Allen-Bradley PowerFlex 70 Enhanced Control, Справочное руководство, Страница: 108 / 170

104 Speed Regulation
Integral Gain
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
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
value of zero. Units are (per unit torque) / (per unit speed). For example, when [Kp
Speed Loop] is 20, the proportional gain block will output 20% motor rated torque
for every 1% error of motor rated speed.
Feed Forward Gain
The first section of the PI regulator is the feed forward block. [Kf Speed Loop]
allows the speed regulator to be dampened during speed changes. To reduce speed
overshoot, reduce the value of [Kf Speed Loop]. During auto-tune, the feed forward
is left open (no dampening).
Speed Desired BW
[Speed Desired BW] sets the speed loop bandwidth and determines the dynamic
behavior of the speed loop. As bandwidth increases, the speed loop becomes more
responsive and can track a faster changing speed reference. Adjusting this
parameter will cause the drive to calculate and change [Ki Speed Loop] and [Kp
Speed Loop] gains. Setting this parameter equal to zero allows manual adjustments
to Ki and Kp.
Total Inertia
[Total Inertia] represents the time in seconds, for a motor coupled to a load to
accelerate from zero to base speed, at rated motor torque. The drive calculates Total
Inertia during the autotune inertia procedure. Adjusting this parameter will cause
the drive to calculate and change [Ki Speed Loop] and [Kp Speed Loop] gains.
Simulator
The simulator mode allows the drive to be operated in a closed loop simulation
mode without a motor connected and is meant for demo purposes only. If a motor is
connected with this mode selected, very erratic and unpredictable operation will
occur.