Power Flow Solvers for Medium Voltage Direct Current (MVDC) Microgrids

Abstract

While high voltage direct current and low voltage direct current architectures have been well researched and developed, this is not the case for medium voltage direct current (MVDC) ones. Regarding recent efforts to develop fast and powerful MVDC circuit breakers, future MVDC networks mainly as MVDC microgrids are being envisaged and studied for power grids, subsea oil and gas electrification, and transportation electrification such as all-electric ships and aircraft (AES, AEA), and thus, new tools, models, and solvers for various studies on DC networks are needed. In this regard, although many educational and commercial power flow (PF) solvers and algorithms have been developed for AC networks, pieces of research can barely be found dealing with PF methods for DC networks. This paper aims to address this technical gap by developing two PF solvers for DC microgrids under constant power generation and loads, namely Zbus method and monotone mapping. Solvers are coded in MATLAB, tested, and validated using an on-broad MVDC microgrid, the fully electrified NASA N3-X aircraft electric power system (EPS), where solutions' existence, uniqueness, and convergence are discussed as well.