Trinh, Quang Vinh
Characterization, optimization and stabilization of the lighting quality aspects of high qualitative hybrid LED-lamps by development of transient LED models.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2013)
Available under Creative Commons Attribution Non-commercial No Derivatives, 2.5.
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|Item Type:||Ph.D. Thesis|
|Title:||Characterization, optimization and stabilization of the lighting quality aspects of high qualitative hybrid LED-lamps by development of transient LED models|
Since the year 1996, when NAKAMURA demonstrated his first InGaN blue LEDs that can be combined with luminescent materials to create high brightness phosphor converted LEDs (PC-LEDs), the third revolution of lighting with LEDs had begun officially. Nowadays, the luminous efficacy of some cold white PC-LEDs can achieve a value of about 140 lm/W. Moreover, by an appropriate combination of color semiconductor LEDs and white PC-LEDs in hybrid LED-lamps, their spectra can be controlled dynamically. However, unfortunately the optical, radiant and colorimetric properties of LEDs vary strongly according to their forward current and their operating temperature. Consequently, it will be impossible to manufacture good and stable quality solid state luminaries, as well to optimize and stabilize their spectra, if LED properties are not characterized appropriately by transient LED models. Therefore, in this thesis the variation of LED properties must be investigated practically and the intrinsic physical and chemical phenomena taking place inside LEDs must be studied entirely. Hence, the difficulties in the applying, control and operation of LEDs will also be recognized. As well, the accurate characterization of the properties of LEDs by the development of the transient LED models will be carried out. Then, these transient LED models will be applied to the optimization and stabilization of the lighting quality aspects of high qualitative hybrid LED-lamps adapted to the colored surface objects. In that, an available LED combination with optimized / stabilized algorithms in the microcontrollers of hybrid LED-lamps will make the solid state luminaries achieve the high and stable lighting quality with the high luminous efficacy and the optimal spectra possible. In addition, color objects in the lighting application must also be identified specifically by their spectral reflectance distributions. As a result, the adaptive and optimal control factors will create the high qualitative hybrid LED-lamps that can satisfy the lighting demand of the color objects. Finally, high quality solid state lighting systems with these hybrid LED-lamps are the main aim of the thesis.
|Place of Publication:||Darmstadt|
|Uncontrolled Keywords:||LED-Model, Hybrid LED-lamp, vertical LED-model|
|Classification DDC:||600 Technik, Medizin, angewandte Wissenschaften > 600 Technik
600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften
600 Technik, Medizin, angewandte Wissenschaften > 660 Technische Chemie
600 Technik, Medizin, angewandte Wissenschaften > 670 Industrielle Fertigung
|Divisions:||18 Department of Electrical Engineering and Information Technology
18 Department of Electrical Engineering and Information Technology > Institute for Electromechanical Design
18 Department of Electrical Engineering and Information Technology > Institute for Electromechanical Design > Light Technology
|Date Deposited:||01 Oct 2013 05:32|
|Last Modified:||01 Oct 2013 05:32|
|Referees:||Tran, Prof. Quoc Khanh and Elsäßer, Prof. Wolfgang Erich|
|Refereed:||10 September 2013|