高效高可靠两级多路无源恒流LED驱动电源研究

In order to improve efficiency and reliability, the two-stage passive-constant-current LED driver with multiple outputs is proposed in this project. The former stage is high frequency AC/AC converter, which converts the commercial line frequency input voltage into high frequency output voltage. The later stage is high frequency AC/DC converter, which converts the high frequency input voltage into direct output current. At the aspect of high frequency AC/AC converter, the constrains and laws to construct single-stage high frequency AC/AC converter will be studied and the characteristics of these converters will be compared. In order to suppress the second harmonic ripple of the high frequency output voltage, the control method related will be studied. Based on these studies above, how to calculate the circuit parameters quantitatively will be performed. Finally, the active virtual capacitor will be studied to realize high frequency AC/AC conversion without any electrolytic capacitors. At the aspect of high frequency AC/DC converter, the topology of it will be studied based on the passive resonant constant current theory. In order to guarantee the precision of output current, the operation modes and coordination of the input and output voltage will be studied. Finally, the sensitivity analysis will be carried out to provide theoritical basis for component selection. Since the proposed LED driver is a complex non-linear high-order multi-converter system, the mathematical model of it will be established. According to the established model, the stability analysis and design will be performed. Finally, the interaction and influence between the internal converters will be studied. The success of this project will promote the modularization and standardization of the LED driver, and may promote the development of the whole LED lighting industry.

针对如何提高效率及可靠性，本项目提出研究两级多路无源恒流LED驱动电源，其中前级高频AC/AC变换器实现工频到高频交流电压变换，后级高频AC/DC变换器实现高频交流电压到直流电流变换。在高频AC/AC变换器方面，将系统研究单级高频AC/AC变换器拓扑约束条件及形成规律，并对拓扑性能进行比较分析，然后研究抑制输出电压幅值两倍工频纹波的控制方法，在此基础上研究参数的定量设计，最后研究有源虚拟电容实现无电解电容变换。在高频AC/DC变换器方面，将基于无源谐振恒流理论研究无源拓扑，然后研究其工作模式以及输入、输出电压配合规律以保证输出电流精度，最后开展灵敏度分析为元件选型提供理论依据。由于提出研究的驱动电源是一个复杂非线性高阶多变换器系统，将建立其数学模型，进行稳定性分析及设计，最后研究内部各变换器之间的相互作用机理及影响。本项目的研究可促进LED驱动电源模块化、标准化，推动LED照明产业的发展。

本项目围绕如何提高LED驱动电源的效率及可靠性开展研究。在基于高频交流电压母线多路恒流LED驱动电源方面，提出了系列单级高频谐振AC/AC变换器并完成了性能分析及电路参数定量设计；构建了系列无源高频AC/DC变换器，研究了其工作模式、输入输出电压的配合规律及灵敏度分析；完成了闭环及开环多路恒流LED驱动电源样机研制，实测驱动效率超过90%。在基于电流母线的多路恒流LED驱动电源方面，分析了基本DC/DC变换器的结构，基于电路理论推演了基本DC/DC变换器拓扑，形成了完整的拓扑理论及分布式电源系统架构，得到了系统稳定性判据；提出了基于直流电流母线的两级及单级输出电流独立控制的多路LED驱动电源，完成了相关拓扑理论、拓扑推演、性能分析、参数定量设计及实验验证。本项目的研究可促进LED驱动电源模块化、标准化，推动LED照明产业的发展。