• Energy Research

This paper presents a distributed Flywheel Energy Storage System (FESS) for mitigating the effects of pulsed loads such as those exist in Shipboard Power Systems (SPS). A comparison between distributed and centralized allocation of FESS was provided with and without the utilization of ultra-capacitors on the DC side. A model for hybrid AC/DC SPS with zonal distribution architecture was built in a simulation software. In order to accurately evaluate the performance of the system, three different case studies are presented with and without the FESS. The results of each case are analyzed and discussed. It can be shown that the distributed allocation of FESS can reduce the overloading on the generators and frequency fluctuations.

A control strategy based on Hamiltonian energy theory is proposed for the wind farm with flywheel energy storage system (FESS). The control of the ratio consensus of the flywheel energy storage system is realized by adjusting the speed of the flywheel energy storage unit. First, the port-controlled Hamilton (PCH) model of the flywheel energy storage unit is established, and the port-controlled Hamiltonian with dissipation (PCH-D) model is obtained by using the feedback stabilization principle of the PCH system. Then, the problem of the ratio consensus control of the flywheel energy storage system is investigated. In order to realize that all flywheel energy storage units can store and release energy at the same rate, the control strategy of Hamilton energy shaping is applied to adjust the speed of flywheel energy storage units. Finally, the effectiveness of the proposed control strategy is verified by simulations.

At the present level of technology the electricity generation has already ceased to be a problem. However, years are passing by under the slogan of seeking for methods of effective energy storage. The energy storage method shall be feasible and environmentally safe. That's why the methods, once regarded as inefficient, are recently taken into consideration. The development in materials technology (carbon fibre, semiconductors, etc.) brought back the concept of a flywheel. This idea has been applied to high-speed flywheel energy storage.

This paper describes how a flywheel demonstration unit will be placed on the International Space Station (ISS) in early 2000. Operation on ISS at this early date will allow adequate time to evaluate flywheel performance prior to the time the selection is made for replacing degraded batteries. If the flywheel performance is good, then the degraded batteries can be replaced with flywheels and the benefits of such a technology can be realized. If the performance is not good, then technology advancements must be made before flywheel energy storage technology is applied to some future space vehicle.

Abstract to study the flywheel energy storage technology, a great number of papers about the researches on and development of high-speed flywheel energy storage system in China and overseas were reviewed and summarized. The technology started early in foreign countries. It developed rapidly and has formed a certain series of products today, while in China, the research on this technology is quite laggard and still in the experimenting stage. Now there is no flywheel energy storage product which can be applied in practice in quantity. Therefore, the research on a new type of efficient and low power consumption energy storage flywheel is of great value and significance today.

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This master thesis was provided by ABB Cooperate Research in Västerås. This study has two major purposes: (1) to identify the characteristics of a flywheel energy storage system (FESS), (2) take the first steps in the development of a simulation model of a FESS. For the first part of this master thesis a literature reviews was conducted with focus on energy storage technologies in general and FESS in particular. The model was developed in the simulation environment PSCAD/EMTDC; with the main purpose to provide working model for future studies of the electrical dynamics of a flywheel energy storage system. The main conclusion of the literature review was that FESS is a promising energy storage solution; up to multiple megawatt scale. However, few large scale installations have so far been built and it is not a mature technology. Therefore further research and development is needed in multiple areas, including high strength composite materials, magnetic bearings and electrical machines. The model was implemented with the necessary control system and tested in a simulation case showing the operational characteristics.