2 optimising resolver behaviour, Optimising resolver behaviour, Optimise resolver behaviour – Lenze 8400 TopLine User Manual

Page 321: 6encoder/feedback system

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Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14

321

6

Encoder/feedback system

6.2

Resolver (X7)

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6.2.2

Optimising resolver behaviour

Due to mounting and production tolerances as well as resolver material property leakage, errors

may occur which, among other things, result in speed-dependent vibration of the actual speed.

These errors are called resolver errors. Resolver errors typically occur in the form of the 1st and 2nd

harmonic. They have two different causes:

1. The inductances of the sine and cosine track of the resolver have slightly different values.
2. Sine and cosine track do not magnetise orthogonally to each other.

Resolver errors due to cause 1 can be corrected by adjusting the gains of the digital/analog

converters which feed the resolver tracks. In the Lenze setting, the gains of both resolver tracks are

preset with identical values.
Resolver errors due to cause 2 can be compensated for by a slight correction of the angle via which

both resolver tracks are fed relative to one another.
When the "Resolver error identification" device command (

C00002/25

) is executed, the gain of the

resolver signals and the angular drift of both resolver tracks is corrected to minimise the resolver

error.

• Select a speed-controlled operating mode (e.g. servo control) for your machine while you

perform a resolver error identification run. During the identification run, speed must be

constant and greater than 500 rpm.

• After a successful resolver error identification run, the resolver automatically uses the following

resolver error parameters which have been identified during the procedure:

• The detected gain can have values from 80 ... 120 %. It makes sense to adjust only one of the two

gains during a resolver error compensation. The other one remains at 100 % (Lenze setting).

• Save the parameter set afterwards to accept the identified resolver error parameters

permanently (device command

C00002/11

).

• If the resolver error compensation is deactivated (

C00417

= "1: Resolver error comp. deact."), the

resolver will resume work with the Lenze setting. However, the identified resolver error

parameters remain saved.

Parameter

Info

Lenze setting

Value Unit

C02862/1

Resolver: cos gain

100.00 %

C02862/2

Resolver: sine gain

100.00 %

C02863

Resolver: Phase error

0.00 %

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