Analysis of LED Driver Topologies with Respect to Power Factor and THD

2018 ◽  
pp. 63-68 ◽  
Author(s):  
Aniruddha Mukherjee ◽  
Trilok Chandra Bansal ◽  
Amit Soni
Keyword(s):  
Power Factor ◽  
Light Output ◽  
Input Power ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Led Driver ◽  
Additional Heat ◽  
Excessive Heat ◽  
Current Input ◽  
The Impact

Light Emitting Diodes (LEDs) are fast replacing incandescent lamps and CFLs in most of the developing nations. The reason can be attributed mainly to the enhanced lifetime and less energy consumption as compared to the other mentioned types. However one important aspect needs attention, the impact of driver on LEDs. LEDs are current controlled devices and hence emit maximum light with increase in current input to the device. This feature, boost up the light output but it increases the junction temperature of the device. Hence additional heat sinks are required to vent out the excessive heat generated due to increase current input to the LEDs. Those additional heat sinks are at times difficult to accommodate. So, designers have made arrangements to vent out the heat from the device. This is achieved by designing fins. However this arrangement is not suitable in places where the ambient temperature is more than normal. Thus, design of LED driver with controlled current input is essential in order to maintain the thermal limit of the device. Secondly, the AC-DC LEDs driver circuits, which are available in the market, are seldom equipped with input power factor and THD improvement circuitry as prescribed in IEC61000– 3–2. This is essential for maintaining the energy efficiency of the nearest utility services and in addition also improves on the current drawn by the device. The following work envisages these issues and proposes corrective driver circuit based on two different driver topologies, buck-boost topology and flyback topology. Both these topologies are proposed in order to address the aspects of power quality and its impact on the life of the device. The simulation were done using Green Point simulation tool from On Semiconductors.

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%.

Correlated Effects of Self-Heating, Light Output, and Efficiency of GaN Light-Emitting Diodes on Junction Temperature

2019 ◽  
Author(s):  
Bikramjit Chatterjee ◽  
James Spencer Lundh ◽  
Daniel Shoemaker ◽  
Tae Kyoung Kim ◽  
Joon Seop Kwak ◽  
...  
Keyword(s):  
Light Output ◽  
Temperature Data ◽  
Junction Temperature ◽  
Multiple Quantum ◽  
Material System ◽  
Optical Performance ◽  
Forward Voltage ◽  
Self Heating ◽  
Environment Temperature ◽  
The Impact

Abstract With the advent of GaN as the major material system in the solid-state lighting industry — high power, high brightness LEDs with wavelength ranging from near UV to white are getting fabricated and part of a tremendously large and ever-increasing market. However, device self-heating and environment temperature significantly deteriorates the LED’s optical performance. Hence, it is extremely important to quantify the device self-heating and its impact on optical performance. In this work, three different characterization techniques were used to calculate temperature rise due to self-heating for an InGaN/GaN LED with 5 pairs of multiple quantum wells. The impact of self-heating and increased environment temperature on the device optical performance were also studied. Nanoparticle assisted Raman thermometry was used for the first time to measure the LED mesa surface temperature. The temperature measured using this technique was compared with temperature data obtained by using the forward voltage method and infrared (IR) thermography. The IR and Raman measurement results were in close agreement while the temperature data obtained from forward voltage method underestimated the temperature by 510%. It was also observed that due to environment temperature increase from 25°C to 100°C, LED optical power output drops by 12%.

scholarly journals Design and Implementation of 150 W AC/DC LED Driver with Unity Power Factor, Low THD, and Dimming Capability

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Ngo Thanh Tung ◽  
Nguyen Dinh Tuyen ◽  
Nguyen Minh Huy ◽  
Nguyen Hoai Phong ◽  
Ngo Cao Cuong ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Power Factor ◽  
Electromagnetic Interference ◽  
Light Emitting Diode ◽  
Power Converter ◽  
Input Power ◽  
Led Driver ◽  
Load Range ◽  
Dc Power ◽  
Wide Range

This paper presents the implementation of a two-stage light-emitting diode (LED) driver based on commercial integrated circuits (IC). The presented LED driver circuit topology, which is designed to drive a 150 W LED module, consists of two stages: AC-DC power factor correction (PFC) stage and DC/DC power converter stage. The implementation of the PFC stage uses IC NCP1608, which uses the critical conduction mode to guarantee a unity input power factor with a wide range of input voltages. The DC/DC power converter with soft-switching characteristics for the entire load range uses IC FLS2100XS. Furthermore, the design of an electromagnetic interference (EMI) filter for the LED driver and the dimming control circuit are discussed in detail. The hardware prototype, an LED lighting system, with a rated power of 150 W/32 V from a nominal 220 V/50 Hz AC voltage supply was tested to show the effectiveness of the design. The presented LED driver was tested for street lighting, and the experimental results show that the power factor (PF) was higher than 0.97, the total harmonics distortion (THD) was lower than 7%, and the efficiency was 91.7% at full load. The results prove that the performance of the presented LED driver complies with the standards: IEC61000-3-2 and CIRSP 15:2009.

scholarly journals Analysis of Converters for Single Phase LED Driver with Input Power Factor Correction

2020 ◽  
Vol 6 (6) ◽  
pp. 92-98
Author(s):  
C K Gowsalya ◽  
Dr. N Narmadhai
Keyword(s):  
Power Factor ◽  
Power Supply ◽  
Single Phase ◽  
Power Factor Correction ◽  
Input Power ◽  
Half Cycle ◽  
Led Driver ◽  
Conduction Loss ◽  
System Components ◽  
Power Factor Improvement

Most of the loads in household are inductive in nature and hence have low power factor. When, the power factor is low the current flowing through the system components will be higher. It results in heating and shortens the life of the system. Hence, power factor improvement is necessary. This paper proposes the comparison of bridgeless Single-ended primary-inductance converter (SEPIC) and bridgeless Landsman converter with the input power factor correction for LED drive application. The gating signal for switches in the converters are generated using PWM generator. Bridgeless configuration is used to reduce the conduction loss in the negative half cycle which improves the efficiency of about 1 to 2% for the entire power supply. In this configuration number of conducting diodes is reduced. This proposed work is designed and simulated using MATLAB / Simulink software. The simulated results from the two converters were analyzed for the input power factor correction.

Design and Implementation of High Power LED Lighting System for Health Care Applications

2019 ◽  
Vol 14 (1) ◽  
pp. 31-37 ◽  
Author(s):  
J. Gnanavadivel ◽  
N.S. Kumar ◽  
S.T.J. Christa ◽  
P. Yogalakshmi
Keyword(s):  
Fuzzy Logic ◽  
Power Factor ◽  
Fuzzy Logic Controller ◽  
Input Power ◽  
Pi Controller ◽  
Healthcare Applications ◽  
Led Driver ◽  
Led Lighting ◽  
Source Current ◽  
Supply Current

Background:A conventional front-end rectifier causes line current distortion and reduces the power factor, which result in lowering power quality for Light Emitting Diode (LED) drive system. Hence, this paper projects the design, simulation and comparison of novel PI tuned by the fuzzy logic controller with the conventional PI controller for modified SEPIC rectifier to produce the required load voltage along with supply-side unity power factor and less distorted supply current with limited harmonic content for LED lighting in healthcare applications. A prototype of 100W, 48V LED driver was developed for testing the performance of the controller.Methods:This paper presents the modified SEPIC LED driver with PI integrated fuzzy and classical PI for controlling voltage. For controlling source current, classical PI is chosen. Both are equipped with the modified SEPIC rectifier. Both conventional PI control and novel fuzzy tuned performances were compared.Results:The proposed control topology operated modified SEPIC rectifier was analyzed and the corresponding power factor and THD were measured. The operational evaluation of the proposed LED driver using fuzzy tuned-PI/PI controller combinations for different output power is provided in Table 2. Sustained regulated DC voltage of 48V was achieved even when the load resistance varied within a specific range. Power factor of 0.9995, which is close to unity, was also achieved. The relative analysis was made with conventional PI and trendy PI integrated FLC controller which is provided in Table 3. The usage of PI integrated fuzzy logic controller minimized the peak overshoot to be around 1.3% and rise time of 0.5s which are lower when compared to the conventional PI controller. With reference to Fig. (8a), the source current THD of the conventional PI controller was observed to be around 7.39%. Having PI integrated FLC, THD was further reduced and for rated load, it was found to be 1.39%. The power factor of the conventional PI controller is around 0.9974. PI integrated fuzzy logic controller improved the power factor to 0.9995 with fuzzy tuned PI controller in action as shown in Fig. (8b). A prototype of 100W, 48V LED driver was developed for testing the performance of the controller. A power quality analyser was employed for measuring power factor and THD, shown in Fig. (10a). 3.633% of harmonic distortions at the source current and 0.9980% of input power factor was achieved for rated load power. 4.510% of supply current THD with 0.9931% input power factor was achieved for low load power.Conclusion:This manuscript suggests a modified single switch SEPIC LED driver for 48V output operated healthcare equipment. Simulation study of this driver shows the better performance. In order to analyze the performance, a comparative study was conducted by using the classical PI and the novel PI integrated fuzzy controller. Satisfactory results regarding enhanced quality of power, regulated load voltage, quick rise time and settling time were achieved. The source current THD has been reduced to around 1.39% which is less than 5% as per the IEEE-516 prescribed standard and the power factor has been improved to 0.9995 by implementing the fuzzy tuned PI controller. The above results favor the suggested modified SEPIC LED driver for practical healthcare applications.

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