Dynamic Modeling and Real-Time Simulation of a Ship Hybrid Power System Using a Mixed-Modeling Approach

The electrification of a ship power-train is growing at a fast pace to improve efficiency and reduce emissions. The implementation of new technologies requires test and validation using various modeling approaches. However, many of the existing models of the ship hybrid power system are too complicated and demand high computational requirements, which make them inappropriate for the real-time applications. The real-time simulation model offers the benefits of testing different control algorithms along with hardware-in-the-loop testing. The bond graph-based dynamic modeling of a ship hybrid power system with a DC grid is presented as applicable to real-time simulation. The overall system model is established using different component models with varying fidelity, so-called mixed-modeling approach. In this approach, the components and control functions are modeled with different complexity such that it can capture the necessary system dynamics while minimizing the computational time. Results show that the modeled system is capable of simulating different operating strategies of the hybrid power system. Moreover, the mixed-modeling approach has enabled the system to simulate in nearly 2.5 times faster than the real-time.