| dc.description.abstract | In this thesis a marine power plant with a battery pack has been modeled using bond graph theory, using the bond graph simulation software 20-sim. The popularity of hybrid power systems are increasing in the marine sector, mainly because it is an effective way to reduce fuel consumption, emissions and maintenance costs. Three control strategies were created to test the model, where each strategy had a different focus. A new control strategy were developed after case study one, were each of the control strategies were tested. The new control strategy, which then would be used in case study two, combined two of the previously tested strategies, to gain the benefits of both.
In case study 2, which was this thesis main case study, the results of two simulations where compared. One simulation ran two gensets and the other ran one genset assisted by a battery pack. The load profile applied was set to resemble an electric crane operation on a dry bulk carrier. The results show that if one genset is replaced with a 362 kWh battery pack, the fuel consumption rate can be reduced by 9.23%, while the maintenance costs for the operation can be reduced by over 50%. The figures are believed to be conservative, since the battery pack model's efficiency rating is lower than the real battery pack, due to an added resistance to make the model stable. The results shows that implementing a battery pack can give significant reductions both environmentally and economically, and should be implemented on all ships that has a diesel-electric power system. | |
