scholarly journals Design a Single Stage AC to DC Converter for LED Driver With Power Factor Improvement

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3312-3318
Keyword(s):  
Power Factor ◽  
Low Voltage ◽  
Input Power ◽  
Boost Converter ◽  
Led Driver ◽  
Peak Voltage ◽  
Flyback Converter ◽  
Snubber Circuit ◽  
Driver Circuit ◽  
Dc Bus

This paper shows the design of a single switch LED driver circuit which is based on the operation of boost converter and flyback converter with power factor correction. In the proposed driver circuit, the boost converter is made to operate in DCM mode for achieving a high power factor and the flyback converter is used for isolating the input-output in order to provide safety. In addition to this, a snubber circuit is also designed for clamping the peak voltage of the main switch into low voltage and also to recycle the leakage inductor energy. A capacitor of low-voltage rating is made to function as the DC bus capacitor due to reason that some amount of the input power is conducted directly towards the output side; the amount of power remaining is then stored in the DC bus capacitor. In this way, the proposed LED driver circuit provides a power factor of greater value, i.e., above 0.95 PF and also a high value of power conversion efficiency, i.e., above 90%.

scholarly journals A Novel Single-Switch Single-Stage LED Driver with Power Factor Correction and Current Balancing Capability

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1340
Author(s):  
Yih-Her Yan ◽  
Hung-Liang Cheng ◽  
Chun-An Cheng ◽  
Yong-Nong Chang ◽  
Zong-Xun Wu
Keyword(s):  
Power Factor ◽  
High Power ◽  
Pulse Width Modulation ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
Boost Converter ◽  
Single Stage ◽  
Led Driver ◽  
Flyback Converter ◽  
High Power Factor

A novel single-switch single-stage high power factor LED driver is proposed by integrating a flyback converter, a buck–boost converter and a current balance circuit. Only an active switch and a corresponding control circuit are used. The LED power can be adjusted by the control scheme of pulse–width modulation (PWM). The flyback converter performs the function of power factor correction (PFC), which is operated at discontinuous-current mode (DCM) to achieve unity power factor and low total current harmonic distortion (THDi). The buck–boost converter regulates the dc-link voltage to obtain smooth dc voltage for the LED. The current–balance circuit applies the principle of ampere-second balance of capacitors to obtain equal current in each LED string. The steady-state analyses for different operation modes is provided, and the mathematical equations for designing component parameters are conducted. Finally, a 90-W prototype circuit with three LED strings was built and tested. Experimental results show that the current in each LED string is indeed consistent. High power factor and low THDi can be achieved. LED power is regulated from 100% to 25% rated power. Satisfactory performance has proved the feasibility of this circuit.

A Single-Switch HPF AC-to-DC Converter with Low Voltage Ripple

2013 ◽  
Vol 284-287 ◽  
pp. 2445-2449
Author(s):  
Hung Liang Cheng ◽  
Chien Hsuan Chang ◽  
Chun An Cheng ◽  
En Chih Chang ◽  
Li Ren Yu
Keyword(s):  
Power Factor ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Boost Converter ◽  
Flyback Converter ◽  
Switching Losses ◽  
Voltage Ripple ◽  
Sinusoidal Waveform ◽  
Conduction Mode

This paper proposed a single-stage single-switch ac-to-dc converter which is derived by integrating a boost converter and a flyback converter. Only one active switch and simple control are required. The boost converter performs as a power-factor corrector (PFC) which is designed to operate at discontinue-conduction mode (DCM) to makes the input current be a sinusoidal waveform and in phase with the input voltage. High power factor and low total current harmonic distortion (THD) are ensured. The flyback converter further regulates the output voltage of the boost converter to provide an isolated dc voltage with low voltage ripple. The flyback converter is designed to operate at continue-conduction mode (CCM) to have the transformer current of a low peak value. It will be effectively reduce the switching stress and the switching losses of semiconductor components. The paper conducts the mathematical equations for the converter circuits, and then designing the circuit parameters. A prototype circuit designed for a 100 W output power was built and tested. Satisfactory results are obtained experimentally.

scholarly journals Dimmable High Power LED Driver Using Fuzzy Logic Controller

2021 ◽  
Vol 5 (2) ◽  
pp. 45
Author(s):  
Rizky Fatur Rochman ◽  
Eka Prasetyono ◽  
Rachma Prilian Eviningsih
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Constant Current ◽  
Led Driver ◽  
Flyback Converter ◽  
Compact Size ◽  
Wide Range ◽  
Driver Circuit ◽  
Converter Topology ◽  
Lighting Loads

The use of lighting loads is one of the crucial matters which increases every year. The increasing use then leads to the development of brighter and longer-lasting sources. In addition, the conventional use of lighting loads today, which only emit light at its maximum intensity, does not allow the consumers to adjust the brightness level as needed. Consequently, this condition may cause energy wastage. The LED lighting system is gaining popularity as it is widely used in a wide range of applications. The advantages of LEDs, such as its compact size and varied lamp colors, replace conventional lighting sources. The linear setting of the driver topology using the flyback converter was aimed to control the LEDs with a constant current in order to adjust the variation of the LED light intensity. The closed-loop driver circuit with flyback converter topology was designed as an LED driver with a given load specification from the LED string. A dimmable feature was included for adjusting the intensity of the light produced by the LEDs. Eventually, the fuzzy logic controller (FLC) method was applied to the integrated change setting to obtain a dynamic response.

Design and Simulation of PFC Converter for Brushless SRM Drive

2016 ◽  
Vol 7 (3) ◽  
pp. 625 ◽  
Author(s):  
M. Rama Subbamma ◽  
V. Madhusudhan ◽  
K.S.R Anjaneyulu
Keyword(s):  
Power Factor ◽  
High Efficiency ◽  
Industrial Applications ◽  
Input Power ◽  
Boost Converter ◽  
Air Conditioner ◽  
Switched Reluctance ◽  
Reluctance Motor ◽  
Bridge Rectifier ◽  
Speed Response

In most of the industrial applications, Switched Reluctance Motor (SRM) is mainly employed due to the reasons like having low maintenance and high efficiency. SRM consists of windings only on its stator, but would not have any windings on rotor thus having very simple construction. The available supply is AC. But AC cannot be directly supplied to SRM when used for air-conditioner application which is employed in this paper. Also power factor in the system needs to be corrected when using a SRM drive. Thus AC supply is fed to power factor correction (PFC) converter which is Buck-Boost converter here in this paper. The output of the PFC converter is fed to SRM through a simple asymmetrical converter. This PFC circuit consists of a simple diode bridge rectifier with Buck-Boost DC-DC converter. A suitable control circuit was proposed to control the input power factor under various loading conditions. This paper gives analysis of SRM drive for air-conditioner application with Buck-Boost converter based PFC circuit. A Matlab/simulink based model is developed and simulation results are presented. Simulation is carried out for different speed response.

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