A speed sensorless control method suitable for high torque start of asynchronous motor

Abstract

The invention discloses a speed sensorless control method suitable for high-torque starting of an asynchronous motor. The α-axis component and β-axis component of the stator current of the asynchronous motor in the αβ coordinate system; establish an adaptive sliding mode observer to calculate the estimated rotational angular velocity of the rotor, the control quantity of the model motor and the estimated magnetic field position angle of the motor rotor; design the current inner loop control Using the sliding mode control method, the estimated rotational speed is directly used as the control quantity, and the stability is judged by the Lyapunov nonlinear design method, and the d-axis component and the q-axis component of the actual control quantity in the dq coordinate system are calculated; the actual control quantity is obtained through coordinate transformation Measure the α-axis component and β-axis component in the αβ coordinate system; perform SVPWM to obtain six PWM signals to realize the control of the asynchronous motor. The present invention estimates the rotational speed of the asynchronous motor based on the rotor flux observation of the adaptive sliding mode observer. Without obtaining the phase difference information in advance, the relationship between the model motor current and the actual motor current is achieved by adjusting the adaptive law parameter of the model motor control quantity. The error between them is zero, which meets the requirements of real-time control, and the response speed is faster. It can realize the direct start of the motor under the high torque load state, and weaken the chattering.

Description

technical field [0001] The invention belongs to the field of motor control, and in particular relates to a speed sensorless control method suitable for high-torque starting of an asynchronous motor. Background technique [0002] In a high-performance motor servo system, in order to obtain an accurate motor speed signal, it is generally necessary to install a speed sensor such as a photoelectric encoder to feed back the speed signal, thereby realizing closed-loop control. However, with the improvement of control requirements, the use of speed sensors will lead to an increase in system cost and a more complex hardware structure, which reduces reliability and cannot be used in harsh environments. The above problems greatly restrict the application of asynchronous motors. So far, researchers have proposed many speed sensorless control methods, but most of them design the identification algorithm from the perspective of the mathematical model of the motor. Start under torque loa...

AI Technical Summary

Problems solved by technology

However, with the improvement of control requirements, the use of speed sensors will lead to an increase in system cost and a more complex hardware structure, which reduces reliability and cannot be used in harsh environments. The above problems greatly restrict the application of asynchronous motors

So far, researchers have proposed many speed sensorless control methods, but most of them design the identification algorithm from the perspective of the mathematical model of the motor. Starting under torque load

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