The voltage controller is overlaid on the selected characteristic. When using the voltage controller, a portion of the available voltage is used as a control reserve. The more dynamic the running, the more control reserve is required. In this case it may be that the voltage for rated operation is not sufficient, and also that the controller starts to oscillate.
If the voltage controller oscillates the gain must be reduced. If substantial variations between the q-current reference and actual values occur during run-up to reference speed in the field-weakening range, the drive may be at the voltage limit. In this case, a check should first be made as to whether the preset maximum value P 0340 CON_FM_Imag has already been reached and can be increased. If the maximum value has not yet been reached, the voltage controller is not dynamic enough and the gain
P 0345 CON_FM_VConKp must be increased.
If no suitable compromise can be found, the voltage threshold as from which the voltage control intervenes must be reduced by the scaling parameter P 0347 CON_FM_VRef . If the response with voltage controller is unproblematic and no particular demands are made in terms of dynamism, the available torque can be optimized by setting P 0347 CON_FM_VRef to values up to 98%.
Copyright © LTi DRiVES GmbH, Januar 2013, ID-Nr.: 0842.26B.1-00 DE