Study of Operating Modes of a Controllable Lighting System Consisting of a Triac Dimmer and a LED Light Source with a Controllable Driver

Abstract

The article covers the study of the effect of a dimmer on operation of a light source and elec tromagnetic compatibility of a controllable light ing system. It is found that with reduction of ac tive power P of a light source its luminous flux and bulb heating temperature decrease, the power factor of the lighting system decreases too with increas ing of the total harmonic distortion current factor of the lighting system. The changes are non-linear. Mathematical expressions related to changes of lu minous flux, heating temperature, power factor and total harmonic distortion caused by change of active power of a light source are obtained. A conclusion is made that together with an opportunity to save ener gy and to increase the operating life of the control lable lighting system application of a dimmer leads to reduction of electric power quality and electro magnetic compatibility of this system. The study also demonstrated that changes in supply voltage also affect operation of the controllable lighting system. Reduced supply voltage causes the high est effect on characteristics of the lighting system. Change in the supply voltage strongly affects the lu minous flux and the heating temperature of the light source and the power factor of the lighting system in operating modes at 0.25 of Pnom and 0.5 of Pnom and the total harmonic distortion in operating modes at 0.75 of Pnom and Pnom.