Digitax DBE1100S, Руководство пользователя

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DigitAx User Guide
Issue code: dgxu4
10-7
Reliable operation at 409.6kHz occurs when the step
height of the frequency input pulse train is
≥
15V.
Make the following settings for frequency reference
control:
1.
Set b14 at 0.
2.
Set b15 at 0.
3.
Set b17 at 0.
Ramps can be selected by setting b7 at 1. When
selected, all three methods of speed control will be
subject to the ramps during changes in speed. All
ramps (acceleration and deceleration in forward and
reverse) are independently controlled, and can be
set in terms of milliseconds per 1000
RPM
in Pr9 ,
Pr10 , Pr11 and Pr12 .
10.10 Methods of torque control
Any of the following three methods can be used to
run the Drive in torque control:
•
Analog input signal
•
Digital input signal
•
Speed control with external torque limit
Warning
Before selecting torque
control, set parameter b2 at
0 to disable the Drive, and
ensure the motor is at
standstill. The Drive can
subsequently be enabled by
setting b2 at 1.
Analog torque control
This mode of operation allows the shaft torque
from the motor to be controlled using an analog
reference applied to terminals B9 and B10. This
input can also be used for master/slave applications
where the motors or their loads are coupled
together in some way to allow load sharing. The
master Drive would be in speed control, and the
current demand output from the master would be
used as the torque reference for the slave.
Protection against excessive motor speed is given
by the Drive tripping on trip
OS
if the speed set in
Pr58
is exceeded.
Use the following procedure to set the Drive in
analog torque reference control:
1. Set
b2
at 0 to disable the Drive
2. Ensure the motor is stopped.
3.
Set b6 at 1 to select torque control.
4. Set
b8
at 0 to select analog torque reference
Digital torque control
The torque reference for the Drive is controlled by
parameter
Pr8 , and is set as the percentage of I
max
.
The range of Pr8 is –100 to +100; the maximum
corresponds to the value of maximum current. (See
Pr42 in Chapter 11 List of Parameters ). This allows
the torque output to be controlled using serial
communications.
Protection against excessive motor speed is given
by the Drive tripping on trip
OS if the speed set in
Pr58 is exceeded.
Use the following procedure to set the Drive for
digital torque reference control:
1. Set
b2
at 0 to disable the Drive.
2. Ensure the motor is stopped.
3.
Set b6 at 1 to select torque control.
4.
Set b8 at 1 to select digital torque reference.
Speed control with external torque limit
Speed control with external torque limit allows the
maximum speed to be controlled while the Drive is
in torque control.
When the motor is under load, the Drive tries to run
the motor at the speed set by the speed reference.
It is prevented from doing so while the output
current (torque) is limited by the value set by the
torque input signal. When the load reduces
sufficiently to reduce the output current to below
the value set by the torque input signal, the motor
speed attains the value set by the speed reference.
When parameter b11 is set at 1, terminal B1 becomes
an analog speed reference input, and controls
parameter
Pr41 . This sets the value of current limit
which in effect applies torque control to the motor.
Use the following procedure:
1.
Set b6 at 0 to select speed control. (See
Methods of speed control for setting up
the Drive for the required speed reference).
2. Set b11 at 1 to select external torque limit.
3.
Set b56 at 0 to disable the external trip
function of terminal B1.
4.
Apply the required signal to terminal B1 (
±
10V
gives torque limited to
±
100% of I
pk
).
(See Pr42 ).