All electric ships dependable design: Implications on project management

Abstract

Dependability has only recently become a unified theory, developing its own taxonomy, lexicon and methods. This newly formed discipline now regroups concepts defined and developed within international rules corpus in different areas of engineering, such as: aerospace, automotive, computing, etc. Applications to marine sector are, at present, partial, lacking in terms of systematic approach and limited in extension. Dependability techniques provide system analysis methods that classify faults, detail consequences with associated risk index. These indications are quintessential in assessing design progress and effectiveness, in discussing issues and consequent modifications required, in quantifying impact of faults in terms of operations, in directing product and documentation development, rendering easier and less conflictual demonstrating specification adherence. Aim of this work is demonstrating dependable design can be obtained with a bearable effort, implanting dependability techniques on an already present ship design substrate, and that dependability techniques may be profitably employed as project management tools

All-Electric Ship Design: From Electrical Propulsion to Integrated Electrical and Electronic Power Systems

“…This causes a lack of interest in dependability techniques, which are considered as checks to be marked to build a ship, rather than powerful tools to be used to attain a better design. Conversely, academics and consultants tend to have an approach to dependability more open than users and designers, as demonstrated by several works in the literature, whose goal is to explain the benefits of an approach to the ship's design more focused on dependability ([66]- [68], only to mention some).…”

Isolated Power System Safety Analysis

“…The EG must also be able to start automatically if the main source of electrical power fails to supply the emergency switchboard. In this case, the EG is automatically started and connected to the emergency switchboard by its automation power management system [9,10].…”

“…For this reason, some interconnections are required to avoid overload or damage to the network. The following feeder combinations, for example, are prohibited [5,10]: When the SG is connected and is supplying the ship electrical installation, a constant speed mode for the main engine has to be chosen, meaning the network frequency. In constant speed mode, the propulsion will be controlled with the help of the pitch adjustments, using the controllable pitch propeller (CPP).…”

“…First, the propulsion type has to be chosen, diesel-mechanic or diesel-electric, then other decisions are made, like the following [10,11]:…”

“…Low-voltage 690V electric network for an isolated power system, for a vessel with diesel-mechanical propulsion [10].…”