Non-Plug and Play Feedback Devices

To set up a AKD drive with a non-plug and play feedback device (for example a resolver or an encoder), you must select a motor from the list of standard or custom motors or enter the motor parameters manually. Once the motor data is entered into WorkBench, an initial set of parameters can be calculated and downloaded to the drive.

Parameters

The following parameters can be initialized to their default values or calculated from user-supplied motor data:

IL.KP

IL.LIMITN

VL.KP

PL.KI = 0 (Default Value)

IL.KFFACC

IL.LIMITP

VL.KI

PL.INTINMAX = 0.419 (Default Value)

IL.KBUSFF

IL.PWMFREQ

VL.LIMITN

PL.INTOUTMAX = 0.419 (Default Value)

IL.FRICTION

IL.KVFF

VL.LIMITP

MOTOR.IPEAK

IL.OFFSET

IL.FOLDFTHRESHU

VL.THRESH

MOTOR.ICONT

IL.INTEN

IL.FOLDWTHRESH

VL.KVFF

MOTOR.PITCH

IL.IVFB

IL.MFOLDD

PL.KP

MOTOR.POLES

IL.KPDRATIO

IL.MFOLDT

PL.KD = 0 (Default Value)

MOTOR.TYPE

Calculations

WorkBench 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

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