A motor rotor positioning method and device, motor, compressor and refrigeration equipment

Abstract

This invention discloses a method, apparatus, motor, compressor, and refrigeration equipment for positioning a motor rotor. The method includes: acquiring a pre-set positioning angle before motor startup; controlling the motor rotor to switch to the positioning angle; and controlling the motor current to gradually increase to the positioning current corresponding to the current positioning angle. This invention reduces the speed of the rotor during the pulling process, prevents rotor oscillation and vibration noise, and improves the user experience.

Description

Technical Field

[0001] This invention relates to the field of electronic and electrical technology, and more specifically, to a method, apparatus, motor, compressor, and refrigeration equipment for positioning a motor rotor. Background Technology

[0002] Currently, some refrigeration equipment (such as inverter refrigerators) occasionally vibrates during startup. The intensity of the vibration varies, affecting the user experience. This startup vibration is mainly caused by an unreasonable DC positioning logic in the compressor motor of the refrigeration equipment, which leads to excessively rapid current changes during startup, causing the rotor to move too quickly and producing vibration.

[0003] There is currently no effective solution to the problem that the motor current of the compressor in the existing refrigeration equipment changes too quickly during startup, causing the rotor to move too fast and vibrate. Summary of the Invention

[0004] This invention provides a method, device, motor, compressor, and refrigeration equipment for positioning a motor rotor, in order to solve the problem in the prior art where the current changes too quickly during the start-up process of the compressor motor in refrigeration equipment, resulting in excessively fast rotor movement and vibration noise.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for positioning a motor rotor, wherein the method includes:

[0006] Before the motor starts, obtain the preset positioning angle;

[0007] The motor rotor is controlled to switch to the positioning angle, and the motor current is controlled to gradually increase to the positioning current corresponding to the current positioning angle.

[0008] Furthermore, the method also includes:

[0009] Before the motor rotor switches the positioning angle, the current of the motor is controlled to return to zero.

[0010] Furthermore, the current of the control motor gradually increases to the positioning current corresponding to the current positioning angle, including:

[0011] Determine whether the positioning current corresponding to the positioning angle is greater than a preset threshold.

[0012] If so, the current of the motor is controlled to rise from the zero segment to the positioning current corresponding to the current positioning angle.

[0013] Furthermore, controlling the motor current to rise from zero segments to the positioning current corresponding to the current positioning angle also includes:

[0014] Based on the magnitude of the positioning current corresponding to the current positioning angle, the current range from zero to the positioning current is divided into multiple segments using different segment thresholds; wherein, the larger the positioning current, the more segments are divided.

[0015] According to the section, the current of the motor is controlled to gradually increase from zero to the positioning current corresponding to the current positioning angle.

[0016] Further, controlling the motor current to gradually increase from zero to the positioning current corresponding to the current positioning angle according to the segment includes:

[0017] The current of the motor is controlled to rise sequentially to different threshold ranges;

[0018] After the motor current rises to the segment threshold each time, the motor current is controlled to remain constant for a preset time period, and then rises to the next segment threshold until it rises to the positioning current corresponding to the current positioning angle.

[0019] Furthermore, after determining whether the positioning current corresponding to the positioning angle is greater than a preset threshold, the method further includes:

[0020] If not, the motor current is controlled to rise from zero at a preset speed to the positioning current corresponding to the current positioning angle.

[0021] Furthermore, when the number of positioning angles is at least two, the difference between two adjacent positioning angles is less than 90°.

[0022] Furthermore, after the control motor rotor switches to the positioning angle and the control motor current gradually increases to the positioning current corresponding to the current positioning angle, the method further includes:

[0023] The motor is controlled to enter an open-loop control program. After the open-loop control program ends, a PWM pulse width modulation wave is output according to the current positioning angle and the positioning current corresponding to the current positioning angle to control the motor to start running.

[0024] The present invention also provides a motor rotor positioning device for implementing the above method, the device comprising:

[0025] The acquisition module is used to acquire a pre-set positioning angle before the motor starts;

[0026] The control module is used to control the motor rotor to switch to the positioning angle and to control the motor current to gradually increase to the positioning current corresponding to the current positioning angle.

[0027] The present invention also provides an electric motor, including the above-described motor rotor positioning device.

[0028] The present invention also provides a compressor, including the above-described motor.

[0029] The present invention also provides a refrigeration device, characterized in that it includes the above-described compressor.

[0030] Furthermore, the refrigeration equipment includes at least one of the following: a refrigerator and an air conditioner.

[0031] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described motor rotor positioning method.

[0032] By applying the technical solution of this invention, a pre-set positioning angle is obtained before the motor starts; the motor rotor is controlled to switch to the positioning angle, and the motor current is controlled to gradually increase to the positioning current corresponding to the current positioning angle. By slowing down the current rise rate, the speed of the rotor during the pulling process can be reduced, preventing rotor oscillation and vibration noise, thus improving the user experience. Attached Figure Description

[0033] Figure 1 This is a flowchart of a motor rotor positioning method according to an embodiment of the present invention;

[0034] Figure 2 This is a motor rotor positioning method according to another embodiment of the present invention;

[0035] Figure 3 This is a graph showing the three-phase current variation during the positioning process according to an embodiment of the present invention.

[0036] Figure 4 This is a flowchart illustrating the process of controlling the motor startup and operation according to an embodiment of the present invention.

[0037] Figure 5 This is a control block diagram for starting and operating a motor according to an embodiment of the present invention;

[0038] Figure 6 This is a structural block diagram of a motor rotor positioning device according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0041] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0042] It should be understood that although the terms first, second, third, etc., may be used to describe positioning currents in embodiments of the present invention, these terms should not be limited to. These terms are only used to distinguish different positioning currents. For example, without departing from the scope of embodiments of the present invention, the first positioning current may also be referred to as the second positioning current, and similarly, the second positioning current may also be referred to as the first positioning current.

[0043] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0044] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0045] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0046] Example 1

[0047] This embodiment provides a method for positioning a motor rotor. Figure 1 The flowchart of the motor rotor positioning method according to an embodiment of the present invention is as follows: Figure 1 As shown, the method includes:

[0048] S101: Before the motor starts, the preset positioning angle is obtained.

[0049] S102, control the motor rotor to switch to the above positioning angle, and control the motor current to gradually increase to the positioning current corresponding to the current positioning angle.

[0050] The motor rotor positioning method of this embodiment obtains a preset positioning angle before the motor starts; controls the motor rotor to switch to the positioning angle, and controls the motor current to gradually increase to the positioning current corresponding to the current positioning angle. By slowing down the current increase rate, the speed of the rotor during the pulling process can be reduced, preventing rotor oscillation and vibration noise, thus improving the user experience.

[0051] To avoid inaccurate positioning angles during the initial positioning, a second, third, or even Nth positioning is performed. This involves controlling the positioning angle to switch to the second positioning angle A2, the third positioning angle A3, and the Nth positioning angle AN. To prevent excessive rotor rotation that could cause large oscillations, the difference between adjacent positioning angles is less than 90°.

[0052] Before the motor rotor switches the positioning angle, the motor current is controlled to return to zero.

[0053] To further control the rate of current increase, the motor current is gradually increased to the positioning current corresponding to the current positioning angle. This includes: determining whether the positioning current corresponding to the current positioning angle is greater than a preset threshold; if so, there will be a problem of the current rising too quickly, causing the motor rotor to oscillate. To avoid this problem, the motor current is controlled to rise from zero in segments to the positioning current corresponding to the current positioning angle; if not, it indicates that the current rise is small and will not cause the motor rotor to oscillate. However, to ensure that the motor current rises at a uniform and stable speed, the motor current needs to be controlled to rise from zero at a preset speed to the positioning current corresponding to the current positioning angle.

[0054] Specifically, controlling the motor current to rise from zero to the positioning current corresponding to the current positioning angle further includes: dividing the current range from zero to the positioning current into multiple segments based on the magnitude of the positioning current corresponding to the current positioning angle through different segment thresholds; wherein, the larger the positioning current, the more segments are divided; and controlling the motor current to gradually rise from zero to the positioning current corresponding to the current positioning angle based on the segments.

[0055] In order to further slow down the rate of current increase, the motor current is controlled to gradually increase from zero to the positioning current corresponding to the current positioning angle according to the segment, including: controlling the motor current to rise sequentially to different segment thresholds; after the motor current rises to the segment threshold each time, controlling the motor current to remain unchanged for a preset time period, and then rising to the next segment threshold, until it rises to the positioning current corresponding to the current positioning angle.

[0056] For example, assuming the positioning angle includes a first positioning angle and a second positioning angle, the positioning current corresponding to the first positioning angle is less than the aforementioned preset threshold, and the positioning current corresponding to the second positioning angle is greater than or equal to the aforementioned preset threshold, then the above method specifically includes:

[0057] The motor rotor is controlled to rotate from any angle to the first positioning angle, and the motor current is controlled to rise from zero at a first preset speed to the first positioning current I1 and continue for a first preset duration; the angle of the motor rotor is kept constant, and the motor current is controlled to return to zero and continue for a second preset duration; the motor rotor is controlled to rotate from the first positioning angle A1 to the second positioning angle A2, and the motor current is controlled to rise from zero at a second preset speed to the current threshold I2 and continue for a third preset duration; the angle of the motor rotor is kept constant, and the motor current is controlled to rise from the current threshold I2 at a third preset speed to the second positioning current I3 and continue for a fourth preset duration.

[0058] The second positioning current I3 is the positioning current corresponding to the second positioning angle A2, the first positioning current I1 is the positioning current corresponding to the first positioning angle A1, and the current threshold I2 is a set segment threshold. In other embodiments of the present invention, the above-mentioned segment threshold can be set to multiple values. In practical applications, if only one segment threshold is set, in order to ensure that the current rises uniformly, the segment threshold is 1 / 2 of the second positioning current I3; if multiple segment thresholds are set, in order to ensure that the current rises uniformly, the current interval from zero to the second positioning current I3 is divided into several sub-current intervals by multiple segment thresholds.

[0059] As can be seen from the above steps, whenever the current rises to the positioning current corresponding to the current positioning angle, the current will be maintained for a period of time before the positioning angle is switched. This operation is to ensure that the current reaches a stable state before controlling the change of the current and switching the positioning angle.

[0060] Figure 2 According to another embodiment of the present invention, a motor rotor positioning method is used, such as... Figure 2 As shown, the method includes the following preferred implementation steps:

[0061] S21, after power-on, enter the first positioning stage, set the first positioning angle A1 and the first positioning current I1, control the motor rotor to switch from any angle to the first positioning angle A1, and control the motor current to rise from zero to the first positioning current I1 at the first preset speed, and maintain it for the first preset duration.

[0062] In this embodiment, the first positioning angle A1 = -90°, the first positioning current I1 = 0.52A, and the positioning current rises from 0 to the first positioning current I1 at a certain speed. In this embodiment, it rises from 0A to 0.52A in 0.15 seconds, and the first preset duration is set to 0.25 seconds.

[0063] S22, enter the second positioning stage, control the motor rotor to keep the first positioning angle A1 unchanged, the positioning current is restored to 0, and maintain the second preset time.

[0064] In this embodiment, the second preset duration is set to 0.1 seconds.

[0065] S23, enter the third positioning stage, set the second positioning angle A2, control the motor rotor to switch from the first positioning angle A1 to the second positioning angle A2, the positioning current rises from 0 to the current threshold I2 at a certain speed, and is maintained for the third preset time.

[0066] In this embodiment, the second positioning angle A2 is set to -150 degrees, the current threshold I2 is set to 0.52A, the current rises from 0A to the current threshold I2 within 0.15 seconds, and the third preset duration is set to 0.45 seconds.

[0067] S24, enter the fourth stage of positioning, control the motor to keep the second positioning angle A2 unchanged, control the positioning current to rise from the current threshold I2 to the second positioning current I3 at a certain speed, and continue for the fourth preset time.

[0068] In this embodiment, within 0.15 seconds, the motor current rises from the current threshold I2 to the second positioning current I3, the second positioning current I3 = 1.04A, and the fourth preset duration is set to 0.25 seconds.

[0069] Figure 3 The diagram shows the three-phase current variation during the positioning process according to an embodiment of the present invention. Figure 3 As shown, in the first positioning stage, the motor current rises from zero to the first positioning current I1 at a first preset speed; in the second positioning stage, the positioning current returns to 0 and is maintained for a second preset duration; in the third positioning stage, the positioning current rises from 0 to the current threshold I2 at a second preset speed and is maintained for a third preset duration; in the fourth positioning stage, the positioning current rises from the current threshold I2 to the second positioning current I3 at a third preset speed and is maintained for a fourth preset duration.

[0070] After switching the positioning angle and controlling the motor current to gradually rise to the positioning current corresponding to the current positioning angle, the method further includes: controlling the motor to enter an open-loop control program, and after the open-loop control program ends, outputting a PWM pulse width modulation wave according to the current positioning angle and the positioning current corresponding to the current positioning angle to control the motor to start running.

[0071] Figure 4 A flowchart illustrating the process of controlling the motor startup and operation according to an embodiment of the present invention is shown below. Figure 4 As shown, a PWM pulse width modulation wave is output based on the current positioning angle and the corresponding positioning current to control the motor to start and run, including:

[0072] S41, calculate the three-phase current of the motor based on the current positioning angle and the positioning current corresponding to the current positioning angle.

[0073] The three-phase current is calculated based on the positioning angle and the corresponding positioning current. Taking the positioning angle as the first positioning angle -90° as an example, the calculation process in the program is as follows: calculate the angle θ = -90° between the α axis in the two-phase stationary coordinate system and the d axis in the rotating coordinate system; calculate the d and q axis currents: Id = 0A, Iq = the first positioning current I1; calculate the α axis current iα and the β axis current iβ in the stationary coordinate system based on Id and Iq; calculate the three-phase currents ia, ib, and ic based on iα and iβ.

[0074] S42 performs a Clarke transformation on the three-phase current of the motor to obtain the current and voltage components in the first stationary coordinate system.

[0075] Figure 5 This is a control block diagram for starting and running a motor according to an embodiment of the present invention, such as... Figure 5 As shown, two phases ia and ib in the three-phase current are transformed into stationary coordinate α-axis current iα and β-axis current iβ. This transformation yields variables iα and iβ, which are derived from the aforementioned values ​​of ia and ib. From the stator's perspective, iα and iβ are mutually orthogonal time-varying current values.

[0076] S43, perform PARK transformation on the current components of the first stationary coordinate system to obtain the current components of the perpendicular and direct axes.

[0077] The stationary coordinate system is rotated to align with the rotor flux based on the transformation angle calculated in the previous iteration of the control loop. iα and iβ are transformed using the PARK transformation to obtain the direct-axis current Id and the quadrature-axis current Iq. Id and Iq are the orthogonal currents transformed into the rotating coordinate system.

[0078] S44, estimate the motor rotor position and speed based on the current and voltage components in the first stationary coordinate system.

[0079] A sliding diaphragm controller or an ATPLL controller is used to estimate the motor rotor position and speed based on the new position angle, where Vα, Vβ, iα, and iβ are input parameters. The new rotor position indicates where the next voltage vector will be located.

[0080] S45 performs PI calculations on the direct and quadrature axis current components and rotational speed.

[0081] The error signal is obtained by comparing the actual values ​​of Id and Iq with their respective reference values ​​(target values) Id* and Iq*. The reference value of Id controls the rotor flux, the reference value of Iq controls the motor torque, the error signal is the input of the PI controller, and the output of the controller is Vd and Vq, which are the voltage vectors to be applied to the motor.

[0082] S46. Perform PARK inverse transformation on the perpendicular and perpendicular axis voltage components obtained after PI calculation to obtain the voltage components in the second stationary coordinate system.

[0083] By using a new angle, the Vd and Vq output values ​​of the PI controller can be inverted to the stationary reference coordinate system to generate the next quadrature voltage values ​​Vα and Vβ.

[0084] S47, perform CLARKE inverse transformation on the voltage components of the second stationary coordinate system to obtain the three-phase voltage.

[0085] The values ​​of Vα and Vβ are obtained by inverse Clarke transformation to yield the three-phase voltages VA, VB, and VC. These three-phase voltages can be used to calculate the duty cycle of a new PWM pulse width modulation waveform to generate the desired voltage vector.

[0086] S48, generate a PWM pulse width modulation wave based on the above three-phase voltages VA, VB and VC to control the motor to start running.

[0087] Example 2

[0088] This embodiment provides a motor rotor positioning device for implementing the above-described motor rotor positioning method. Figure 6 This is a structural block diagram of a motor rotor positioning device according to an embodiment of the present invention, such as... Figure 6 As shown, the device includes:

[0089] The acquisition module 10 is used to acquire a pre-set positioning angle before the motor starts.

[0090] The control module 20 is used to control the motor rotor to switch to the positioning angle and control the motor current to gradually increase to the positioning current corresponding to the current positioning angle.

[0091] In this embodiment, the motor rotor positioning device controls the motor rotor to switch to the positioning angle through the control module 20, and controls the motor current to gradually rise to the positioning current corresponding to the current positioning angle. By slowing down the current rise rate, the speed of the rotor during the pulling process can be reduced, preventing the rotor from oscillating and causing vibration noise, thus improving the user experience.

[0092] To avoid inaccurate positioning angles during the initial positioning, a second, third, or even Nth positioning is performed. This involves controlling the positioning angle to switch to the second positioning angle A2, the third positioning angle A3, and the Nth positioning angle AN. When there are at least two positioning angles, the difference between adjacent positioning angles is less than 90° to prevent the rotor from rotating too much.

[0093] The control module 20 is also used to: control the motor current to return to zero before the motor rotor switches the positioning angle.

[0094] To further control the rate of current increase, the control module 20 is also configured to: determine whether the positioning current corresponding to the positioning angle is greater than a preset threshold; if not, control the motor current to rise from zero at a preset speed to the positioning current corresponding to the current positioning angle; if yes, control the motor current to rise from zero in segments to the positioning current corresponding to the current positioning angle. Specifically, controlling the motor current to rise from zero in segments to the positioning current corresponding to the current positioning angle includes: controlling the motor current to rise sequentially to different segment thresholds; after the motor current rises to each segment threshold, controlling the motor current to remain constant for a preset time period, and then rising to the next segment threshold, until it rises to the positioning current corresponding to the current positioning angle.

[0095] In this embodiment, the positioning angle includes a first positioning angle and a second positioning angle, wherein the first positioning angle is smaller than the second positioning angle. If the positioning current corresponding to the first positioning angle is less than the aforementioned preset threshold, and the positioning current corresponding to the second positioning angle is greater than or equal to the aforementioned preset threshold, then the control module 20 is specifically used for:

[0096] The motor rotor is controlled to rotate from any angle to the first positioning angle, and the motor current is controlled to rise from zero to the first positioning current at a first preset speed and continue for a first preset duration; the angle of the motor rotor is kept unchanged, and the motor current is controlled to return to zero and continue for a second preset duration; the motor rotor is controlled to rotate from the first positioning angle to the second positioning angle, and the motor current is controlled to rise from zero to the second positioning current at a second preset speed and continue for a third preset duration; the angle of the motor rotor is kept unchanged, and the motor current is controlled to rise from the second positioning current to the third positioning current at a third preset speed and continue for a fourth preset duration.

[0097] The second positioning current I3 is the positioning current corresponding to the second positioning angle A2, the first positioning current I1 is the positioning current corresponding to the first positioning angle A1, and the current threshold I2 is a set segment threshold. In other embodiments of the present invention, the above-mentioned segment threshold can be set to multiple values. In practical applications, if only one segment threshold is set, in order to ensure that the current rises uniformly, the segment threshold is 1 / 2 of the second positioning current I3; if multiple segment thresholds are set, in order to ensure that the current rises uniformly, the current interval from zero to the second positioning current I3 is divided into several sub-current intervals by multiple segment thresholds.

[0098] The control module 20 is also used to: after switching the positioning angle and controlling the motor current to gradually rise to the positioning current corresponding to the current positioning angle, control the motor to enter the open-loop control program, and after ending the open-loop control program, output a PWM pulse width modulation wave according to the current positioning angle and the positioning current corresponding to the current positioning angle to control the motor to start running.

[0099] Example 3

[0100] This embodiment provides a motor, including the motor rotor positioning device in the above embodiment, which is used to control the switching of positioning angle and slow down the current rise rate to achieve the purpose of accurate positioning angle, reduce the speed during rotor pulling, prevent rotor oscillation and vibration noise, and improve user experience.

[0101] Example 4

[0102] This embodiment provides a compressor, including the motor described in the above embodiment.

[0103] Example 5

[0104] This embodiment provides a refrigeration device, including the compressor described in the above embodiment. In some embodiments of the present invention, the refrigeration device includes a refrigerator or an air conditioner.

[0105] Example 6

[0106] This embodiment provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the motor rotor positioning method in the above embodiment.

[0107] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of positioning an electric machine rotor, characterized by, The method includes: Before the motor starts, obtain the preset positioning angle; The motor rotor is controlled to switch to the positioning angle, and the motor current is controlled to gradually increase to the positioning current corresponding to the current positioning angle; including: determining whether the positioning current corresponding to the positioning angle is greater than a preset threshold; if not, the motor current is controlled to increase from zero to the positioning current corresponding to the current positioning angle at a preset speed; if yes, the motor current is controlled to increase from zero in segments to the positioning current corresponding to the current positioning angle.

2. The method of claim 1, wherein, The method further includes: Before the motor rotor switches the positioning angle, the current of the motor is controlled to return to zero.

3. The method of claim 1, wherein, Controlling the motor current to rise from zero segments to the positioning current corresponding to the current positioning angle also includes: Based on the magnitude of the positioning current corresponding to the current positioning angle, the current range from zero to the positioning current is divided into multiple segments using different segment thresholds; wherein, the larger the positioning current, the more segments are divided. According to the section, the current of the motor is controlled to gradually increase from zero to the positioning current corresponding to the current positioning angle.

4. The method according to claim 3, characterized in that, The motor current is controlled to gradually increase from zero to the positioning current corresponding to the current positioning angle according to the segment, including: The current of the motor is controlled to rise sequentially to different threshold ranges; After the motor current rises to the segment threshold each time, the motor current is controlled to remain constant for a preset time period, and then rises to the next segment threshold until it rises to the positioning current corresponding to the current positioning angle.

5. The method according to claim 1, characterized in that, When the number of positioning angles is at least two, the difference between two adjacent positioning angles is less than 90°.

6. The method according to claim 1, characterized in that, After the control motor rotor switches from any angle to the positioning angle, and the control motor current gradually increases to the positioning current corresponding to the current positioning angle, the method further includes: The motor is controlled to enter an open-loop control program. After the open-loop control program ends, a PWM pulse width modulation wave is output according to the current positioning angle and the positioning current corresponding to the current positioning angle to control the motor to start running.

7. A motor rotor positioning device for implementing the method according to any one of claims 1 to 6, characterized in that, The device includes: The acquisition module is used to acquire a pre-set positioning angle before the motor starts; The control module is used to control the motor rotor to switch from any angle to the positioning angle, and to control the motor current to gradually increase to the positioning current corresponding to the current positioning angle.

8. An electric motor, characterized in that, Includes the motor rotor positioning device as described in claim 7.

9. A compressor, characterized in that, Includes the motor as described in claim 8.

10. A refrigeration device, characterized in that, Includes the compressor described in claim 9.

11. The refrigeration equipment according to claim 10, characterized in that, The refrigeration equipment includes at least one of the following: a refrigerator and an air conditioner.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 6.

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