Online recognition method for asynchronous electromotor rotor resistance

Abstract

The invention relates to an online identification method on the rotor resistance of an asynchronous motor, and the method is used for optimizing resistance parameters in the vector control with a speed transducer. The invention includes the following procedures of collecting the electromagnetic torque Te and the psi 2parameter of the flux linkage of a rotor, identifying the rotor resistance according to the electromagnetic torque Te and the psi 2 parameter of the flux linkage of the rotor by the formula that r2 is equals to 3 / 2Pn omegas psi <2>2 / Te, among which the p n is the number of the pole-pair of the motor, and the omega s is the slip angular frequency, taking the identified rotor resistance as the parameter to implement the vector control of the motor. The online identification method of the invention can identify the rotor resistance of the asynchronous motor on line on the vector control of the motor with the speed transducer by a voltage model method, thereby being simple and practical, and having higher precision. The invention can identify the resistance parameter of the rotor on line accurately under any condition that load exists, and the resistance parameter is stable. Experiments prove that the invention can obtain right resistance parameter of the motor rotor accurately whether the motor is in cold state or in hot state.

Description

technical field [0001] The invention relates to a method for identifying the rotor resistance of a motor, in particular to an on-line identification method for the rotor resistance of an asynchronous motor which has high recognition accuracy and can improve the vector control performance of the motor. Background technique [0002] With the rapid progress of power electronics technology and the continuous deepening of AC motor speed regulation theory. The application of asynchronous motors is becoming more and more widespread. The vector control of the motor usually adopts the rotor flux orientation strategy, and the orientation accuracy of the magnetic field is greatly affected by the parameters on the rotor side. The main reason is that the parameters of the rotor resistance have a great influence, and this parameter changes greatly with the temperature of the motor. The resistance value in the hot state of the motor may be more than 20% higher than that in the cold state....

AI Technical Summary

Problems solved by technology

[0004] At present, as the precision and efficiency requirements of industrial production and processing technology become higher and higher, more and more occasions use vector control with speed sensor, and for vector control with speed sensor, the rotor resistance has a greater influence on the accuracy of magnetic field orientation , if the rotor resistance parameter used for control differs greatly from the actual rotor resistance parameter, it will cause relatively large field weakening and overexcitation effects, which will affect the control performance. It is very meaningful to study the online identification of rotor resistance with speed sensor

[0005] It can be known from domestic and foreign literature that many technicians are researching on-line identification technology of rotor resistance with speed sensor, but the methods are often implemented with complicated methods and low precision.

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