Design Of LED Driver With Half Bridge LLC Resonant Converter

As the global demand to reduce energy consumption, energy-saving technology is being rapidly expanded. Traditional LED lighting power supply with the program either low efficiency or performance is unstable. Resonant converter with high frequency, high power density and high efficiency characteristics, so it’s use has become increasingly widespread. LLC resonant converter because while both the no-load ability and resonant tank circuit current reflects the severity of the load capacity, and reflects the incomparable advantage of ordinary series resonant converter and parallel resonant converter can be a better solution PWM conversion the existence of shortcomings, which has been very widely used, especially in the LED drive power field, by the greatly sought after in the industry.LLC resonant converter with primary-side switch tube easily in the full load range to achieve ZVS the secondary diode easy to achieve ZCS, resonant inductor and transformer magnetizing inductance easy to implement integration, as well as a wide range of input voltage has been widespread concern. Compared with traditional resonant converter, significant improvement in characteristics, in the control method, the parameters of design and performance moderator is relatively complex, so to obtain a set of effective design methods, precise control of the converter’s output we become very important.This paper briefly describes the LLC resonant converter and its research status, summarize the main advantages, then a detailed analysis of the working principle of the three modes of LLC resonant converter and the corresponding waveform; Then, using the fundamental frequency component method Export LLC the equivalent circuit of the converter, the establishment of a converter gain and the basic parameters Q, k, n of a theoretical model of the relationship obtained through the analysis of the model, to ensure that the inverter switching MOS tube to achieve ZVS and ZCS rectifier LLC parameter design method. Finally, according to the model of computer simulation to achieve the optimal design of these three basic parameters, and further to the the L6599controller chip design produced a half-bridge LLC resonant converter. Through a series of experiments and waveform analysis, and ultimately get the expected experimental results also proved that, the actual analysis is inseparable from the theory, theoretical calculations require experimental operation given argument.