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[en] A superconductor flywheel energy storage system (SFES) is an electro-mechanical battery which transforms electrical energy into mechanical energy for storage, and vice versa. Many aspects of the quasi-static behavior of flywheel rotors still need to be studied closely, and the rotors require a stable and highly efficient supporting system such as high temperature superconductor (HTS) bearings, which offer dynamic stability without the use of active control. Quasi-static properties of HTS bearings in the radial direction provide data to solve problems which may occur in a running system. Since stiffness in countering rotor vibration is the main parameter for designing an HTS bearing system, we investigated the quasi-static properties of the magnetic force between permanent magnets(PMs) and HTS bulks in the radial direction. We measured radial stiffness, and discovered that bearing stiffness varied greatly depending on the number of active HTS bulks. This is valuable data for predicting the change in stiffness during partial HTS bearing failure. The quasi-static test results are used for optimal design and performance prediction for the 100 kWh class superconductor bearing.
[en] A superconductor flywheel energy storage(SFES) system is mainly act an electro-mechanical battery which transfers mechanical energy into electrical form and vice versa. SFES system consists of a pair of non-contacting High Temperature Superconductor (HTS) bearings with a very low frictional loss. But it is essential to design an efficient HTS bearing considering with rotor dynamic properties through correct calculation of stiffness in order to support a huge composite flywheel rotor with high energy storage density. Static properties of HTS bearings provide data to solve problems which may occur easily in a running system. Since stiffness to counter vibration is the main parameter in designing an HTS bearing system, we investigate HTS bearing magnetic force through static properties between the Permanent Magnet(PM) and HTS. We measured axial / radial stiffness and found bearing stiffness can be easily changed by activated vibration direction between PM and HTS bulk. These results are used to determine the optimal design for a 10 kWh SFES.
[en] This project's mission was to achieve significant advances in the practical application of bulk high-temperature superconductor (HTS) materials to energy-storage systems. The ultimate product was planned as an operational prototype of a flywheel system on an HTS suspension. While the final prototype flywheel did not complete the final offsite demonstration phase of the program, invaluable lessons learned were captured on the laboratory demonstration units that will lead to the successful deployment of a future HTS-stabilized, composite-flywheel energy-storage system (FESS)
[en] Flywheel energy storage system (FESS) is defined as a high speed rotating flywheel system that can save surplus electric power. The FESS is proposed as an efficient energy storage system because it can accumulate a large amount of energy when it is operated at a high rotating speed and no mechanical problems are encountered. The FESS consists of a shaft, flywheel, motor/generator, bearings, and case. It is difficult to simulate rotor dynamics using common structure simulation programs because these programs are based on the 3D model and complex input rotating conditions. Therefore, in this paper, a program for the FESS based on the 2D FEM was developed. The 2D FEM can model easier than 3D, and it can present the multi-layer rotor with different material each other. Stiffness changing of the shaft caused by shrink fitting of the hub can be inputted to get clear solving results. The results obtained using the program were compared with those obtained using the common programs to determine any errors
[en] In Canada 1778 petajoules of energy were used in 2002 for heating buildings (and for hot water supply) and 136 petajoules were used for cooling the buildings. Most of that heating is accomplished by burning fossil fuels and other combustible materials, directly producing CO_2. About 544 petajoules of the heating and 130 petajoules of cooling use electricity as the energy source, producing CO_2 at the power generators, which generally rely on coal and natural gas to supply the extra power that is needed during the peak heating and cooling demand periods. The annual CO_2 production from these demands is estimated to be 101 million tonnes. These energy demands can be met using heat extracted from the air and stored in the ground. The advantages of using this technology include a reduction in the consumption of fossil fuels for power generation and an enhanced potential to use renewable energy sources like wind turbines and solar power sources. (author)
[en] Superconducting magnetic energy storage (SMES) systems offering flexible, reliable, and fast acting power compensation are applicable to power systems to improve power system stabilities and to advance power qualities. The authors have summarized researches on SMES applications to power systems. Furthermore, various SMES applications to power systems have been described briefly and some crucial schematic diagrams and equations are given. In addition, this study presents valuable suggestions for future studies of SMES applications to power systems. Hence, this paper is helpful for co-researchers who want to know about the status of SMES applications to power systems. (topical review)
[en] The starting point of any pulsed power setup is the energy storage system. This article discusses the characteristics of various energy storage devices useful for high power pulse discharges. The energy storage systems discussed are capacitative storage such as capacitor and Marx bank, inductive storage systems and explosively driven flux compression generators. (author)
[en] Since the dry storage of SNF (Spent Nuclear Fuel) assemblies has many merits, such as easy maintenance, low operational cost, few corrosion problems, low probability of radioactivity release, and no production of the secondary waste, it has been widely accepted by nuclear power plants in many countries, and becomes the major operational management trend of spent fuel before permanent disposal. Therefore, it is necessary to develop the optimal design technology of the dry storage system of SNF assemblies for the purpose of the domestic application. One of the key points related to the development of dry storage systems for SNF with high burn-up is that the decay heat should be efficiently removed by passive cooling. This paper represents the thermal performance of HCSM (Horizontal Concrete Storage Module) that is generally categorized into vault-type storage system