开关DC-DC变换器恒频定关断时间控制技术研究  

Research on the Constant-frequency Fixed Off-time Control Technique for Switching Buck Converters

作　　者：史国栋[1] 董伟[1] 包伯成[1] 冯霏[1] 

机构地区：[1]常州大学信息科学与工程学院,江苏常州213164

出　　处：《自动化仪表》2016年第1期88-92,共5页Process Automation Instrumentation

基　　金：国家自然科学基金面上资助项目(编号:51177140)

摘　　要：针对固定关断时间(FOT)控制开关变换器开关频率随输入输出电压波动、增加开关电源损耗、不利于EMI滤波器综合设计等缺点,提出了一种基于输入输出电压反馈调节的恒频固定关断时间(CF-FOT)控制技术。通过增加输入输出电压反馈环路,使固定关断时间随输入输出电压动态调整,以确保开关频率恒定,从而消除了输入输出电压波动对开关频率的影响。PSIM仿真与实验结果表明,CF-FOT控制技术具有良好的可行性,提升了原FOT控制开关变换器的性能。The switching frequency of switching converter controlled by fixed off time （FOT） control is fluctuating follow the input and output voltage, this may increase the loss of switching power supply, and unfavorable to the integrated design of EMI filter. Thus the constant frequency fixed off time （CF-FOT） control technology based on feedback regulation of input and output voltages is proposed. By adding an input and output voltage feedback loop ,the fixed off time can dynamically be adjusted by the input and output voltage ,so fixed switching frequency can be ensured, and the influence of input and output voltages is eliminated. The PSIM simulation and experimental results indicate that CF-FOT control technology possesses excellent feasibility,improves the performance of the original FOT controlled switching converters.

关 键 词：开关变换器 BUCK变换器 开关电源 开关频率 固定关断时间控制脉冲频率调制(PFM) 脉宽调制(PWM) 

分 类 号：TH86[机械工程—仪器科学与技术] TP13[机械工程—精密仪器及机械]