CN113719973B

CN113719973B - Air conditioner headwind control method and device, air conditioner and readable storage medium

Info

Publication number: CN113719973B
Application number: CN202111003980.7A
Authority: CN
Inventors: 张高廷; 潘高强; 王庆磊; 陈良新; 胡春华; 陈显京
Original assignee: TCL Air Conditioner Zhongshan Co Ltd
Current assignee: TCL Air Conditioner Zhongshan Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2023-03-10
Anticipated expiration: 2041-08-30
Also published as: CN113719973A

Abstract

The application provides an air conditioner headwind control method and device, an air conditioner and a readable storage medium. The headwind control method of the air conditioner comprises the following steps: acquiring the fan rotating speed of a fan in an air conditioner outdoor unit when the fan rotates against the wind; determining a self-generating current value of the fan according to the rotating speed of the fan; and adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value, and generating braking torque in the motor to brake the fan, so that the terminal connection state of the motor can be adjusted according to different self-generating current values. And when the self-generating current value is large, the terminal connection state is adjusted to be a short-circuit state, so that the self-generating current value is consumed in the motor, and a braking torque is generated. When the self-generating current value is small, the terminal connection state is adjusted to be a normal working state, and a part of the self-generating current value is allowed to flow out of the motor, so that the self-generating current value is reduced, the demagnetization of the motor is avoided, the fan is effectively braked, and the influence on the performance of the motor is avoided.

Description

Air conditioner headwind control method and device, air conditioner and readable storage medium

Technical Field

The application relates to the field of air conditioner control, in particular to an air conditioner upwind control method and device, an air conditioner and a readable storage medium.

Background

When the outdoor unit of the air conditioner is installed outdoors and a strong wind exists outside, the fan of the outdoor unit of the air conditioner is reversed due to the influence of external wind. If the fan is started according to a normal program at this time, a large current is generated to impact the control panel instantly, and the controller is easy to burn. Therefore, it is necessary to research a method for starting an outdoor unit of an air conditioner against the wind.

In the existing method for controlling the upwind of the air conditioner, only how to brake a fan in an outdoor unit of the air conditioner is considered, but the influence of a braking method on the performance of a motor in the braking process is not considered, so that the irreversible influence on the performance of the motor is easily caused while braking. Therefore, a control method capable of braking without affecting the performance of the motor is needed.

Disclosure of Invention

The application provides a method and a device for controlling the headwind of an air conditioner, the air conditioner and a readable storage medium, and aims to solve the problem that the existing method for controlling the headwind of the air conditioner can cause irreversible influence on the performance of a motor.

In a first aspect, the present application provides a method for controlling an upwind of an air conditioner, the method comprising:

acquiring the fan rotating speed of a fan in an air conditioner outdoor unit when the fan rotates against the wind;

determining a self-generating current value of the fan according to the rotating speed of the fan;

and adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value, and generating a braking torque in the motor to brake the fan, wherein the terminal connection state comprises a short circuit state and a normal working state.

In one possible implementation manner of the present application, the adjusting a terminal connection state of a motor in the outdoor unit of an air conditioner according to the self-generating current value to generate a braking torque in the motor so as to brake the fan includes:

comparing the self-generating current value with a preset demagnetization current value;

if the self-generating current value is smaller than the preset demagnetization current value, an inverter in the outdoor unit of the air conditioner is adjusted to be in a turn-off state that all upper bridge arms are disconnected, the terminal state of a motor is adjusted to be in a short-circuit state, and braking torque is generated in the motor so as to brake the fan;

if the self-generating current value is larger than or equal to the preset demagnetization current value, the inverter in the outdoor unit of the air conditioner is adjusted to be in a conducting state, and the terminal state of the motor is adjusted to be in a normal working state, so that the self-generating current value is reduced until the self-generating current value is smaller than the preset demagnetization current value.

In a possible implementation manner of the present application, if the self-generating current value is smaller than the preset demagnetization current value, the inverter in the outdoor unit of the air conditioner is adjusted to be in a turn-off state in which all upper bridge arms are turned off, and the terminal state of the motor is adjusted to be in a short-circuit state, so that a braking torque is generated in the motor, so that after the fan is braked, the method further includes:

acquiring the rotating speed of the fan after braking and the turn-off time of the inverter in a turn-off state;

if the rotating speed after braking is greater than a preset extreme rotating speed and/or the turn-off time is greater than a preset time threshold, acquiring the current position of a rotor in the fan;

determining a compensation current direction according to the current position;

and inputting a torque compensation current into the motor according to the direction of the compensation current, wherein the torque compensation current is used for generating a torque for reducing the rotating speed after braking.

In a possible implementation manner of the present application, after determining a self-generating current value of the fan according to the fan rotation speed, the method further includes:

acquiring the current rotor speed of a rotor in the fan;

calculating to obtain the current flux linkage of a motor in the fan according to the current rotor rotating speed and the self-generating current value;

if the current flux linkage belongs to a preset delivery flux linkage range, inputting a torque compensation current into the fan, wherein the torque compensation current is used for generating a torque for reducing the rotating speed of the fan;

and if the current flux linkage does not belong to the preset factory flux linkage range, adjusting the terminal connection state of a motor in the outdoor unit of the air conditioner according to the comparison result between the self-generating current value and the preset demagnetization current value, and generating a braking torque in the motor so as to brake the fan.

In one possible implementation manner of the present application, a fan speed of a fan of an outdoor unit of an air conditioner when the fan rotates against the wind includes:

obtaining phase current of a fan driving motor in an air conditioner outdoor unit;

calculating to obtain the counter electromotive force generated by a fan in the air conditioner outdoor unit when the fan rotates according to the phase current;

judging the rotation direction of the fan according to the counter electromotive force;

and if the rotating direction is reverse, acquiring the fan rotating speed of the fan.

In one possible implementation manner of the present application, before obtaining a fan rotation speed of a fan of an outdoor unit of an air conditioner when the fan rotates against wind, the method further includes:

acquiring the electric quantity of an energy storage capacitor in an inverter of an outdoor unit of an air conditioner, wherein the energy storage capacitor is used for storing self-generating current generated when a fan rotates against the wind;

if the electric quantity is larger than or equal to a preset limit electric quantity, discharging the energy storage capacitor through a pull-down circuit in the outdoor unit of the air conditioner until the electric quantity is smaller than the limit electric quantity;

and if the electric quantity in the energy storage capacitor is smaller than the preset limit electric quantity, executing the step of acquiring the rotating speed of the fan of the outdoor unit of the air conditioner when the fan rotates against the wind.

In a possible implementation manner of the present application, the determining the self-generating current value of the fan according to the fan rotation speed includes:

acquiring a stator coil resistor of a motor in the fan and a preset back electromotive force coefficient;

and calculating to obtain the self-generating current value of the fan according to the resistance of the stator coil, the back electromotive force coefficient and the rotating speed of the fan.

In a second aspect, the present application provides an air conditioner headwind control device, comprising:

the system comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring the fan rotating speed of a fan in an air conditioner outdoor unit when the fan rotates against the wind;

the determining unit is used for determining the self-generating current value of the fan according to the rotating speed of the fan;

and the brake unit is used for adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value and generating brake torque in the motor so as to brake the fan, wherein the terminal connection state comprises a short-circuit state and a normal working state.

In one possible implementation manner of the present application, the brake unit is further configured to:

if the self-generating current value is smaller than the preset demagnetization current value, adjusting an inverter in the outdoor unit of the air conditioner to be in a turn-off state in which all upper bridge arms are disconnected, adjusting a terminal state of a motor to be in a short-circuit state, and generating braking torque in the motor so as to brake the fan;

if the rotating speed after braking is greater than a preset extreme rotating speed and/or the turn-off time is greater than a preset time threshold value, acquiring the current position of a rotor in the fan;

determining the direction of the compensating current according to the current position;

In one possible implementation manner of the present application, the upwind control device of the air conditioner further includes a flux linkage calculating unit, where the flux linkage calculating unit is configured to:

acquiring the current rotor rotating speed of a rotor in the fan;

and if the current flux linkage does not belong to the preset outgoing flux linkage range, adjusting the terminal connection state of a motor in the outdoor unit of the air conditioner according to the comparison result between the self-generating current value and the preset demagnetizing current value, and generating braking torque in the motor so as to brake the fan.

In one possible implementation manner of the present application, the obtaining unit is further configured to:

In one possible implementation manner of the present application, the upwind control device of the air conditioner further includes an electric quantity obtaining unit, where the electric quantity obtaining unit is configured to:

In one possible implementation manner of the present application, the determining unit is further configured to:

In a third aspect, the present application further provides an air conditioner, where the air conditioner includes a processor and a memory, where the memory stores a computer program, and the processor executes the steps in any one of the methods for controlling an upwind of an air conditioner provided in the present application when calling the computer program in the memory.

In a fourth aspect, the present application further provides a readable storage medium, on which a computer program is stored, the computer program being loaded by a processor to execute the steps in the upwind control method of the air conditioner.

In summary, the present application includes: acquiring the fan rotating speed of a fan in an air conditioner outdoor unit when the fan rotates against the wind; determining a self-generating current value of the fan according to the rotating speed of the fan; and adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value, and generating braking torque in the motor so as to brake the fan. According to the method for controlling the upwind of the air conditioner, the terminal connection state of the motor can be controlled according to different self-generating current values, the terminal connection state is adjusted to be in a short-circuit state when the self-generating current value is large, so that the self-generating current value is completely consumed in the motor, the braking torque for braking can be generated, the terminal connection state is adjusted to be in a normal working state when the self-generating current value is small, a part of self-generating current value is allowed to flow out of the motor, and the self-generating current value is reduced to avoid demagnetization of the motor, so that the upwind rotating fan can be effectively braked, and the situation that the performance of the motor is influenced by the self-generating current generated by upwind rotation can be avoided.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a block diagram illustrating a method for controlling a headwind of an air conditioner according to an embodiment of the present disclosure;

fig. 2 is a schematic view of an application scenario of an upwind control method of an air conditioner according to an embodiment of the present application;

fig. 3 is a schematic flow chart of an upwind control method of an air conditioner provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of an inverter provided in an embodiment of the present application;

FIG. 5 is a schematic flow chart of braking based on torque compensation current provided in the embodiments of the present application;

FIG. 6 is a schematic flow chart of a method for selecting braking according to a current flux linkage provided in an embodiment of the present application;

fig. 7 is a schematic structural view of an embodiment of an upwind control device of an air conditioner provided in an embodiment of the present application;

fig. 8 is a schematic structural diagram of an embodiment of an air conditioner provided in the embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

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

The following description is presented to enable any person skilled in the art to make and use the application. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known processes have not been described in detail so as not to obscure the description of the embodiments of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in the embodiments herein.

Referring to fig. 1, fig. 1 is a fan module structure provided in an embodiment of the present application. The PI module is a proportional-integral-derivative Controller (PID Controller) for adjusting a signal, the MTPA module is a Maximum torque current ratio (Maximum torque current ratio) control module for performing Maximum torque current ratio control on a motor, the SVPWM module is a Space Vector Pulse Width Modulation (SVPWM) unit for generating a signal for controlling an inverter, the INV module is an inverter unit and may include an inverter, in this embodiment, the IPMSM module is a three-phase bridge inverter and may include a salient permanent magnet synchronous motor (IPMSM), the converter module is configured to Convert a three-phase current into a direct axis current and a quadrature axis current, the Status Detection is a module for determining a rotation direction of a fan, the windup Start-up module is a unit for determining a self-generating current value and adjusting an inverter strategy according to the self-generating current value, for example, the windup Start-up module may be configured to compare a self-generating current value with a preset demagnetization current value. The Location Estimation module is a unit for acquiring the rotor position.

The embodiment of the application provides an air conditioner headwind control method and device, an air conditioner and a readable storage medium. The upwind control device of the air conditioner can be integrated in the air conditioner, the air conditioner can adopt a working mode of independent operation or an equipment cluster, and for example, the air conditioner can be a multi-connected air conditioner.

The main body of the method for controlling the headwind of the air conditioner according to the embodiment of the present application may be the headwind control device of the air conditioner provided by the embodiment of the present application, or may be the air conditioner, and hereinafter, the air conditioner will be explained as the main body of the air conditioner by way of example, and it should be noted that the air conditioner is taken as the main body of the air conditioner by way of example only for convenience of understanding, and the air conditioner is not limited to the present application.

Referring to fig. 2, fig. 2 is a schematic view of a scene of an upwind control system of an air conditioner according to an embodiment of the present application. The air conditioner headwind control system may include an air conditioner 100, and an air conditioner headwind control device is integrated in the air conditioner 100.

In addition, as shown in fig. 2, the upwind control system of the air conditioner may further include a memory 200 for storing data.

It should be noted that the scene schematic diagram of the air conditioner upwind control system shown in fig. 2 is only an example, and the air conditioner upwind control system and the scene described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation to the technical solution provided in the embodiment of the present application, and it is known by a person skilled in the art that the technical solution provided in the embodiment of the present invention is also applicable to similar technical problems with the evolution of the air conditioner upwind control system and the occurrence of a new service scene.

Referring to fig. 3, fig. 3 is a schematic flow chart of a method for controlling headwind of an air conditioner according to an embodiment of the present disclosure. It should be noted that, although a logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in an order different than that shown or described herein. The method for controlling the headwind of the air conditioner comprises the following steps 201 to 204, wherein:

201. the method comprises the steps of obtaining the rotating speed of a fan in an outdoor unit of the air conditioner when the fan rotates against the wind.

The upwind rotation refers to the rotation of the fan blades in the fan in the direction opposite to the normal working direction. For example, if the fan rotates clockwise when working normally, the fan rotates upwind when the fan rotates anticlockwise.

The reason why the fan rotates upwind is mainly related to environmental wind, and in seasides or plateau areas with large wind power, if the outdoor unit is not started, and the fan blades do not obtain the torque provided by the motor, the fan can be blown by the environmental wind, and when the wind direction is opposite to the rotating direction in normal work, the fan rotates upwind.

If the outdoor unit is directly started when the fan rotates against the wind at a high rotating speed, overcurrent is easily caused to burn out an Intelligent Power Module (IPM) in the air conditioner, and a serious person can cause demagnetization of the motor. Therefore, when the fan rotates against the wind, the rotating speed of the fan is first reduced, even kept in a static state, and then the outdoor unit is started.

In step 201, the air conditioner may first determine whether the fan is rotating against the wind, and then calculate the fan speed of the fan. Or the air conditioner can acquire the rotating speed of the fan, then judge whether the fan rotates against the wind or not according to the rotating speed, and if the fan rotates against the wind, take the rotating speed as the rotating speed of the fan.

Specifically, the rotation speed of the fan can be obtained from the phase current in the fan motor, and then whether the fan is rotating upwind is determined according to the rotation speed. This moment acquire the fan rotational speed of fan when the headwind rotation in the outdoor unit of air-conditioner, include:

(1) Phase current of a fan driving motor in an air conditioner outdoor unit is obtained.

The phase current refers to the current flowing through each phase of load in a three-phase power supply of the fan. Specifically, the air conditioner may detect the phase current through a current detection unit provided in the blower, or may read a parameter of the three-phase power supply to obtain the phase current.

(2) And calculating the back electromotive force generated by the fan in the air conditioner outdoor unit when the fan rotates according to the phase current.

The back electromotive force is a terminal voltage between two phases of the fan when the outdoor unit of the air conditioner is not started. Illustratively, the back electromotive force may include a voltage between the U-direction and the V-direction in the three phases, and a voltage between the U-direction and the W-direction in the three phases. The air conditioner may calculate the back electromotive force according to the phase current and the resistance parameter on each phase, or the air conditioner may detect the back electromotive force directly through a preset electromotive force detecting unit.

(3) And judging the rotation direction of the fan according to the counter electromotive force.

The rotation direction refers to the direction of rotation of the fan, and can be indicated by clockwise or counterclockwise rotation, or by forward rotation or reverse rotation. When the rotation direction is represented by positive rotation and negative rotation, the positive rotation refers to the rotation direction when the fan normally works, and the negative rotation refers to the rotation direction opposite to the positive rotation. If the rotation direction is reversed, the fan is in a state of rotating against the wind because the outdoor unit of the air conditioner is not started at present.

For example, the air conditioner may determine the rotation direction of the fan by equation (1) to equation (4):

E _q ＝(2E _a -E _b -E _c ) /3 formula (2)

θ＝tan2 ^-1 (-E _d ，E _q ) Formula (4)

Wherein, U _uv Is the voltage between the U and V directions in the three phases, U _uw Is the voltage between the U and W directions in the three phases, E _q Is the back electromotive force vector of the quadrature axis, E _d Is the back electromotive force vector of the straight axis, and θ is the angle of rotation of the fan.

After the rotation angle theta of the fan is obtained, the air conditioner can conduct derivation processing on theta for time, and the rotation direction of the fan is judged according to the positive and negative of the derivation result. If the derivative result is negative, the rotation angle of the fan in unit time is a negative angle, namely the direction of the rotation angle is opposite to the direction of the fan in normal rotation, so that the rotation direction of the fan is reversed. Conversely, if the result of the derivation is positive, it indicates that the fan rotates by a positive angle per unit time, that is, the direction of the positive angle is the same as the direction in which the fan normally rotates, and therefore the rotation direction of the fan is positive.

(4) And if the rotating direction is reverse, acquiring the fan rotating speed of the fan.

The fan speed refers to the rotational speed of the fan. The fan speed may be expressed in terms of the number of fan revolutions per unit time. For example, the fan speed may be the number of fan revolutions per minute or the number of fan revolutions per second.

Taking the step (3) as an example, if the air conditioner judges the rotation direction according to the derivative result of θ, the derivative result is the rotation speed of the fan. Therefore, if the obtained derivative result is negative, the air conditioner can use the absolute value of the derivative result as the fan rotating speed. Or the air conditioner may also detect the rotation speed of the fan in other manners, which is not limited in the embodiment of the present application.

202. And determining the self-generating current value of the fan according to the rotating speed of the fan.

The self-generating current value refers to a current value of current generated in the motor when the fan rotates against the wind. When the fan rotates against the wind, the rotor in the fan cuts the magnetic induction lines to generate current, so that the motor is equivalent to a generator and can generate self-generating current flowing to other components in the fan.

Illustratively, the self-generating current value may be calculated by a stator coil resistance of the motor. At this moment, determining the self-generating current value of the fan according to the fan rotating speed comprises the following steps:

(A) And acquiring the resistance of a stator coil of a motor in the fan and a preset back electromotive force coefficient.

(B) And calculating the self-generating current value of the fan according to the resistance of the stator coil, the back electromotive force coefficient and the rotating speed of the fan.

Specifically, the air conditioner can calculate the self-generating current value of the fan through formula (5):

wherein I is the self-generating current value, omega is the rotating speed of the fan, and K _e The coefficient is a preset coefficient for the back electromotive force coefficient, and R is the resistance of the stator coil of the motor. The air conditioner can obtain stator coil resistance and back electromotive force coefficient through reading inside memory space, or can also be through stator coil resistance and the back electromotive force coefficient that networking module search motor model corresponds, and this application embodiment does not restrict this.

203. And adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value, and generating a braking torque in the motor so as to brake the fan.

The terminal connection state refers to a connection state of three-phase terminals of the motor. The terminal connection state may include a short state and a normal operation state. When the terminal connection state is the short circuit state, the short circuit between the three-phase terminal of motor, consequently from the power generation current can only transmit in the motor, can't transmit to the outside from the motor. When the terminal connection state is a normal operation state, the three-phase terminals of the motor are respectively connected with other components, such as a bridge arm of the inverter, so that the self-generating current can be transmitted to the outside of the motor.

The braking torque refers to torque which is generated in the motor by self-generating current and blocks the fan from rotating against the wind.

The air conditioner can change the working mode of the inverter and adjust the terminal connection state of the motor. The inverter is a component for converting direct current input by a direct current power supply into alternating current, and is generally connected to a motor in the fan to provide electric energy for the motor to generate torque for the fan to rotate during normal operation. If the passage between the inverter and the motor is cut off, the terminals of the motor are in short circuit, and the flow of the self-generating current is limited in the motor, so that when the fan rotates against the wind, the passage between the motor and the inverter can be blocked by adjusting the inverter, the self-generating current is prevented from forming a loop in the fan to burn out a direct-current power supply, the self-generating current can form a braking torque in the motor, and the fan is braked. Specifically, the formula for forming the braking torque by the self-generating current is shown as formula (6):

T _em ＝P _n [Kei _q +(L _d -L _q )i _d i _q ]formula (6)

Wherein, T _em Is the braking torque, P _n Is the pole pair number of the permanent magnet motor, ke is the back electromotive force coefficient, i _q And i _d Is a direct-axis current value and a quadrature-axis current value, L, corresponding to the self-generating current _d Is a direct axis inductor, L _q Is a quadrature axis inductor. It can be seen that the larger the self-generating current value is, the larger i _q And i _d The larger, L is due to the permanent magnet motor commonly used in outdoor unit of air conditioner _d Greater than L _q Therefore, the larger the self-generating current value is, the generated braking torque T _em The larger the brake, the better the brake effect on the fan. Therefore, the method in the embodiment of the application can adaptively brake the fan, and when the wind power is high and the rotating speed of the fan is high, the generated braking torque is large, so that the braking effect on the fan is better.

And wind power greatly leads to the fan rotational speed fast, and then when producing great spontaneous electric current value, can switch on the route between dc-to-ac converter and the motor, allow partly spontaneous electric current to flow out the motor to reduce the current value of spontaneous electric current in the motor, avoid leading to the motor demagnetization from the spontaneous electric current is too big. Demagnetization refers to a process that a magnet loses magnetism and returns to magnetic neutrality, and if the motor is demagnetized, normal working performance of the motor is affected.

Specifically, the air conditioner may control the inverter by adjusting a terminal connection state of a motor in the outdoor unit of the air conditioner according to the self-generating current value and generating a braking torque in the motor of the fan to brake the fan, including:

(a10) And comparing the self-generating current value with a preset demagnetization current value.

The preset demagnetization current value may be a current value at which permanent magnets on a rotor in the motor generate demagnetization. If the current value generated in the motor when the fan rotates against the wind reaches 10 amperes and the permanent magnets on the rotor demagnetize, the preset demagnetization current value may be set to 10 amperes. In order to improve the fault-tolerant rate, a current value lower than the current value when the permanent magnet is demagnetized can be used as the preset demagnetization current value. If the current value generated in the motor when the fan rotates against the wind reaches 10 amperes, the permanent magnet on the rotor can be demagnetized, the preset demagnetization current value can be set to be 8 amperes or 9 amperes, and the irreversible influence on the performance of the motor due to demagnetization of the permanent magnet during comparison is avoided.

The reason for comparing the self-generating current value with the preset demagnetization current value is to judge whether the current generated by the upwind rotation of the current fan can cause the motor to be demagnetized, if the current cannot cause the demagnetization, the air conditioner can turn off the passage between the inverter and the motor, and if the current can cause the demagnetization, the air conditioner needs to turn on the passage between the inverter and the motor, and allow a part of self-generating current to flow into the inverter to form a loop with the direct-current power supply so as to reduce the self-generating current value.

(a21) If the self-generating current value is smaller than the preset demagnetization current value, the inverter in the air conditioner outdoor unit is adjusted to be in a turn-off state in which all upper bridge arms are disconnected, the terminal state of the motor is adjusted to be in a short-circuit state, and braking torque is generated in the motor so as to brake the fan.

If the self-generating current value is smaller than the preset demagnetization current value, the fact that the motor is not demagnetized due to the current generated by the upwind rotation of the fan at the moment is indicated, therefore, the air conditioner can shut off a path between the inverter and the motor, and particularly, all the upper bridge arms can be disconnected. Referring to fig. 4, fig. 4 shows the connection among the DC power source, the inverter, and the Motor, where DC is the DC power source, S1 to S6 are the bridge arms in the inverter, S1 to S3 are the upper bridge arms, S4 to S6 are the lower bridge arms, S1 and S4 are one phase, S2 and S5 are one phase, S3 and S6 are one phase, motor is the Motor, and C is the energy storage capacitor. For a three-phase bridge inverter commonly used in an outdoor unit of an air conditioner, an operation mode is changed by changing off and on states of a bridge arm, and referring to table 1, the three-phase bridge inverter has 8 operation modes in total.

TABLE 1

Wherein Sa is a phase of S1 and S4, sb is a phase of S2 and S5, sc is a phase of S3 and S6, and when the value is 1, it means that the upper arm is on and the lower arm is off, and when the value is 0, it means that the upper arm is off and the lower arm is on.

If the self-generating current value is smaller than the preset demagnetization current value, the air conditioner can adjust the three-phase bridge inverter to be in a working mode 7 in the table 1, namely, in a turn-off state that all upper bridge arms are turned off. At the moment, because the upper bridge arm is completely disconnected, the self-generating current cannot form a loop between the direct current power supply and the motor, and the direct current power supply cannot be burnt. And the self-generating current which cannot form a loop can only be consumed in the motor, so that the braking torque in the formula (6) can be generated to brake the fan.

It should be noted that a current threshold for stopping braking may be preset, and if the self-generating current value is smaller than the current threshold, it indicates that the rotating speed of the fan rotating against the wind is already low, and the air conditioner outdoor unit may be normally started, and at this time, the air conditioner stops executing the method for controlling the air conditioner against the wind in the embodiment of the present application. Or, a rotation speed threshold for stopping braking may be preset, and if the rotation speed of the fan acquired by the air conditioner is less than the rotation speed threshold, it indicates that the outdoor unit of the air conditioner can be normally started, and at this time, the air conditioner stops executing the method for controlling the upwind of the air conditioner according to the embodiment of the present application.

(a22) If the self-generating current value is larger than or equal to the preset demagnetization current value, the inverter in the outdoor unit of the air conditioner is adjusted to be in a conducting state, and the terminal state of the motor is adjusted to be in a normal working state, so that the self-generating current value is reduced until the self-generating current value is smaller than the preset demagnetization current value.

The on state refers to a state in which all upper arms are not turned off, and taking table 1 as an example, the on state may be the operation mode 8, or may be another operation mode other than the operation modes 7 and 8.

If the self-generating current value is larger than or equal to the preset demagnetization current value, the air conditioner can adjust the three-phase bridge inverter to be in the working mode 8 in the table 1, namely all upper bridge arms are switched on, and the self-generating current can charge the energy storage capacitor in the graph 4 at the moment, so that the self-generating current value can be reduced, and the motor demagnetization can be avoided.

It should be noted that, while step (a 22) is executed, the air conditioner still continuously obtains the self-generating current value, and when the self-generating current value is reduced to be smaller than the preset demagnetization current value, the air conditioner executes step (a 21).

In order to ensure that the energy storage capacitor can store the self-generating current when the inverter is adjusted to be in a conducting state, and achieve the aim of reducing the self-generating current value, the air conditioner can firstly judge whether the energy storage capacitor is fully charged. Before the obtaining of the fan speed of the outdoor unit of the air conditioner when the fan rotates against the wind, the method further includes:

(b10) The method comprises the steps of obtaining the electric quantity of an energy storage capacitor in an inverter of the outdoor unit of the air conditioner, wherein the energy storage capacitor is used for storing self-generating current generated when a fan rotates against the wind.

Referring to fig. 4, the storage capacitor may refer to C in fig. 4. The reason for detecting the electric quantity of the energy storage capacitor is to judge whether the energy storage capacitor is fully charged at present and cannot be charged any more. If the energy storage capacitor can not be charged any more, the self-generating current value can not be reduced even if the inverter is adjusted to be in a conducting state by the air conditioner, and therefore the self-generating current still can cause demagnetization.

(b21) And if the electric quantity is greater than or equal to the preset limit electric quantity, discharging the energy storage capacitor through a pull-down circuit in the outdoor unit of the air conditioner until the electric quantity is less than the limit electric quantity.

And the limit electric quantity is used for evaluating whether the energy storage capacitor is fully charged or not, and if the electric quantity is greater than or equal to the limit electric quantity, the energy storage capacitor is fully charged. The limit electric quantity may be a maximum capacity of the energy storage capacitor, or may be a value smaller than the maximum capacity, for example, the maximum capacity of the energy storage capacitor is 25 joules, and the limit electric quantity may be 25 joules, or may be 24 joules.

When the electric quantity is greater than or equal to the limit electric quantity, the air conditioner needs to discharge the energy storage capacitor so as to reserve enough capacity to store the self-generating current. Specifically, the air conditioner can pull down the energy storage capacitor to ground through a pull-down circuit pre-arranged in an outdoor unit of the air conditioner, so as to achieve the purpose of discharging. The structure of the pull-down circuit can refer to the existing pull-down circuit, and details are not repeated.

(b22) And if the electric quantity in the energy storage capacitor is smaller than the preset limit electric quantity, executing the step of acquiring the rotating speed of the fan of the outdoor unit of the air conditioner when the fan rotates against the wind.

And when the electric quantity is less than the limit electric quantity, the energy storage capacitor has enough capacity to store the self-generating current. Steps 201-203 may be performed at this point.

To sum up, the embodiment of the present application includes: acquiring the fan rotating speed of a fan in an air conditioner outdoor unit when the fan rotates against the wind; determining a self-generating current value of the fan according to the rotating speed of the fan; and adjusting the terminal connection state of a motor in the air conditioner outdoor unit according to the self-generating current value, and generating braking torque in the motor so as to brake the fan. The upwind control method of the air conditioner can control the terminal connection state of the motor according to different self-generating current values, when the self-generating current value is large, the terminal connection state is adjusted to be in a short-circuit state, so that the self-generating current value is completely consumed in the motor, the braking torque for braking can be generated, when the self-generating current value is small, the terminal connection state is adjusted to be in a normal working state, a part of the self-generating current value is allowed to flow out of the motor, the self-generating current value is reduced, and demagnetization of the motor is avoided, so that the upwind rotating fan can be effectively braked, and the situation that the performance of the motor is influenced by the self-generating current generated by upwind rotation can be avoided.

In some embodiments, the air conditioner may further perform the second stage braking when effective braking cannot be achieved only by adjusting the connection state of the terminals by inputting the compensation current. Referring to fig. 5, at this time, if the self-power-generation current value is smaller than the preset demagnetization current value, the inverter in the outdoor unit of the air conditioner is adjusted to be in a turn-off state in which all upper bridge arms are turned off, the terminal state of the motor is adjusted to be in a short-circuit state, and a braking torque is generated in the motor, so that after the fan is braked, the method further includes:

301. and acquiring the rotating speed of the fan after braking and the turn-off time of the inverter in a turn-off state.

The post-braking rotating speed refers to the rotating speed obtained after the fan is braked by adjusting the connection state of the terminal. The post-braking rotation speed may be a rotation speed obtained by the air conditioner after a period of time in which the terminal connection state of the motor is adjusted to the short-circuit state. For example, the air conditioner may detect the rotation speed of the fan to obtain the post-braking rotation speed 30 seconds after the terminal connection state of the motor is adjusted to the short-circuit state, that is, 30 seconds after all the upper arms of the inverter are disconnected. The purpose of obtaining the rotating speed after braking is to judge whether the fan can be effectively braked by only adjusting the terminal state of the motor.

The off time is the time elapsed since the upper arm of the inverter was completely disconnected. For example, if the terminal connection state of the motor is kept in a short-circuit state all the time, that is, the upper arm of the inverter is kept in a state of being completely disconnected all the time, the turn-off time may be the time elapsed from when the upper arm of the inverter is completely disconnected until the air conditioner acquires the rotation speed after braking. For example, if the rotation speed of the fan is detected 30 seconds after the air conditioner turns off all the upper arms of the inverter, the turn-off time is 30 seconds.

302. And if the rotating speed after braking is greater than a preset extreme rotating speed and/or the turn-off time is greater than a preset time threshold value, acquiring the current position of the rotor in the fan.

The extreme rotating speed is a preset value used for evaluating whether the rotating speed is too large after braking, and if the rotating speed is larger than the extreme rotating speed after braking, the fact that the upwind rotating speed of the fan cannot be effectively reduced still by adjusting the connection state of the rotor of the motor is indicated.

The time threshold is also a preset value for evaluating whether the upwind rotation speed of the fan can be effectively reduced by adjusting the rotor connection state of the motor. If the turn-off time is larger than the time threshold, the terminal is short-circuited for a long time, and the upwind rotating speed of the fan cannot be reduced after the braking torque is generated.

If at least one of the rotating speed is greater than the extreme rotating speed and the turn-off time is greater than the time threshold value after braking is established, the upwind rotating speed of the fan cannot be effectively reduced by adjusting the rotor connection state of the motor. Assuming that the limit rotation speed is 1300 rpm and the time threshold is 30 seconds, if the terminal is adjusted to be in the short-circuit state for 30 seconds, the acquired rotation speed after braking is 1500 rpm, and no matter whether the terminal connection state of the motor is adjusted to be in the normal working state within the 30 seconds, that is, whether the short-circuit state lasts for 30 seconds, it is considered that the upwind rotation speed of the fan cannot be effectively reduced by adjusting the rotor connection state of the motor. Or after braking, the rotating speed is less than or equal to the extreme rotating speed, but not less than the rotating speed threshold value explained in the step (a 21), and the short-circuit state lasts for 30 seconds, it can also be considered that the upwind rotating speed of the fan cannot be effectively reduced by adjusting the rotor connection state of the motor.

303. And determining the direction of the compensation current according to the current position.

The compensation current direction refers to a current direction of current for further reducing the fan speed. The induced magnetic fields in different directions can be generated by inputting variable currents in different directions into the motor, and the input variable currents can be currents with constant change rates in order to keep the induced magnetic fields stable. Specifically, when the current position of the rotor is different, the direction of the required force is different when the fan brakes, and it can also be understood that the torque direction of the required torque is different, and the compensation current direction is related to the torque direction generating the torque, so that the compensation current direction is determined according to the position of the rotor.

304. And inputting a torque compensation current into the motor according to the direction of the compensation current, wherein the torque compensation current is used for generating a torque for reducing the rotating speed after braking.

The torque compensation current is a current for further reducing the rotation speed of the fan, and as described in step 303, the torque compensation current is a variation current, and the variation rate of the torque compensation current may be determined according to the magnitude of the rotation speed after braking. If the rotating speed is larger after braking, the change current with larger change rate can be used as the torque compensation current so as to brake the fan as soon as possible. If the torque is small after braking, the change current with small change rate can be used as the torque compensation current to avoid over braking.

The air conditioner may input the torque compensation current into the motor according to the determined compensation current direction, for example, the air conditioner may input the torque compensation current into an a-axis of the motor to generate a torque to reduce a rotational speed after braking.

In some embodiments, whether the motor is demagnetized or not can be judged according to the condition of flux linkage in the motor, and different braking modes are respectively adopted for two conditions of demagnetization and demagnetization. Referring to fig. 6, the current rotor speed of the rotor in the wind turbine is obtained at this time;

401. and calculating to obtain the current flux linkage of the motor in the fan according to the current rotor rotating speed and the self-generating current value.

Specifically, the air conditioner may obtain the current flux linkage by calculating according to equation (7):

wherein u is _q Is the quadrature axis voltage of the motor, i _q Is quadrature axis current of the motor, i _d Is the direct axis current of the motor u _q 、i _q And i _d All can be obtained by self-generating current value L _q Is the quadrature axis inductance of the motor, t isTime, R is phase resistance, L _d Is the direct axis inductance, ω is the current rotor speed, P _n Is the pole pair number of the permanent magnet motor.

402A, if the current flux linkage belongs to a preset factory flux linkage range, inputting a torque compensation current into the fan, wherein the torque compensation current is used for generating a torque for reducing the rotating speed of the fan.

The factory flux linkage range is a flux linkage range used for evaluating whether the motor is demagnetized. Assuming that the outgoing flux linkage of the motor is n, the outgoing flux linkage range may be [ n, + ∞ ]. If the current flux linkage belongs to the range of the factory flux linkage, the motor is not demagnetized, so that braking can be performed by a method of inputting a torque compensation current.

402B, if the current flux linkage does not belong to the preset outgoing flux linkage range, adjusting the terminal connection state of the motor in the outdoor unit of the air conditioner according to the comparison result between the self-generating current value and the preset demagnetizing current value, and generating braking torque in the motor so as to brake the fan.

If the current flux linkage does not belong to the factory flux linkage range, demagnetization of the motor is shown, and if the brake is carried out by adopting a torque compensation current method, the input torque compensation current can further aggravate the situation of demagnetization, so that a mode of adjusting the connection state of the terminals can be adopted, the probability of demagnetization can be reduced as much as possible, the motor can be protected, and the brake can be realized.

In order to better implement the motor control method in the embodiment of the present application, on the basis of the motor control method, an upwind control device of an air conditioner is further provided in the embodiment of the present application, as shown in fig. 7, which is a schematic structural diagram of an embodiment of the upwind control device of the air conditioner in the embodiment of the present application, and the upwind control device 500 of the air conditioner includes:

an obtaining unit 501, configured to obtain a fan rotation speed of a fan in an outdoor unit of an air conditioner when the fan rotates against the wind;

a determining unit 502, configured to determine a self-generating current value of the fan according to the fan rotation speed;

and a brake unit 503, configured to adjust a terminal connection state of a motor in the outdoor unit of the air conditioner according to the self-generating current value, and generate a braking torque in the motor, so as to brake the fan, where the terminal connection state includes a short-circuit state and a normal working state.

In one possible implementation manner of the present application, the braking unit 503 is further configured to:

determining a compensation current direction according to the current position;

In one possible implementation manner of the present application, the air conditioner upwind control device 500 further includes a flux linkage calculating unit 504, where the flux linkage calculating unit 504 is configured to:

acquiring the current rotor rotating speed of a rotor in the fan;

In a possible implementation manner of the present application, the obtaining unit 501 is further configured to:

In one possible implementation manner of the present application, the air conditioner upwind control device 500 further includes an electric quantity obtaining unit 505, where the electric quantity obtaining unit 505 is configured to:

In a possible implementation manner of the present application, the determining unit 502 is further configured to:

and calculating the self-generating current value of the fan according to the resistance of the stator coil, the back electromotive force coefficient and the rotating speed of the fan.

In specific implementation, the above units may be implemented as independent entities, or may be combined arbitrarily, and implemented as the same or several entities, and specific implementations of the above units may refer to the foregoing method embodiment, which is not described herein again.

Since the upwind control device of the air conditioner can execute the steps in the motor control method in any embodiment of the present application, the beneficial effects that can be realized by the motor control method in any embodiment of the present application can be realized, which are detailed in the foregoing description and will not be repeated herein.

In addition, in order to better implement the motor control method in the embodiment of the present application, based on the motor control method, the embodiment of the present application further provides an air conditioner, referring to fig. 8, fig. 8 shows a schematic structural diagram of the air conditioner in the embodiment of the present application, specifically, the air conditioner provided in the embodiment of the present application includes a processor 601, and the processor 601 is configured to implement each step of the motor control method in any embodiment when executing a computer program stored in a memory 602; alternatively, the processor 601 is configured to implement the functions of the units in the corresponding embodiment of fig. 7 when executing the computer program stored in the memory 602.

Illustratively, a computer program may be partitioned into one or more modules/units, which are stored in memory 602 and executed by processor 601 to implement embodiments of the present application. One or more modules/units may be a series of computer program instruction segments capable of performing certain functions, the instruction segments being used to describe the execution of a computer program in a computer device.

The air conditioner may include, but is not limited to, a processor 601, a memory 602. Those skilled in the art will appreciate that the illustration is merely an example of an air conditioner and is not meant to be limiting, and may include more or less components than those illustrated, or may combine some components, or different components, for example, the air conditioner may further include input and output devices, network access devices, buses, etc., and the processor 601, the memory 602, the input and output devices, the network access devices, etc., are connected via the buses.

The Processor 601 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. The general purpose processor may be a microprocessor or the processor may be any conventional processor or the like, the processor being the control center of the air conditioner and connected to the various parts of the overall air conditioner by various interfaces and lines.

The memory 602 may be used for storing computer programs and/or modules, and the processor 601 may implement various functions of the computer apparatus by executing or executing the computer programs and/or modules stored in the memory 602 and calling data stored in the memory 602. The memory 602 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, video data, etc.) created according to the use of the air conditioner, etc. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), at least one magnetic disk storage device, a Flash memory device, or other volatile solid state storage device.

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the upwind control device of the air conditioner, the air conditioner and the corresponding units thereof described above may refer to the description of the motor control method in any embodiment, and are not described herein again in detail.

It will be understood by those skilled in the art that all or part of the steps of the methods of the above embodiments may be performed by instructions or by associated hardware controlled by the instructions, which may be stored in a computer readable storage medium and loaded and executed by a processor.

For this reason, an embodiment of the present application provides a computer-readable storage medium, where multiple instructions are stored, and the instructions can be loaded by a processor to execute steps in a motor control method in any embodiment of the present application, and specific operations may refer to descriptions of the motor control method in any embodiment, and are not described herein again.

Wherein the computer-readable storage medium may include: read Only Memory (ROM), random Access Memory (RAM), magnetic or optical disks, and the like.

Since the instructions stored in the computer-readable storage medium can execute the steps in the motor control method in any embodiment of the present application, the beneficial effects that can be achieved by the motor control method in any embodiment of the present application can be achieved, for details, see the foregoing description, and are not described again here.

The foregoing describes in detail a motor control method, a motor control device, a storage medium, and an air conditioner provided in the embodiments of the present application, and specific examples are applied herein to explain the principles and implementations of the present application, and the description of the foregoing embodiments is only used to help understand the method and the core ideas of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and the application scope may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. An air conditioner upwind control method is characterized by comprising the following steps:

determining the self-generating current value of the fan according to the rotating speed of the fan;

2. The method of claim 1, wherein if the self-generating current value is less than the predetermined demagnetization current value, the inverter of the outdoor unit is adjusted to an off state in which all upper arms of the inverter are turned off, the terminal state of the motor is adjusted to a short-circuit state, and a braking torque is generated in the motor to brake the fan, and the method further comprises:

3. An air conditioner upwind control method according to claim 1, wherein after determining a self-generating current value of the fan according to the fan rotation speed, the method further comprises:

acquiring the current rotor rotating speed of a rotor in the fan;

4. The method of claim 1, wherein the fan speed of the fan of the outdoor unit of the air conditioner when the fan rotates against the wind comprises:

5. The method of claim 1, wherein the obtaining of the fan speed of the fan of the outdoor unit before the fan speed is rotated against the wind, further comprises:

and if the electric quantity in the energy storage capacitor is smaller than a preset limit electric quantity, executing the step of acquiring the rotating speed of a fan in the outdoor unit of the air conditioner when the fan rotates against the wind.

6. The method for controlling the upwind of the air conditioner according to any one of claims 1 to 5, wherein the determining the self-generating current value of the fan according to the rotation speed of the fan comprises:

7. An air conditioner headwind control device, comprising:

the brake unit is used for comparing the self-generating current value with a preset demagnetization current value;

8. An air conditioner, comprising a processor and a memory, wherein the memory stores a computer program, and the processor executes the method for controlling the headwind of the air conditioner according to any one of claims 1 to 6 when calling the computer program in the memory.

9. A readable storage medium having stored thereon a computer program to be loaded by a processor for performing the steps of the method for controlling an air conditioner in an upwind direction according to any one of claims 1 to 6.