Method for identifying rotational inertia transient state of induction motor

The present invention relates to the field of motor control, especially to a method for identifying a rotational inertia transient state of an induction motor. The method is used for vector control ofan induction motor in an operation condition of a speed sensorless. The current identification method is too large in computing amount and cannot meet the requirement of accurate estimation of the transient state. The method provided by the invention comprises the following steps in order: (1) detecting a three-phase stator voltage and current, and respectively marking the voltage and the currentas a vector us and a vector is; (2) according to a [gamma]-type equivalent circuit, calculating a stator flux and a rotor flux; (3) calculating the electromagnetic torque; (4) calculating a rotationspeed; (5) filtering the calculated rotation speed signals; (6) calculating a load torque; and (7) constructing the adaptive identification of the rotational inertia transient state. The rotational inertia information is extrac