ENERTRON has developed a bidirectional converter for Flywheel
Energy Storage.
The specific application for which this converter was developed
is a bidirectional converter with IGBT that controls a Flywheel
Energy Storage Switch Reluctance Machine and a second IGBT
converter connected to the grid.
This last converter permits an independent remote control of the
active and reactive power. This feature makes this converter
suitable for weak grids where it is necessary to stabilize the
voltage by controlling the reactive power feeded by the inverter.
The main features of the two converters that make up the system
are:
Grid side converter. It is a three phase IGBT converter with
DSP-based field oriented control and generation of three phase
currents with low harmonic content (<5% at nominal power). It
allows the control of the active and reactive powers to and into
the grid.
Generador side converter. It is a bidirectional converter
specifically designed for a switch reluctance machine operating
at 30.000 rpm maximum. The functioning strategies are
implemented in a control with DSP and microcontroller.
Overpower dissipation system (chopper). It is necessary to
provide the system with a energy sinking unit to dissipate the
power that cannot be stored in the flywheel energy storage
system.
Both converters include serial communication for external
monitorinag and permit the modification of the operation
parameters through keyboard and display. This facilitates the
tracking of the converter operation.
Both converters include start and stop sequencial
procedures controlled by each converter’s microcontroller. |
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The picture above shows a 50 kW prototype including the grid side
converter, flywheel storage converter and chopper.
The following image shows the converter output currents at nominal power.
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