Tuning procedure – Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control User Manual

Page 282

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Commissioning 4-77

7000 “C” Frame

7000L-UM300I-EN-P – Juen 2013

Tuning Procedure

The PowerFlex “C” Frame medium voltage drive must be tuned to
the motor and load to which it is connected. There are six drive
functions that require tuning. These are listed below in the order in
which they are usually performed:

1. Commutation Inductance

2. Current Regulator

3. Motor stator resistance

4. Motor leakage inductance

5. Flux Regulator

6. Speed Regulator


The first four functions can be tuned with the motor stationary, but
the tuning of the flux and speed regulators requires the motor to
rotate.


NOTE: You will need to have a minimum of SERVICE level access
to complete manual tuning. If you do not have SERVICE level
access, please contact the factory.

1. Commutation Inductance

(Required for all drives with firmware 3.004 or later. For all
previous firmware revisions, it is required for 18-pulse drives only.)


The commutation inductance is used in the hardware reconstruction
of the line voltage to compensate for commutation notches. It is also
used in the calculation of the line converter retard limit to ensure
proper operation under all conditions of line voltage and load current
when regenerating. If the commutation inductance parameter is not
correctly adjusted, the resulting distortion in the reconstructed line
voltage may cause line synchronization faults.


The commutation inductance parameter is tuned with the drive
operating in the dc current test mode. Although the commutation
inductance was tuned during factory test, it must be retuned during
commissioning because its value is determined by the impedance of
the input transformer and harmonic filter (if present). The following
autotune procedure can be used:


Commutation Inductance Autotuning


1. Set parameter "Autotune Select" in the Autotuning parameter

group to Comm Induct. The drive will go into dc current test
mode.


2. Start the drive. The dc current will increase in steps up to

approximately rated current in about 2 seconds. When the current
reaches its maximum value, the drive shuts off.

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