Speed Regulator - Allen-Bradley PowerFlex 70 Reference Manual

Speed Regulator

through. This is due to the positive and negative minimum speeds. If the
reference is positive and less than the positive minimum, it is set to the positive
minimum. If the reference is negative and greater than negative minimum, it is set
to the negative minimum. If the minimum is not 0, hysteresis is applied at 0 to
prevent bouncing between positive and negative minimums. See below.
Max Spd
Min Spd
– Max Spd – Max Spd
Maximum frequency
The maximum frequency defines the maximum reference frequency. The actual
output frequency may be greater as a result of slip compensation and other types
of regulation. This parameter also defines scaling for frequency reference. This is
the frequency that corresponds to 32767 counts when the frequency reference is
provided by a network.
The drive takes the speed reference that is specified by the speed
FV
Vector
reference control loop and compares it to the speed feedback. The speed
regulator uses proportional and integral gains to adjust the torque reference that
is sent to the motor. This torque reference attempts to operate the motor at the
specified speed. This regulator also produces a high bandwidth response to speed
command and load changes.
Integral Gain
FV
Vector
The integral gain block outputs a torque command relative to the error
integrated over a period of time.
[Ki Speed Loop] sets the integral gain of the speed regulator. Its value is
automatically calculated based on the bandwidth setting in [Speed Desired BW].
Integral gain may be manually adjusted by setting [Speed Desired BW] to a value
of zero. Units are (per unit torque/sec) / (per unit speed). For example, when [Ki
Speed Loop] is 50 and the speed error is 1%, the integral output will integrate
from 0 to 50% motor rated torque in 1 second.
Proportional Gain
Vector FV
The proportional gain determines how much of a speed error occurs during a
load transient.
[Kp Speed Loop] sets the proportional gain of the speed regulator. Its value is
automatically calculated based on the bandwidth setting in [Speed Desired BW].
Proportional gain may be manually adjusted by setting [Speed Desired BW] to a
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
Max Spd
Min Spd
Band
– Min Spd
Speed Regulator
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