
• /
• pp.57-65
• /
• 2007

This paper presents the design of single phase PFC(Power Factor Correction) using a DSP(TMS320F2812). In order to realize the proposed boost PFC converter in average current mode control, the DSP requires the A/D sampling values for a line input voltage, a inductor current, and the output voltage of the converter. Because of a FET switching noise, these sampling values contain a high frequency noise and switching ripple. The solution of A/D sampling keeps away from the switching point. Because the PWM duty is changed from 5% to 95%, we can#t decide a fixed sampling time. In this paper, the three A/D converters of the DSP are started using the prediction algorithm for the FET ON/OFF time at every sampling cycle(40 KHz). Implemented A/D sampling algorithm with only one timer of the DSP is very simple and gives the autostart of these A/D converters. From the experimental result, it was shown that the power factor was about 0.99 at wide input voltage, and the output ripple voltage was smaller than 5 Vpp at 80 Vdc output. Finally the parameters and gains of PI controllers are controlled by serial communication with Windows Xp based PC. Also it was shown that the implemented PFC converter can achieve the feasibility and the usefulness.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.4
• /
• pp.21-28
• /
• 2006

In this paper, the proposed full-bridge high frequency isolated zoo voltage and zero current switching phase shifted pulse width modulation(ZVZCS PS-PWM)DC-DC converter among fuel cell generation system consist of 1.2[kW] fuel cell of Nexa Power Module, full-bridge DC-DC converter to boost the fuel cell low voltage($28{\sim}43[%]$) to 380[VDC] and a single phase full-bridge inverter is implemented to produce AC output(220[VAC], 60[Hz]). A tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed full-bridge high frequency isolated ZVZCS PS-PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of $93{\sim}97[%]$ is obtained over the wide output voltage regulation ranges and load variations.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.11 no.3
• /
• pp.201-208
• /
• 2006

An alternative to the nuclear and fossil fuel power is renewable energy technologies (hydro, wind, solar and ocean), and the research about the highest efficiency machinery have been processed. The high-power LED is the representative one among those. In this paper, a high efficiency lighting system using a battery charged with solar or wind power is proposed for a high power LED. And a new efficient converter called 'Back-boost' is proposed. The validity of the lighting system scheme is verified by experimental results based on a laboratory prototype.

• Journal of Power Electronics
• /
• v.10 no.2
• /
• pp.132-137
• /
• 2010

Interleaving techniques are widely used to reduce input/output ripples and to increase the power capacity of boost converters operating in critical conduction mode. Two types of phase-shift control schemes are studied in this paper, the turn-on time shifting method and the turn-off time shifting method. It is found that although the turn-off time shifting method exhibits better performance, it suffers from sub-harmonic oscillations at high input voltages. To solve this problem, an intensive quantitative analysis of the sub-harmonic oscillation phenomenon is made in this paper. Based upon that, a novel modified turn off time shifting control scheme for interleaved boost converters operating in critical conduction mode is proposed. An important advantage of this scheme is that both the master phase and the slave phase can operate stably in critical conduction mode without any oscillations in the full input voltage range. This method is implemented with a FPGA based digital PWM control platform, and tests were carried out on a two-phase interleaved boost PFC converter prototype. Experimental results demonstrated the feasibility and performance of the proposed phase-shift control scheme.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.6
• /
• pp.29-36
• /
• 2015

This paper presents an LED backlight driver IC consisting of three linear current regulators and an output-voltage regulation loop with a self-adjustable reference voltage. In the proposed LED driver, the output voltage is controlled by dual feedback loops. The first loop senses and controls the output voltage, and the second loop senses the voltage drop of the linear current regulator and adjusts the reference voltage. With these feedback loops, the voltage drop of the linear current regulator is maintained at a minimum value, at which the driver efficiency is maximized. The output of the driver is a three-channel LED setup with four LEDs in each channel. The luminance is adjusted by the PWM dimming signal. The proposed driver is designed by a $0.35-{\mu}m$ 60-V high-voltage process, resulting in an experimental maximum efficiency of approximately 85%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.1
• /
• pp.51-58
• /
• 2001

Recently, DC-DC converters significantly increase the total losses as rising switching frequency. Trnditional soft switching technique for reducing switching losses even increase voltage/Clment stress of switch In this paper, Resonant circuit for soft switching is connected in parallel with power stage and only operates just before tum-on of the main sWItch. Therefore, ills doesn't affect the total circuit QI'||'&'||'pound;ration. The object of tIns paper is to make the linearized equivalent loss mxleIs. and to analyze the total losses by experiment. ZVT-PWlvI converter designed with 170-260[V] input, 400[V] 5[A] output, and 100[kHz] switching frequency is tested respectively with 500[W], 1[kW], 1.5[kW], and 2[kW] loads. The total losses in input 220[V], 2[kW] load are analyzed by usirm the linearized equivalent loss models.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.385-388
• /
• 2001

In this paper, the gearless traction machine drive system using a permanent-maget motor for high-speed elevators is addressed. This application of permanent-magnet motor to the elevator traction machine enables several improvements including higher efficiency, better ride comfort, smaller size and weight, and so on. PWM boost converter is also adopted so that DC-link voltage regulation, hi-directional power flow, and controllable power factor with reduced input current harmonics are possible. To increase reliability and performance, the control board, which can include the car and group controller as well as PWM converter and inverter controller, is designed based on TMS320VC33 DSP The simulator system for high-speed elevators has been developed so that the drive system of high-speed elevator can be tested without my limitation on ride distance and the load condition. Some experimental results are given to verify the effectiveness of the developed system.