Indirect assessment of photometric parameters of LED lighting systems

Abstract

The paper proposes a method of the indirect measurement of photometric parameters of LED lighting systems. It is based on a physicomathematical model that establishes the correlation between illuminance, electrical power consumption, and energy efficiency ratio of the luminaire. The laboratory test bench is used to verify the model. It comprises LED modules, measuring instruments, and photometric sensors. Dependences are suggested for the luminous flux and illuminance on the electrical operating conditions and LED chip temperature. It is found that an increase in the chip temperature by every 10 °C leads to an illuminance decrease by approximately 4–6%, which matches theoretical calculations. A comparison of the experimental data with the model predictions shows a deviation not over 7%, thereby confirming the adequacy of the proposed method. The latter includes diagnostics of the operating LED installation without the use of the expensive photometric equipment. Recommendations are given for this method to control the luminous flux degradation in LED luminaires and to improve the operational efficiency of lighting systems. The proposed method for indirect measuring luminous flux is tested at OOO “Global Light” and OOO “Light Engineering” (Karaganda, Kazakhstan) during an incoming quality control for manufactured luminaires.