Online adjustment method for PI (proportion integrate) parameter of asynchronous motor

Abstract

The invention relates to an online adjustment method for a PI (proportion integrate) parameter of an asynchronous motor, the method comprises the following steps of formulating a control rule table for changing values of parameters P and I according to certain principle; judging a current operation state of the motor according to an operating speed of the motor; adopting a conventional PI control when the motor operates at a stable speed; when the motor operates at an accelerating speed or a reducing speed, adopting a fuzzy PI control to carry out an online self-adjustment for the PI parameter until the motor operates in a stable state, the self-adjustment comprises that according to a distribution scope of a rotation speed deviation value e and the value of a changing rate ec of the rotation speed deviation, a domain and scale coefficients Ke and Kec of e and ec are defined to obtain a novel control rule table; setting an initial value for the PI parameter; and carrying out the online self-adjustment for the PI parameter. By the adoption of a fuzzy self-adaptive PI control method, the PI parameter is adjusted to enable the current PI parameter to always meet the requirement of current working condition, the reaction time can be accelerated by utilizing the method to adjust the PI parameter, and dynamic performance of the motor is improved.

Description

technical field [0001] The invention relates to a frequency conversion speed regulation system, in particular to an online adjustment method for PI parameters of an asynchronous motor. Background technique [0002] Traditional PI controllers are widely used in industrial fields and have achieved good results. However, conventional PI controllers are generally only suitable for linear systems, and Kp and Ki parameters cannot be adjusted online according to actual conditions. In view of the non-linear factors such as friction, motor cogging effect, and large speed deviation range in the frequency conversion speed regulation system, it is difficult for the conventional PI controller to accurately control the entire process of speed regulation. [0003] When the system state changes, such as the process of acceleration and deceleration of the asynchronous motor, especially when the motor starts or stops quickly, the range of speed deviation and speed deviation change rate is re...

AI Technical Summary

Problems solved by technology

However, conventional PI controllers are generally only suitable for linear systems, and Kp and Ki parameters cannot be adjusted online according to actual conditions.

In view of the non-linear factors such as friction, motor cogging, and large speed deviation range in the frequency conversion speed regulation system, it is difficult for the conventional PI controller to accurately control the entire process of speed regulation

[0003] When the system state changes, such as the process of acceleration and deceleration of the asynchronous motor, especially when the motor starts or stops quickly, the range of speed deviation and speed deviation change rate is relatively wide, and the parameters of the conventional PI controller cannot be adjusted automatically. thereby degrading the performance of the controller

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