Curtis 1297 - Field Check

Curtis PMC 1297 Manual
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3 A — PROGRAMMABLE TRACTION PARAMETERS: Field
Fig. 19 Field current
relative to armature
current, with field map
parameter set at 50%
and at 25%.
ARMATURE CURRENT
FIELD CURRENT
Field Map Start Field Map Midpoint Current Limit
0
0
Min Field
Max Field
Field Map
(50%)
ARMATURE CURRENT
FIELD CURRENT
Field Map Start Field Map Midpoint Current Limit
0
0
Min Field
Max Field
Field Map
(25%)
programmed drive current limit). This point is referred to as the Field Map
Midpoint.
With the field map parameter set at 50%, the motor’s field current
increases linearly with increasing armature current—thus emulating a series
wound motor. Decreasing the field map parameter 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 as its load increases; however, the motor’s capability to produce torque at
these higher speeds will decrease.
The field map parameter is tuned as part of the vehicle performance
adjustment process (Section 5).
FIELD CHECK
The field check parameter enables the field open fault check, when it is pro-
grammed On. In applications where the motor field is too low to provide valid
fault data (< 5 amps at 97% PWM), this parameter should be programmed Off.
In most applications, it should be programmed On.