Matrix Series D Users Manual
34
Part No.
INSTR-025 REL. 071207
FILTER DESCRIPTION
The MTE Matrix Filter® is a low pass filter
containing proprietary technology, which
makes it particularly useful for harmonic
mitigation of adjustable speed drives. Figure
20 shows a block diagram of the filter.
Three phase AC power is connected to the
Harmonic Mitigating reactor HMR section
which contains patented circuitry which
inhibits oscillation of the filter with the AC
power system. Shunt resistors and
capacitor panels make up the rest of the
filter. Because of the capacitor bank the
filter operates with leading power factor at
light loads, but unlike trap filters the MTE
Matrix Filter® does not produce significant
voltage rise at the point of common coupling
with the power system.
The Matrix Filter® is suitable for use with
AC and DC drives and they can be used in
both regenerative and non-regenerative
applications when properly selected. For AC
regenerative drives application consult the
factory.
Filters for variable torque AC drives rated
7.5 Hp and above should be selected for a
filter output current rating greater than or
equal to the motor current rating. If the
motor current rating is not available, use the
NEC motor current rating.
Filters for variable torque AC drives rated 2
– 5 Hp should be selected for a filter output
current rating greater than or equal to 105%
of the motor current rating. If the motor
current rating is not available, select on the
basis of 105% of the NEC motor current
rating.
Filters for variable torque AC drives rated
less than 1.5 Hp should be selected for an
output current rating greater than or equal to
110% of the motor current rating or 110%
OF the NEC motor current rating.
For constant torque, AC and DC drive
applications operating from six pulse
rectifier front ends selected a filter current
rating according to application engineering
note “Matrix Filter® Operation in Constant
Torque Applications with Six Pulse
Rectifiers” or consult MTE engineering. For
phase controlled DC drive applications,
select filter current rating per application
note “Matrix Filter® with Phase Controlled
DC Drivers.
Where a single filter is used to feed multiple
drives, the output current rating of the filter
should be selected to equal the total current
rating of the individual drives when
calculated according to the instructions
above.
Because the filter supplies harmonic
currents required by the drive, linear loads
(such as space heaters, incandescent
lighting and AC motors operated across the
line) should not be connected to the output
of the filter
.
