Asynchronous motor field weakening control method, device and controller

The invention provides a field weakening control method and device for an asynchronous motor and a controller, and the method comprises the steps: obtaining a given value and an actual value of an excitation current, and a given value and an actual value of a torque current, and carrying out the control processing through a current regulator, and obtaining a given voltage; performing space vector modulation on the given voltage to obtain a control signal corresponding to the inverter; controlling an inverter to drive a motor according to the control signal; wherein the excitation current given value is obtained by adding an excitation current rated value and a voltage closed-loop output value, the output value is obtained by carrying out proportional-integral adjustment and amplitude limiter processing on the difference between the optimized reference voltage and the given voltage of the previous period, and the optimized reference voltage is formed by a no-load voltage and a load voltage according to an orth