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Westek Electronics specialises in
harmonics mitigation filters for
power circuits, converters,
inverters, UPS systems, variable
speed drives and other non-linear
loads such as induction furnaces.
The product scope also includes
harmonics filtering for solid-state
inverter system outputs including
variable speed drives and common
mode IGBT switching noise filters to
extend variable speed motor life.
Passive filters available cover a
large range of currents to 600
amperes and higher and for voltages
to 600 Volt. Filters with broadband
response are available and these are
suitable for harmonics mitigation in
variable as well as multiple loads.
The use of harmonics filters is
highly recommended since sub-station
transformers are not normally rated
for high harmonic content loads and
can therefore be stressed beyond
their permitted temperature rise.
Westek Electronics supplies
active filters for general harmonic
mitigation tasks including the
unloading of harmonic content from
building risers, unloading of switch
boards and static power factor
correction installations.
Three-phase as well as single-phase
active filters (the latter are
particularly useful for IT loads on
sub-distribution board level) are
available to very large ratings
appropriate to entire building and
factory loads. |
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A large range of line and
load reactors as well as DC link
chokes are also available.
Reactors are available for
suppression of 5th and 3rd
harmonics and the use of DC link
chokes supplements line reactors
in that less impedance and
therefore less motor torque
limitations are imposed through
the reduction of input voltage.
Westek Electronics also supplies
sine wave filters and dV/dt
filters. The sine wave filters
are particularly useful for use
in variable speed drives with
small- and non-fluctuating
loads. The dV/dt filters on the
other hand can be used in
situations where dynamic loads
are encountered and are highly
recommended for applications
involving long cable runs.
Without the use of such a
filter, dangerously high voltage
can be built up that damage both
the cable as well as the
insulation of connected loads
such as variable speed motors.
Common mode filters which in
effect short circuit the leakage
current caused by the inverter
stage of variable speed drives,
feeding this back to the DC
link, extend motor life greatly
by preventing the flow of this
current to earth via the motor
bearings and frame. |
