POLITECHNIKA WARSZAWSKA

8. Conclusions
In case of the ANN based speed estimator
• Application of artificial NN speed estimators for PWM inverter-fed
induction motors creates many new schemes.
• One of the simplest NN estimator schemes is based on combination of
the voltage and current rotor flux estimation proposed in [115].
• This thesis shows the possibility of improvement of the classical
scheme, using new structure (Section 5.3). The implementation of the
improved system and new NN method based on digital signal processor
TMS320C31 is presented and experimental results are shown.
• The speed tracking by the ANN based estimator is good in steady state
and in dynamical state.
In the case of the sensorless Field Oriented Control (FOC)
• The steady state operation and dynamical behaviour is correct.
• There is a very fast torque response,
• The system allows the independent control of rotor flux and motor
torque,
• There is no problem with start and stop of the system,
• Even without speed sensor the system behaviour is correct in low speed
region,
• Sensorless FOC of induction motor, described in this thesis, could be
used in the high performance motor drives of the electrical vehicles (for
example hybrid cars) and in the factories, in which the measurement of
the mechanical speed is expensive or even impossible
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