Asynchronous motor control method based on MRAS

Abstract

The invention discloses an asynchronous motor control method based on an MRAS. The method comprises the steps of acquiring a three-phase stator current and voltage of an asynchronous motor, and generating a torque current feedback quantity and exciting current feedback through Clark and Park conversion in sequence; acquiring a rotor angular speed feedback quantity through an improved MRAS, outputting a torque current after a difference value between the rotor angular speed feedback quantity and a preset rotating speed is adjusted through a speed controller, and outputting a first voltage afterthe difference value between the torque current and the torque current feedback quantity is input into a first PI adjuster; inputting the difference value between a preset exciting current and an exciting current feedback quantity into a second PI regulator and then outputting a second voltage; carrying out Park inverse transformation on the first voltage and the second voltage to generate a two-phase control voltage sum, and inputting the two-phase control voltage sum into SVPWM to be modulated into PWM modulation waves; and controlling a three-phase full-bridge inverter switching device through the PWM modulation waves, and controlling operation of an asynchronous motor. In the invention, low-speed stability of the asynchronous motor is improved, and an electromagnetic torque ripple isreduced.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to an MRAS-based asynchronous motor control method. Background technique [0002] Asynchronous motors, also known as induction motors, are AC motors that generate electromagnetic torque through the interaction of the air-gap rotating magnetic field and the induced current of the rotor winding, thereby realizing the conversion of electromechanical energy into mechanical energy. It has a wide range of applications in industrial, civil, military and other fields. [0003] Using model reference adaptive system (MRAS) to estimate the speed has the advantages of simple method and little influence of motor parameters. However, there are certain defects in MRAS when using the voltage model to determine the flux linkage. The initial value of the integral is required in the voltage model, so In the actual control system, initial positioning is required, and the initial position cannot b...

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Problems solved by technology

[0003] Using model reference adaptive system (MRAS) to estimate the speed has the advantages of simple method and little influence of motor parameters. However, there are certain defects in MRAS when using the voltage model to determine the flux linkage. The initial value of the integral is required in the voltage model, so In the actual control system, initial positioning is required, and the initial position cannot be determined, which will cause problems of DC bias and integral saturation, which will affect the dynamic characteristics of the motor, especially at low speeds. The impact on the flux linkage is more obvious

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