A High-Efficiency Isolated-Type Three-Port Bidirectional DC/DC Converter for Photovoltaic Systems Yu-En Wu and Pin-Nan Chiu Department of Electronic Engineering, National Kaohsiung First University of Science and Technology,Taiwan

A High-Efficiency Isolated-Type Three-Port Bidirectional DC/DC Converter for Photovoltaic Systems Yu-En Wu * and Pin-Nan Chiu Department of Electronic Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung 824, Taiwan
 Abstract
This paper proposes a novel high-efficiency isolated three-port bidirectional DC/DC device for photovoltaic (PV) systems. The device contains a high step-up converter for PV modules to supply power to the DC bus, and a bidirectional charge/discharge control circuit for the battery with an improved boost-flyback converter. When the PV modules supply sufficient energy, their output can be stepped up and energy supply to the DC bus and charging of the battery can be achieved simultaneously. However, when the energy supplied is insufficient, the battery provides energy to the DC bus. When the proposed converter is operated in the step-down mode, the DC-blocking capacitor on the high-voltage side is used to reduce the voltage on the transformer and achieve high step-down performance. Moreover, to improve the overall efficiency of the system, the energy stored in the leakage inductance is recycled and supplied to the DC-blocking capacitor during operation in the step-up mode. Finally, to verify the feasibility and practicability of the proposed devices, a 500 W three-port bidirectional DC/DC devices was implemented. The highest efficiencies achieved for operation in different modes were as follows: high step-up mode for the PV modules, 95.2%; battery step-up mode, 94.2%; and step-down mode, 97.6%. View Full-Text Keywords: isolated type; three-port bidirectional converter; photovoltaic systems.
LINK ORIGINAL
http://www.mdpi.com/1996-1073/10/4/434

A PSR single-stage flyback LED driver with simple line regulation and quasi-resonant operation Nie Weidong(聂卫东) 1; 2; Ž, Yu Zongguang(于宗光) 1 , Wang Haibing(王海兵) 2 , Guo Bin(郭斌) 2 , Teng Long(滕龙) 2 , and Yang Lihang(杨力航) -Department of Electronic Engineering, Jiangnan University China

Abstract:
A single-stage flyback driving integrated circuit (IC) for light-emitting diodes (LEDs) is proposed. With an average primary-side current estimation and negative feedback networks, the driver operates in the boundary conduction mode (BCM), while the output current can be derived and regulated precisely. By means of a simple external resistor divider, a compensation voltage is produced on the ISEN pin during the turn-on period of the primary MOSFET to improve the line regulation performance. On the other hand, since the delay time between the time that the secondary diode current reaches zero and the turn-on time of the MOSFET can be automatically adjusted, the MOSFET can always turn on at the valley voltage even if the inductance of the primary winding varies with the output power, resulting in quasi-resonant switching for different primary inductances. The driving IC is fabricated in a Dongbu HiTek’s 0.35 m bipolar-CMOS-DMOS process. An 18 W LED driver is finally built and tested. Results show that the driver has an average efficiency larger than 86%, a power factor larger than 0.97, and works under the universal input voltage (85–265 V) with the LED current variation within 0.5%.

VIEW FULL TEXT
http://www.jos.ac.cn/bdtxben/ch/reader/create_pdf.aspx?file_no=13122603

LINK ALTERNATIVO
http://www.mediafire.com/file/85fyffk0jdxtehq/A_PSR_single-stage_flyback_LED_driver_with_simple_line_regulation.pdf

A Single-Stage High-Power-Factor Light-Emitting Diode (LED) Driver with Coupled Inductors for Streetlight Applications - Chun-An Cheng, Chien-Hsuan Chang, Hung-Liang Cheng , Ching-Hsien Tseng and Tsung-Yuan Chung-Department of Electrical Engineering, I-Shou University,TAIWAN

A Single-Stage High-Power-Factor Light-Emitting Diode (LED) Driver with Coupled Inductors for Streetlight Applications Chun-An Cheng, Chien-Hsuan Chang, Hung-Liang Cheng *, Ching-Hsien Tseng and Tsung-Yuan Chung Department of Electrical Engineering, I-Shou University, Dashu District, Kaohsiung City 84001, Taiwan;

Abstract: 
This paper presents and implements a single-stage high-power-factor light-emitting diode (LED) driver with coupled inductors, suitable for streetlight applications. The presented LED driver integrates an interleaved buck-boost power factor correction (PFC) converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power conversion circuit. Coupled inductors inside the interleaved buck-boost PFC converter sub-circuit are designed to operate in discontinuous conduction mode (DCM) for achieving input-current shaping, and the half-bridge-type series resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS) on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the presented driver features a high power factor, low total harmonic distortion (THD) of input current, and soft switching. Finally, a prototype driver is developed and implemented to supply a 165-W-rated LED streetlight module with utility-line input voltages ranging from 210 to 230 V.

View Full-Text :
http://www.mdpi.com/2076-3417/7/2/167/pdf

A Single-Stage LED Tube Lamp Driver with Power-Factor Corrections and Soft Switching for Energy-Saving Indoor Lighting Applications Chun-An Cheng Department of Electrical Engineering Taiwan

Abstract:
This paper presents a single-stage alternating current (AC)/direct current (DC) light-emitting diode (LED) tube lamp driver for energy-saving indoor lighting applications; this driver features power-factor corrections and soft switching, and also integrates a dual buck-boost converter with coupled inductors and a half-bridge series resonant converter cascaded with a bridge rectifier into a single-stage power-conversion topology. The features of the presented driver are high efficiency (>91%), satisfying power factor (PF > 0.96), low input-current total-harmonic distortion (THD < 10%), low output voltage ripple factor (switching (ZVS) obtained on both power switches. Operational principles are described in detail, and experimental results obtained from an 18W-rated LED tube lamp for T8/T10 fluorescent lamp replacements with input utility-line voltages ranging from 100 V to 120 V have demonstrated the functionality of the presented driver suitable for indoor lighting applications.

LINK ORIGINAL View Full-Text
http://www.mdpi.com/2076-3417/7/2/115/pdf

LED lighting control driver design and development of the 12V‐12W class using the voltage controlled ring oscillator - Ki-Soo Kwon Department of Electronic Engineering Graduate School Yeungnam University

LED lighting control driver design and development of the 12V‐12W class using the
voltage controlled ring oscillator

Ki-Soo Kwon
Department of Electronic Engineering
Graduate School
Yeungnam University


Abstract
This paper presents a Pulse Width Modulation (PWM) controller and circuits for the high power LED (Light Emitting Diode) driver. The controller is available for the remote control through four major operation modes of ON, OFF, Emergency and Power saving using the serial communication. The entire driver circuits use a DC‐DC converter such a Boost topology with dimming, current, thermal control and communication functions for hallway lighting and automobile applications. According to the type and power of LED, a driver IC has already been developed and is produced. This driver IC makes the constant current and constant voltage available. However, if the LED driver allows delicate dimming control and thermal dissipation through allowance of LED off time, PWM control is needed. Therefore, a MCU (Microcontroller unit) for the PWM control as well as a driver IC for driving LEDs is needed. If this operation is embedded at this driver IC, the expense can be reduced. The LED controller integrated circuit (IC) was designed, simulated and fabricated in 0.35μm Magnachip/Hynix.