Dynamic Load and Storage Integration

Abstract

Abstract-Modern technology combined with the desire to minimize the size and weight of a ship's power system are leading to renewed interest in more electric or all electric ships. An important characteristic of the emerging ship power system is an increasing level of load variability, with some future pulsed loads requiring peak power in excess of the available steadystate power. This inevitably leads to the need for some additional energy storage beyond that inherent in the fuel.With the current and evolving technology, it appears that storage will be in the form of batteries, rotating machines, and capacitors. All of these are in use on ships today and all have enjoyed significant technological improvements over the last decade. Moreover all are expected to be further enhanced by today's materials research. A key benefit of storage is that, when it can be justified for a given load, it can have additional beneficial uses such as ride-through capability to restart a gas turbine if there is an unanticipated power loss; alternatively, storage can be used to stabilize the power grid when switching large loads. Knowing when to stage gas turbine utilization versus energy storage is a key subject in this paper. The clear need for storage has raised the opportunity to design a comprehensive storage system, sometimes called an energy magazine, that can combine intermittent generation as well as any or all of the other storage technologies to provide a smaller, lighter and better performing system than would individual storage solutions for each potential application.

Review of Ship Microgrids: System Architectures, Storage Technologies and Power Quality Aspects

“…The Li-Ion batteries are maintenance free and also have the highest lifetime (at 80% depth-of-discharge (DoD)) over other battery types available in the market [37]. The battery technology continues to evolve with the help of nanotechnology, hence more power and energy dense batteries are likely to be manufactured in the future [35]. It must be noted that much higher current could be drawn beyond the rated current, however, it will degrade the battery performance and ultimately the lifespan.…”

“…The harmonic mitigation strategies are proposed for both voltage and current harmonics in microgrids. The most commonly proposed methods are selective harmonic current injection for current harmonic mitigation [55,56,61], virtual grid impedance [31,32], resistive active power filter [59], repetitive control methods [60], and using additional devices such as D-STATCOM [35].…”

Past, Present, and Future Challenges of the Marine Vessel’s Electrical Power System

“…3), both sides should have the same power generating capacity. The future shipboard power system may have an elegant solution to the optimal prime mover loading problem involving Energy Storage Systems (ESS) [35], [36], that can store excess power to achieve ideal prime mover loading conditions, which, among other scenarios, can be used to give a green approach to harbors without emissions.…”

Hierarchical Control Design for a Shipboard Power System With DC Distribution and Energy Storage Aboard Future More-Electric Ships

“…zero-emission operation in port) can be easily enabled. In this case, future DC-SPSs are expected to be the flexible platform which allows using various power sources as well as effectively supporting onboard loads with different characteristics, such as dynamic and pulsed-power loads [18]. However, the system-level control and management will remain a challenging issue, especially considering the fastchanging load conditions and mission setting of the vessel.…”