چكيده به لاتين
Today, a significant portion of the electricity produced in the world is spent on lighting. According to statistics released by the International Energy Agency, 20% of the electricity generated is consumed in the lighting sector. Therefore, a well-lit lighting system can help to reduce the consumption of electrical energy and the problems of the living environment. Therefore, extensive research is being done to achieve optimal light sources with less energy consumption. Today, technological advances have had a significant impact on the improvement of lighting systems and the introduction of new lighting sources. In the meantime, light emitting diodes have been considered and welcomed due to advantages such as high efficiency, lumens ratio, high power, low cost compared to other light sources. Unlike some conventional lighting systems, such as incandescent lamps, light-emitting diodes require a constant current to operate, and therefore use electronic power converters with current-control capability to operate them. Output is inevitable. On the other hand, some existing standards, such as IEC 61000-3-2, require the use of a power factor correction structure to increase the power factor and reduce the injection of harmonic components into the network. Therefore, LED starter circuits generally have a two-tier structure, including a power factor correction converter at the input and a DC-DC converter to inject constant current into the LEDs. On the other hand, in these structures, the connection between the power factor correction section and the DC-DC converter is established through a capacitor (DC link capacitor). Generally, this type of capacitors is selected from the electrolytic type and has a very short lifespan compared to other components used in the converter. Therefore, the use of these capacitors leads to a reduction in the life and reliability of the entire converter. Due to the role of the LED driver circuit in the use of LEDs, the improvement in the LED driver circuits will expand the use of LEDs, so today extensive research is being done on it.
The aim of this dissertation is to achieve a structure with a minimum of components used and the ability to reduce the capacity of the electrolytic capacitor as much as possible by observing all the necessary considerations to run the light emitting diodes.
