Coordination of Large Pulsed Loads on Future Electric Ships

Abstract

Part of the technical versatility of future all-electric ships is the potential ability to share large amounts of power among a variety of high-power loads. To help evaluate this potential and to provide information to help guide technology selection, a physics-based model of a power train for an electric ship has been developed and implemented on three modeling platforms. Using this model, three different investigations have been carried out to explore aspects of the behavior of a rotating machine power source for a shipboard rail launcher. These were: 1) influence of rapid charging of the rotating machine system on the ship power system; 2) use of the stored energy in the rotating machines to improve ship power quality; and 3) use of the stored energy in the rotating machines to power a pulsed free-electron laser. Each study highlighted different integration opportunities and challenges. The first showed that, because the charging of the rail launchers was through 5-MW motors, there could be a voltage sag for a few cycles, but this could easily be managed so that the sag could be reduced to an inconsequential level. The second study showed that, with appropriate power electronics, the stored energy in the rail launcher power supply can be used to correct power quality problems introduced by other ship systems. Finally, the stored energy in the launcher power supply can be used to fire a free electron laser for ship defense. This feature opens the possibility of routine operation of the entire ship at highest efficiency, i.e., with the smallest number of gas turbines operating near full power, while providing stored energy needed for ship defense.Index Terms-Electric ship, energy storage, power system, pulse loads.

A review of measurement and analysis of electric power quality on shipboard power system networks

“…Other control methods using DSTATCOM have been proposed in [29][30][31], voltage source converters [32], or in [33][34][35][36][37] in order to mitigate the impact of pulse loads and to maintain the stability in shipboard electric power system. The use of flywheels and battery energy storage systems is proposed to improve the efficiency and the quality of voltage supply [38,39].…”

Dynamic Load and Storage Integration

“…The first published work [19] that showed the technical feasibility of multi-usage storage systems addressed firing a free electron laser or an electromagnetic gun or enhancing the power quality of the ship power grid from a single storage system. That early work has been broadened and advanced by many in the development community.…”

Optimisation-based control for electrified vehicles: challenges and opportunities

“…As another energy source onboard the mobile platform, its safety issues have also been brought into the spotlight with several high-profile incidents, calling for serious attention and stimulating intensive research efforts. For ships, the special needs of high power impulse are provided by high power density energy storage systems, such as flywheels, ultra-capacitor banks and other advanced energy storage systems (Domaschk, Ouroua, Hebner, Bowlin, & Colson, 2007), while batteries are used to accommodate high energy density storage requirements. Moreover, hybrid energy storage where complementary storage mechanisms are involved can be exploited to achieve reduced cost and improved performance (Hou, Sun, & Hofmann, 2014).…”