磁集成Buck变换器在超级电容充电系统中的建模

Modeling of magnetic integration Buck converter with supercapacitors charging system

同步整流Buck变换器广泛应用于低压充电场合,变换器中采用的交错并联磁集成技术能够有效地减小电感电流纹波,增加变换功率,提高变换器的工作可靠性,同时提高系统的动态响应速度。在超级电容充电阶段,采用状态空间平均法,推导了三相交错并联磁集成同步整流Buck变换器在电流连续模式(CCM)下的大信号和小信号模型,得到了系统开环传递函数。利用Matlab仿真软件得到整个系统开环幅频和相频特性曲线,并以此为依据优化设计控制器的补偿网络以提高系统的稳定性和瞬态响应速度,最后通过仿真和实验进行了验证。

Synchronous rectifier Buck converter is widely used in low voltage charging situation. Using interleaving magnetic integration technology can effectively reduce the inductor current ripple,increase transform power and enhance converter efficiency,and at the same time can improve the system dynamic response speed. At the stage of super capacitor charging,using state-space average method,a big single mode and a small single mode of a 3-phase interleaved magnetic integration synchronous rectifier Buck converter under CCM mode are obtained. This paper proposes the open-loop transfer functions of the current and voltage circuit. Then the amplitude-frequency curve and phase-frequency curve are plotted by a Matlab simulation,based on which the feedback loop compensation design is given for optimization design of the controller,improving system stability and dynamic response speed. The results of the analysis are verified through experiment and simulation.