Field Map - Curtis 1244 User Manual

Curtis 1244 Manual,
Rev. E
3 — PROGRAMMABLE PARAMETERS:
Care should be taken to ensure that high Field Map Start values do not
move the motor's operating characteristics outside its safe commutation area.
Recommendations for adjusting the Field Map Start parameter to achieve vari-
ous performance characteristics are provided in Section 6: Vehicle Performance
Adjustment Guidelines.

FIELD MAP

The field map parameter defines the variation of the field winding current as a
function of armature current. It controls how much field current is applied for a
given armature current, and is adjustable from 0% to 100%, in 5% increments.
The Field Map parameter is set as a percentage of the field current between
the Field Min and Field Max values. As shown in Figure 19, the Field Map
parameter increases or decreases the field current at the armature current that is
halfway between the Field Map Start current and the controller's programmed
drive current limit. This point on the armature current curve is referred to as
the Field Map Midpoint.
With the Field Map set at 50% and the Field Map Start set at zero, the
motor's field current increases linearly with increasing armature current—thus
emulating a series wound motor. Decreasing the field map setting reduces the
field current at a given armature current, i.e., it weakens the field. As the field
current is reduced, the motor will be able to maintain speeds closer to the
maximum speed value.
Care should be taken to ensure that excessively low Field Map values do
not move the motor's operating characteristics outside its safe commutation
region. Recommendations for adjusting the Field Map parameter to achieve
various performance characteristics are provided in Section 6: Vehicle Perfor-
mance Adjustment Guidelines.
Field Control Parameters
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