Research On LLC Resonant Converter With Wide Voltage Range Output For Intelligent Lighting

To meet the needs of energy saving,environmental protection and urban construction,intelligent lighting and green lighting have come to the fore,and have been supported by national policies.Light-Emitting Diode(LED)drivers,as the core component of intelligent lighting system,has attracted much attention.Therefore,the development of LED drivers with high efficiency,wide voltage output,and expandable capacity is of great significance for the healthy development of the lighting industry,the construction of smart cities,and the promotion of the energy consumption revolution.In this dissertation,AC/DC High-efficiency Wide-Voltage Output Converter of Intelligent Lighting System have been investigated.Due to high efficiency,simple structure,easy implementation,excellent soft-switching characteristics and zero-current switching(ZCS)of rectifier diodes,LLC resonant converter is ideally suited as a post-circuit topology for AC/DC converters in intelligent lighting systems.First of all,in this paper,the overall scheme of AC/DC High-efficiency Wide-Voltage Output Converter is determined based on the analysis of the natural current sharing characteristics of the five commonly used LLC converter module combination technologies,taking into account the power level of the converter and the reliable working requirements in high temperature environments.In this paper,interleaved Boost PFC converter is used in the preceding stage design.By virtue of its inherent advantages,it has solved the problem of hot spots such as inductors and other magnetic components.The high efficiency of the converter is realized by the phase management technology of the analog chip.In this paper,the working principle is analyzed,design methods and results of the inductor design and device selection in the main circuit are given,and the experimental analysis is completed.In order to realize wide-voltage output requirement of the converter,half-bridge LLC resonant converter with Series-Parallel connected transformers topologies is used in the latter stage design.On the basis of this topology,the flexible transform theory is applied to broaden the voltage output range of 1 times,and the purpose of wide-voltage output is achieved.The operating principle of circuit are analyzed.Based on the fundamental analysis method,the modeling analysis is completed,the expression of the voltage gain is deduced and the simulation is completed.Then,a wide range of output voltage parameter LLC resonant network resonant converter are designed,summarizes the resonant network parameters design process,and the magnetic device design method and results are given.At last,the peripheral circuit of analog chip,driving circuit,voltage and current loop in converter is described.Finally,A prototype with input AC voltage range of 100-277 V,output of 80-340 VDC,constant current 1.05 A,which had made in the laboratory,and debugged the prototype.The simulation and experimental measurements of five output voltages are completed under three input voltage levels.The correctness and effectiveness of the theoretical analysis and the key parameters design is verified by experiments.