Large-signal analysis of a DC-DC buck power converter operating with constant power load

The dynamic properties of the buck converter operating with a constant power load are studied in this paper. This configuration is present in DC-DC converters feeding power converters tightly regulated in multi-converter power electronics systems. The dynamic behavior of converters loaded by constant power loads differs from the behavior of converters loaded by resistors or current generators. The purpose of this paper is to address the closed-loop behavior of the buck converter feeding a constant power load. Based on a comprehensive large-signal analysis of the converter, the basin of attraction of the equilibrium point is defined. This region, in general, excludes the low range of the output voltage affecting the transient stability, forcing proper coordination between the converter and loads during start-up.