• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.2
• /
• pp.216-223
• /
• 1996

The active power factor control AC/DC converter needs a current loop compensator to obtain better dynamic characteristics and power factor performance, but the optimal design of a current loop compensator is difficult because the AC/DC converter is a nonlinear system having periodically varying poles and zeros. The predictive current control scheme generates a control input using the dynamic equations of the AC/DC converter so that the dynamic of the AC/DC converter is included in the controller and the necessary bandwidth and the gain characteristics of the current control loop are satisfied. And as a result, a compensator becomes unnecessary and the current loop shows the improved current loop characteristics. In this paper, a power factor controller without current loop compensator by adopting a predictive current control scheme is designed and the designed power factor controller is modelled by using a small signal perturbation modelling technique, and simulated to investigate its small signal characteristics. A 200 W power factor control AC/DC converter is built to verify the effectiveness of the proposed power factor controller.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.4
• /
• pp.334-341
• /
• 2011

This paper presents a design and implementation of DC/DC converter with very wide input voltage ranges for EPBS whose input voltage is from 30V to 400V and output voltage is 48V. This converter is comprised of two stages that one is for control and the other is for only galvanic isolation. The proposed converter uses the hard-switched buck-boost topology for control purpose and soft-switched LLC resonant converter for isolation. The proposed converter has been verified with 300W design.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.3
• /
• pp.373-379
• /
• 2019

Nowadays, the IoT portable electronic devices have become more useful and diverse, so they require various supply voltage levels to operate. This paper presents a DC-DC buck converter with pulse width modulation (PWM) for portable electronic devices. The proposed step-down DC-DC converter consists of passive elements such as capacitors, inductors, and resistors and an integrated chip (IC) for signal control to reduce power consumption and improves ripple voltage with the resolution. The proposed DC-DC converter is simulated and analyzed in PSPICE circuit design platform, and implemented on the prototype PCB board with a Texas Instruments LM5165 IC. The proposed buck converter is showed 92.6% of peak efficiency including a load current range of 4-10 mA, 3.29 mV of the voltage ripple at 5 V output voltage for the supply voltage 12 V. Measured and Simulated power efficiency are made good agreement with each other.

• Journal of Power Electronics
• /
• v.8 no.3
• /
• pp.201-209
• /
• 2008

This paper presents the modeling and design of a digital controller for a phase-shifted full-bridge converter (PSFBC) in a discrete-time domain. The discretized PSFBC model is first derived and then analyzed considering the sampling effect and the system parameters. Based on this model, the digital controller is directly designed in a discrete-time domain. The simulation and experimental results are provided to show the validity of the proposed modeling and controller design.

• Proceedings of the KIPE Conference
• /
• 2004.07b
• /
• pp.579-582
• /
• 2004

This paper presents controller design of a static var compensator using PWM Cuk AC-AC converter. The PWM Cuk AC-AC converter is modelled by using complex circuit DQ transformation and perturbed around the operating point whereby the small signal system characteristics is analytically obtained. Finally, the PSIM simulations show the validity of the modelling and analysis.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.350-354
• /
• 2004

This paper presents theoretical and practical details about the design, implementation, and performance of a series resonant do-to-dc converter using planar magnetics. Result of sinusoidal analysis are used to predict the voltage gain and conversion efficiency. The performance of a prototype converter is presented including the efficiency measurement and theoretical loss breakdown.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2002.05a
• /
• pp.177-181
• /
• 2002

In this paper, the design of 12bit pipeline BiCMOS A/D converter presented. A BiCMOS operational amplifier and comparator suitable for use in the pipeline A/D converter. The main features is low distortion track-and-hold with 0-300MHz input bandwidth, and a proprietary 12bit multi-stage quantizer.

• Proceedings of the IEEK Conference
• /
• 2000.11b
• /
• pp.164-167
• /
• 2000

This paper introduces the design of high-speed analog-to-digital converter for hard disk drive (HDD) read channel. This is based on autozero technique for low-error rate, and Double Speed Dual ADC(DSDA) technique lot efficiently increasing the conversion speed of A/D converter. This An is designed by 6bit resolution, 800M sample/s maximum conversion rate, 390㎽ power dissipation, one clock cycle latency in 0.65 $\mu\textrm{m}$ CMOS technology.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.37 no.6
• /
• pp.376-382
• /
• 1988

A small-signal low-frequency disturbance of the input line affects the regulated-output voltage of the series resonant converter. To mitigate the detrimental effect, the output feedback PI-controller is employed. Small-signal linear models are represented to characterize the closed loop series resonant converter system. Design equations for the PI-controller which satisfy stability and percent ripple conditions are derived from the closed-loop linear model. Experimental results are presented which show excellent correlation with theory.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.177-179
• /
• 2013

This paper presents an LED driver which requires a high voltage gain (5-6 times). To achieve a high voltage gain, the tapped-inductor boost converter topology was used and through the analysis of converter's steady-state and its dynamic characteristics, the product design's reliability and validity were verified.