Permanent magnet synchronous motor rotor location full-order sliding mode observation device and method

Abstract

The invention provides a permanent magnet synchronous motor rotor location full-order sliding mode observation device and method. The device comprises a full-order sliding mode observer, a saturationfunction processing module and a phase-locked loop module; in the method provided by the invention, an observation value as shown in description of the stator current can be output after the stator voltage us of the permanent magnet synchronous motor processed through a full-order sliding mode observer; the current error as shown in description is obtained after making the difference processing onthe value as shown in description and the stator current value is; a sliding mode function control vector F(S) is output after the value as shown in description processed through the saturation function processing module; the sliding mode function control vector F(S) in the saturation function processing module adopts a hyperbolic tangent function with adjustable boundary layer thickness, the adjusting of the boundary layer thickness is performed according to the rotating speed self-adaptive law of the switch gain gr, the counter electromotive force observation error as shown in description is obtained after the FS processed through a sliding mode gain matrix G1, the back counter observation value as shown in description is output after the value as shown in description processed througha full-order sliding mode observer; the value as shown in description is served as a state variable to be fed back to the full-order sliding mode observer to participate the update computation; a permanent magnet synchronous motor rotor location observation value as shown in description and the rotating speed observation value as shown in description are output after the value as shown in description is processed through the phase-locked loop module.

Description

technical field [0001] The invention belongs to the field of motor control, and in particular relates to a full-order sliding mode observation device and method for the rotor position of a permanent magnet synchronous motor. Background technique [0002] In high-performance applications, mechanical sensors such as incremental photoelectric encoders, magnetic encoders, resolvers, and Hall position sensors are widely used to detect rotor information. These mechanical sensors can detect the rotor position and rotational speed of the rotor's rotating state, but it is difficult to detect the initial position of the rotor or need to be replaced with a more complete and more expensive detection device. In addition, the mechanical sensor requires a large number of leads, which reduces the reliability of the system, thereby limiting the application of permanent magnet synchronous motors in some special occasions. Especially in some harsh environments, such as mechanical sensors unde...

AI Technical Summary

Problems solved by technology

[0004] The traditional sliding mode observer has the following problems: using the sign function as the switching function causes the system to have high-frequency chattering problems, and the back EMF signal also contains high-frequency harmonic components; the introduction of the low-pass filter will cause phase delay and thus A phase compensation module has to be added; when extracting the rotor position information, the arctangent function is used to calculate, and the look-up table method will occupy a large amount of DSP memory, and it is often difficult to achieve the expected accuracy

In view of the above problems, one of the existing chattering suppression methods is to directly replace the switching function with a conventional saturation function, so that the control between the boundary layers becomes continuous, but the sliding mode gain of this method is a fixed value , which makes the sliding mode gain applicable in the low-speed section unable to meet the gain requirements in the middle and high-speed stages, which greatly reduces the chattering suppression effect of the control system

Introducing the terminal sliding mode surface into the sliding mode observer is another commonly used chattering suppression method. This method can speed up the convergence of the error variable to the required value by introducing the terminal function. However, this method has a large workload for parameter setting. Complicated operations, etc.

In addition, methods such as adding a Kalman filter and a neural network controller to the output of the sliding mode observer are also used to weaken the system chattering and increase the observation accuracy of the rotor position, but these algorithms are relatively complicated compared with the present invention. To a certain extent, it affects its application and promotion in the practice of motor position sensorless control.

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