临界连续模式下高功率LED驱动电源谐振控制方法

针对传统LED驱动电源谐振控制方法电路控制谐波异常导致输出电流过冲、电压稳定控制效果差和时延高等问题,提出了临界连续模式下高功率LED驱动电源谐振控制方法。结合PFC和LLC半桥两种方式,控制LED驱动电源谐振部分的频率变化值,选取开关恒流源,选取FSFR2100集成控制芯片作为控制芯片。在临界连续模式下,计算高功率LED驱动电源电路中电感值、滤波电容,以此为参量依据,设定电路中的电压范围与最小开关频率、输出功率等,校正PFC电路控制谐波。以PFC控制器所计算的电流与电压数据为基础,计算谐振频率值,通过谐振网络部分调整电压增益,确保LED驱动电源开关管实现零电压开关,实现临界连续模式下高功率LED驱动电源谐振控制。实验结果表明,采用该方法进行谐振控制的LED驱动电源,工作效率和PF值分别保持在88%和0.99以上,并且开关损耗低,未出现电流过冲,输入电压与输出电流波形相同,整体控制效果较好。

Resonance Control Method for High-power LED Drive Power Supply in Critical Continuous Mode

Using the resonant control method of high power LED drive power supply under critical continuous mode, it can effectively solve the traditional LED drive power supply cannot realize the independent regulation of resonant frequency under critical continuous mode, resulting in the drive power supply cannot achieve the zero voltage switch, and the switch loss is high. This method combines PFC with LLC half-bridge. The PFC controller uses Boost topology method to calculate the power, inductance, and capacitance of the LED drive power supply to correct the PFC circuit. The corrected PFC circuit can be used to input current waveforms. Harmonic control, Synchronize it with input voltage waveform to realize zero voltage switch; The LLC resonant converter is based on the current and voltage data calculated by the PFC controller. After calculating the resonant frequency, the voltage gain is partially adjusted through the resonant network to ensure that the switch tube realizes a zero voltage switch, reduces the switching loss of the LED drive power supply, and realizes high power LED drive power supply. Resonance control. The experimental results show that the operating efficiency and PF value of the LED drive power supply with resonance control are above 88 % and 0.99, and the switching loss is low.