PSI- Issue 9

Mohammed Ezzahi et al. / Procedia Structural Integrity 9 (2018) 221–228 Author name / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 8. Measured and simulated speed in hyper-synchronous mode By using the sensorless systems and specially the extended Kalaman filter (EKF) we were able to estimate exactly the speed, the magnetic field, the position and the torque by adopting a decoupled modeling of the magnetic field and the torque as shown above. Thes estimations allowed us to ensure a complete integrity of the wind power system by reducing the maintenance concerns related to the sensors.

Fig. 9. (a) Estimated (simulated) and measured speed, (b) estimated rotor magnetic field, (c) estimated position and (d) estimated torque.

7. Conclusion Standard field oriented control (FOC) schemes used to command wind turbine-driven DFIGs uses regulators with cascaded current and power loops, which require the use of an incremental encoder or Sensorless WPS. Although stator-side active and reactive powers can be independently governed by adopting those control schemes, the system transient performance degrades as the actual values of the DFIG resistances and inductances deviate from those based on which the control system tuning was carried out during the early stage of installation. In addition, the optimum