Optimal Operation and Sizing of Energy Storage System for a Ship Electrical Power System

摘要

In a Ship-based power system, depending on the type of ship and its operation, load profile could be very dynamic. The dynamic load demand is met by the use of multiple diesel-generators running in parallel with higher than normal ramping. These generators are typically oversized to meet the highly dynamic load demand. During the period of low demand, generators are operated on a suboptimal loading point. This leads to increased fuel consumption and higher mechanical stress on the generators which makes the operation inefficient. Using an energy storage system as a buffer allows operation of generators in their cost-efficient point making the overall operation cost and energy efficient. This paper addresses the selection of type and size of the energy storage system for a ship electrical power system. Firstly, the optimal operating strategy based on a multiobjective cost function for a different combination of storage systems have been formulated. Secondly, the best-suited energy storage system are determined by comparing parameters like the fuel consumption, capital cost, replacement cost and size for a target operational life of 5 years. Results show that an energy storage system not only reduces the fuel consumption but also restricts the operation of generators beyond their normal operating limits.