阅读说明：本技术 异步电机的控制方法、装置、设备和计算机可读存储介质 (Control method, device and equipment of asynchronous motor and computer readable storage medium ) 是由 刘军锋 胡超 张兵 于 2020-12-10 设计创作，主要内容包括：一种异步电机的控制方法、装置、设备和计算机可读存储介质,其中,控制方法中通过根据目标斜坡频率曲线确定当前频率值,进而确定当前电压值和当前电压空间角度,并根据当前电压值和补偿电压值确定给定电压值,进而根据给定电压值和当前电压空间角度调节逆变电路的开关时序,以通过逆变电路控制异步电机,兼顾了异步电机在启停过程中不同频率下的输入电压电流相应调节,使得异步电机启停过程的力矩和速度保持平稳；且实现了在当前频率值较小时,逆变电路的输出电流稳定在设定值,进而保证足够的输出力矩,使逆变电路的输出电压能够自动适应,调试简单,解决了传统的异步电机的控制方法中存在启停过程力矩不稳定,速度不平稳,且调试复杂的问题。(A control method, a device, equipment and a computer readable storage medium of an asynchronous motor are provided, wherein in the control method, a current frequency value is determined according to a target slope frequency curve, a current voltage value and a current voltage space angle are further determined, a given voltage value is determined according to the current voltage value and a compensation voltage value, and then the switching time sequence of an inverter circuit is adjusted according to the given voltage value and the current voltage space angle, so that the asynchronous motor is controlled through the inverter circuit, and the corresponding adjustment of input voltage and current of the asynchronous motor under different frequencies in the starting and stopping process is considered, so that the torque and the speed of the asynchronous motor in the starting and stopping process are kept stable; and when the current frequency value is small, the output current of the inverter circuit is stabilized at a set value, so that enough output torque is ensured, the output voltage of the inverter circuit can be automatically adapted, the debugging is simple, and the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process in the traditional control method of the asynchronous motor are solved.)

1. A control method of an asynchronous machine, characterized in that it comprises:

determining a current frequency value corresponding to a current time point according to a target slope frequency curve, wherein the target slope frequency curve is generated according to a target frequency, takes time as an independent variable, takes frequency as a dependent variable, and takes the target frequency as a peak value of the frequency;

determining a current voltage value and a current voltage space angle corresponding to the current frequency value;

if the current frequency value is greater than or equal to a first preset frequency threshold value, taking the current voltage value as a given voltage value;

if the current frequency value is smaller than the first preset frequency threshold value, taking a value obtained by adding a compensation voltage value to the current voltage value as the given voltage value, wherein the compensation voltage value is determined according to the feedback current and the preset current of the asynchronous motor;

and adjusting the switching time sequence of an inverter circuit according to the given voltage value and the current voltage space angle so as to control the asynchronous motor through the inverter circuit.

2. The control method of claim 1, wherein if the current frequency value is smaller than the first preset frequency threshold, the determining a value obtained by adding a compensation voltage value to the current voltage value as the given voltage value comprises:

collecting the feedback current of the asynchronous motor at the current time point;

generating a first compensation voltage value according to the asynchronous motor feedback current and the preset current;

if the current frequency value is smaller than a second preset frequency threshold value, taking the first compensation voltage value as the compensation voltage value and carrying out backup, and adding the compensation voltage value and the current voltage value to obtain the given voltage value; and

if the current frequency value is greater than or equal to the second preset frequency threshold value, determining a second compensation voltage value according to a first frequency-voltage curve, taking the second compensation voltage value as the compensation voltage value, and adding the compensation voltage value and the current voltage value to obtain the given voltage value; the first frequency-voltage curve is a frequency-voltage curve which takes frequency as an independent variable, takes voltage as a dependent variable and takes the first compensation voltage value which is backed up as a peak value.

3. The control method of claim 2, wherein generating a first compensation voltage value based on the asynchronous machine feedback current and a preset current comprises:

obtaining an adjusting current value according to the difference value of the preset current and the feedback current of the asynchronous motor;

and carrying out PI regulation on the regulated current value to obtain the first compensation voltage value.

4. The control method according to any one of claims 1 to 3, wherein before determining the current frequency value corresponding to the current time point according to the target ramp frequency curve, the method further comprises:

and determining the target frequency according to the target rotating speed of the asynchronous motor.

5. A control method according to any one of claims 1 to 3, wherein said determining a current voltage value and a current voltage space angle corresponding to said current frequency value comprises:

integrating the current frequency value to determine the current voltage space angle;

and determining the current voltage value corresponding to the current frequency value according to a second frequency-voltage curve, wherein the second frequency-voltage curve is a VF control curve which takes the current frequency value as an independent variable and takes the current voltage value as a dependent variable.

6. A control device for an asynchronous machine, characterized in that it comprises:

the device comprises a ramp frequency generating unit, a frequency calculating unit and a frequency calculating unit, wherein the ramp frequency generating unit is used for determining a current frequency value corresponding to a current time point according to a target ramp frequency curve, the target ramp frequency curve is generated according to a target frequency, the target ramp frequency curve takes time as an independent variable, frequency as a dependent variable and the target frequency as a peak value of the frequency;

an angle integrator for determining a current voltage space angle corresponding to the current frequency value;

the VF curve calculation unit is used for determining a current voltage value corresponding to the current frequency value;

the compensation voltage calculation unit is used for generating a compensation voltage value when the current frequency value is greater than or equal to a first preset frequency threshold value, and the compensation voltage value is determined according to the feedback current of the asynchronous motor and the preset current;

a first adder unit; the current voltage value is used as a given voltage value, or a value obtained by adding a compensation voltage value to the current voltage value is used as the given voltage value; and

and the space vector PWM unit is used for adjusting the switching time sequence of an inverter circuit according to the given voltage value and the current voltage space angle so as to control the asynchronous motor through the inverter circuit.

7. The control device according to claim 6, wherein the compensation voltage calculation unit includes:

the acquisition unit is used for acquiring the feedback current of the asynchronous motor at the current time point;

the first compensation voltage value calculating unit is used for generating a first compensation voltage value according to the asynchronous motor feedback current and the preset current;

a compensation voltage determining unit, configured to, when the current frequency value is smaller than a second preset frequency threshold, use the first compensation voltage value as the compensation voltage value, and backup the first compensation voltage value, and when the current frequency value is greater than or equal to the second preset frequency threshold, determine a second compensation voltage value according to a first frequency-voltage curve, and use the second compensation voltage value as the compensation voltage value, where the first frequency-voltage curve is a frequency-voltage curve that takes frequency as an independent variable, voltage as a dependent variable, and the backed-up first compensation voltage value as a peak value; and

the first switching unit is used for outputting the compensation voltage value to the first adder unit when the current frequency value is smaller than a first preset frequency threshold value, and stopping outputting when the current frequency value is larger than or equal to the first preset frequency threshold value.

8. The control apparatus of claim 7, wherein the compensation voltage determining unit comprises:

the compensation voltage backup unit is used for backing up the first compensation voltage value;

a second compensation voltage value calculating unit, configured to determine a second compensation voltage value according to a first frequency voltage curve, and use the second compensation voltage value as the compensation voltage value, where the first frequency voltage curve is a frequency voltage curve that takes frequency as an independent variable, takes voltage as a dependent variable, and takes the backed-up first compensation voltage value as a peak value;

the second switch unit is connected between the first compensation voltage value calculating unit and the compensation voltage backup unit;

the third switching unit is connected between the compensation voltage backup unit and the second compensation voltage value calculating unit;

the first input end of the one-out-of-multiple switching unit is connected with the second compensation voltage value calculating unit, the second input end of the one-out-of-multiple switching unit is connected with the first compensation voltage value calculating unit, and the output end of the one-out-of-multiple switching unit is connected with the first switching unit; and

the first enabling module is used for controlling the second switch unit to be closed, the third switch unit to be opened and the second input end and the output end of the one-of-multiple switch unit to be closed when the current frequency value is smaller than the second preset frequency threshold value; and the frequency control unit is used for controlling the second switch unit to be opened, the third switch unit to be closed and the first input end and the output end of the one-of-multiple switch unit to be closed when the current frequency value is smaller than the second preset frequency threshold value.

9. A control device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the steps of the control method according to any of claims 1 to 5 are implemented when the computer program is executed by the processor.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the control method according to any one of claims 1 to 5.

Technical Field

The present application belongs to the field of motor control technologies, and in particular, to a method, an apparatus, a device, and a computer-readable storage medium for controlling an asynchronous motor.

Background

At present, the construction elevator is generally driven by an asynchronous motor, and the asynchronous motor is controlled by a frequency converter to realize the speed regulation control of the lift car. The core requirements of the construction elevator on the asynchronous motor transmission system are that the starting torque is large, the starting and stopping processes are stable, the starting is not provided with obvious lifting feeling, and the stopping is not provided with obvious stopping feeling. However, the control of conventional asynchronous machines is generally divided into two cases: firstly, the vector control without a speed sensor is adopted, the scheme needs to acquire more accurate asynchronous motor parameters, the control effect is greatly influenced by the asynchronous motor parameters, and vector control loops are more, so that the debugging workload is larger for obtaining satisfactory start-stop experience; and secondly, the conventional voltage frequency conversion (VF) control is adopted, the parameters of the asynchronous motor are not relied on, but the torque characteristic of a low-speed section needs to be adjusted to obtain a stable starting torque, meanwhile, the VF control has poor adaptability, especially for different loads, the torques required by starting and stopping are different, so that the starting and stopping are difficult to be considered, and repeated debugging is often required.

Therefore, the traditional control method of the asynchronous motor has the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process.

Disclosure of Invention

The application aims to provide a control method, a control device, control equipment and a computer readable storage medium of an asynchronous motor, and aims to solve the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process of the traditional control method of the asynchronous motor.

A first aspect of an embodiment of the present application provides a control method for an asynchronous motor, where the control method includes:

determining a current frequency value corresponding to a current time point according to a target slope frequency curve, wherein the target slope frequency curve is generated according to a target frequency, takes time as an independent variable, takes frequency as a dependent variable, and takes the target frequency as a peak value of the frequency;

determining a current voltage value and a current voltage space angle corresponding to the current frequency value;

if the current frequency value is greater than or equal to a first preset frequency threshold value, taking the current voltage value as a given voltage value;

if the current frequency value is smaller than the first preset frequency threshold value, taking a value obtained by adding a compensation voltage value to the current voltage value as the given voltage value, wherein the compensation voltage value is determined according to the feedback current and the preset current of the asynchronous motor;

and adjusting the switching time sequence of an inverter circuit according to the given voltage value and the current voltage space angle so as to control the asynchronous motor through the inverter circuit.

A second aspect of an embodiment of the present application provides a control device of an asynchronous motor, including:

the device comprises a ramp frequency generating unit, a frequency calculating unit and a frequency calculating unit, wherein the ramp frequency generating unit is used for determining a current frequency value corresponding to a current time point according to a target ramp frequency curve, the target ramp frequency curve is generated according to a target frequency, the target ramp frequency curve takes time as an independent variable, frequency as a dependent variable and the target frequency as a peak value of the frequency;

an angle integrator for determining a current voltage space angle corresponding to the current frequency value;

the VF curve calculation unit is used for determining a current voltage value corresponding to the current frequency value;

the compensation voltage calculation unit is used for generating a compensation voltage value when the current frequency value is greater than or equal to a first preset frequency threshold value, and the compensation voltage value is determined according to the feedback current of the asynchronous motor and the preset current;

a first adder unit; the current voltage value is used as a given voltage value, or a value obtained by adding a compensation voltage value to the current voltage value is used as the given voltage value; and

and the space vector PWM unit is used for adjusting the switching time sequence of an inverter circuit according to the given voltage value and the current voltage space angle so as to control the asynchronous motor through the inverter circuit.

A third aspect of embodiments of the present application provides a control device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the method as described above when executing the computer program.

A fourth aspect of embodiments of the present application provides a computer-readable storage medium, which stores a computer program, which, when executed by a processor, implements the steps of the method as described above.

According to the control method of the asynchronous motor, the current frequency value corresponding to the current time point is determined according to the target slope frequency curve, the current voltage value and the current voltage space angle corresponding to the current frequency value are determined, when the current frequency value is smaller than the first preset frequency threshold value, the value obtained by adding the current voltage value and the compensation voltage value is used as the given voltage value, the switching time sequence of the inverter circuit is adjusted according to the given voltage value and the current voltage space angle, so that the asynchronous motor is controlled through the inverter circuit, the corresponding adjustment of input voltage and current of the asynchronous motor under different frequencies in the starting and stopping process is considered, and the torque and the speed of the asynchronous motor in the starting and stopping process are kept stable; and when the current frequency value is small, the output current of the inverter circuit is stabilized at a set value, so that enough output torque is ensured, the output voltage of the inverter circuit can be automatically adapted, the debugging is simple, and the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process in the traditional control method of the asynchronous motor are solved.

Drawings

Fig. 1 is a detailed flowchart of a control method of an asynchronous motor according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a target ramp frequency curve;

FIG. 3 is a diagram of a second frequency-voltage curve;

FIG. 4 is a detailed flowchart of step S400 of the control method shown in FIG. 1;

FIG. 5 is a diagram of a first frequency-voltage curve;

fig. 6 is a schematic structural diagram of a control device of an asynchronous motor according to an embodiment of the present application;

FIG. 7 is an exemplary circuit schematic of a compensation voltage calculation unit in the control apparatus shown in FIG. 6;

fig. 8 is a schematic diagram of a control device provided in an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, refer to an orientation or positional relationship illustrated in the drawings for convenience in describing the present application and to simplify description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Fig. 1 shows a specific flowchart of a control method of an asynchronous motor 50 provided in a first aspect of an embodiment of the present application, and for convenience of description, only the parts related to the embodiment are shown, and detailed description is as follows:

the control method of the asynchronous motor 50 in the present embodiment includes:

step S100: determining a current frequency value f corresponding to a current time point according to a target slope frequency curve_{_ramp}The target ramp frequency curve is based on the target frequency f_{_set}The generated frequency is dependent on time and frequency, and has a target frequency f_{_set}A ramp curve that is the peak of the frequency;

it is understood that the ramp curve is a ramp curve that generates a ramp frequency f _ ramp generated at a set acceleration and deceleration time, as shown in fig. 2. Before step S100, the target rotation speed n of the asynchronous motor may be used₀Determined target frequency f_{_set}. Where n is the rotational speed (rpm) of the asynchronous machine 50, which can be determined according to the formula f np/60; f-supply frequency (hz); p-the pole pair number of the rotating field of the asynchronous machine 50. At start-up (zero speed) -target speed n₀Throughout the phase of stopping (zero speed), the target acceleration/deceleration rule may be applied such that the asynchronous machine 50, at the start, may reach the target speed n at a fixed first acceleration₀And from the target speed n at the time of stopping at the second acceleration₀Equalization stops to zero, i.e.:

it is understood that 0 to t₁For starting the asynchronous machine 50 to reach the target speed n₀Time period of (d), t₁～t₂Maintaining a target speed n for the asynchronous machine 50₀Time period of operation, when the frequency is the target frequency f_{_set}，t₂After the asynchronous machine 50 rotates at a target speed n₀And stopping working until the rotating speed is zero.

Step S200: determining the current frequency value f_{_ramp}Corresponding current voltage value V_{_amp}And the current voltage space angle V_{_theta}；

It should be understood that the current frequency value f can be obtained by comparing the current frequency value f_{_ramp}To carry outIntegration to obtain the determined and current frequency value f_{_ramp}Corresponding current voltage space angle V_{_theta}。

It should be understood that the current frequency value f may be determined from the VF curve corresponding to the asynchronous motor 50_{_ramp}Corresponding current voltage value V_{_amp}。

It will be appreciated that by basing the current frequency value f_{_ramp}To determine the corresponding present voltage value V_{_amp}And the current voltage space angle V_{_theta}The current voltage value V can be adjusted in real time according to different frequency requirements in the whole process from the start to the normal operation and then to the stop of the asynchronous motor 50_{_amp}And the current voltage space angle V_{_theta}Therefore, in the process of controlling the asynchronous motor 50, the starting and stopping feeling of the asynchronous motor 50 can be considered, and the asynchronous motor 50 can stably run at any stage.

Optionally, in an embodiment, step S200 specifically includes:

1. for the current frequency value f_{_ramp}Integrating to determine the present voltage space angle V_{_theta}；

2. Determining the current frequency value f according to the second frequency-voltage curve_{_ramp}Corresponding current voltage value V_{_amp}Wherein the second frequency-voltage curve is represented by the current frequency value f_{_ramp}As independent variable, with the current voltage value V_{_amp}VF control curve for dependent variable.

It should be understood that the second frequency-voltage curve is a VF curve, and the specific corresponding value of the VF curve can be uniquely determined according to the rated operating parameter values of the asynchronous motor 50, such as the VF curve shown in fig. 3.

Step S300: if the current frequency value f_{_ramp}If the current voltage value is greater than or equal to the first preset frequency threshold value, the current voltage value V is used_{_amp}As a given voltage value V_{_ref}；

Optionally, the first preset frequency threshold may be adjusted according to a frequency corresponding to a fixed input current value that needs to be maintained by the asynchronous motor 50, and the first preset frequency threshold is lower than the rated frequency of the asynchronous motor 50, and may be set to 40% of the rated frequency of the asynchronous motor 50, for example.

Step S400: if the current frequency value f_{_ramp}If the current voltage value is less than the first preset frequency threshold value, the current voltage value V is set_{_amp}Adding a compensation voltage value V_{_comp}The obtained value is used as a given voltage value V_{_ref}Compensating the voltage value V_{_comp}Determined according to the feedback current and the preset current of the asynchronous motor 50;

it will be appreciated that by setting the current frequency value f_{_ramp}When the frequency is less than the first frequency threshold value, the compensation voltage value V determined according to the feedback current and the preset current of the asynchronous motor 50_{_comp}With the current voltage value V_{_amp}Adding, introducing a current closed-loop control, so that at the present frequency value f_{_ramp}When the frequency is smaller than the first frequency threshold, the output voltage of the inverter circuit 40 can be automatically adapted, so that the asynchronous motor 50 can have stable starting torque when being started, and the condition of control unbalance is avoided.

Step S500: according to a given voltage value V_{_ref}And the current voltage space angle V_{_theta}The switching timing of the inverter circuit 40 is adjusted to control the asynchronous motor 50 through the inverter circuit 40.

It is understood that the asynchronous motor 50 is connected to the inverter circuit 40.

It should be understood that, i.e., using Space Vector Pulse Width Modulation (SVPWM) technique, a given voltage value V is_{_ref}For a desired voltage value, i.e. a given voltage value V_{_ref}And the current voltage space angle V_{_theta}A voltage space vector is formed, and a three-phase Pulse Width Modulation (PWM) wave for controlling the inverter circuit 40 is directly generated from the voltage space vector by using a space vector PWM technique, thereby controlling the output of the inverter circuit 40.

In the control method of the asynchronous motor 50 in the embodiment, the current frequency value f corresponding to the current time point is determined according to the target slope frequency curve_{_ramp}Determining the current frequency value f_{_ramp}Corresponding current voltage value V_{_amp}And the current voltage space angle V_{_theta}And at the current frequency value f_{_ramp}Less than a first predetermined frequencyWhen the rate is threshold, the current voltage value V is set_{_amp}Adding a compensation voltage value V_{_comp}The obtained value is used as a given voltage value V_{_ref}According to a given voltage value V_{_ref}And the current voltage space angle V_{_theta}The switching time sequence of the inverter circuit 40 is adjusted to control the voltage and the current output to the asynchronous motor 50 by the inverter circuit 40, so that the asynchronous motor 50 is controlled by the inverter circuit 40, and the corresponding adjustment of the input voltage and the input current of the asynchronous motor 50 under different frequencies in the starting and stopping processes is considered, so that the torque and the speed of the asynchronous motor 50 in the starting and stopping processes are kept stable; and realize that at the current frequency value f_{_ramp}When the current is small, the output current of the inverter circuit 40 is stabilized at a set value, so that sufficient output torque is ensured, the output voltage of the inverter circuit 40 can be automatically adapted, the debugging is simple, and the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process in the traditional control method of the asynchronous motor 50 are solved.

Referring to fig. 4, in one embodiment, step S400 includes:

step S410: collecting the feedback current of the asynchronous motor 50 at the current time point;

it should be understood that the feedback current of the asynchronous motor 50 may be collected by a current collecting device or chip such as a current sensor, a sampling resistor, etc., and the feedback current of the asynchronous motor 50 is the input current of the asynchronous motor 50, i.e., the output current of the inverter circuit 40.

Step S420: generating a first compensation voltage value V according to the feedback current and the preset current of the asynchronous motor 50_{_comp1}；

It should be understood that, when the asynchronous motor 50 feeds back the current as the phase current, the amplitude of the feedback current is obtained by calculating the amplitude of the current, the preset current is subtracted from the amplitude of the feedback current to obtain the regulated current, and the regulated current is subjected to proportional integral control (PI) regulation to generate the first compensation voltage value V_{_comp1}。

Optionally, in an embodiment, step S420 specifically includes:

step S421: obtaining an adjusting current value according to a difference value between a preset current and a feedback current of the asynchronous motor 50;

step S422: carrying out PI regulation on the regulated current value to obtain a first compensation voltage value V_{_comp1}。

It should be understood that in the present embodiment, by performing PI regulation on the current, the output current of the inverter circuit 40 is stabilized at the set value, so as to ensure that the asynchronous motor 50 has sufficient output torque, and the output voltage can be automatically adapted.

Step S430: if the current frequency value f_{_ramp}Less than a second predetermined frequency threshold f_{_th}Then the first compensation voltage value V is set_{_comp1}As a compensation voltage value V_{_comp}And backup is carried out to compensate the voltage value V_{_comp}With the current voltage value V_{_amp}Adding to obtain a given voltage value V_{_ref}；

It should be understood that the first compensation voltage value V is_{_comp1}When backup is carried out, the latter first compensation voltage value V_{_comp1}Covering the previous compensation voltage value V_{_comp}。

Step S440: if the current frequency value f_{_ramp}Greater than or equal to a second preset frequency threshold f_{_th}Determining a second compensation voltage value V according to the first frequency-voltage curve_{_comp2}Second compensation voltage value V_{_comp2}As a compensation voltage value V_{_comp}Compensating the voltage value V_{_comp}With the current voltage value V_{_amp}Adding to obtain a given voltage value V_{_ref}(ii) a Wherein the first frequency-voltage curve is a first compensation voltage value V which takes frequency as an independent variable, takes voltage as a dependent variable and takes backup_{_comp1}The frequency voltage curve is the peak.

It should be understood that, as shown in FIG. 5, the first frequency-voltage curve represents the frequency as an independent variable and the second compensation voltage value V_{_comp2}Is a direct proportional function of the dependent variable, wherein the proportionality coefficient is less than zero, and a second predetermined frequency threshold f_{_th}Corresponding second compensation voltage value V_{_comp2}Equal to the first compensation voltage value V of the backup_{_comp1}(ii) a When the second compensation voltage value V_{_comp2}When the frequency is equal to zero, the corresponding frequency is the compensation cut-off frequency f_{_end}Can beTo pass a second preset frequency threshold f_{_th}And compensating the cut-off frequency f_{_end}And determining a scaling factor. Compensating the cut-off frequency f_{_end}May be equal to the first preset frequency threshold value.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Referring to fig. 6, a second aspect of the present embodiment provides a control device 10 for an asynchronous motor 50, the asynchronous motor 50 is connected to an inverter circuit 40, and the three-phase power 20 outputs power to the inverter circuit through a rectifier circuit 30, and the control device 10 includes: ramp frequency generating unit 200, angle integrator 400, VF curve calculating unit 300, compensation voltage calculating unit 800, first adder unit 500, and space vector PWM unit 700, where the output end of ramp frequency generating unit 200 is connected to the input end of angle integrator 400 and the input end of VF curve calculating unit 300, the output end of VF curve calculating unit 300 is connected to the first input end of first adder unit 500, the output end of compensation voltage calculating unit 800 is connected to the second input end of first adder unit 500, the output ends of angle integrator 400 and first adder unit 500 are respectively connected to the input end of space vector PWM unit 700, and the output end of space vector PWM unit 700 is connected to the control circuit of inverter circuit 40.

The ramp frequency generation unit 200 is configured to determine a current frequency value f corresponding to a current time point according to a target ramp frequency curve_{_ramp}Wherein the target ramp frequency curve is based on the target frequency f_{_set}The generated frequency is dependent on time and frequency, and has a target frequency f_{_set}A ramp curve that is the peak of the frequency; the angle integrator 400 is used to determine the current frequency value f_{_ramp}Corresponding current voltage space angle V_{_theta}(ii) a The VF curve calculating unit 300 is used to determine the current frequency value f_{_ramp}Corresponding current voltage value V_{_amp}(ii) a A compensation voltage calculation unit 800 for calculating a current frequency value f_{_ramp}Is greater thanOr equal to the first preset frequency threshold value, and generating a compensation voltage value V_{_comp}Compensating the voltage value V_{_comp}Determined according to the feedback current and the preset current of the asynchronous motor 50; a first adder unit 500; for measuring at the present voltage value V_{_amp}As a given voltage value V_{_ref}Or else the present voltage value V_{_amp}Adding a compensation voltage value V_{_comp}The obtained value is used as a given voltage value V_{_ref}(ii) a Space vector PWM unit 700 for generating a PWM signal according to a given voltage value V_{_ref}And the current voltage space angle V_{_theta}The switching timing of the inverter circuit 40 is adjusted to control the asynchronous motor 50 through the inverter circuit 40.

It should be understood that the ramp frequency generating unit 200 includes a ramp frequency generating unit according to the target rotation speed n₀Generating a target frequency f_{_set}For the target ramp frequency curve, reference may be made specifically to the description of the first aspect of the embodiments of the present application. The angle integrator 400 is a frequency angle integrator 400. The VF curve calculation unit 300 includes the asynchronous motor 50VF curve function. The space vector PWM unit 700 is a three-phase PWM wave generating unit based on a space vector pulse width modulation technique for generating a three-phase PWM wave according to a current voltage space angle V_{_theta}And a given voltage value V_{_ref}The three-phase PWM wave for controlling the inverter circuit 40 is generated to adjust the switching timing of the inverter circuit 40, thereby controlling the asynchronous motor 50 through the inverter circuit 40, for example, by controlling the magnitude of the voltage and current output to the asynchronous motor 50 by the inverter circuit 40 to control the asynchronous motor 50.

The control device 10 of the asynchronous motor 50 in the present embodiment determines the current frequency value f according to the current time point by using the ramp frequency generating unit 200, the angle integrator 400, the VF curve calculating unit 300, the compensation voltage calculating unit 800, the first adder unit 500, and the space vector PWM unit 700_{_ramp}And further determining the present voltage value V_{_amp}And the current voltage space angle V_{_theta}And at the current frequency value f_{_ramp}When the current voltage value is less than a first preset frequency threshold value, the current voltage value V is converted into a voltage value V_{_amp}Plus a compensation voltage value V determined by the feedback current and the preset current of the asynchronous motor 50_{_comp}To obtain a given voltage value V_{_ref}And according to a given voltage value V_{_ref}And the current voltage space angle V_{_theta}The switching time sequence of the inverter circuit 40 is adjusted to control the asynchronous motor 50 through the inverter circuit 40, and corresponding adjustment of input voltage and current of the asynchronous motor 50 under different frequencies in the starting and stopping processes is considered, so that the torque and the speed of the asynchronous motor 50 in the starting and stopping processes are kept stable; and realize that at the current frequency value f_{_ramp}When the current is small, the output current of the inverter circuit 40 is stabilized at a set value, so that the asynchronous motor 50 is ensured to have enough output torque, the output voltage of the inverter circuit 40 can be automatically adapted, the debugging is simple, and the problems of unstable torque, unstable speed and complex debugging in the starting and stopping process in the traditional control method of the asynchronous motor 50 are solved.

Referring to fig. 7, in one embodiment, the compensation voltage calculating unit 800 includes: the sampling circuit comprises a collecting unit 810, a first compensation voltage value calculating unit 820, a compensation voltage determining unit 830 and a first switching unit 840, wherein the collecting end of the collecting unit 810 is connected with the output end of the inverter circuit 40, the output end of the collecting unit 810 is connected with the input end of the first compensation voltage value calculating unit 820, the output end of the first compensation voltage value calculating unit 820 is connected with the input end of the compensation voltage determining unit 830, the output end of the compensation voltage determining unit 830 is connected with the first end of the first switching unit 840, and the second end of the first switching unit 840 is connected with the second input end of the first adder unit 500.

The collecting unit 810 is configured to collect feedback current of the asynchronous motor 50 at a current time point; the first compensation voltage value calculating unit 820 is used for generating a first compensation voltage value V according to the feedback current and the preset current of the asynchronous motor 50_{_comp1}(ii) a The compensation voltage determining unit 830 is used for determining the current frequency value f_{_ramp}Less than a second predetermined frequency threshold f_{_th}Then the first compensation voltage value V is set_{_comp1}As a compensation voltage value V_{_comp}And for the first compensation voltage value V_{_comp1}Making a backup and for the current frequency value f_{_ramp}Greater than or equal to a second preset frequency threshold f_{_th}Determining a second compensation voltage value V according to the first frequency-voltage curve_{_comp2}Second compensationVoltage value V_{_comp2}As a compensation voltage value V_{_comp}Wherein the first frequency-voltage curve is a first compensation voltage value V with frequency as an independent variable, voltage as a dependent variable and backup_{_comp1}A frequency-voltage curve at a peak; the first switching unit 840 is used for determining the current frequency value f_{_ramp}When the frequency is less than the first preset frequency threshold value, the compensation voltage value V is output_{_comp}To the first adder unit 500, and when the current frequency value f_{_ramp}And stopping outputting when the frequency is greater than or equal to the first preset frequency threshold.

Optionally, referring to fig. 7, the collecting unit 810 may be formed by a current collecting device such as a current sensor; when the phase current is collected by the collecting unit 810, the collecting unit 810 further includes a current amplitude calculating unit 811 for calculating and outputting a current amplitude of the feedback current of the asynchronous motor 50.

Optionally, referring to fig. 7, the first compensation voltage value calculating unit 820 includes a current instruction generating unit 821, a second adder unit 822, and a PI regulator 823, wherein a positive input terminal of the second adder unit 822 is connected to an output terminal of the current instruction generating unit 821, a negative input terminal of the second adder unit 822 is connected to an output terminal of the collecting unit 810, an output terminal of the second adder unit 822 is connected to an input terminal of the PI regulator 823, and an output terminal of the PI regulator 823 is connected to an input terminal of the compensation voltage determining unit 830. The current instruction generating unit 821 is used to output a preset current. The second adder unit 822 is configured to perform a difference between the preset current and the feedback current of the asynchronous motor 50 and output the difference as a regulated current. The PI regulator 823 is configured to perform proportional integration on the regulating current to obtain a first compensation voltage value V corresponding to the regulating current_{_comp1}。

Optionally, referring to fig. 7, the first switch unit 840 may be composed of a second enabling module 842 and a controllable switch 841, the second enabling module 842 being used for determining the current frequency value f_{_ramp}When the frequency is less than the first preset frequency threshold, the controllable switch 841 is controlled to close to output the compensation voltage value V_{_comp}To the first adder unit 500 and is configured to control the controllable switch 841 to be switched off when the current frequency is greater than or equal to a first preset frequency threshold.The second enabling module 842 may be a microprocessor or the like.

Referring to fig. 7, in one embodiment, the compensation voltage determining unit 830 includes: compensation voltage backup unit 832, second compensation voltage value V_{_comp}A calculating unit 834, a second switching unit 831, a third switching unit 833, a one-out-of-multiple switching unit 835 and a first enabling module 836, wherein a first end of the second switching unit 831 is connected to an output end of the first compensation voltage value calculating unit 820, a second end of the second switching unit 831 is connected to an input end of the compensation voltage backup unit 832, an output end of the compensation voltage backup unit 832 is connected to a first end of the third switching unit 833, a second end of the third switching unit 833 is connected to a second compensation voltage value V_{_comp}The input terminal of the calculating unit 834 is connected to the second compensation voltage value V_{_comp}An output end of the calculating unit 834 is connected to a first input end of the one-out-of-multiple switching unit 835, a second input end of the one-out-of-multiple switching unit 835 is connected to an output end of the first compensation voltage value calculating unit 820, an output end of the one-out-of-multiple switching unit 835 is connected to an output end of the first switching unit 840, and control ends of the second switching unit 831, the third switching unit 833, and the one-out-of-multiple switching unit 835 are respectively connected to the first enabling module 836.

The compensation voltage backup unit 832 is used for compensating the first compensation voltage value V_{_comp1}Carrying out backup; second compensation voltage value V_{_comp}The calculating unit 834 is for determining a second compensation voltage value V according to the first frequency-voltage curve_{_comp2}Second compensation voltage value V_{_comp2}As a compensation voltage value V_{_comp}Wherein the first frequency-voltage curve is a first compensation voltage value V with frequency as an independent variable, voltage as a dependent variable and backup_{_comp1}A frequency-voltage curve at a peak; the second switching unit 831 is connected between the first compensation voltage value calculating unit 820 and the compensation voltage backup unit 832, and is configured to control on-off connection between the first compensation voltage value calculating unit 820 and the compensation voltage backup unit 832; the third switching unit 833 is connected to the compensation voltage backup unit 832 and the second compensation voltage value V_{_comp}Between the computing units 834 for controlling the compensation voltage backup unit 832 and the second compensationVoltage value V_{_comp}On-off connection between the computing units 834; the one-out-of-multiple switch unit 835 is used for outputting a first compensation voltage value V_{_comp1}Or a second compensation voltage value V_{_comp2}(ii) a The first enabling module 836 is used for determining the current frequency value f_{_ramp}Less than a second predetermined frequency threshold f_{_th}The second switch unit 831 is controlled to be closed, the third switch unit 833 is controlled to be opened, and the second input end and the output end of the one-of-multiple switch unit 835 are controlled to be closed; and for when the current frequency value f_{_ramp}Less than a second predetermined frequency threshold f_{_th}And controls the second switching unit 831 to be opened, the third switching unit 833 to be closed, and the first input terminal and the output terminal of the one-of-multiple switching unit 835 to be closed.

It should be understood that the second and third switching units 831 and 833 may be configured as an electronic switching device having a control terminal or a dummy switch. The one-out-of-multiple switch unit 835 may be formed of an electronic device such as a multiplexer, a single-pole double-throw switch, or a dummy switch. The first enabling module 836 may be a microprocessor or the like.

Fig. 8 is a schematic diagram of a control device according to an embodiment of the present application. The control device in this embodiment may be used for a construction hoist, and in other embodiments, may be used for other devices. As shown in fig. 8, the control device 6 of this embodiment includes: a processor 60, a memory 61 and a computer program 62 stored in said memory 61 and executable on said processor 60. The processor 60, when executing the computer program 62, implements the steps in the various control method embodiments described above, such as the steps S100 to S500 shown in fig. 1. Alternatively, the processor 60, when executing the computer program 62, implements the functions of each module/unit in the above-mentioned device embodiments, such as the functions of the modules 100 to 700 shown in fig. 6.

Illustratively, the computer program 62 may be partitioned into one or more modules/units that are stored in the memory 61 and executed by the processor 60 to accomplish the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 62 in the control device 6. For example, the computer program 62 may be partitioned into a synchronization module, a summarization module, an acquisition module, a return module (a module in a virtual device).

The control device 6 may be a desktop computer, a notebook, a palm computer, a cloud server, or other computing devices. The control device may include, but is not limited to, a processor 60, a memory 61. It will be appreciated by those skilled in the art that fig. 8 is merely an example of the control device 6 and does not constitute a limitation of the control device 6 and may include more or less components than those shown, or some components may be combined, or different components, for example the control device may also include input output devices, network access devices, buses, etc.

The Processor 60 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 61 may be an internal storage unit of the control device 6, such as a hard disk or a memory of the control device 6. The memory 61 may also be an external storage device of the control device 6, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like provided on the control device 6. Further, the memory 61 may also include both an internal storage unit of the control device 6 and an external storage device. The memory 61 is used for storing the computer programs and other programs and data required by the control device. The memory 61 may also be used to temporarily store data that has been output or is to be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be realized by a computer program, which can be stored in a computer-readable storage medium and can realize the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.