R&D

World’s Largest Superconducting Flywheel Power Storage System Test Machine Completed andTest Operation Started

PDF Download

April 15, 2015
Railway Technical Research Institute
Kubotek Corporation
Furukawa Electric Co., Ltd.
Mirapro Co., Ltd.
Public Enterprise Bureau of Yamanashi Prefecture

The Railway Technical Research Institute (RTRI) has been developing a superconducting flywheel power storage system, as a next-generation power storage system, jointly with Kubotek Corporation, Furukawa Electric Co., Ltd., Mirapro Co., Ltd. and the Public Enterprise Bureau of Yamanashi Prefecture. This development has been supported by the New Energy and Industrial Technology Development Organization as a one of the projects for “the Technical Development for Safe, Low-Cost, Large-Capacity Battery Systems.”

Now the world’s largest-class superconducting flywheel power storage system with a superconducting magnetic bearing was completed and test operation was started.

The flywheel power storage system is capable of storing electricity in the form of kinetic energy by rotating a flywheel, and converting the rotating power again to electricity, if necessary. Since this rechargeable battery does not deteriorate over time, it can be used for many purposes. For example, being combined with rather unstable power-generation systems such as photovoltaic or wind-power generation, it can help stabilize power supplies. It is also possible to apply this system to railways in order to prevent regenerative cancellation. For this system, RTRI developed a superconducting magnetic bearing composed of a high-temperature superconducting coil and high-temperature superconducting bulk. In this system, the flywheel is levitated by the superconducting magnetic bearing without contact. Therefore, the power loss is minimal although a large flywheel is used, and it is a very practical system which enables stable power generation over a long period.

The completed system is the world’s largest-class flywheel power storage system using a superconducting magnetic bearing. It has 300-kW output capability and 100-kWh storage capacity, and contains a CFRP (carbon-fiber-reinforced-plastic) flywheel. This flywheel is 2 m in diameter and weighs 4 tons, and is rotated with a superconducting magnetic bearing at a maximum speed of 6,000 RPM. This is the world’s first superconducting magnetic bearing which uses superconducting material both for its rotor and bearing, and is capable of supporting heavy weight, although it is a compact-sized system.

The details of this technical development will be presented at the 91st Cryogenic and Superconducting Engineering Technical Meeting scheduled on May 27, 2015. Grid-connection tests with a megawatt-class solar power plant will also be started this summer at Komekurayama in Yamanashi Prefecture.

This system has been developed jointly with Kubotek Corporation, Furukawa Electric Co., Ltd., Mirapro Co., Ltd., and the Public Enterprise Bureau of Yamanashi Prefecture, in a project known as “the Technical Development for Safe, Low-Cost, Large-Capacity Battery System - the Development of the Next-Generation Flywheel Power Storage System” sponsored by the New Energy and Industrial Technology Development Organization (NEDO).


* You can see all the photos and figures in the PDF file above.