2-164 Torque Performance Modes
Autotune
[Autotune]
The purpose of Autotune is to identify the motor flux current and stator
resistance for use in Sensorless Vector Control and Economizer modes. The
result of the flux current test procedure is stored in the parameter [Flux
Current]. The product of [Flux Current] and the result of the stator
resistance test procedure will be stored in the parameter [IR Voltage Drop].
There are two options for autotuning:
• Static - the motor shaft will not rotate during this test.
• Dynamic - the motor shaft will rotate during this test.
The static test determines only stator resistance, while the dynamic
Autotune procedure determines both the stator resistance and motor flux
current.
[IR Voltage Drop] is used by the IR Compensation procedure to provide
additional voltage at all frequencies to offset the voltage drop developed
across the stator resistance. An accurate calculation of the [IR Voltage
Drop] will ensure higher starting torque and better performance at low
speed operation.
If it is not possible or desirable to run the Autotune tests, there are two other
methods for the drive to determine the [IR Voltage Drop] and [Flux Current]
parameters. One method retrieves the default parameters stored in the power
EEprom, and the other method calculates them from the user-entered motor
nameplate data parameters.
If the stator resistance and flux current of the motor are known, the user can
calculate the voltage drop across the stator resistance and directly enter
these values into the [Flux Current] and [IR Voltage Drop] parameters.
The user must enter motor nameplate data into the following parameters for
the Autotune procedure to obtain accurate results:
[Motor NP Volts]
[Motor NP Hertz]
[Motor NP Power]
In addition to the motor nameplate parameters, the user must also enter a
value in the [Autotune] parameter to determine which Autotune tests to
perform.
The following options for the [Autotune] parameter are as follows:
0 = Ready
1 = Static Tune
2 = Rotate Tune
3 = Calculate
The procedure to identify the motor flux current, stator resistance, and IR
voltage drop is started with the [Autotune] parameter. The tests are initiated
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