Prediction-Based Correction Method for Indirect Rotor Field Orientation Deviation of Induction Motor

Abstract

The invention provides a prediction-based orientation deviation correction method for the rotor field of an induction motor and belongs to the technical field of AC induction motor control. The methodcomprises the steps of predicting the obtained torque current and the magnetic-field current of the induction motor in a rotational coordinate system; comparing the above torque current and the abovemagnetic-field current with a torque current and a magnetic-field current obtained by a vector control system in the rotating coordinate system; based on the deviation between the above currents, obtaining the directional deviation angle of the magnetic field by utilizing a regulator, and realizing the deviation correction. According to the invention, the accuracy of the magnetic field orientation of the conventional induction motor vector control method is improved. The method is especially suitable for the improvement of the directional accuracy of the speed operation in the weak magnetic region.

Description

technical field [0001] The invention belongs to the technical field of AC induction motor control, in particular to an induction motor indirect rotor field orientation control method, which is used for correcting the field orientation deviation angle. Background technique [0002] AC motor frequency conversion speed regulation methods mainly include open-loop V / f speed regulation and closed-loop speed regulation. Closed-loop speed regulation is also called vector control method, which specifically includes indirect rotor field orientation, direct rotor field orientation, and direct stator field orientation. Among them, the indirect rotor field orientation is widely used because it needs less hardware and has high control performance. [0003] The principle of indirect rotor field-oriented vector control of induction motors is as follows: the rotating coordinate system is established on the direction of the rotor magnetic field, and through this coordinate, the stator current...

AI Technical Summary

Problems solved by technology

The calculation of the rotor field orientation angle in the actual system involves some parameters of the motor and the d-axis and q-axis command currents in the rotating coordinate system, so the inaccurate parameters used in the calculation process will cause a large deviation in the field orientation angle, especially When the motor works in the field-weakening high-speed area, due to the change of the magnetic field caused by temperature rise and field weakening, the motor parameters will change more obviously. If real-time and accurate parameter updates cannot be performed, the error change of the magnetic field orientation will be further aggravated. At the same time, Due to the inaccurate field orientation and the decline of current control performance in the field weakening area, the d-axis and q-axis current command values ​​are different from the actual values, which will also lead to deviations in field orientation

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