PowerFlex 750-Series AC Drives User Manual

Programming and Parameters 3-73FileGroupNameDescriptionNo.642 755 Servo Lock GainServo Lock GainSets the gain of an additional integrator in the Vector control mode speedregulator. The effect of Servo Lock is to increase stiffness of the speed responseto a load disturbance. It behaves like a position regulator with velocity feedforward, but without the pulse accuracy of a true position regulator. Gain shouldnormally be set to less than 1/3 speed regulator bandwidth, or for the desiredresponse. A value of zero disables this feature.643 SpdReg AntiBckupSpeed Regulator Anti-backupAllows control of over-shoot/under-shoot in the step response of the Vectorcontrol mode speed regulator. Over-shoot/under-shoot can be effectivelyeliminated with a setting of 0.3, which will remove backup of the motor shaft whenzero speed is reached. This parameter has no affect on the drive's response toload changes. A value of zero disables this feature.Over-ShootValuesUnits: /SecDefault: 0.000Min/Max: 0.000 / 300.000Default: 0.0000Min/Max: 0.0000 / 0.5000Read-WriteData TypeRW RealRW RealErrorOver-ShootSPEED CONTROLSpeed RegulatorReferenceFeedback, SpdReg AntiBckup = 0.0Feedback, SpdReg AntiBckup = 0.3Under-ShootErrorUnder-Shoot644 Spd Err Fltr BWSpeed Error Filter BandwidthSets the bandwidth of a 2nd order Butterworth low pass filter that is located in theproportional gain section of the speed regulator (in FV motor control modes). Itfilters a signal that is derived from P641 [Speed Error]. The purpose of this filter isto reduce quantization noise.When P636 [Speed Reg BW] is set to a non-zero value, this filter will beautomatically set. If P636 [Speed Reg BW] is set to zero, this filter setting mustbe manually adjusted. It is normally set to at least 3 to 5 times the value of P636[Speed Reg BW]. A value of zero disables the filter.The rules that are used to set the error filter bandwidth in automatic mode are asfollows:1. If the primary motor velocity feedback is Open Loop, then the error filter is setto 5 times P636 [Speed Reg BW].2. If a primary motor velocity feedback device has been selected and P704[InAdp LdObs Mode] = 1 “InertiaAdapt,” then the error filter is set to 3 timesP636 [Speed Reg BW].3. If a primary motor velocity feedback device has been selected and P704[InAdp LdObs Mode] = 0 “Disabled” or 2 “LoadObserver” then the error filter isusing a table look up value determined by the setting of P126 [Pri VelFdbkFltr].Important: When Auto Tach Switchover is enabled through P635 [Spd OptionsCntl], this filter adjustment applies only to the primary feedback source. The filtersetting P651 [AltSpdErr FltrBW] is used for the alternate feedback source.645 Speed Reg KpSpeed Regulator KpSets the proportional gain of the speed regulator (in FV motor control modes).This value is automatically calculated based on the bandwidth setting in P636[Speed Reg BW] and P76 [Total Inertia]. The proportional gain may be manuallyadjusted by setting P636 [Speed Reg BW] to a value of zero. Proportional gainhas effective scaling of (per unit torque) / (per unit speed). The maximumallowable value of this parameter is limited by P76 [Total Inertia] and P646 [SpdReg Max Kp].646 Speed Reg Max KpSpeed Regulator Maximum KpLimits the maximum value of P645 [Speed Reg Kp] and P649 [Alt Speed RegKp]. When gains are automatically calculated, this parameter is necessary to limitthe amplification of noise with increased inertia.Units: R/SDefault: 50.00Min/Max: 0.00 / 8000.00Default: 20.00Min/Max: 0.00 / P646 [Speed Reg Max Kp]Default: 3000.00Min/Max: 0.00 / 3000.00RW RealRW RealRW RealPowerFlex 750-Series User Manual – Publication 750-UM001C-EN-P – September 2009