Average-value modeling of a peak-current controlled galvanically-isolated DC-DC converter for shipboard power distribution

Abstract

The average-value model of a peak-current controlled dc-dc converter with galvanic isolation is derived and its accuracy is demonstrated. The two main contributions of this paper are the development of a new peak-current based control which ensures that load fault currents do not propagate through the system and the derivation of an average-value model for the chosen converter topology with the aforementioned control. The proposed control strategy is shown to yield excellent fault performance. The average-value model (AVM) accurately captures most low-frequency dynamics and is much faster to evaluate than a waveform-level model which includes switching. The subject converter and its control are intended for use in a part of a larger distribution system and, in particular, a shipboard DC power system. The comparison between the AVM and a waveform-level model of a laboratory scale DC-DC converter demonstrates the accuracy of the AVM.