AC Motor Speed ​​Tracking Control Method

Abstract

The invention discloses a rotating speed tracking control method adopting adaptive PI control. When a motor restarts, operating frequency and phase signal of the motor can be obtained simultaneously through simple PI control, besides, the motor torque is stable in the whole tracking process under constant control of current amplitude, identification of the operating frequency of the motor can be completed in 2-5 electric cycles, response is fast, and torque control is smooth. The method is simple in algorithm and easy to implement without addition of system cost.

Description

technical field [0001] The invention relates to a speed tracking control method of an alternating current motor. Background technique [0002] In many motor-driven systems without speed sensors, especially in applications such as fans and water pumps, the moment of inertia of the rotor connection equipment is large, and it usually takes a long time to go from a rotating state to a standstill. If the inverter is powered off and the motor is running at a high speed, it will be powered on again and directly started. Since the running state of the motor, especially the running frequency, cannot be judged, it will often cause the motor to overcurrent, which will affect the inverter, the motor and its driving equipment. will cause damage. If the motor is completely stopped and then accelerates from zero through the inverter, there will be a waste of time and low efficiency. In order to prevent the abnormality when the inverter starts with speed, the speed control system of the m...

AI Technical Summary

Problems solved by technology

[0004] For motor speed tracking control, in the prior art, software algorithms are generally used to identify the speed. For example, the method of frequency scanning in the Chinese patent application with the application number "201210453696.4" and the name "High Voltage Variable Frequency Motor Idling Speed ​​Tracking Method", such as the application The Chinese patent application No. "201310695259.8" titled "A Motor Speed ​​Tracking Control Method Based on Adaptive Fuzzy Neural Network" passed the method of establishing a fuzzy neural network, such as the application No. The method of flux linkage estimation is passed in the Chinese patent application of "speed tracking method, speed control device and AC motor", such as the Chinese patent application with the application number "201510831699.0" and the name "a high-voltage inverter speed tracking restart method". The method of torque current tracking, such as the method of extending the Kalman filter in the Chinese patent application with the application number "201610322986.3" and the name "A Permanent Magnet Synchronous Motor Speed ​​Tracking Control Method", all of the above methods can realize the control of the motor speed tracking, but the implementation is more complicated, which is not conducive to the realization of the digital controller; and most of the above methods are judged based on the torque current being zero or the input power of the motor passing through zero, and are affected by the dynamic characteristics of the control algorithm during the entire speed tracking process. The motor will be constantly in the state of power generation and electric switching, and there will be torque fluctuations and a certain amount of current impact

Images