Curtis 1297 - Page 78

Curtis PMC 1297 Manual
70
Preliminary on Verso page is set with right edge at 7 and 7/8,
and the top (as on the Recto page) at 1/4.
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Tuning the Controller to the Motor
The 1297 controller has the flexibility to be tuned to nearly any separately
excited motor from any manufacturer. Parameters in the 13XX programmer’s
Program Menu allow full control of the motor’s maximum armature current
during driving and braking and full control of the motor’s maximum and
minimum field current as well as the field current relationship to the armature
current. This flexibility allows motor performance to be maximized while
protecting it from operating outside its safe commutation region.
In order to properly tune the controller, the following information should
be obtained from the motor manufacturer:
– peak motor armature current rating
– maximum motor field current rating
– minimum motor field current rating
– motor field resistance, hot and cold.
The performance of a separately excited motor depends on temperature. This is
due to the change in field winding resistance as the motor heats up through use.
When the field winding temperature increases, so does its resistance; therefore,
the maximum current that can be forced through the winding is reduced.
Reductions in the field current over the motor’s typical operating temperature
range can be 10% to 50%. Since the maximum available field current deter-
mines the maximum torque that can be produced by the motor, the vehicle’s
performance under load and up inclines will change as the motor heats up. The
change in performance can be limited by tuning the motor when it is hot rather
than cold. Therefore, it is recommended that the following procedure be
performed with a hot motor.
STEP 1. Using the programmer’s Program Menu, set the Drive Current
Limit parameter in each mode to the smaller of: (a) the motor’s
peak armature current rating, or (b) the controller’s full rated
drive current. This setting can be adjusted later to establish the
desired vehicle driving feel in each mode.
STEP 2. Set the Braking Current Limit parameter in each mode to the
smaller of: (a) the motor’s peak armature current rating, or (b) the
controller’s full rated braking current. This setting can be adjusted
later to establish the desired vehicle braking feel in each mode.
STEP 3. To set the Field Max parameter, first decide whether you want to
maintain consistent vehicle operation throughout the motor’s
temperature range. If you do, proceed to Step 4. If, however,
maintaining operational consistency across motor temperature is
not a concern—but achieving maximum torque is—proceed to
Step 5.
5 — VEHICLE PERFORMANCE ADJUSTMENT: Traction Tuning