Calculations; Current Loop; Velocity Loop; Slider Tuning - Kollmorgen AKD PDMM series User Manual

AKD PDMM User Guide | 7.3.2 Calculations
IL.OFFSET
IL.INTEN
IL.IVFB
IL.KPDRATIO

7.3.2 Calculations

KAS IDE uses the following equations to calculate parameter values.

Current Loop

The current loop proportional gain (IL.KP) must be such that the current loop closed loop crossover
frequency/bandwidth (BW) nominal is the lesser of 2000 Hz or (PWM Frequency/4).
Then, with this frequency:
IL.KP = 2*π*(desired bandwidth in Hz)*(motor L line-line in H)
Setting the D and Q components

Velocity Loop

VL.KP = (2*π*75)*(2*Jm/Kt) = 300*PI*Jm/Kt
VL.KI = 5

Slider Tuning

The slider tuning algorithm in KAS IDE currently uses the following algorithm.

Input - Motor Data

The values for inertia, Jm (Kg / cm2), and torque constant, Kt (Nm/A), are obtained from either the SFD or
the motor model number that you select.

Constants

Velocity Loop Bandwidth – BW = The default value is 75Hz.
Input - Inertia Ratio – Q = The default is 1.

Output - Control Loop Gains

VL.KP = 2 * π * BW * Jm * (1+Q) * 0.0001/Kt
VL.KPI = BW*0.08 -1 (minimum of 1)
PL.KP = BW/5

7.4 Foldback

The foldback feature in the AKD PDMM protects both the motor and the drive from overheating. Two cur-
rent foldback algorithms run in parallel in the drive: the drive foldback algorithm and the motor foldback
algorithm. Each algorithm uses different sets of parameters. Each algorithm has its own foldback current
limit, IL.DIFOLD (drive foldback) and IL.MIFOLD (motor foldback). The overall foldback current limit is the
minimum of the two at any given moment.
IL.IFOLD = min (IL.DIFOLD, IL.MIFOLD).
IL.FOLDFTHRESHU
IL.FOLDWTHRESH
IL.MFOLDD
IL.MFOLDT
VL.THRESH MOTOR.ICONT
VL.KVFF MOTOR.PITCH
PL.KP MOTOR.POLES
PL.KD = 0 (Default MOTOR.TYPE
Value)
Kollmorgen™ | December 2012 47