Active Damping Control and Parameter Design Method for ISOP-Based Load Converter in DC Distribution System

To meet the diversified requirements of active damping configuration in a dc distribution system, the input-series-output-parallel (ISOP) load converter based on phase-shifted full-bridge (PSFB) modules is investigated in this article. The reduced-order impedance model of the PSFB-based ISOP converter with common-duty-ratio control is established first, and then the active damping control strategies using the primary- and secondary-side voltages are proposed, respectively. By reformulating the stability criterion in the form of impedance-frequency curves and using the impedance sensitivity, the sensitivity of resonance frequency is derived to develop a method for designing the parameters of active compensators. Finally, the experimental results demonstrate the effectiveness of the proposed active damping control strategies and parameter design method.