Optimal operation of diesel generator and battery energy storage system for total fuel cost minimization in hybrid power system

This study addresses the challenge of optimizing the operation of the diesel generator (DG) and battery energy storage system (BESS) to minimize the total fuel cost in a hybrid tugboat application, using the Whale Optimization Algorithm (WOA), a metaheuristic optimization algorithm. A specific fuel consumption (SFC) curve and an optimal control algorithm are developed to enhance the performance of the hybrid tugboat. Various case studies examine the impacts of different tugboat mode durations on the optimal operation of DG and BESS. The effectiveness of WOA is validated with other optimization algorithms. From the developed SFC curve and optimal control algorithm, the optimal DG operating conditions to improve fuel efficiency are determined. As a result, through the optimized operation of DG and BESS suggested by WOA, the total fuel cost of the hybrid tugboat is reduced by 9.23 % compared to the conventional tugboat. In contrast to other algorithms, WOA performed exceptionally well in achieving the optimal operation of DG and BESS, with the highest total fuel cost savings and the smallest BESS operating capacity. The findings highlight that DG should be utilized mostly during the operating mode with the longest duration and higher load demand to minimize the total fuel cost.