Maritime DC microgrids - a combination of microgrid technologies and maritime onboard power system for future ships

Abstract

DC power distribution system is being considered as an attractive alternative to its traditional AC counterpart in many fields of applications and, in particular, for maritime onboard power systems. The adoption of DC power architecture would bring a broad range of benefits to the onboard power system. Not only frequency-related constraints are eliminated, which allows high-speed smaller generators to be used, but also new fault-tolerant configurations involving power electronics, generation control, as well as smart systemic management. For these reasons, DC power systems become natural alternative to the conventional AC power systems in the field of future maritime applications. Moreover, the inevitable cabin structure of maritime applications naturally separate the large-scale power system into several zonal parts. Furthermore, it is expected that the zonal parts can maintain autonomous power supply for a short time, which make the system highly consist with DC microgrids. In this content, it is foreseeable that the advanced research outcomes in the field of DC microgrid are also compatible with maritime onboard power systems. In this paper, DC power architectures, control and coordination methods, and specific issues of maritime onboard power system, fuel efficiency optimization and systemic reconfiguration are outlined, referring to state-of-the-art realizations as well as to novel concept designs presently under development and investigation.

A Review of the Conceptualization and Operational Management of Seaport Microgrids on the Shore and Seaside

“…DC distribution systems are now gradually used for various applications such as aircraft, automotive, Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 21 October 2021 marine, and manufacturing industries [79] [80]. Z. Jin et al [81] investigate the combination concept from DC microgrids with a maritime onboard power system for AES.…”

“…In the maritime sector, the adoption of DC topology brings an enormous range of advantages to the onboard power system by eliminating the frequency constraint, allowing utilization of high-speed generators, and providing systematic management [81]. R. Prenc et al [82] stated that DC ship power systems in the maritime sector prevailed over the AC systems due to the following reasons; 1) improvements in prime mover performance and fuel cost savings, 2) reduction in weight and space, 3) unity power factor for generators, 4) low transmission losses, 5) faster and easier parallel connection of generators, 6) flexible and simple implementation of ESSs.…”

A comprehensive review of distribution generation integratedDCmicrogrid protection: issues, strategies, and future direction

“…Design of a better protection scheme of DC microgrid system is a formidable task due to many factors like: (1) difficulties in extinguishing arc unlike happens naturally in AC systems (eg, not having zero crossing point for current interruption), 17 (2) lack of adequate grounding system, 10 (3) sensitivity of converters toward fault and control systems, (4) complex characteristics of DERs, 3 (5) change of short-circuit fault current with a different mode of operation and lack of proper standards, 18 and (6) filter capacitors discharge with respect to short circuit causes a rapid increase in transient fault current peak. 19 The main objective of this paper is to represent the current research developments with analysis to aware and help researchers to understand the issues of DC microgrid protection and futuristic possibilities for finding better protection schemes in this direction. In recent times, although many studies and reviews are focused on energy management, topology structure, and control method, the design of the protection scheme has not F I G U R E 1 Architecture of DC microgrid system drawn enough attention.…”

Frequency-division power sharing and hierarchical control design for DC shipboard microgrids with hybrid energy storage systems

“…Several diesel-electric hybrid propulsion systems with both series and parallel configurations have been tested by prototype vessels [7][8][9]. In addition to the fuel saving effect, ESSs can also contribute to the reliability and survivability of such a physically isolated power system, thus being recognized to be promising in future marine vessels [10][11][12][13][14]. Besides that, DC distribution, especially in medium voltage DC (MVDC) level, has drawn great attention from civilian and naval vessels for its better efficiency and compatibility to support these emerging power sources and electric propulsion.…”

“…It requires bidirectional power support to improve efficiency. Therefore, the control and management of ESSs are playing a vital role in these two applications [10][11][12][13][14][15][16]. However, the high requirement on both power and energy densities of marine applications is either hard or costly to meet by single type ESSs.…”