Sensorless vector control (SLV)
SLV control is a further technological development of V/f control. If increased demands are placed on the three-phase motor, it generally requires a control which uses a sensor, e.g. incremental encoder on the motor shaft, so that the measured motor speed is fed back to the control loop. However, SLV control does not need a sensor. This is where the term sensorless originates.
However, it is just as high-performance as vector control which requires sensor feed back. The motor speed is calculated in the frequency inverter using a mathematical motor model. The downstream control provides the correct torque in the respective operating state.
SLV control has the following advantages over V/f control:
- Short reaction times with setpoint value changes
- Short response times with load changes
- High torque, even at low speeds (e.g. DV51 start torque > 200 % at approx. 1 Hz)
- High speed stability with load change
These advantages can be used with the DV51 without the requirement for comprehensive adjustment work. The new innovative control method means that "auto tuning" or similar processes for determination of the motor characteristics are no longer necessary.
