Resolver Error Compensation - Lenze i950 Commissioning Manual

12.2.2.1

Resolver error compensation

The actual position detected by the resolver is not exactly the same as the real physical posi-
tion. There are always deviations to a lesser or greater extent.
An identification run of the resolver automatically generates the adjustment values required
for compensation of the resolver error.
The values calculated have a counteractive corrective effect on the underlying cause in the
following parameters:
Cause
Sine and cosine track do not magnetise orthogonally to each other.
The inductances of the sine and cosine track of the resolver have slightly
different values.
Conditions for executing the identification run
1. Mechanical motor / inverter connection
If possible, execute the identification run before the motor is installed in the machine.
•
Bigger load changes at the motor may have a negative impact on the identification
result.
Motor and resolver must be properly connected to the inverter.
•
The motor must rotate freely.
•
2. Voltage supply of the inverter
The inverter must be supplied with mains voltage. Check: 0x6041, bit 4 = TRUE.
•
The control electronics must be supplied with voltage. For this purpose, some designs
•
require an external voltage source.
3. Correct setting of the following data in the »EASY Starter« engineering tool:
Number of resolver pole pairs (0x2C43)
•
Speed-controlled or position-controlled motor in servo control
•
4. The inverter must be connected "online" to the engineering tool.
Possible responses during the execution
The identification method can cause an uneven motor running during the identification.
•
The direction of rotation can change.
•
This does not have a negative impact on the quality of the identification. In this case, the
inverter automatically interrupts the identification run and automatically continues it if a
constant speed is reached again.
If the motor already installed in the machine does not have sufficient range in one direc-
•
tion for executing the identification run, you can also reverse the driving direction while
the identification is active. In this case, the identification automatically switches to the
"Identification temporarily interrupted ". The status is deactivated as soon as a constant
speed has been reached again.
In the event of an interruption, the identification run is stopped. An error mes-
sage is displayed.
If 0 % is set, the gain of the respective resolver track is only 95 % of the Lenze
setting.
The detected gain can assume values in the range of 0 ... 100 %.
In case of a successful resolver error compensation, only one of the two gains is
adjusted. The other value remains at 100 %.
How to run an identification
If possible, execute the identification run before the motor is installed in the
machine. If relatively big load changes occur in the kinematics to be moved, this
may have a negative impact on the result of the identification run.
Configuring the feedback system
Second feedback system for the techology application
Remedy
0x2C44:001
Correction of the angle by means of which the two resolver tracks are
supplied in a manner relative to one another.
0x2C44:002 and 0x2C44:003
Adjusting the gains of the digital-analog converters which feed the
resolver tracks.
Resolver settings
191