Thermal–electrical–luminous model of multi-chip polychromatic LED luminaire

Huang, Bin‐Juine; Tang, Chun-Wen

doi:10.1016/j.applthermaleng.2009.05.024

Cited by 38 publications

(22 citation statements)

References 15 publications

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“…Example 1. Consider the approximated thermal system dynamics model of the LED luminaire in [37] and suppose that there is a time delay of 0.877 seconds, i.e. G s ð Þ ¼ 0:18949 s þ 0; 002022 ð Þ s þ 0:001647 e À0:877s (74)…”

Section: Numerical Examplesmentioning

confidence: 99%

All‐Stabilizing Proportional Controllers for First‐Order Bi‐Proper Systems with Time Delay: An Analytical Derivation

Nesimioğlu

Söylemez

2016

Asian Journal of Control

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In this paper, a simple derivation for an all-stabilizing proportional controller set for first-order bi-proper systems with time delay is proposed. In contrast to proper systems, an extremely limited number of studies are available in the literature for such bi-proper systems. To fill this gap in the literature, broader aspects of the stabilizing set are taken into consideration. The effect of zero on the stabilizing set is clearly discussed and we also prove that, when their zeros are placed symmetrically to the origin, the stabilizing set of non-minimum phase plant is always smaller than that of the minimum phase one. Moreover, for an open-loop unstable plant, maximum allowable time delay (MATD) is explicitly expressed as a function of the locations of the pole and zero. From that function, it is shown that for a minimum phase plant, the supremum of the MATD is two times that of the time constant of the plant and the infimum of the MATD is the time constant of the plant. We also prove that the supremum is the time constant and the infimum is zero for a non-minimum phase plant.

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Section: Numerical Examplesmentioning

confidence: 99%

All‐Stabilizing Proportional Controllers for First‐Order Bi‐Proper Systems with Time Delay: An Analytical Derivation

Nesimioğlu

Söylemez

2016

Asian Journal of Control

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“…So far, environment protection and energy saving have generated considerable research interest, the white light emitting diodes (WLEDs) have been developed rapidly in the commercial market and widely used in various lighting fields [5][6][7]. Early devices only provided lighting in one direction and could not meet the requirements for omnidirectional luminescent applications [8][9][10]. The flexible spiral LED filament bulbs combine the bulb shell of traditional incandescent bulbs with a new LED filament to achieve 360-degree illumination [11,12].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Different Filament Arrangements on Thermal and Optical Performances of LED Bulbs

et al. 2020

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The influences on thermal and optical performances of light emitting diode (LED) bulbs with three different filament arrangements are investigated in detail. The average junction temperature, temperature of the surface of the bulb, and luminous flux of three samples all increased with increasing power. The thermal performance test results show that between the average junction, temperature and power were linear. The junction temperatures of the three samples at a power of 3.5 W were 102.48, 98.46, and 88.88 • C. The optical performance test results revealed that the luminous flux and efficiency in the two vertical filament arrangements were closely related to each other and higher than that of the horizontal filament arrangement. A numerical model of LED filament bulbs was established by the Floefd 17.2 software for analyzing the temperature distribution of the cross section and the gas flow path inside the bulb. The simulation results illustrated that the average temperatures of three samples were 105.88, 101.83, and 96.12 • C. Additionally, the gas flow inside the bulb of the two vertical filament arrangements was subject to forming a thermal cycle during operation work more than that of the horizontal filament arrangement. As a result, the flexible spiral LED filament bulb is feasible as a new light source.

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“…This indicates that the transfer function is not time invariant, but instead depends on the input power. The identified zeros, poles and gains at different input power levels are averaged in [20], resulting in a linear time invariant (LTI) model. The averaged LTI model cannot describe the power dependence of the LED thermal dynamics, especially when the parameters largely vary in the operating range of the power.…”

Section: Introductionmentioning

confidence: 99%

Identification and Robust Control of the Nonlinear Photoelectrothermal Dynamics of LED Systems

Dong

Zhang

2017

IEEE Trans. Ind. Electron.

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In lighting systems consisting light emitting diodes (LEDs), excessive temperature is a main cause of degraded luminous efficacy, which leads to reduced average illuminance and distorted illumination rendering. Modeling the thermal dynamics of LEDs is hence essential in designing thermal dissipators and controllers for maintaining constant illuminance or chromaticity. In the existing literature, both physical modeling and system identification have been proposed, which all find the dependence of the temperature on the input power. When the power fluctuates, e.g. due to dimming control, the thermal dynamics becomes nonlinear. Moreover, when a photoelectrothermal (PET) model is used in control synthesis, the nonlinearity due to the product of the temperature dependent efficacy and the input power must be considered. These nonlinearities are either ignored or linearized in most existing methods. The main contribution of this work is treating the aforementioned nonlinearities in a linear parameter varying (LPV) framework. First, the nonlinear thermal dynamics is identified by LPV system identification techniques. Then, a controller to track reference illuminance is designed by H∞ control techniques to be robust to both the temperature and the disturbance from ambient light. The identification data and the designed controller are collected from and verified on real experimental setup.

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Thermal–electrical–luminous model of multi-chip polychromatic LED luminaire

Cited by 38 publications

References 15 publications

All‐Stabilizing Proportional Controllers for First‐Order Bi‐Proper Systems with Time Delay: An Analytical Derivation

All‐Stabilizing Proportional Controllers for First‐Order Bi‐Proper Systems with Time Delay: An Analytical Derivation

The Effect of Different Filament Arrangements on Thermal and Optical Performances of LED Bulbs

Identification and Robust Control of the Nonlinear Photoelectrothermal Dynamics of LED Systems

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