A vector control method for AC asynchronous motor without speed sensor

Abstract

The invention discloses a vector control method of an alternating current asynchronous motor non-speed sensor, wherein a controller figures out rotor magnetic flux by using a voltage model, then calculates rotor speeds and synchronic angular speeds according to a magnetic flux sum, and then obtains magnetic flux linkage angles according to the synchronic angular speeds, and then obtains exciting current and torque current according to rotating transformation of coordinates, and then calculates the given torque current according to speed closed loops, and then calculates d-axis voltage and q-axis voltage according to feed-forward of the given exciting current and the given torque current. Because resistance information of the rotors is not included in the algorithm, the algorithm can be less affected by parametric variation of an asynchronous motor. The method of non-speed sensor vector quantity control adopting magnetic flux estimation and speed estimation can greatly reduce dependency of vector control on motor parameters, and has good low frequency torque and speed stabilizing precision features.

Description

technical field [0001] The invention relates to the technical field of asynchronous motor control, in particular to a vector control method for an AC asynchronous motor without a speed sensor. Background technique [0002] Common frequency conversion speed regulation control methods of asynchronous motors mainly include VF control and vector control. Among them, the VF control method is mainly applied to loads such as fans and pumps due to its simple control. However, it cannot be applied to occasions that require high load starting torque and speed accuracy, and the load carrying capacity is poor. With the continuous development and progress of industrial and agricultural production, people have higher and higher requirements for speed regulation. The induction motor vector control is based on the motor dynamic model, such as figure 2 As shown, it decouples the motor current according to the field orientation, obtains the torque current component and the excitation curren...

AI Technical Summary

Problems solved by technology

The induction motor vector control is based on the motor dynamic model, such as figure 2 As shown, it decouples the motor current according to the field orientation, obtains the torque current component and the excitation current component, and then controls them separately, so as to obtain a fast speed response and run very smoothly. However, the performance of vector control It has a great relationship with the accuracy of the motor parameters, and the control algorithm is very complicated

[0003] Therefore, the existing control methods for asynchronous motors not only have low control precision, but also have complex control algorithms

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