Mute constant-rotating-speed control method for brushless motor of high-speed blender

Abstract

A mute constant-rotating-speed control method for a brushless motor of a high-speed blender comprises the steps: in each SVPWM control period, obtaining the rotating speed of an SVPWM control signal of the brushless direct-current motor, and judging whether the rotating speed is larger than a set value or not; if the rotating speed is greater than the set value, judging whether the freewheeling time of the brushless direct-current motor is over or not in the high-level time of the SVPWM control period; if the freewheeling time is over, continuously sampling the current on the three-phase lineof the brushless direct-current motor for multiple times through multiple channels of an ADC module; carrying out CLARKE and PARK conversion on the sampled data to obtain Iqs and Ids; obtaining voltage vectors Vds and Vqs needing to be adjusted through a PID regulator; and carrying out PARK inverse transformation on the Vds and Vqs, and inputting the transformed Vds and Vqs into an SVPWM module, so that the whole motor is controlled to realize constant-rotating-speed output, and the constant power is stable. The brushless motor is controlled by adopting an FOC control technology, and noise hardly affects normal work and rest of people during work.

Description

technical field [0001] The invention relates to the field of food cooking machines (such as mixers, wall breaking machines, soybean milk machines or juice extractors), in particular to a method for controlling the silent and constant rotational speed of a brushless motor of a wall breaking machine. Background technique [0002] Existing breakers in the market are driven by carbon brush motors. Because of the characteristics of carbon brush motors, the rotation speed will change in a negative correlation with the actual amount of food and the degree of softness and hardness. For example, the nominal speed of a carbon brush motor is 30,000 RPM, but The actual speed will drop to 3000-5000RPM when whipping ingredients, resulting in low crushing efficiency, poor high-speed performance, and easy vibration; the noise during work is usually ≥ 85 decibels, which is very noisy and seriously affects people's normal work and rest. The operation of the carbon brush motor needs to rely on...

AI Technical Summary

Problems solved by technology

[0002] Existing breakers in the market are driven by carbon brush motors. Because of the characteristics of carbon brush motors, the rotation speed will change in a negative correlation with the actual amount of food and the degree of softness and hardness. For example, the nominal speed of a carbon brush motor is 30,000 RPM, but The actual speed will drop to 3000-5000RPM when whipping ingredients, resulting in low crushing efficiency, and poor high-speed performance, which is prone to vibration; the noise is usually ≥ 85 decibels during work, which is very noisy and seriously affects people's normal work and rest.

The operation of the carbon brush motor needs to rely on the carbon brush and the commutator for non-stop commutation. There is friction between the two, resulting in reduced efficiency, easy to generate heat, and short life. When the carbon brush is worn out, the motor is basically damaged.

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