Analysis of Energy Storage Implementation on Dynamically Positioned Vessels

Abstract

Blackout prevention on dynamically positioned vessels during closed bus bar operation, which allows more efficient and eco-friendly operation of main diesel generators, is the subject of numerous studies. Developed solutions rely mostly on the ability of propulsion frequency converters to limit the power flow from the grid to propulsion motors almost instantly, which reduces available torque until the power system is fully restored after failure. In this paper, a different approach is presented where large scale energy storage is used to take part of the load during the time interval from failure of one of the generators until the synchronization and loading of a stand-by generator. In order to analyze power system behavior during the worst case fault scenario and peak power situations, and to determine the required parameters of the energy storage system, a dynamic simulation model of a ship electrical power system is used. It is concluded that implementation of large scale energy storage can increase the stability and reliability of a vessel’s electrical power system without the need for the reduction of propulsion power during a fault. Based on parameters obtained from simulations, existing energy storage systems were evaluated, and the possibility of their implementation in the maritime transportation sector was considered. Finally, an evaluation model of energy storage implementation cost-effectiveness was presented.

Optimizing Load Frequency Control in Standalone Marine Microgrids Using Meta-Heuristic Techniques

“…The basic transfer-function-based diesel engine governor model is shown in Figure 1 [56], where the actual speed, ω r , is compared with the reference speed, ω ref . The prime-mover mechanical torque is derived as a percentage of the nominal power and provided by the output of the actuator [57]. The mechanical torque is [57] transferred to the engine delay block of time delay, Ta.…”

“…The prime-mover mechanical torque is derived as a percentage of the nominal power and provided by the output of the actuator [57]. The mechanical torque is [57] transferred to the engine delay block of time delay, Ta. The mechanical power, P mec , is the product of the time delay and the rotor actual angular speed, ω r , which is the input for the mechanical part of the synchronous generator.…”

Fault Diagnosis Technology for Ship Electrical Power System

“…At present, most ships use AC electric propulsion systems. Because the electrical equipment of the ship mainly comprises inductive loads, the load current will cause demagnetization of the synchronous generator, and the load change will alter the power grid voltage of the ship [19]. To ensure stable operation of the power system, the excitation system will adjust the excitation current supplied to the generator according to the load change, make the generator terminal voltage return to the given value, and realize stability of the generator terminal voltage.…”