Design Of 200W Dimmable LED Driving Power Supply

Light-emitting-diode (LED) light is a new type of lighting source seen in the late 20th century, and becoming a new research hotpot from then on because of its high efficiency, energy saving, environmental protection, long life and high reliability. However, different from traditional lighting, LED has nonlinear optical, thermal and electrical characteristics, which makes it impossible to connect to the mains directly. In order to obtain stable lighting conditions for LED, the mains should go through complex voltage and current conversion circuit. Especially in high-power LED applications, the requirements of high-efficiency and high power factor make it more difficult to design LED driving power supply. In addition, as modern illumination proposes the demand of comfort and environmental protection, if we can realize the intelligent dimming of LED, we can not only exert the energy-saving advantage of LED but also extend its lifetime simultaneously.Exactly based on the consideration of realizing these properties and requirements of LED driving power supply, this thesis has researched high-power dimmable LED driving power supply and designed a set of 200W dimmable LED driving power supply. It has the properties of high-efficiency, high power factor, high output power, and dimmable.The main contribusions of this thesis are summarized as follows:1.We do some research on the lighting theory of LED as well as its electrical and optical properties, and analysis the conditons of obtaining stable lighting. In order to realize the demands of high-efficiency and high power factor, we design PFC and LLC circuit after we have been familiar with their principle. And we design the dimming circuit based on PIC16F microchip to obtain dimming property after we have studied the principle of dimming. Morever, taking the practical application of engineering into account, we design the EMI filter and thermal performance to improve the reliability of the driving power supply.2.After we have finished the design of hardware and software, we produce a 200W dimming LED driving power supply sample. For a long time’s commissioning, the performance of the LED driving power supply can meet the requirements and we achieve the target of the research.