Gain a solid understanding of Light-Emitting Diode (LED) Systems Theory with this unique book. Written by a leading expert in LED lighting, it links together the photometric, electrical, thermal and chromatic elements of LED systems into a single, unified framework, and explores their complex interactions with one another.Get to grips with chromatic, photometric and thermal modelling of LED systemsDiscover new techniques for precise dimming and colour control Learn methods for determining system parameters and internal variablesGain insight into advanced applications for LED system design and optimizationProviding straightforward and intuitive explanations, this is an ideal guide for professional engineers, graduate students and researchers working on solid-state lighting systems and smart lighting, and those taking advanced courses on LED devices and systems.
Author(s): Ron Hui
Publisher: Cambridge University Press
Year: 2017
Language: English
Pages: 152
Tags: Light Emitting Diodes, Optoelectronic Devices: Thermal Properties
Contents......Page 8
Preface......Page 12
1.2 Light Emission in Traditional Light Sources and LEDs......Page 16
1.3 Heat Loss Mechanisms of Traditional Light Sources and LEDs......Page 19
1.4 LED Structures and their Thermal Equivalent Models......Page 20
References......Page 23
2.1 Luminous Intensity, Luminous Flux and Luminous Efficacy......Page 24
2.2 Models for the Steady-State PET Theory......Page 27
2.2.2 Linking Thermal Quantity (Heat) with Photometric Quantity (Light)......Page 28
2.2.4 Linking Photometric, Electric and Thermal Quantities together......Page 29
2.3 Important Meanings behind PET Theory......Page 32
2.4 Achieving Maximum Luminous Flux with Proper Thermal Design......Page 35
2.5 Optimal Design Procedure for LED Systems......Page 37
References......Page 39
3.2 Models for the Dynamic PET Theory......Page 42
3.2.1 Time-Domain Junction-to-Case Temperature and Heatsink Temperature......Page 44
3.2.2 Time-Domain Luminous Efficacy and Luminous Flux......Page 46
3.3.1 Variation of Luminous Flux with Time......Page 48
3.3.2 Prediction of Internal Junction Temperature......Page 51
References......Page 54
4.1.1 Experimental Approach: The Silicon Oil Bath Method......Page 56
4.1.2 Determination of Heat Dissipation Coefficient from Optical Power......Page 58
4.2.1 Theory......Page 59
4.2.2 Applications......Page 64
4.3.1 Theory......Page 65
4.3.2 Application......Page 67
References......Page 70
5.1 Spectral Power Distribution......Page 72
5.2 Practical Spectral Power Modelling Process......Page 75
5.2.1 Temperature Dependence of the Peak Wavelength and FWHM......Page 76
5.2.2 Temperature Dependence of the Popt_phosphor / Popt_b Ratio......Page 80
5.3 Determination of Junction Temperature, CCT and CRI using the Dynamic PET Theory Framework......Page 83
5.3.1 Temperature and Electrical Power Dependence of the Optical Power......Page 84
5.3.2 Time Dependence of the Junction Temperature......Page 86
5.4 Application of the Extended PET Theory to CCT and CRI Prediction......Page 87
5.4.2 Dynamic Measurements......Page 89
5.4.3 Use of the Spectral Model as a Dynamic Modelling Tool......Page 92
References......Page 96
6.1 A Partitioned Grid Model for an LED System......Page 98
6.2 Generalized Partitioned Model for an mn LED Array Structure......Page 103
6.3 PET Modelling of Non-Identical LED Devices in Array Structures......Page 104
6.4 Chromatic Modelling of LED Array Systems with Non-Identical LED Devices......Page 106
6.5.1 An LED System with Identical LED Devices......Page 108
6.5.2 An LED System with Non-Identical LED Devices......Page 112
References......Page 115
7 Precise Dimming and Colour Control of LED Systems......Page 118
7.1 Traditional Linear Colour Control and its Drawbacks......Page 119
7.2.1 Nonlinear CCT Function of White LED Systems with Variable CCT......Page 121
7.2.2 Mutual Thermal Dependence of Different LED Types......Page 123
7.2.3 Parameter Determination for the Nonlinear Luminous Flux Functions......Page 126
7.3 Precise Dimming and Colour Control......Page 129
7.3.2 Averaged CCT for Warm-White LED as a Function of DT......Page 130
7.3.3 Mixed CCT Based on the Nonlinear Method......Page 131
7.4 Practical Implementation of Precise Dimming and Colour Control......Page 133
References......Page 134
8.1 Design of Smart LED Street Lighting for Weak Power Grids......Page 136
8.2 Structural Designs of LED Devices and Systems......Page 141
8.2.1 System Level......Page 143
8.2.2 Device Level......Page 145
8.3 Other Advanced Topics and Future Trends of LED Technologies......Page 148
References......Page 150
Index......Page 152
