无电解电容的宽范围输入电压半桥LLC数控开关电源设计

目前半桥LLC谐振电源中大多采用电解电容进行滤波,针对电解电容的电解液挥发产生的寿命低缺点。本设计采用了高寿命的CBB电容来代替电解电容进行滤波。但CBB电容容值低,滤波效果差,带来电压纹波大,输入电压范围宽的问题,因此本设计以STM32作为主控芯片,采用变频控制(PFM)与变脉宽控制(PWM)相结合的控制方法解决这一问题。经试验验证,本设计在使用CBB电容代替电解电容,宽输入电压范围的情况下,能够在一定的电压纹波内达到稳压效果,可以实现电源的高寿命。

Wide Range input Voltage Half-bridge LLC Digital Switching Power Supply Design Without Electrolytic Capacitor

At present,half bridge LLC resonant power supply mostly uses electrolytic capacitor to filter,aiming at the low life of electrolyte volatilization of electrolytic capacitor.In this design,CBB capacitor with high life is used to filter instead of electrolytic capacitor.However,CBB has low capacitance value and poor filtering effect,which leads to the problems of large voltage ripple and wide input voltage range.Therefore,STM32 is used as the main control chip in this design,which is solved by the combination of frequency conversion control (PFM) and variable pulse width control (PWM).It is verified by experiments that the design can achieve the stable voltage effect in a certain voltage ripple and the high life of power supply when CBB capacitor is used instead of electrolytic capacitor and the input voltage range is wide.