Economic Fuel Dispatch of Diesel Generators in Offshore SupportVessels

In a typical offshore support vessel, a number of diesel generators are installed to supply itselectrical demand. Specific fuel consumption (SFC) of a diesel unit changes nonlinearly with respect to its power generation. Hence, this paper presents an economic fuel dispatch strategy for multi-diesel units operated in offshore support vessels using the cubic spline interpolation curve fittings of the SFC-power nonlinear relations. A mixed-integer nonlinear programming problem is coded under generalized algebraic mathematical modeling system (GAMS) and solved using branch-and-reduce optimization navigator tool to minimize the hour-ahead specific fuel consumption of the diesel-electric propulsion system. The upper and lower bounds of the power generation within each non-linear operating interval as well as the load-generation balance constraint are involved in simulations. The hourly power generation and the specific fuel consumption of each diesel generator are selected as positive decision variables. Equal and unequal power generation capacities are considered for four and six diesel units in two case studies. Numerical results demonstrated that GAMS is able to find better and more effective solutions than genetic algorithm and particle swarm optimization method in lower calculation time and less computational burden.