Abstract: The control objective of a single operating PWM (pulse-width- modulated) DC/DC (direct current-to-direct current) power supply is to maintain the output voltage close to the reference. In the case of parallel operating power supplies the control objective is enriched with the demand of keping the power distribution between the units close to a specified pattern. The paper suggests a model for parallel operating DC/DC converters. The physical meaning of the parameters of the model are discussed. Finely the paper suggests a structured model uncertainty description based on measurements, simulations and "experience". For a control designer, this paper could be a starting point in a control-law synthesis.
Key words: Pulse width modulation, multy variable control, DC/DC converter.