Speed sensorless control method for large torque starting of asynchronous motor

Abstract

The invention discloses a speed sensorless control method for large torque starting of an asynchronous motor. The method comprises: A-phase and B-phase currents of a motor stator and a direct-currentbus voltage of an inverter are collected and a corresponding C-phase current is calculated; coordinate transformation is carried out to obtain an alpha-axis component and a beta-axis component of a stator current of an asynchronous motor under an alpha-beta coordinate system are obtained; an adaptive sliding mode observer is established, a rotor estimate rotation angular speed, a model motor control value and a motor rotor estimation magnetic-field position angle are calculated; a current inner-loop controller is designed, the estimation rotation speed is used as a control value directly by using a sliding mode control method, and determination is carried out stably by using a Lyapunov nonlinear design method, and a d-axis component and a q-axis component of an actual control value under adq coordinate system are calculated; coordinate transformation is carried out to obtain an alpha-axis component and a beta-axis component of the actual control value under the alpha-beta coordinate system; and SVPWM is carried out to obtain six-paht PWM signals to realize controlling of an asynchronous motor. According to the invention, the rotation speed of the asynchronous motor is estimated based on the rotator flux linkage observation of the adaptive sliding mode observer; the error between the model motor current and the actual motor current becomes zero by adjusting the adaptive law parameter of the model motor control value under the circumstance that the phase difference information is not obtained in advance; the real-time control requirement is met; the response speed is fast; direct starting of the motor in a large-torque load state is realized; and buffeting is weakened.

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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