Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 157)

Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011 157
Detailed Drive Operation Chapter 1
Integral Gain
The speed droop is subtracted from the filtered speed error (after the servo lock is
added and the anti-backup is subtracted). This signal is then sent to the integral
gain block. The integral gain block outputs a torque command relative to the
error integrated over a period of time.
Parameter 82 [Spd Reg I Gain] sets the integral gain of the speed regulator. It's
value is automatically calculated based on the bandwidth setting in [Spd Reg
BW] and the inertia of the system in [Total Inertia]. Integral gain may be
manually adjusted by setting [Spd Reg BW] to a value of zero. Units are (per unit
torque/sec) / (per unit speed). For example, when [Spd Reg I Gain] is 50 and the
speed error is 1%, the integral output will integrate from 0 to 50% motor rated
torque in 1 second.
When parameter 153 [Control Options], bit 12 “Jog-NoInteg” is turned on, this
tells the speed regulator not to use the integral gain during jog commands.
When parameter 151 [Logic Command], bit 5 “SReg IntgHld” is turned on, the
Integrator holds its output at the present level until the bit is turned off again.
When parameter 151 [Logic Command], bit 6 “SReg IntgRst” is turned on, the
output of the integrator is set to 0. When bit 6 is turned back off, the integrator
output starts integrating up again from 0.
When parameter 153 [Control Options], bit 18 “SpdRegPreset” is turned on, the
value in parameter 303 [Motor Torque Ref ] is added to the integrator output.
When bit 18 “SpdRegPreset” is turned off, parameter 87 [SReg Trq Preset]
(default of 0 per unit) is added to the integrator output.
Parameter 101 [SpdReg Integ Out] contains the value of the torque output from
the integrator. This parameter is in per unit so that a value of 1 equals rated motor
torque.
Droop
Droop is used to “shed” load and is usually used when a soft coupling of two
motors is present in an application. For more information on droop, see
Droop
on page 47 .
Speed Regulator Output Limits
The outputs from the proportional block and integrator block are summed
together, creating a torque reference. This torque reference is limited by
parameter 102 [Spd Reg Pos Lim] and parameter 103 [Spd Reg Neg Lim].