Modeling and Simulation of All-Electric Ships With Low-Voltage DC Hybrid Power Systems

ABSTRACT:

DC hybrid power systems are of interest for future low emission, fuel-efficient vessels. In spite of the advantages they offer on board a ship, they result in a complex, interconnected system, which requires effective analysis tools to enable a full realization of the advantages. Modelling and simulation are essential tools to facilitate design, analysis, and optimization of the system. This paper reviews modelling of hybrid electric ship components including mechanical and electrical elements. Power electronic converters are modelled by non-linear averaging methods to suit system-level studies. A unified model for bidirectional converters is proposed to avoid transitions between two separate models. A simulation platform using the derived models is developed for the system-level analysis of hybrid electric ships. Simulation results of power sharing among two diesel generators, a fuel cell module, and an energy storage system are presented for three modes of operation.

KEYWORDS:

1.      DC distribution systems

2.      Modeling

3.      Simulation

4.      Transportation.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

                               Fig. 1. Single-line diagram overview of a typical shipboard dc hybrid electric power system.

CONCLUSION:

Modeling of an all-electric ship with low-voltage dc power system was carried out. Averaging methods were used to model the power electronic converters by neglecting high-frequency switching behaviour inorder to reduce the computation burden and time. A simulation platform was developed using the derived models of different components for system-level studies. The simulation results for a sailing profile of an all-electric ship showed how the dynamic behaviors of different mechanical and electrical variables can be observed and studied by using the simulation program. Providing significant savings in terms of time and computational intensity, the presented simulation platform could be useful for long-term or repetitive simulations that are required for research on all-electric ship dc power systems.

REFERENCES:

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