摘要
为使Buck变换器在负载电压上升至接近输入电压的低压差情形仍可稳定控制其电感电流,且能随负载变化实现斩波状态与直通状态的自动切换,提出宽占空比峰值电流型准PWM/PFM混合控制。该控制方法在中占空比区间为准PWM控制,在高占空比区间为PFM控制。采用该控制方法的Buck变换器可在上限值高达100%的宽占空比范围实现其电感电流的稳定控制,并能随负载变化在斩波状态与直通状态之间自动切换,使变换器以直通为工作常态时具备主动限制负载过电流的伺服特性。仿真研究结果验证了宽占空比峰值电流型准PWM/PFM混合控制原理及实现的正确性与有效性。
In order to make buck converter realize the steadily control of its inductor current when the load voltage rises to be close to the input voltage,and automatically switch between chopper state and direct conduction state,the peak current mode Quasi-PWM/PFM hybrid control with wide duty cycle range is proposed.The proposed control method includes the quasi-PWM control with middle duty cycle and the PFM control with high duty cycle.The buck converter using this control method can realize the stable control of current of its inductor in wide range of duty cycle up to 100%,and achieve the automatic switching between chopper state and direct conduction state,and so the converter has servo characteristics to limit overcurrent of load when the converter take the direct conduction state as normal working state.Simulation results verify the correctness and effectiveness of the principle and implementation of the peak current mode Quasi-PWM/PFM hybrid control with wide duty cycle range.
出处
《通信电源技术》
2016年第6期46-49,142,共5页
Telecom Power Technology
基金
泸州职业技术学院青年基金项目K-1124
泸州市重点科研项目2015-S-53(3/5)
关键词
准PWM/PFM
混合控制
宽占空比
斩波状态
直通状态
伺服特性
quasi-PWM/PFM
hybrid control
wide duty cycle range
chopper state
direct conduction state
servo characteristics
