Average Modeling of DC-DC Converters for DC Shipboard Microgrids with Constant Power Loads

Abstract

DC microgrids represent an interesting opportunity for shipboard power system applications, where the integration of dc-interfaced resources is needed. However, maintaining system stability becomes a major challenge in the presence of constant power loads, which exhibit a negative incremental resistance behavior. This work is focused on developing an equivalent linearized model of a DC microgrid, composed by a DC-DC converter used to interface a DC source, such as a battery, with a main dc-bus supplying a constant power load. The state space averaging technique has been employed to develop an unified continuous model of the system under study. The model is then linearized to allow the tuning of regulators and ensuring system stability. Finally, real-time simulations are exploited to validate the proposed methodology.