固定导通时间分段双频率控制CCM Boost PFC变换器

Piecewise Constant On-time Bi-Frequency Controlled CCM Boost PFC Converter

为提高电感电流连续导电模式(CCM) Boost PFC变换器的动态响应性能,提出固定导通时间分段双频率(Piecewise Constant On-time Bi-frequency,分段COT-BF)控制技术。分段COT-BF控制器电流内环与电压外环解耦,获得宽带宽的电压外环以提高PFC变换器的瞬态响应速度;采用变频控制,降低输入电压峰值点附近的开关频率,减少开关损耗从而提高效率。研究结果表明,与平均电流控制CCM Boost PFC变换器相比,分段COT-BF控制CCM Boost PFC变换器具有更快的响应速度、更高的效率,同时保持高功率因数(PF)和低总谐波畸变(THD)。

To improve the dynamic response performance of the CCM Boost PFC converter, a piecewise constant on-time bi-frequency (Piecewise COT-BF) control technique is proposed. The proposed Piecewise COT-BF controller decouples inner current loop and outer voltage loop, thus a wide bandwidth outer voltage loop can be obtained to improve the transient response speed of the PFC converter. In addition, the pulse frequency modulation (PFM) control is used to reduce the switching frequency near the peak input voltage and the switching loos to improve the efficiency. The research results show that compared with the average current mode (ACM) controlled CCM Boost PFC converter, the Piecewise COT-BF controlled CCM Boost PFC converter has faster response speed and higher circuit efficiency while maintaining high power factor (PF) and low total harmonic distortion (THD).