Stabilizing controller design for multi-bus MVDC distribution systems using a passivity based stability criterion and positive feed-forward control

Advances in switching power electronic converter technology have brought about a resurgence of interest in the use of DC power distribution systems for a variety of applications. However, the notional power electronic based DC distribution system is a complex and extensively interconnected system consisting of multiple power converters. As a result, a number of system-level challenges related to stability arise due to interaction among multiple converter subsystems. The design of this type of system is difficult due to the general lack of proper analysis tools and limited understanding of the problem. This paper addresses the stability analysis of multi-bus MVDC converter systems using an unterminated two-port modeling technique to construct the impedance of all system buses. Evaluation of these system bus impedances utilizing the recently proposed Passivity Based Stability Criterion allows for a proper determination of overall system stability. A stabilizing controller is designed using a Positive Feed-Forward control technique to ensure passivity of the system buses and guarantee stability and performance.