SENSORLESS SPEED ROTOR FLUX ORIENTED CONTROL OF THREE PHASE INDUCTION MOTOR

Sensorless speed rotor flux oriented control of induction motor drives it is known to produce high performance because of decoupling rotor flux and torque producing current components of stator currents. This paper describes a simple and robust sensorles speed rotor flux oriented control system for three phase induction motor drives that it is adequate for high dynamic applications. To control the rotor speed of the induction motor drives, a PI controller is included in the speed control system. A hysteresis current controllers are applied for changing the magnitude and the frequency of the output voltage of the PWM voltage source inverter which fed the induction motor. In order to verify the proposed sensorlees speed control system, the model of the system is implemented in MATLAB Simulink software, which is suitable for testing the dynamic simulation. Simulation results shows that the reference and rotor speed of induction motor are very closed to each-other under step load torque changes

The formulation of state equations for linear electric circuits with perfect magnetic couplings: the case of nondegenerate circuits

In this paper, we have described a systematic method for the formulation of the state equations of linear circuits without topological degenerations, which contain perfect magnetic couplings, which are couplings with zero determinant of the inductance matrix. In these circuits, 'hidden' relationships appear between the capacitor voltages and inductor currents. According to the proposed procedure, all capacitors and inductors of the circuit are replaced by independent and dependent sources, creating in this way a resistive circuit. Afterwards, the state equations are written by solving the circuit using one of the known methods of the electrical circuits