A Power Switching Control Method of Buck Converter Based on Power Switching Model

In green energy generation system, the power of converters is commonly required to be regulated. Due to the existing of power electronic device, the converters are typical nonlinear system. The traditional linearized modeling methods of DC/DC converter are derived by ignoring of high-frequency system states components and averaging them in a switching period. Thus, it cannot accurately describe the working process of converter. The traditional control methods, which based on the linearization model of DC/DC converter, only guarantee the performance of system near the predefined working point. In this paper, based on the switching system theory, a power switching model of Buck converter is built to describe the power state varying process without linearization and averaging. Meanwhile, a switching rule is design to regulate the power of Buck converter directly based on the switching of subsystems. The proposed method has merits of very simple control structure, no control parameters, no pulse width modulation block and, strong robustness to circuit parameters uncertainty. The simulation comparison results verify the effectiveness and superiority of proposed methods.