Series Loss-Free Resistor as Stabilizing Active Damping of Constant-Power Load Systems

This paper presents the detailed design of an active damping system for the stabilization of an open-loop boost converter in constant-power load (CPL) operation. The reported work analyzes the steady-state regime of the interconnection of a boost converter supplying a CPL, and a loss-free resistor (LFR) in series with the converter input port (SLFR) performing the active damping. The LFR behavior is obtained by peak current mode control (PCMC) imposing proportionality between the steady-state average values of current and voltage in the SLFR input port. The isolated SEPIC fulfills the topological constraints of the interconnection and is selected to implement the SLFR. Finally, PSIM simulations and measurements from a 500 W prototype are in good agreement with the theoretical predictions and illustrate the system stabilization around the specified steady-state operating point for different values of the CPL power.