Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

The optimal design of power system on cruise ships
Shen Wu1, Tie Li1,2*, Shoaib Ahmed1, Bin Wang1
1.State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University
2.Institute of Power Plants and Automation, Shanghai Jiao Tong University

alternative energies integration. On the contrary, due to the introductionof huge amounts of electric components, the loss of power conversion
still can be observed, which leads to a negative effect on system energy
efficiency(Fan and Xiao, 2019). With the strict legislation of emissions,hybrid power systems including internal combustion engines andbatteries as well as PV solar has been issued in medium-sized ships
which sail in inland waters and on short voyages. In addition, in merchantmarine applications, dual fuel engines have been used to replace diesel
engines to reduce greenhouse gases.

ABSTRACTThis paper presents a design method of the ship power system
containing optimal configuration and assessment. A multi-factor andmulti-level A.J.Klee-based method was established considering thesystem reliability, fuel consumption, emissions, and cost during the shipvoyage, after which the optimal comparison of different types of prime
movers including diesel /dual fuel engines and their capacities wasconducted and analyzed. The case study shows that by using the DF
engines and ESS, the CO2 emissions can be reduced by up to 56.6%, andthe fuel consumption reduction and carbon tax due to the load shifting ofESS enables the return within the life cycle.
KEYWORDS: Ship power systems; Optimal design; Emissions andfuel consumption.

INTRODUCTION
With the growth of demand to meet the requirements of emissions inthe shipping industry, the optimization of power systems has become themost feasible way. Especially, considering the working features of large
cruise ships, more concern was attracted to their potential to achieve
clear shipping and transportation in the areas of ports and near the lands.
To reduce the emissions of power systems during the voyages, various
measures were presented including ship speed management, system
configuration optimization as well as renewable energies. In particular,
the studies on ship power systems are mainly focused on hybrid systems
and green-fueled engines. The energy storage systems and LNG engines
have been used widely in marine applications and showed great potential
to improve energy efficiency and lower CO2 emissions.
The conventional power systems of cruise ships are consisted of main
engines and shafts to drive the propeller directly. With the growing
concern on the improvement of ship energy efficiency, the all-electricships were proposed as shown in Fig.1 (Nuchturee and Li, 2018). A large
cruise propulsion system usually uses an integrated electric propulsion
system, mainly consisting of internal combustion engines, inverter,transformer, power distribution systems, propeller, motor, and control
system. The internal combustion engines are used to serve as generators
to produce power for propulsion and daily life on ships. Differ fromdriving a propeller via a gearbox, internal combustion engines operating
as auxiliary engines will be able to offset the power demand fluctuations
caused by transient waves and winds during the propulsion. All power
can be integrated and distributed based on the advanced power
management strategies to provide advantages on prime mover efficiency,
general arrangement flexibility, reliability, and feasibility to facilitateFig.1 diagram of integrated electric propulsion

However, due to the shortages of power density, the batteries aremainly configured in hybrid power systems to splitting the load demandof ship propulsion (Yuan, 2020; Sciberras, 2017; Lan, 2015), and thecosts of new energies during the whole life cycle still be the main
challenge to more applications in the shipping industry, which need pays
more attention. Compared with cargo ships, the power system of thecruise ship is more complex and flexible in configuration and needs
higher standards and requirements. Consequently, many indicators suchas fuel consumption, emissions, reliability, redundancy, and spatial
saturation need to be qualified and compared to meet the guidelines.
Since the dimensions of each indicator are different, dimensionlessresearch is necessary for system-level evaluation.
The paper aims to establish the optimal method of ship hybrid powersystems considering the dual fuel engines and energy storage systems
based on a simulation model to enable lower emissions and the minimum
costs in the whole life cycle. In this work, a case study was implemented
based on the energy flow model and rule-based system energy
management strategy built in MATLAB/SIMULINK, the capacity
optimization and evaluation of diesel engines were carried out, and theintroduction of dual fuel engines and energy storage system wasdiscussed.

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