Flywheel batteries come around again

Theoretical and experimental analysis of the lubricating system of a high speed multiplier

“…This pressure will be adjusted at 10 bars. Two manometers (5) are used, one before and one after the oil filter (9). If the pressure difference between the two pressures is more than 1.72 bars, the oil filter must be changed.…”

“…Different types of hybrid car systems based on flywheel energy storage were developed [4]- [7]. Flywheel energy storage is also used in space applications, as UPS in case of a power failure and as energy regulator in electrical grids [8], [9]. In order to accumulate maximum of energy at high speed, if the flywheel diameter is less than 50 cm it has to operate at speeds above 15000 rpm in a low friction environment like vacuum in order to minimize friction [10].…”

Technology and Key Strategy of IE4 Permanent Magnet Brushless DC Motor Drive for Electric Vehicle Application

“…The efficiency of the fuel cell depends on the power drawn, higher the power drawn, lower is the efficiency. Losses occur due to the voltage drop on the internal resistance and the fuel cells have relatively longer response time [43][44][45]. Also, fuel cells are more expensive than the other batteries.…”

Limits, Modeling and Design of High-Speed Permanent Magnet Machines

“…An example of such a special application is 60.000 rpm, 4.1 kW magnetically levitated flywheel which NASA intends to use as a replacement for batteries on the space stations [173].…”