摘要 |
An electrically driven mooring includes a winding drum (101), an alternating current motor (103) arranged to drive the winding drum, a frequency conversion unit (104) connected to the alternating current motor, and a control unit (105) arranged to control the frequency conversion unit on the basis of an indicator for tension of the mooring rope. The control unit is arranged to compute a flux space vector for modelling a stator flux of the alternating current motor, to compute a torque estimate on the basis of the flux space vector and a space vector of stator currents, and to use the torque estimate as the indicator for the tension of the mooring rope. Hence, a need for a force sensor on the mooring rope and a need for a speed/position sensor on the motor shaft can be avoided.
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