Curtis 1238SE - Page 92

8A — AUTOMATED ACIM MOTORCHARACTERIZATION PROCEDURE
Curtis 1232E/34E/36E/38E & 1232SE/34SE/36SE/38SE Manual, os 31 – May 2017 Return to TOC
pg. 88
16. Run the Field Weakening test.
is test will enable you to decide between a more ecient (less torque) or more torque (less
ecient) operation above the base speed, by adjusting the Field Weakening Drive parameter.
Note: the present Field Weakening Drive value (0%) was determined by the above auto-
characterization routine, and is not the default value (100%) in the native OS intended for the Curtis
dynamometer characterized motors when a motor type (number) is utilized. e dierences are:
Auto Characterized: Field Weakening Drive is adjusted UP from 0% to the max Field
Weakening Drive determined in this text.
Dyno Characterized: Field Weakening Drive is adjusted DOWN from 100%
(can be set from 0–100%)
Increasing this parameter toward 100% will progressively allow more torque (along with more
current) at high motor speeds, but increasing it too much will actually reduce torque while still
driving a great deal of current. e auto-characterization value of 0% will give the most ecient
motor operation, but will not give the highest torque at high speeds.
If more torque is required at high speeds, run this Field Weakening Drive test.
On the 1313 programmer, add these two items to the Favorites shortcut, along with Field
Weakening Drive parameter, so you can easily toggle between them:
Parameters (Program) » Motor » Control Algorithms » 0-ACIM » Field Weakening Control » Field Weakening Drive
Parameters (Program) » Vehicle » Capture Speed 1, 2
Monitor » Vehicle » Time Between Speeds
Set Capture Speed 1 and 2 to values that are close to the Max Speed setting. e Capture Speed
1 and 2 values MUST be set higher than the measured FW Base Speed in step 15 (because Field
Weakening only aects performance at speeds above the “base speed”). Ideally the Capture
Speed 1, 2 values should be above the second corner point of the motor torque – speed curve.
For example, if the Max Speed is set to 4000 rpm, set Capture Speed 1 = 3500 rpm and Capture
Speed 2 = 3800 rpm:
Parameters (Program) » Speed Mode Express » Max Speed
Parameters (Program) » Speed Mode » Speed Controller » Max Speed
Parameters (Program) » Torque Mode » Speed Limiter » Max Speed
From a stop, apply full throttle to accelerate to a speed greater than Capture Speed 2. Note the
value displayed in Monitor » Vehicle » Time Between Speeds.
Now increase the Field Weakening Drive setting and repeat the acceleration in the same
direction, with the same load, and with the same full throttle and again note the Time Between
Speeds value.
Keep adjusting the Field Weakening Drive value and repeating the test until you nd the Field
Weakening Drive value that results in the smallest Time Between Speeds. is Field Weakening
Drive value should be used for applications that require the most torque at high speeds.
Some Field Weakening Drive settings may result in a test acceleration run where Capture Speed 2 cannot
be obtained. ese Field Weakening Drive settings cannot provide enough torque to get the vehicle past
Capture Speed 2, and thus can be ignored.
Use the Field Weakening Drive setting that best matches the application. It will be somewhere between
0% (most ecient, least motor heating) and the setting found in this test (highest torque at high speeds).
NOTE: e Field Weakening Drive setting will have no eect at motor speeds below FW Base Speed.
17. Return to Chapter 6 and complete Initial Setup Steps 12 through 14.
Quick Links:
Max Speed
Express Mode p.31
Speed Mode p.32
Torque Mode p.39
Capture Speed 1,2 p.64
Field Weakening Drive p.56
Time Between Speeds p.77