Page 22 - Industrial Technology January 2020

MACHINE BUILDING

ENERGY ON THE FLY

DRIVES AND CONTROLS

Steel housing

YOU CAN’T REINVENT THE FLYWHEEL, BUT YOU CAN REVOLUTIONISE
IT. WHEREVER THERE IS A NEED FOR LARGE NUMBERS OF CHARGING
AND DISCHARGING CYCLES, THE ENWHEEL FLYWHEEL SYSTEM SETS Active magnetic
bearing
NEW STANDARDS. DRIVE CONTROLLERS AND SINE-WAVE FILTERS
CONTROL ENERGY FLOW IN THESE KINETIC ENERGY STORAGE UNITS Vacuum

he efficient and optimised use of electricity Carbon-fibre rotor
generated from renewable energies calls for an
appropriate form of storage. In the recently
Tdeveloped EnWheel flywheel energy storage units Generator and motor
from German company Stornetic, Combivert F6 drive
controllers from KEB control the energy flow together with
Active magnetic
specially developed sine-wave filters.
bearing
Leitmarkt Agentur NRW achieved this with the help of
the EU-funded Quirinus project, which focuses on
developing sustainable security of supply. This is ensured
by high and efficient system stability in increasingly
decentralised generation plants that feed their power into
the grid on a fluctuating basis. The surplus energy is therefore the lowest electrical losses on the rotor side of l System solution with drive controller and sine-wave
stored in electrochemical storage systems (Li-Ion or the drive. filter for THD values less than 1.5%
SuperCap) or as kinetic energy in flywheels. These forms The ‘Speed Search’ function, which is further l Idle Mode via Speed Search function up to 45,000
of storage are particularly attractive in order to absorb optimised by its use in the F6 drive controller, is revolutions per minute.
peak loads and therefore keep the supply network responsible for the load application and release of the l Operation of the motor with optimised switching
constant. Flywheel energy storage units are particularly flywheel rotor in Idle mode, which ensures an immediate frequency at output frequencies up to 750Hz.
suitable for ensuring consistent capacity over many charge connection to the rotating rotor up to maximum speed. l Optimum overall efficiency.
and discharge cycles. Stornetic develops and produces Due to the possible load release in Idle mode, the l Fast response times and high power gradients without
storage systems of this kind with DuraStor. complete switching losses of the IGBTs in the drive diminishing performance over the entire service life of the
In the event of an energy surplus, the EnWheel controller are eliminated for yet another contribution to system.
accelerates an active magnetically mounted carbon-fibre better energy utilisation. With this and other successful projects in the
rotor up to 45,000 revolutions per minute. The drive is Fields of application are increasingly created by the renewables sector, KEB has demonstrated its value as a
disabled for interim storage of rotational energy (Idle concept of “microgrids” to compensate for peak loads and successful partner and influential supplier with the
mode). As the rotor rotates freely in a vacuum, there are thus the stabilisation of local grids. The solution offers a knowledge, experience and breadth of products to help
virtually zero friction losses. If energy is required, the drive number of benefits: companies overcome their application challenges.
synchronises to the rotating rotor and feeds the ‘braking
energy’ back into the network.
In addition to shutdown and synchronisation on the
rotating rotor, the cooling of the motor with low heat
transfer in the vacuum is one of the particular challenges.
In the new generation of flywheel energy storage units,
KEB Combivert F6 drive controllers function in
combination with specially developed sine-wave filters to
control the energy flows in the flywheel energy storage
units. The efficiency optimisation in the overall system is
based on an ideally tailored package consisting of a drive
controller, sine-wave filter and synchronous motor in the
EnWheel with minimised harmonic content (THD) and
“

FLYWHEEL ENERGY STORAGE
UNITS ARE IDEALLY SUITED TO
ENSURING CONSISTENT
CAPACITY OVER MANY CHARGE
AND DISCHARGE CYCLES

MORE INFORMATION: www.keb.co.uk • info@keb.co.uk • Tel: 01933 402220

INDUSTRIAL TECHNOLOGY • January 2020
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