Integration of a bi-directional DC-DC converter model into a real-time system simulation of a shipboard medium voltage DC system

A bi-directional dc/dc converter model is investigated for a notional Medium Voltage DC (MVDC) shipboard power system to improve energy flexibility and deal with peak energy demand in shipboard power system. Surplus energy in the MVDC system during light load condition can be captured by energy storages distributed in local load zones through the bi-directional dc/dc converters and then can be used during heavy load condition or black starting of the MVDC system. In this paper, the derivation process of the small-signal average models of the isolated-type bi-directional dc/dc converter is presented for controller design. This paper also presents the controller optimization process using intelligent optimal searching algorithm, Particle Swarm Optimization, for optimizing dynamic and steady-state control performance of a bi-directional dc/dc converter. The control performance of the proposed controller is evaluated using frequency-domain analysis and time-domain simulation of the large-scale notional MVDC shipboard power system using the Real-Time Digital Simulator.