Induction motor control method

摘要

In a procedure for controlling an induction motor fed by a phase-sequence inverter and a DC intermediate circuit, the discrete-time field-oriented control results from sampling and control intervals that are synchronous with the stator frequency. Using a discrete-time flux observer (7) processing the stator variables, the rotor flux is evaluated followed by synchronisation with the actual currents flowing in the motor. To eliminate the commutation effects in the sampling of data, the voltages are sampled 60 electrical degrees after each commutation. By using the flux observer, a discretisation of the relevant differential equations is obtained; equations are given in the text.