Multiphysics Modeling and Co-Simulation of Ship Electric Power and Propulsion Systems for Virtual Testing and Verification

This article proposes a framework for multiphysics modeling and co-simulation of electrified ships, aimed at system-level verification. The framework encompasses the development of dynamic time-domain models for ship power and propulsion systems (SPPSs) with multilayered control systems. The global system model is divided into subsystems with respect to the engineering domains and potential delivery packages of the constituent components, and the subsystems are transformed into model building blocks, namely Functional Mock-up Unit (FMUs). The component models are implemented with varying fidelity, to capture their diverse dynamics depending on the application. A co-simulation setup is then established using the Functional Mock-up Interface (FMI) to integrate the FMUs and to perform co-simulations of the entire system through the Open Simulation Platform (OSP). The resulting FMU/FMI setup enables virtual testing with synchronous and accelerated performance while offering flexibility in terms of model fidelity and characterization. As the case study, a full power and propulsion system for a coastal vessel with a dc grid is simulated under a realistic operating profile. The co-simulation results are validated against a monolithic simulation model with identical parameters, demonstrating the robustness and accuracy of the developed setup. The results prove that the proposed framework effectively represents the system dynamics and allows virtual testing with real-time factors (RTFs) higher than unity.