Toward P-HiL testing of high-power systems: A similarity-based scaling reduction framework with numerical validation applied to ship electrification

High-power systems find broad application across numerous domains, from stationary setups to the growing heavy-duty transportation sector. However, the testing and validation phases of such systems, which involve considerable power levels, pose significant challenges to their deployment. In the same context, Power-Hardware-in-The-Loop testing faces similar obstacles, related to cost and availability of suitable test benches, while being necessary during product development and validation. This study explores a similitude-based rescaling methodology intended for conducting representative Power-Hardware-in-The-Loop simulations on reduced-power test benches. The detailed process focuses on the inclusion of hardware components whose similarity-based rescaling is non-trivial. A propulsion system for a hybrid electric boat is considered, including a battery pack, a proton-exchange membrane fuel cell and power converters. The Π-theorem is applied on simulated system parts while the novel approach is employed on elements intended to be emulated with real components. Specifically, the proton-exchange membrane fuel cell and power converters are adapted through input/output manipulation and efficiency adaptation, respectively. The proposed methodology is numerically evaluated through a simulation-based control scenario, including a realistic power profile and constraints representative of the available low-power-scale hardware components. Results reveal a significant similitude error reduction for key system parameters compared to a naively scaled scenario.