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.
The PI voltage controller can be optimized by adaptation of the P gain P 0345 CON_FM_VConKp, integral-action time P 0346 CON_FM_VConTn and filter time constant for motor voltage feedback P 0344 CON_FM_VConTF. Parameter P 0347 CON_FM_VRef sets the voltage reference, though the threshold needs to be reduced in response to rising demands as this maintains a kind of voltage reserve for dynamic control processes. A certain voltage reserve is necessary for stable operation. It is specified by way of parameter P 0347 CON_FM_VRef (>100%).The value should be set high ( > 90%) where there are high demands in terms of dynamism. For less dynamic response, the maximum attainable torque can be optimized by higher values (> 90%).
Parameters
| P. no. | Parameter name | Function |
|---|---|---|
| P 0344 | CON_FM_VConTF | Time constant of voltage controller actual value filter |
| P 0345 | CON_FM_VConKp | Voltage controller gain factor Kp |
| P 0346 | CON_FM_VConTn | Voltage controller integral-action time Tn |
| P 0347 | CON_FM_VRef | Voltage controller reference (as % of the current DC link voltage) If the value 0 % is set, the controller is not active. |
| P 0458 | MOT_SNom | Rated speed of the motor |
Tabelle: Parameter description, voltage controller
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NOTE: If the control reserve is too small, the inverter typically shuts off with an overcurrent error. |
Copyright © LTi DRiVES GmbH, Januar 2013, ID-Nr.: 0842.26B.1-00 DE