基于输入输出线性化的三电平Boost PFC控制策略

Three-level Boost PFC control strategy based on input-output linearization

针对传统双闭环控制动态调节时间过长的问题,提出了一种基于输入输出线性化的三电平Boost PFC变换器控制策略。首先,分析了三电平Boost PFC变换器的工作模态,建立了状态空间方程;然后,推导出三电平Boost PFC变换器输入输出非线性模型,判断线性化的可行性,进而对系统进行线性化;最后,利用经典控制理论设计控制器,并增加电压平衡控制,保证变换器的中点电位平衡。仿真结果表明:负载恒定时,输入电流可跟随输入电压相位变化并保持正弦波形,电流波形更为平滑;负载跳变时,电压电流调节迅速,输出电压除纹波稍有变化外,电压平均值保持恒定。证明了所提控制策略具备良好的动、静态特性及强鲁棒性。

Aiming at the problem that the dynamic adjustment time of traditional double-closed-loop control is too long,a three-level Boost PFC converter control strategy based on input and output linearization is proposed.Firstly,the working mode of the three-level Boost PFC converter is analyzed,and the state-space equation is established;Then,the input-output nonlinear model of the three-level Boost PFC converter is derived,and the feasibility of linearization is judged,and then the system is linearized;Finally,the controller is designed by using classical control theory,and the voltage balance control is added to ensure the midpoint potential balance of the converter.The simulation results show that when the load is constant,the input current can maintain the sinusoidal waveform with the phase change of the input voltage,and the current waveform is smoother.When the load jumps,the voltage and current are adjusted quickly,and the output voltage is kept constant except for a slight change in ripple,indicating that the proposed control strategy has good dynamic and static characteristics and strong robustness.