Modeling, Simulation, and Full-Scale Validation of an On-Board Hybrid AC/DC Power System

Abstract

Modern propulsion systems rely on the capabilities of power electronics, linking fuel-driven prime movers to energy storage systems (ESSs) in hybrid topologies. Early-stage simulation models are essential to predict and mitigate potentially unstable modes and ensure system reliability from design-to-operational phases. This article presents an experimentally validated modeling approach for hybrid electric propulsion systems. The system models are derived using nonlinear ordinary differential equations and are thus suitable for simulation environments. First, the modeling methodology is implemented to establish the limitations followed by the derivation of the power system components and their controllers. The engine-generator control parameters are then estimated through rigorous trial and error simulations. Finally, an aggregated state space model is constructed. The system model is validated through simulations along with full-scale experimental tests. A use case is identified such as an offshore supply vessel, and the tests are performed on-board. Three different test scenarios are defined considering changes in the control and operational parameters, such as the generator loading, active front-end (AFE) rectifiers’ current and dc voltage controllers, and their proportional gains, respectively. The results demonstrate consistency between the simulations and experimental tests and prove the effectiveness of the proposed method in describing dynamical phenomena and capturing potential instabilities.