A Speed ​​Estimation Method of Bearingless Asynchronous Motor

Abstract

The invention discloses a rotational speed estimation method for a bearingless asynchronous motor. The method includes: according to a mathematical model of the asynchronous motor, establishing a system state equation and an observational equation; determining a covariance matrix of the system noise and the observation noise and a covariance initial matrix of the error of estimation; generating 2N+1 sigma points and the corresponding power values through unscented transformation and then calculating the further predictive value of a set of the points; calculating the further predictive value of the system state quantity and the covariance and the predictive observed quantity; and acquiring the mean value and the covariance through the weighted sum; calculating kalman gain matrix and status update and covariance update. This new kalman filtering algorithm spreads the statistical property of the stochastic process through the sampling point instead of utilizing first order linearization method in EKF, therefore, this algorithm has higher estimation precision. Besides, the attenuation factor is introduced when the prior error is calculated, which makes the filter much more relies on the measurement value in the estimation process, the influence of the state estimation uncertainty is reduced and the robustness of the system is enhanced.

Description

technical field

[0001] The invention is a speed estimation method of a bearingless asynchronous motor based on an attenuation memory unscented Kalman filter algorithm. A new strategy is provided for the speedless operation of the bearingless asynchronous motor, which is suitable for the high-performance control of the bearingless motor, and belongs to the technical field of electric drive control equipment. Background technique

[0002] Traditional motor rotor speed is usually detected by mechanical speed sensors, but for bearingless asynchronous motors, there are problems in installation, connection and reliability when using mechanical speed sensors. And the sensor itself is mechanically difficult to realize the high-speed and ultra-high-speed operation of the motor, which seriously limits the excellent high-speed performance of the bearingless asynchronous motor. Therefore, the speed sensorless technology has become an effective means to solve the problem of bearingless ...

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