Firmware Manual

9000X AF Drives
MN04004001E
For more information visit: www.eaton.com
A-3
August 2010
Appendix A
Closed Loop Parameters
ID612 to ID621
Select the Closed loop control mode by setting value 3 or 4 for ID600.
Closed loop control mode (see Page 8-57) is used when enhanced performance near zero
speed and better static speed accuracy with higher speeds are needed. Closed loop control
mode is based on “rotor flux oriented current vector control”. With this controlling principle,
the phase currents are divided into a torque producing current portion and a magnetizing
current portion. Thus, the squirrel cage induction machine can be controlled in a fashion of
a separately excited DC motor.
Note: These parameters can be used with SVXP drive only.
Example: Motor Control Mode = 3 (Closed loop speed control)
This is the usual operation mode when fast response times, high accuracy or controlled run
at zero frequencies are needed. Encoder board should be connected to slot C of the control
unit. Set the encoder P/R-parameter (P7.3.1.1). Run in open loop and check the encoder speed
and direction (V7.3.2.2). Change the direction parameter (P7.3.1.2) or switch the phases of
motor cables if necessary. Do not run if encoder speed is wrong. Program the no-load current
to ID612 and set ID619 (Slip Adjust) to get the voltage slightly above the linear V/Hz-curve
with the motor frequency at about 66% of the nominal motor frequency. The Motor Nominal
Speed parameter (ID112) is critical. The Current Limit parameter (ID107) controls the
available torque linearly in relative to motor nominal current.