AMD2000 Series - Servo Drive - User Manual
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DS619-0-00-0019 - Rev 0
ANCA Motion
If Motor Type =IM V/F
When the user has selected to pair the drive with an induction motor, there are other options available for the
motor control. The AMD2000 gives the user the ability to control the speed of induction motors using Voltage
over Frequency (V/F). V/F control switches ON when the velocity command from either the position control loop
or an externally originating NC velocity command via IDN S-0-0036 / 36 exceeds the minimum speed threshold
defined via IDN P-0-0219 / 32987.
Warning:
It is NOT recommended practice for Induction Motor V/F Control to be driven from the position
control loop, as difficulties with low speed control using this technique may cause undesirable or unexpected
motions.
When V/F control is turned on, VF control
– max current (P-0-0215 / 32983) is issued as the current command; if
the velocity command drops below the minimum (P-0-0219 / 32987) then braking is executed with the stop
current (P-0-0216 / 32984) and stop voltage (P-0-0217 / 32985) for the duration of the stop time (P-0-0218 /
32986).
The V/F curve is produced as a look-up table with inputs specifying the number of break points (P-0-212/32980)
and corresponding velocity and voltage break points (P-0-213/32981, P-0-214/32982).
Figure 10-23 Voltage / Frequency Curve Example
Number of break points (up to 5):
P-0-0212 = 3
Velocity break points [RPM]:
P-0-0213 = [450, 6000, 7000]
Voltage limit break points [V]:
P-0-0214 = [25, 294, 339]
Applying Current Control Loop Parameters (for PMSM or IM V/F)
Tuning parameters for the current control loops may be configured at any time; however such configuration is not
applied until either the drive re-
enable is carried out (see “Operation Modes” elsewhere in this manual) or
manually triggered by the user.
To manually trigger a current control loop re-tune
10
, the user may execute the
Motor Control Tuning Procedure Command (P-0-510 / 33278) by changing its default value from 0 to 3
(essentially setting its two least significant bits to 11 from their default setting which is 00). Doing this ‘execution’
will also re-tune the torque control loop.
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The user should note that the drive software looks for a rising edge
change in P-0-510 / 33278 from 0 to 3, so it may be useful to check that the parameter is set to 0 prior to making
the change to 3 for execution or the retuning may not occur.
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A “re-tune” is an internally executed recalibration and calculation of the necessary control variables for efficient execution of the desired control
behaviour. It does NOT mean the drive changes any variables or gains in the control loops as set by the user.
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Note that a similar execution command exists for the position and velocity control loops, called the Servo Control Tuning Procedure Command
(P-0-187 / 32955). The user should be made aware that if the Servo Control Tuning Procedure Command
is executed, it ALSO re-tunes the
current and torque control loops at the same time.
