Step Load Response Analysis of DC/DC Converter With Constant Power Load

Due to negative impedance characteristic of constant power load (CPL), buck converter with CPL and resistive load has different step load response processes, and system performance may be affected by CPL. With averaged large signal model and phase plane method, the step load response processes of averaged current control buck converter are analyzed in detail. The analysis indicates that there are two types and four processes of step load characteristics. When source converter is cascaded with CPL, step load performance remains unaffected by constraining its output voltage dip value. It could be implemented by larger inductor current limited value and higher current loop bandwidth. The experimental results verified the analysis.