Analysis and Modeling of the Hybrid Vessel's Electrical Power System

TL;DR

The work develops AC and DC hybrid vessel power-system models in ETAP using authentic vessel data to enable time-domain analyses, short-circuit calculations, and protection coordination. It demonstrates inverter-assisted peak shaving and dynamic responses in AC grids and appraises DC-grid behavior with attention to battery and converter contributions, while acknowledging ETAP limitations in fully capturing battery dynamics and DC power balance. Differences between theoretical calculations and simulations are attributed to time-constant modeling and DC-side approximations, motivating a gradual transition toward digital-twin deployment for troubleshooting and design optimization. The study also discusses protection strategies based on $I^2t$ criteria to assure selective fault clearance, with practical implications for future hybrid ships.

Abstract

With the maritime industry poised on the cusp of a hybrid revolution, the design and analysis of advanced vessel systems have become paramount for engineers. This paper presents AC and DC electrical hybrid power system models in ETAP, the simulation software that can be adapted to engineer future hybrid vessels. These models are also a step towards a digital twin model that can help in troubleshooting and preventing issues, reducing risk and engineering time. The testing of the models is focused on time domain analysis, short-circuit currents, and protection \& coordination. The models are based on actual vessels and manufacturer parameters are used where available.

Figures (7)

• Figure 1: Single line diagram of the studied AC grid
• Figure 2: Inverter active and reactive power
• Figure 3: Generator active and reactive powers
• Figure 4: Inverter and generators active and reactive power
• Figure 5: Single line diagram of the studied DC grid