Dimmable driver for light-emitting diode with total harmonic distortion improved

2012 ◽  
Vol 5 (1) ◽  
pp. 59 ◽  
Author(s):  
K.I. Hwu ◽  
W.C. Tu
Keyword(s):  
Light Emitting Diode ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Light Emitting

scholarly journals Research of the Negative Influence of Dimmed LED Luminaires in Context of Smart Installations

2021 ◽  
Vol 13 (17) ◽  
pp. 9753
Author(s):  
Peter Drgona ◽  
Peter Durana ◽  
Tibor Betko
Keyword(s):  
Power Factor ◽  
Light Emitting Diode ◽  
Harmonic Distortion ◽  
Negative Influence ◽  
Total Harmonic Distortion ◽  
Correction Function ◽  
Inrush Current ◽  
Inrush Currents ◽  
Negative Impacts ◽  
Led Drivers

This article deals with the investigation of the negative impacts of dimmed public, industrial and office LED (light emitting diode) light installations. This approach is required due to the uncertain design of LED ballasts, while manufacturers do not implement the required PFC (power factor correction) function. Therefore, the focus is on a brief description of the principles of negative influences such as: low power factor, high inrush current and high total harmonic distortion based on direct confrontation with actual standards (IESC EN, NEMA, ENERGY STAR). Further, the behavior of LED drivers is explained under nominal load and dimmed up to critical level. Presented findings confirm issues reported by users from larger installations where LED fittings are dimmed over a certain level. The article includes recommendations for consumers and producers of LED fittings about main issues from the scientific and user points of view. Presented facts conclude on the necessity of studying the marginal operating state of LED fittings aiming at THD (total harmonic distortion), PF (real power factor) and inrush currents.

scholarly journals A New Circuit Design of AC/DC Converter for T8 LED Tube

2021 ◽  
Vol 11 (1) ◽  
pp. 421
Author(s):  
Sunghwan Kim ◽  
Haiyoung Jung
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Harmonic Distortion ◽  
High Quality ◽  
Current Harmonics ◽  
Light Emitting ◽  
Class D ◽  
Straight Line ◽  
Converter Topology ◽  
Driving Circuit

This study is about an improved high-quality light-emitting diode (LED) converter for a T8 LED tube. The converter is separated into the AC driving circuit and DC driving circuit. Also, the LED tube was applied with an output ripple eliminator for the optical performance. The AC driving circuit and DC driving circuit are assembled at the end of the LED tube in a G13 base and a G13 base dummy, respectively, and the output ripple eliminator is located on an LED PCB. The proposed LED converter is founded on a SSBB (single-stage buck-boost) converter topology and was designed for 10 W operation for a 600 mm T8 LED tube. The light waveform of the LED tube was measured by a photosensor. The waveform had almost no ripple and was the same as a straight line. The average calculated percent flicker of the proposed LED converter was an average of 1.9% at 100 and 240 VAC, 50 and 60 Hz. The proposed converter has lower power efficiency than a conventional converter by 2.7% at 100–240 VAC, but it still has high power efficiency (>87%). The measurement results represent that the LED output current regulation is below 0.92% at 100–240 VAC and the converter obtains the power factor more than 0.84 and the total harmonic distortion is less than 14.3%. All of the current harmonics reach the IEC 61000-3-2 Class D standards for high-quality LED converters.

scholarly journals Non-Intrusive Identification of Load Patterns in Smart Homes Using Percentage Total Harmonic Distortion

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4628 ◽  
Author(s):  
Hari Prasad Devarapalli ◽  
V. S. S. Siva Sarma Dhanikonda ◽  
Sitarama Brahmam Gunturi
Keyword(s):  
Light Emitting Diode ◽  
Harmonic Distortion ◽  
Electricity Consumption ◽  
Side Lobe ◽  
Vital Role ◽  
Total Harmonic Distortion ◽  
Distribution Grid ◽  
Digital Controllers ◽  
Nonlinear Loads ◽  
Harmonic Pollution

Demand Response (DR) plays a vital role in a smart grid, helping consumers plan their usage patterns and optimize electricity consumption and also reduce harmonic pollution in a distribution grid without compromising on their needs. The first step of DR is the disaggregation of loads and identifying them individually. The literature suggests that this is accomplished through electric features. Present-day households are using modern power electronic-based nonlinear loads such as LED (Light Emitting Diode) lamps, electronic regulators and digital controllers to reduce the electricity consumption. Furthermore, usage of SMPS (Switched-Mode Power Supply) for computing and mobile phone chargers is increasing in every home. These nonlinear loads, while reducing electricity consumption, also introduce harmonic pollution into the distribution grid. This article presents a deterministic approach to the non-intrusive identification of load patterns using percentage Total Harmonic Distortion (THD) for DR management from a Power Quality perspective. The percentage THD of various combinations of loads is estimated by enhanced dual-spectrum line interpolated FFT (Fast Fourier Transform) with a four-term minimal side-lobe window using a LabVIEW-based hardware setup in real time. The results demonstrate that percentage THD identifies a different combination of loads effectively and advocates alternate load combinations for recommending to the consumer to reduce harmonic pollution in the distribution grid.

A Universal Input, Single-Stage AC–DC LED Driver for an Auditorium Light

2018 ◽  
Vol 28 (02) ◽  
pp. 1950024 ◽  
Author(s):  
Amit Agrawal ◽  
Ashish Shrivastava ◽  
Kartick C. Jana
Keyword(s):  
Power Quality ◽  
Light Emitting Diode ◽  
State Space Model ◽  
Harmonic Distortion ◽  
Feedback System ◽  
International Standards ◽  
System Stability ◽  
Crest Factor ◽  
Led Driver ◽  
Light Emitting

Analysis, design and simulation of 126[Formula: see text]W power supply with better power quality are presented in the proposed work to run an auditorium light emitting diode (LED) light operating at universal AC input mains (90–270[Formula: see text]V). A single-ended primary inductance converter (SEPIC) topology is designed and driven in continuous conduction mode (CCM) with advance feedback system to maintain constant voltage at output. A proportional integral (PI) controller is also proposed to make the system stable, and stability analysis is discussed in detail with the help of transfer function derived from the state space model. Bode, Nyquist and Polar plots are clearly drawn using the MATLAB tool to claim the system stability. For justification of mathematical analysis, a simulation of the proposed LED driver is also performed in MATLAB–Simulink using sim-power toolbox. The simulation results show the improved value of power quality indices like power factor (PF), total harmonic distortion (THD) and crest factor (CF) with constant rating of 84[Formula: see text]V, 1.5[Formula: see text]A at output. Improved PF and reduced THD are under the limit of international standards like IEC-61000-3-2 Class C requirement.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

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