阅读说明：本技术 破壁机无刷马达的静音恒转速控制方法 (Mute constant-rotating-speed control method of brushless motor of wall breaking machine ) 是由 黄启超 于 2020-04-29 设计创作，主要内容包括：一种破壁机无刷马达的静音恒转速控制方法,包括：在每个SVPWM控制周期内,获取无刷直流电机的SVPWM控制信号的转速,并判断转速是否大于设定值；如果转速大于设定值,则在所述SVPWM控制周期的高电平时间内先判断所述无刷直流电机的续流时间是否结束；如果所述续流时间结束,则再通过ADC模块的多通道对所述无刷直流电机的三相线上电流进行连续多次采样；将采样到的数据通过CLARKE和PARK换算得到Iqs和Ids；利用PID调节器得到需要调整的电压矢量Vds和Vqs；将Vds和Vqs经过PARK反变换后输入到SVPWM模块,从而实现整个电机控制恒转速输出,恒功率稳定。本发明采用FOC控制技术实现对无刷马达控制,工作时噪音几乎不会影响人们的正常作息。(A mute constant rotating speed control method of a brushless motor of a wall breaking machine comprises the steps of obtaining the rotating speed of SVPWM control signals of the brushless direct current motor in each SVPWM control period, judging whether the rotating speed is larger than a set value or not, judging whether follow current time of the brushless direct current motor is finished or not in high level time of the SVPWM control period if the rotating speed is larger than the set value, continuously sampling current on three phase lines of the brushless direct current motor for multiple times through multiple channels of an ADC module if the follow current time is finished, converting the sampled data through C L ARKE and PARK to obtain Iqs and Ids, obtaining voltage vectors Vds and Vqs needing to be adjusted through a PID regulator, inputting the converted data into the SVPWM module after PARK inverse transformation, and accordingly achieving constant rotating speed output of the whole motor control and constant power stability.)

1. A mute constant rotating speed control method of a brushless motor of a wall breaking machine is characterized by comprising the following steps:

in each SVPWM control period, acquiring the duty ratio, the current value, the rotor position and the rotating speed of an SVPWM control signal of the brushless direct current motor, and judging whether the rotating speed is greater than a set value;

if the rotating speed is at a set value, judging whether the follow current time of the brushless direct current motor is finished or not in the high level time of the SVPWM control period;

if the follow current time is over, continuously sampling the current on the three-phase line of the brushless direct current motor for multiple times through multiple channels of the ADC module;

converting the sampled data into Iqs and Ids through a C L ARKE and PARK coordinate model established in a control system;

respectively obtaining voltage vectors Vds and Vqs which need to be adjusted by utilizing a PID regulator according to the output of the FOC controller and the Iqs and the Ids;

vds and Vqs are subjected to inverse PARK conversion and then input to the SVPWM module, so that the whole motor can control constant rotating speed output, and constant power is stable.

Technical Field

The invention relates to the field of food processors (such as mixers, wall breaking machines, soybean milk machines or juicers), in particular to a mute constant-rotation-speed control method of a brushless motor of a wall breaking machine.

Background

The existing wall breaking machine in the market is driven by a carbon brush motor, because of the characteristics of the carbon brush motor, the rotating speed is subjected to negative correlation change along with the actual food material amount and different hardness degrees during working, for example, the nominal rotating speed of the carbon brush motor is 30000RPM, but the actual rotating speed is reduced to 3000-5000 RPM during stirring the food materials, so that the crushing efficiency is low, the high-speed performance is poor, and the vibration is easy to generate; the noise is usually more than or equal to 85 decibels during working, and is very noisy, and the normal work and rest of people are seriously influenced. The carbon brush motor needs to be continuously commutated by the carbon brush and the commutator during operation, friction exists between the carbon brush motor and the commutator, efficiency is reduced, heat is easily generated, the service life is short, the carbon brush is worn out, and the motor is basically damaged.

Disclosure of Invention

The invention provides a mute constant rotating speed control method of a brushless motor of a wall breaking machine, which aims to solve at least one technical problem.

In order to solve the above problems, as an aspect of the present invention, there is provided a mute constant rotation speed control method for a brushless motor of a wall breaking machine, comprising:

in each SVPWM control period, acquiring the duty ratio, the current value, the rotor position and the rotating speed of an SVPWM control signal of the brushless direct current motor, and judging whether the rotating speed is greater than a set value;

if the rotating speed is greater than the set value, judging whether the follow current time of the brushless direct current motor is finished or not in the high level time of the SVPWM control period;

if the follow current time is over, continuously sampling the current on the three-phase line of the brushless direct current motor for multiple times through multiple channels of the ADC module;

converting the sampled data into Iqs and Ids through a C L ARKE and PARK coordinate model established in a control system;

respectively obtaining voltage vectors Vds and Vqs which need to be adjusted by utilizing a PID regulator according to the output of the FOC controller and the Iqs and the Ids;

vds and Vqs are subjected to inverse PARK conversion and then input to the SVPWM module, so that the whole motor can control constant rotating speed output, and constant power is stable.

The brushless motor is mainly controlled by FOC control technology, the current speed of the motor is calculated by detecting the current value of a three-phase coil of the motor through high-frequency injection, and the constant speed control is carried out by PID control technology inside the motor, so that the noise is smaller than or equal to 75 decibels during working, and the normal work and rest of people are hardly influenced.

Drawings

FIG. 1 schematically illustrates the FOC speed control schematic of the present invention.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

As shown in fig. 1, in one aspect of the present invention, a mute constant rotation speed control method for a brushless motor of a wall breaking machine is provided, which is applied to the field of food processors (such as a blender, a wall breaking machine, a soymilk maker or a juicer), and is used for reducing noise generated during the operation of wall breaking machine products, thereby reducing noise pollution caused by the operation of the wall breaking machine and affecting the health of people.

The terms in the figure 1 are explained as FOC, rotor magnetic field orientation control, 3phase inverter, three-phase converter, PID, proportional integral derivative, SVPWM, space vector pulse width modulation, AC Mains, main alternating current, Circlelimitation, voltage limiting circle, PARK inverse transformation, PARK inverse transformation, C L ARKE, Clark transformation, Wr is input signal, Wr is output signal, similarly, Iqs and Ids are input signal, Iqs and Ids are output signal, PARK inverse transformation and cirleimitation module is used for converting Vds and Vqs into voltage vector coordinate system, Vds and d axis voltage, Vqs and q axis voltage on coordinate system, Iqs and q axis current value, and Ids and d axis current value on coordinate system.

The inverter in fig. 1 includes a rectifier bridge, an electrolytic capacitor, and a three-phase bridge converter, where a first input end of the rectifier bridge is connected to a live line of an ac power input, a second input end of the rectifier bridge is connected to a zero line of the ac power input, and the rectifier bridge converts the ac power into a dc power. The positive terminal of electrolytic capacitor with the first output of rectifier bridge links to each other, electrolytic capacitor's negative pole end with the second output of rectifier bridge links to each other and connects the ground of reference, electrolytic capacitor's both ends still are connected with on the motor three-phase converter module, motor three-phase conversion module with driving motor links to each other, electrolytic capacitor is used for right DC power source carries out the steady voltage and handles to supply with the DC power source after the steady voltage is handled motor three-phase conversion module, with through the machine controller system is right driving motor controls.

The mute constant rotating speed control method comprising the wall breaking machine brushless motor comprises the following steps:

step 1, acquiring the duty ratio, the current value, the rotor position and the rotating speed of an SVPWM control signal of a brushless direct current motor in each SVPWM control period, and judging whether the rotating speed is greater than a set value;

step 2, if the rotating speed is greater than a set value, judging whether the follow current time of the brushless direct current motor is finished or not in the high level time of the SVPWM control period;

step 3, if the follow current time is over, continuously sampling the current on the three-phase line of the brushless direct current motor for multiple times through multiple channels of the ADC module;

step 4, converting the sampled data through a C L ARKE and PARK coordinate model established in the control system to obtain Iqs and Ids;

step 5, respectively obtaining voltage vectors Vds and Vqs to be adjusted by utilizing a PID (proportion integration differentiation) regulator according to the motor angular speed output by an FOC (rotor field orientation control) controller and the working currents Iqs and Ids of the brushless motor;

and 6, performing inverse PARK conversion on Vds and Vqs and inputting the Vqs into an SVPWM module, so that the whole motor can control constant rotating speed output and the constant power is stable.

In the technical scheme, the speed/position feedback module of the rotor in the control system provides an angle signal of the rotor for the FOC algorithm and provides a speed signal for the speed outer ring, and the whole system can be quickly and accurately controlled to a target rotating speed in the running process, so that the constant rotating speed running of the whole system is realized; and the whole FOC control system is used for controlling the brushless direct current motor according to the modulated SVPWM control signal.

By adopting the technical scheme, aiming at the problems that the noise of the existing food processor in the market is usually more than 85 decibels, and the noise is very noisy and affects the normal work and rest of people seriously in the working process, the invention can change the traditional carbon brush motor into the brushless motor, thereby providing the constant-rotating-speed mute wall breaking machine adopting the brushless motor, the brushless motor mainly adopts the FOC control technology to realize the control of the motor, the speed feedback detects the current value of a three-phase coil of the motor through high-frequency injection to calculate the current rotating speed of the motor, and the PID control technology is adopted to carry out constant-speed control inside the motor, so the noise is smaller and less than or equal to 75 decibels during working, and the normal work and rest of people can hardly be affected.

The invention has the following advantages: (1) the FOC control is smooth, the vibration is small, the output efficiency of the whole machine is high, and the rotating speed characteristic is good; (2) the motor noise is low; (3) the motor starts to climb heavy load and accelerate, so that the motor efficiency is higher; (4) the PID control technology reacts quickly in the whole motor regulation process.

After the brushless motor device is adopted, the rotating speed is constant when the food material is stirred, if the nominal rotating speed is 12000RPM, the actual rotating speed of the brushless motor adopting the PID control technology reaches the nominal value of 12000RP when the food material is stirred, so the breaking rate is higher, the noise is smaller and less than or equal to 75 decibels when the brushless motor works, and the normal work and rest of people can not be influenced almost.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.