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There is no one single solution that can meet the all the requirements and operational needs of all vessel types. However, all-electric systems (AES) and hybrid systems are increasingly being considered for propulsion in more vessel segments. An electric infrastructure makes it is easier to integrate electricity-producing energy sources and carriers that are available now or will be developed in future. This kind of future-proofing is important amid the rapid development of, and infrastructure to supply, carbon-neutral energy sources and energy storage systems (ESS). It is not possible to foresee what solutions will become available during the more than 20-year lifetime of a vessel in a changing and ever-stricter regulatory environment.
ESS with batteries are increasingly being deployed in marine power and propulsion systems. However, due to limited energy density, and as they require charging from shore, battery systems can only function as the main power supply for vessels in short-distance shipping segments. For larger ocean-going ship types, fuel cell systems are being considered and developed as a feasible clean-energy source solution. Pilot projects are currently underway as proof of concept, and it is expected that fuel cell systems will replace combustion engines as the main power source in certain ship segments in the future.
In order to provide optimal performance and energy efficiency, an AES requires a more sophisticated power management system (PMS) versus traditional diesel-electric propulsion. The new concept is being called ‘PEMS’ (power and energy management system) so as to emphasize that not only instantaneous power is being controlled, as in the past, but also controlling the availability of energy within a certain time frame. An accurate plant model is therefore essential for system studies and optimal design of control algorithms.
This paper describes a DC-grid, fuel-cell powered hybrid shipboard power system using an average modeling method. A Hardware-in-the-Loop (HIL) platform was set up to perform accurate real-time system behavior, which is essential for system verification. Both the numerical and real-time models were validated against a lab-based, reduced-scale hybrid power plant.