Asynchronous motor vector control rotor winding temperature on-line monitoring method

Abstract

The invention relates to an asynchronous motor vector control rotor winding temperature on-line monitoring method comprising the following steps: 1) carrying out rotor magnetic field accurate orientation based on load angle compensation correction according to current and voltage signals under d-q synchronous rotation coordinates; 2) estimating a rotor time constant on the basis of accurate orientation of a rotor magnetic field and correction and compensation of slip frequency; 3) estimating the rotor time constant value in a short time when the motor is started for the first time to reach stable rotating speed, and obtaining a motor cooling medium detection temperature; 4) estimating the current rotor time constant value in the normal working process of the motor, obtaining the motor cooling medium detection temperature corresponding to the moment, and estimating the rotor winding temperature in real time; and 5) obtaining the temperature rise of the rotor winding. Compared with the methods in the prior art, the method has the advantages that the rotor magnetic field orientation is accurate, the robustness is good, the temperature monitoring of the rotor winding is conveniently realized, and the method is not influenced by the characteristics of hardware equipment, the electromagnetic interference of a working environment and the like.

Description

technical field [0001] The invention relates to the technical field of asynchronous motor monitoring, in particular to an online monitoring method for rotor winding temperature under vector control of asynchronous motors. Background technique [0002] Rotor field-oriented vector control of asynchronous motors with frequency conversion and speed regulation can transform the inherent nonlinear mechanical characteristics of asynchronous motors into linear mechanical characteristics similar to those of DC motors, and the current and flux linkages are completely decoupled, enabling the speed control of DC motors Basic conditions for good performance. Therefore, rotor field orientation is the most worthy of in-depth research and perfect control technology in the vector control of asynchronous motors. However, during the decades of development of the rotor field oriented vector control technology, due to the influence of the motor rotor resistance Rr and the time constant Tr great...

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Problems solved by technology

The obvious disadvantage of this type of method is that it greatly increases the complexity of the control system, and may even have serious negative effects on the stability, reliability, speed and accuracy of the control system

[0004] 2. Various flux observation techniques, such as full-order state observers, sliding mode observers, Kalman filters, model reference observers, etc., still have various problems. In the research and experiment stage, there is still a long way to go for the accurate observation of the magnetic flux of the AC motor

Since the rotor is rotating at a high speed when the motor is running, it is very difficult to implement the direct temperature measurement method using sensor elements embedded in the rotor coil, and it will bring hidden dangers to the safe and stable operation of the motor.

Some scholars have proposed methods such as non-contact measurement based on infrared thermal devices and optical measurement technology based on GaAs crystal temperature sensitive devices, but such technologies are limited by factors such as the characteristics of the sensor itself and the electromagnetic interference in the working environment. Therefore, most It is still in the stage of experimental research and has not been maturely applied in the field of motor rotor temperature measurement

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