Altivar
®
58 TRX AC Drives
Speed Regulation (Constant Torque Rated Products)
© 2000–2003 Schneider Electric All Rights Reserved
96
09/2003
SPEED REGULATION (CONSTANT TORQUE RATED PRODUCTS)
Figures 1 and 2 are speed/torque plots of an ATV58 TRX Type H controller operating in constant torque
mode with an off-the-shelf AC motor operating in open loop mode (without an encoder or tachometer
feedback from the motor) and in closed loop mode (with a 1024 pulse per revolution encoder feedback
from the motor). To demonstrate the speed regulation capabilities, these plots were generated by
operating the drive from no load at zero speed to full load at various speeds. The autotune feature was
configured. The gain parameter was adjusted to 50% and the stability parameter was adjusted to 50%.
Note the speed regulation capability of the ATV58 TRX drive controller as exhibited by the portion of the
speed torque curve that is nearly perpendicular to the Y-axis.
Maximum Transient Torque
Figures 3 and 4 are speed/torque plots of an ATV58 TRX Type H drive controller operating in constant
torque mode with an off-the-shelf AC motor operating in open loop mode (without an encoder or
tachometer feedback from the motor) and in closed loop mode (with a 1024 pulse per revolution encoder
feedback from the motor). To demonstrate the torque producing capabilities, these plots were generated
by operating the drive from no load at zero speed to maximum transient torque at various speeds. The
autotune feature was configured. The gain parameter was adjusted to 50% and the stability parameter
was adjusted to 50%. The available overtorque is a function of the motor design category. For typical
NEMA Design B motors, the ATV58 TRX controller can deliver 200% of the nominal motor torque for 2
seconds, and 170% for 60 seconds.
Note the 200% transient torque produced by the ATV58 TRX Type H model, and note the torque
producing capabilities at very low speeds.
Operation in overspeed:
• In overspeed operation, the voltage no longer increases with the frequency, resulting in reduced
induction in the motor which results in loss of torque. Consult the motor manufacturer to ensure that
the motor can operate in overspeed.
• For a special motor, the nominal frequency and the maximum frequency can be adjusted between 10
and 500 Hz using the keypad display, PowerSuite, or Commissioning software.
Figure 1: ATV58 TRX Type H Controller Open Loop
Speed Regulation: 0.5 s Transition from No Load to 100%
Load
Figure 2: ATV58 TRX Type H Controller w/ Digital Encoder Card
Speed Regulation: 0.5 s Transition from No Load to 100% Load
Figure 3: ATV58 TRX Type H Controller Open Loop
Maximum Transient Torque
Figure 4: ATV58 TRX Type H Controller w/ Digital Encoder
Card, Maximum Transient Torque
100%
75%
50%
25%
0%
036 10 20 30 40 50 60Hz
Percentage of Rated Torque
TypeHOpnSpd.eps
100%
75%
50%
25%
0%
036 10 20 30 40 50 60Hz
Percentage of Rated Torque
Ty p e HE n cS p d . e p s
250%
150%
100%
50%
0%
036 10 20 30 40 50 60Hz
200%
Percentage of Rated Torque
TypeHOpnTrq.eps
250%
150%
100%
50%
0%
036 10 20 30 40 50 60Hz
200%
Percentage of Rated Torque
TypeHEncTrq.eps
