Source-Reflected Load Interactions in a Regulated Converter

The use of distributed power supply (DPS) systems is continuously growing in powering different electronic systems and equipment. The systems compose of regulated switched-mode converters, which typically operate in a cascaded configuration constituting a dynamically demanding constellation prone to instability and performance degradation. It is well known that the origin of the interactions is the different impedances distributed within the system. The mechanism and characterizing parameters causing the source-reflected interactions is investigated in this paper both theoretically and experimentally using a buck converter under voltage-mode (VM), peak-current-mode (PCM) and input-voltage-feedforward (IVFF) control. The reflected interactions would be eliminated if the forward-voltage transfer function can be made zero but in practice such a condition cannot be fully achieved. The investigations show that the VM-controlled convert is very sensitive to the source-reflected interactions