Motor Locked Rotor Detection Method and Device, Drive Assembly and Power Tool

Abstract

The present disclosure relates to a method and device for detecting motor stalling, a drive assembly, and a power tool. The method includes: obtaining three-phase currents and a bus voltage of a three-phase motor; determining a space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents; if, within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, then it is determined that the three-phase motor is in a state of motor stalling, enabling fast and accurate stalling detection without relying on an angle observer.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor control, and in particular, to a method and device for detecting motor stall, a drive assembly, and a power tool. Background Art

[0002] Once a brushless DC motor stalls, the stator current increases sharply, and the stator voltage acts entirely on the stator winding, which may cause a risk of burning if the time is too long. Therefore, it is of great significance to detect whether the motor stalls. Summary of the Invention

[0003] According to one aspect of the present disclosure, there is provided a method for detecting motor stall, the method including:

[0004] Obtaining three-phase currents and a bus voltage of a three-phase motor;

[0005] Determining a space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents;

[0006] If, within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, it is determined that the three-phase motor is in a state of motor stall.

[0007] In a possible implementation manner, the determining the space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents includes:

[0008] Performing a Clarke transformation and a Park transformation on the three-phase currents in sequence to obtain an excitation current and a torque current;

[0009] Obtaining a first intermediate voltage by using the excitation current and a preset excitation current, and obtaining a second intermediate voltage by using the torque current and a preset torque current;

[0010] Determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage.

[0011] In a possible implementation manner, the determining the space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents further includes:

[0012] Performing an inverse Park transformation on the first intermediate voltage and the second intermediate voltage in sequence to obtain a first voltage, a second voltage, and a third voltage;

[0013] Determine the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage;

[0014] Determine the target operation equation according to the target SVPWM sector and the first correspondence, where the first correspondence includes the correspondence between each sector and each operation equation, and the operation equation is used to determine the duty cycle according to the voltage;

[0015] Determine the maximum duty cycle and the minimum duty cycle of the SVPWM three-phase duty cycle according to the first voltage, the second voltage, the third voltage, and the target operation equation.

[0016] In a possible implementation manner, the determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage includes:

[0017] Determine the root mean square of the first intermediate voltage and the second intermediate voltage;

[0018] Determine the SVPWM output voltage according to the root mean square of the first intermediate voltage and the second intermediate voltage.

[0019] In a possible implementation manner, the determining the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage includes:

[0020] If the first voltage is positive, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the first sector;

[0021] If the first voltage is positive, the second voltage is negative, and the third voltage is negative, determine that the target SVPWM sector is the second sector;

[0022] If the first voltage is positive, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the third sector;

[0023] If the first voltage is negative, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the fourth sector;

[0024] If the first voltage is negative, the second voltage is positive, and the third voltage is positive, determine that the target SVPWM sector is the fifth sector;

[0025] If the first voltage is negative, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the sixth sector.

[0026] In a possible implementation manner, determining the target operation equation according to the target SVPWM sector and the first corresponding relationship includes any one of the following:

[0027] If the target SVPWM sector is the first sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% - (U1 + U2) / 2, Tmax = 50% - (U1 + U2) / 2 + U1 + U2, where, Tmin represents the minimum duty cycle, Tmax represents the maximum duty cycle, U1 represents the first voltage, and U2 represents the second voltage;

[0028] If the target SVPWM sector is the second sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% + (U2 + U3) / 2, Tmax = 50% + (U2 + U3) / 2 - U3 - U2, where, U3 represents the third voltage;

[0029] If the target SVPWM sector is the third sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% - (U1 + U3) / 2, Tmax = 50% - (U1 + U3) / 2 + U3 + U1;

[0030] If the target SVPWM sector is the fourth sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% + (U1 + U2) / 2, Tmax = 50% + (U1 + U2) / 2 - U2 - U1;

[0031] If the target SVPWM sector is the fifth sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% - (U2 + U3) / 2, Tmax = 50% - (U2 + U3) / 2 + U2 + U3;

[0032] If the target SVPWM sector is the sixth sector, determining the target operation equation according to the first corresponding relationship as: Tmin = 50% + (U1 + U3) / 2, Tmax = 50% + (U1 + U3) / 2 - U1 - U3.

[0033] In a possible implementation manner, the three-phase motor is a three-phase brushless DC motor.

[0034] According to an aspect of the present disclosure, there is provided a motor stall detection device, the device includes:

[0035] An acquisition module, which acquires the three-phase current and the bus voltage of the three-phase motor;

[0036] A first determination module, configured to determine a space vector pulse width modulation (SVPWM) output voltage for driving the three-phase motor and SVPWM three-phase duty ratios according to the three-phase current.

[0037] A second determination module, configured to: if, within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, determine that the three-phase motor is in a state of motor stall.

[0038] According to one aspect of the present disclosure, there is provided a driving assembly, and the driving assembly includes the motor stall detection device described above.

[0039] According to one aspect of the present disclosure, there is provided a power tool, and the power tool includes the driving assembly described above.

[0040] According to one aspect of the present disclosure, there is provided an electronic device, including: a processor; a memory for storing instructions executable by the processor; wherein the processor is configured to call the instructions stored in the memory to execute the above method.

[0041] According to one aspect of the present disclosure, there is provided a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the above method is implemented.

[0042] In the motor stall detection method according to the embodiments of the present disclosure, by obtaining the three-phase current and the bus voltage of the three-phase motor; determining the space vector pulse width modulation (SVPWM) output voltage for driving the three-phase motor and the SVPWM three-phase duty ratios according to the three-phase current; if, within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, determine that the three-phase motor is in a state of motor stall, without relying on an angle observer, and performing stall detection quickly and accurately.

[0043] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present disclosure. Other features and aspects of the present disclosure will become clear according to the following detailed description of the exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings herein are incorporated into the specification and form a part of the specification, and these drawings show embodiments consistent with the present disclosure and are used together with the specification to illustrate the technical solutions of the present disclosure.

[0045] Figure 1 The flowchart of the motor locked-rotor detection method according to an embodiment of the present disclosure is shown.

[0046] Figure 2a The schematic diagram of the application scenario of the motor locked-rotor detection method according to an embodiment of the present disclosure is shown.

[0047] Figure 2b The schematic diagram of a motor drive device according to an embodiment of the present disclosure is shown.

[0048] Figure 3 The flowchart of the motor locked-rotor detection method according to an embodiment of the present disclosure is shown.

[0049] Figure 4a The schematic diagram of performing the Clarke transformation according to an embodiment of the present disclosure is shown. Figure 4b The schematic diagram of performing the Park transformation according to an embodiment of the present disclosure is shown.

[0050] Figure 4c The schematic diagram of performing the inverse Park transformation according to an embodiment of the present disclosure is shown. Figure 4d The schematic diagram of performing the inverse Clarke transformation according to an embodiment of the present disclosure is shown.

[0051] Figure 5 The schematic diagram of the motor space vector according to an embodiment of the present disclosure is shown.

[0052] Figure 6 The schematic diagram of space vector pulse width modulation (SVPWM) according to an embodiment of the present disclosure is shown.

[0053] Figure 7 The block diagram of the motor locked-rotor detection device according to an embodiment of the present disclosure is shown.

[0054] Figure 8 The block diagram of an electronic device according to an embodiment of the present disclosure is shown.

[0055] Figure 9 The block diagram of an electronic device according to an embodiment of the present disclosure is shown. Detailed implementation manners

[0056] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0057] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present disclosure.

[0058] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present disclosure, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0059] In the present disclosure, unless otherwise clearly defined and limited, the terms such as "mounted", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0060] The special term "exemplary" herein means "serving as an example, an embodiment or illustrative". Any embodiment described as "exemplary" here does not have to be construed as superior or better than other embodiments.

[0061] The term "and / or" in this article is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" in this article means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set composed of A, B, and C.

[0062] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that the present disclosure can be implemented without some specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present disclosure.

[0063] The related art generally relies on an angle observer to determine whether a stall occurs by judging that the angular velocity is close to 0 or the angle increment is close to 0. However, the solution for judging whether a stall occurs through an angle observer has low accuracy, and moreover, the accuracy of its judgment depends on the precision of the angle observer, resulting in a high cost.

[0064] An embodiment of the present disclosure provides a method for detecting motor stall, the method including: acquiring three-phase currents and a bus voltage of a three-phase motor; determining a space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents; if within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, then determining that the three-phase motor is in a state of motor stall, which can perform stall detection quickly and accurately without relying on an angle observer.

[0065] Please refer to Figure 1 , Figure 1 which shows a flowchart of the method for detecting motor stall according to an embodiment of the present disclosure.

[0066] As Figure 1 shown, the method includes:

[0067] Step S11, acquiring three-phase currents and a bus voltage of a three-phase motor;

[0068] Step S12, determining a space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase currents;

[0069] Step S13, if within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, then determining that the three-phase motor is in a state of motor stall.

[0070] The embodiment of the present disclosure does not limit the specific manner of acquiring the three-phase currents and the bus voltage of the three-phase motor, and those skilled in the art can select a suitable manner to implement according to the actual situation and needs. The following is an exemplary introduction.

[0071] Please refer to Figure 2a , Figure 2a which shows a schematic diagram of an application scenario of the method for detecting motor stall according to an embodiment of the present disclosure.

[0072] The method for detecting motor stall can be applied to as Figure 2aIn the motor drive device shown, the device includes a three-phase motor 10, a three-phase full-bridge inverter 20, a detection module 30, a drive module 40, and a control module 50.

[0073] The three-phase full-bridge inverter 20 includes a first arm, a second arm, and a third arm. Each arm includes an upper arm and a lower arm. Transistors are provided on both the upper arm and the lower arm of each arm. The three-phase full-bridge inverter 20 is used to drive the three-phase motor 10. The first arm, the second arm, and the third arm respectively correspond to the first phase, the second phase, and the third phase of the three-phase motor 10.

[0074] The drive module 40 is connected to each transistor of the three-phase full-bridge inverter 20 and is used to output drive signals to control the three-phase full-bridge inverter 20 to drive the three-phase motor 10.

[0075] The detection module 30 is connected between the upper arm and the lower arm of each arm of the three-phase full-bridge inverter 20 and is used to detect the phase current and bus voltage of each phase of the three-phase motor 10.

[0076] The control module 50 is connected to the detection module 30 and the drive module 40.

[0077] The motor stall detection method according to an embodiment of the present disclosure can be executed by the control module 50 to determine whether the three-phase motor 10 is stalled.

[0078] An exemplary introduction to possible implementation manners of each module in the motor drive device is given below.

[0079] Please refer to Figure 2b , Figure 2b which shows a schematic diagram of a motor drive device according to an embodiment of the present disclosure.

[0080] As Figure 2b shown, the three-phase full-bridge inverter 20 may include a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, and a sixth transistor Q6. The first transistor Q1 and the fourth transistor Q4 form the first arm, and the fourth transistor Q4 is the lower arm. The second transistor Q2 and the fifth transistor Q5 form the second arm, and the fifth transistor Q5 is the lower arm. The third transistor Q3 and the sixth transistor Q6 form the third arm, and the sixth transistor Q6 is the lower arm. Among them, one ends of the windings of the three-phase motor 10 are electrically connected, and the other ends of the windings are respectively electrically connected between the first transistor Q1 and the fourth transistor Q4, between the second transistor Q2 and the fifth transistor Q5, and between the third transistor Q3 and the sixth transistor Q6.

[0081] In a possible implementation, the first transistor Q1, the second transistor Q2, the third transistor Q3, the fourth transistor Q4, the fifth transistor Q5, and the sixth transistor Q6 can be Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) or Insulated Gate Bipolar Transistors (IGBTs). Among them, the transistors can be implemented based on silicon carbide (SiC) or gallium nitride (GaN) to improve performance.

[0082] In a possible implementation, as Figure 2b shown, the three-phase full-bridge inverter 20 can further include a plurality of first input resistors, a plurality of second input resistors, and a plurality of input capacitors to filter the input signal. The stator of the three-phase motor 10 includes a first winding A, a second winding B, and a third winding C. Among them, the gates of the transistors of the three-phase full-bridge inverter 20 are electrically connected to the second ends of the first input resistors, the first ends of the second input resistors, and the first ends of the input capacitors. The sources of the transistors of the three-phase full-bridge inverter 20 are electrically connected to the second ends of the input capacitors and the second ends of the second input resistors. The first ends of the first input resistors are used to input control signals.

[0083] Among them, the drains of the first transistor Q1, the second transistor Q2, and the third transistor Q3 are electrically connected, and the sources of the fourth transistor Q4, the fifth transistor Q5, and the sixth transistor Q6 are electrically connected.

[0084] The source of the first transistor Q1 is electrically connected to the drain of the fourth transistor Q4 and the first end of the first winding. The source of the second transistor Q2 is electrically connected to the drain of the fifth transistor Q5 and the first end of the second winding. The source of the third transistor Q3 is electrically connected to the drain of the sixth transistor Q6 and the first end of the third winding.

[0085] The second ends of the first winding A, the second winding B, and the third winding C are grounded.

[0086] In an example, as Figure 2bAs shown, the first input resistor may include a first resistor R1, a third resistor R3, a fifth resistor R5, a seventh resistor R7, a ninth resistor R9, and an eleventh resistor R11. The second input resistor may include a second resistor R2, a fourth resistor R4, a sixth resistor R6, an eighth resistor R8, a tenth resistor R10, and a twelfth resistor R12. The input capacitor may include a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6.

[0087] In one example, the three-phase full-bridge inverter 20 may further include a plurality of freewheeling diodes disposed between the source and drain of each transistor for providing a freewheeling path when the transistor is turned off to prevent damage to the transistor.

[0088] In a possible implementation, the three-phase motor 10 may be a three-phase brushless DC motor.

[0089] In one example, in the embodiment of the present disclosure, by electrically connecting one end of each winding of the stator, and the other ends of the windings are respectively electrically connected between the first transistor Q1 and the fourth transistor Q4, between the second transistor Q2 and the fifth transistor Q5, and between the third transistor Q3 and the sixth transistor Q6, a Y-connection (or star connection) of the three-phase motor 10 is achieved.

[0090] In one example, as Figure 2b shown, the three-phase motor 10 may include a first winding A, a second winding B, and a third winding C (corresponding to phase A, phase B, and phase C respectively, and corresponding to the first bridge arm, the second bridge arm, and the third bridge arm). One end of the first winding A is electrically connected between the first transistor Q1 and the fourth transistor Q4, one end of the second winding B is electrically connected between the second transistor Q2 and the fifth transistor Q5, and one end of the third winding C is electrically connected between the third transistor Q3 and the sixth transistor Q6.

[0091] In a possible implementation, as Figure 2b shown, the detection module 30 includes a voltage detection unit 310 and a current detection unit 320, which are respectively connected between the upper bridge arm and the lower bridge arm of each phase of the three-phase full-bridge inverter 20. Among them, the voltage detection unit 310 includes a first detection resistor Re1 and a second detection resistor Re2. The first end of the first detection resistor Re1 is connected to the bus of the three-phase motor (the drain of the first transistor Q1, the drain of the second transistor Q2, and the drain of the third transistor Q3), and the second end of the first detection resistor Re1 is connected to the first end of the second detection resistor Re2 for outputting the detected bus voltage Vde. The second end of the second detection resistor Re2 is grounded.

[0092] The embodiments of the present disclosure do not limit the specific implementation manner of the current detection unit 320, and those skilled in the art can select appropriate technical solutions according to actual situations and needs to implement it.

[0093] In a possible implementation manner, the driving module 40 of the embodiments of the present disclosure can be implemented by a dedicated motor driving chip or can be built by discrete devices. In this regard, the embodiments of the present disclosure do not make any limitations.

[0094] The control module 50 of the embodiments of the present disclosure may include a processing component, where the processing component includes but is not limited to a single processor, or discrete components, or a combination of a processor and discrete components. The processor may include a controller in an electronic device having an instruction execution function, and the processor may be implemented in any suitable manner. For example, it is implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components. Inside the processor, the executable instructions may be executed through hardware circuits such as logic gates, switches, application specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. The embodiments of the present disclosure do not limit the specific implementation manner of the control module 50.

[0095] Please refer to Figure 3 , Figure 3 which shows a flowchart of a motor stall detection method according to an embodiment of the present disclosure.

[0096] In a possible implementation manner, as Figure 3 shown, step S12 of determining the space vector pulse width modulation SVPWM (Space Vector Pulse Width Modulation) output voltage and the SVPWM three-phase duty ratio for driving the three-phase motor according to the three-phase current may include:

[0097] Step S121: Perform Clarke transformation and Park transformation on the three-phase current in sequence to obtain the excitation current and the torque current;

[0098] Please refer to Figure 4a and Figure 4b , Figure 4a which shows a schematic diagram of Clarke transformation in an embodiment of the present disclosure, Figure 4b and which shows a schematic diagram of Park transformation in an embodiment of the present disclosure.

[0099] In an example, asFigure 4a As shown, through the Clarke transformation, the embodiments of the present disclosure can convert the time-domain components (three-phase currents Ia, Ib, Ic) of a three-phase system (in the abc coordinate system) into two components (Iα, Iβ) in the orthogonal stationary coordinate system (α, β).

[0100] In one example, as Figure 4b shown, through the Park transformation, the embodiments of the present disclosure can convert the two components (Iα, Iβ) in the orthogonal stationary coordinate system (α, β) into the exciting current Id and the torque current Iq in the rotating coordinate system (d, q).

[0101] The embodiments of the present disclosure do not limit the specific manner of the Clarke transformation and the Park transformation, and those skilled in the art can refer to related technologies to implement them.

[0102] Step S122, obtaining a first intermediate voltage by using the exciting current and a preset exciting current, and obtaining a second intermediate voltage by using the torque current and a preset torque current;

[0103] The embodiments of the present disclosure do not limit the specific implementation manner of obtaining the first intermediate voltage by using the exciting current and the preset exciting current, and obtaining the second intermediate voltage by using the torque current and the preset torque current. Those skilled in the art can select relevant technologies to implement according to the actual situation and needs. For example, the embodiments of the present disclosure can use a pre-configured PI control loop (which can also be called a PI controller), and input the preset exciting current (expected value) and the exciting current Id into the PI control loop to obtain the first intermediate voltage; similarly, the preset torque current and the torque current Iq can be input into the PI control loop to obtain the second intermediate voltage.

[0104] Step S123, determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage.

[0105] The embodiments of the present disclosure do not limit the specific implementation manner of determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage. Those skilled in the art can select a suitable manner to implement according to the actual situation and needs. Exemplarily, step S123 determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage may include: determining the root mean square of the first intermediate voltage and the second intermediate voltage; determining the SVPWM output voltage according to the root mean square of the first intermediate voltage and the second intermediate voltage. For example, the root mean square of the first intermediate voltage and the second intermediate voltage can be used as the SVPWM output voltage.

[0106] In the embodiments of the present disclosure, the three-phase current is sequentially subjected to Clarke transformation and Park transformation to obtain the exciting current and the torque current. The first intermediate voltage is obtained by using the exciting current and a preset exciting current, and the second intermediate voltage is obtained by using the torque current and a preset torque current. The SVPWM output voltage can be quickly and accurately determined according to the first intermediate voltage and the second intermediate voltage.

[0107] In the embodiments of the present disclosure, a three-phase full-bridge inverter 20 is used to drive a three-phase motor 10. Therefore, the driving module 40 performs driving control based on SVPWM. The main idea of SVPWM is to use the ideal flux circle of the stator of a three-phase symmetrical motor when powered by three-phase symmetrical sinusoidal voltages as a reference standard, and make appropriate switching of different switching modes of the three-phase inverter to form a PWM wave, and use the formed actual flux vector to track its accurate flux circle. For the specific introduction of SVPWM, please refer to the description of related technologies and will not be elaborated here.

[0108] In a possible implementation manner, as Figure 3 shown, step S12 for determining the space vector pulse width modulation (SVPWM) output voltage and the SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current may further include:

[0109] Step S124, performing inverse Park transformation on the first intermediate voltage and the second intermediate voltage in sequence to obtain a first voltage, a second voltage, and a third voltage;

[0110] Please refer to Figure 4c and Figure 4d , Figure 4c which shows a schematic diagram of performing inverse Park transformation in the embodiments of the present disclosure, Figure 4d and which shows a schematic diagram of performing inverse Clarke transformation in the embodiments of the present disclosure.

[0111] In an example, as Figure 4c shown, through inverse Park transformation, the embodiments of the present disclosure can convert two voltage components (the first intermediate voltage Ud and the second intermediate voltage Uq) in the rotating coordinate system (d, q) into two components (Uα, Uβ) in the orthogonal stationary coordinate system (α, β).

[0112] In an example, as Figure 4d shown, through inverse Clarke transformation, the embodiments of the present disclosure can convert two components (Uα, Uβ) in the orthogonal stationary coordinate system (α, β) into time-domain components (the first voltage U1, the second voltage U2, and the third voltage U3) of a three-phase system (in the abc coordinate system).

[0113] The embodiments of the present disclosure do not limit the specific manner of inverse Clarke transformation and inverse Park transformation, and those skilled in the art can refer to related technologies to implement them.

[0114] Step S125: Determine the target SVPWM sector according to the polarities of the first voltage, the second voltage, and the third voltage.

[0115] The embodiments of the present disclosure do not limit the specific implementation manner of determining the target SVPWM sector according to the polarities of the first voltage, the second voltage, and the third voltage. Those skilled in the art can implement it according to related technologies. Exemplarily, determining the target SVPWM sector according to the polarities of the first voltage, the second voltage, and the third voltage includes:

[0116] If the first voltage is positive (identified by the symbol \"+\"), the second voltage is positive, and the third voltage is negative (identified by the symbol \"-\"), determine that the target SVPWM sector is the first sector;

[0117] If the first voltage is positive, the second voltage is negative, and the third voltage is negative, determine that the target SVPWM sector is the second sector;

[0118] If the first voltage is positive, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the third sector;

[0119] If the first voltage is negative, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the fourth sector;

[0120] If the first voltage is negative, the second voltage is positive, and the third voltage is positive, determine that the target SVPWM sector is the fifth sector;

[0121] If the first voltage is negative, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the sixth sector.

[0122] Exemplarily, the target SVPWM sector can be determined according to the polarities of the first voltage, the second voltage, and the third voltage with reference to Table 1.

[0123] Table 1

[0124] U1 symbol U2 symbol U3 symbol Sector + + - 1 + - - 2 + - + 3 - - + 4 - + + 5 - + - 6

[0125] Exemplarily, the sector numbers 1 to 6 in Table 1 correspond to the first sector to the sixth sector respectively.

[0126] Step S126: Determine the target operation equation according to the target SVPWM sector and the first correspondence relationship, where the first correspondence relationship includes the correspondence relationship between each sector and each operation equation, and the operation equation is used to determine the duty cycle according to the voltage.

[0127] In the embodiments of the present disclosure, a target operation equation is determined according to the target SVPWM sector and the first correspondence relationship, where the first correspondence relationship includes the correspondence relationship between each sector and each operation equation. The specific implementation manner of the operation equation for determining the duty ratio according to the voltage is not limited, and the specific operation equation is not limited. Those skilled in the art can set it according to the actual situation and needs. Exemplarily, the determination of the target operation equation according to the target SVPWM sector and the first correspondence relationship may include any one of the following:

[0128] If the target SVPWM sector is the first sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% - (U1 + U2) / 2, Tmax = 50% - (U1 + U2) / 2 + U1 + U2, where Tmin represents the minimum duty ratio, Tmax represents the maximum duty ratio, U1 represents the first voltage, and U2 represents the second voltage;

[0129] If the target SVPWM sector is the second sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% + (U2 + U3) / 2, Tmax = 50% + (U2 + U3) / 2 - U3 - U2, where U3 represents the third voltage;

[0130] If the target SVPWM sector is the third sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% - (U1 + U3) / 2, Tmax = 50% - (U1 + U3) / 2 + U3 + U1;

[0131] If the target SVPWM sector is the fourth sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% + (U1 + U2) / 2, Tmax = 50% + (U1 + U2) / 2 - U2 - U1;

[0132] If the target SVPWM sector is the fifth sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% - (U2 + U3) / 2, Tmax = 50% - (U2 + U3) / 2 + U2 + U3;

[0133] If the target SVPWM sector is the sixth sector, then according to the first correspondence relationship, the target operation equation is determined as: Tmin = 50% + (U1 + U3) / 2, Tmax = 50% + (U1 + U3) / 2 - U1 - U3.

[0134] Exemplarily, the first correspondence relationship between the sector and the operation equation may be as shown in Table 2.

[0135] Table 2

[0136] Sector Minimum duty cycle (unit: %) Medium duty cycle (unit: %) Maximum duty cycle (unit: %) 1 50% - (U1 + U2) / 2 50% - (U1 + U2) / 2 + U1 50% - (U1 + U2) / 2 + U1 + U2 2 50% + (U2 + U3) / 2 50% + (U2 + U3) / 2 - U3 50% + (U2 + U3) / 2 - U3 - U2 3 50% - (U1 + U3) / 2 50% - (U1 + U3) / 2 + U3 50% - (U1 + U3) / 2 + U3 + U1 4 50% + (U1 + U2) / 2 50% + (U1 + U2) / 2 - U2 50% + (U1 + U2) / 2 - U2 - U1 5 50% - (U2 + U3) / 2 50% - (U2 + U3) / 2 + U2 50% - (U2 + U3) / 2 + U2 + U3 6 50% + (U1 + U3) / 2 50% + (U1 + U3) / 2 - U1 50% + (U1 + U3) / 2 - U1 - U3

[0137] Exemplarily, the intermediate duty ratio in Table 2 is between the minimum duty ratio and the maximum duty ratio.

[0138] Exemplarily, the correspondence between the positive and negative polarities of the voltage in Table 1 and the SVPWM sectors, and the first correspondence in Table 2 can be determined in advance, stored in the storage module, and called when needed to determine the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage, and determine the target operation equation according to the target SVPWM sector and the first correspondence.

[0139] In one example, the storage module may include a computer-readable storage medium, and the computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memories), static random access memories (SRAM), programmable read-only memories (PROM), portable compact disk read-only memories (CD-ROM), digital versatile disks (DVD), memory sticks, floppy disks, mechanical coding devices, such as punch cards or raised structures in grooves storing instructions thereon, and any suitable combination of the above. The computer-readable storage medium used herein is not construed as an instantaneous signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagated through waveguides or other transmission media (e.g., optical pulses through fiber optic cables), or electrical signals transmitted through wires.

[0140] Step S127, determine the maximum duty ratio and the minimum duty ratio of the SVPWM three-phase duty ratio according to the first voltage, the second voltage, the third voltage, and the target operation equation.

[0141] After determining the target operation equation, the embodiments of the present disclosure can quickly and accurately determine the maximum duty ratio and the minimum duty ratio of the SVPWM three-phase duty ratio according to the first voltage, the second voltage, the third voltage, and the target operation equation.

[0142] The principle of determining whether a stall occurs in the embodiments of the present disclosure will be introduced exemplarily below.

[0143] Please refer to Figure 5 ,Figure 5 Shows a schematic diagram of the motor space vector according to an embodiment of the present disclosure.

[0144] In one example, the dynamic balance equation of the DC brushless motor voltage is:

[0145]

[0146] Where, u s represents the motor phase voltage, r represents the stator phase resistance, L represents the stator phase inductance, i s represents the phase current, e s represents the back electromotive force, represents i s differentiated with respect to time t.

[0147] Exemplarily, when the motor is in a steady state, since the current change rate is close to 0, the above formula becomes

[0148] u s = i s r + e s Formula 2

[0149] When the motor load increases sharply, according to the electric drive formula:

[0150]

[0151] Where, T e represents the electromagnetic torque of the motor, T L represents the load torque, Bω represents the damping torque;

[0152] It can be seen from Formula 3 that when T e is less than L a negative angular acceleration will be generated, the motor speed will drop sharply, and the angular velocity ω will drop sharply.

[0153] In one example, Figure 5 the respective variables in are: ω is the electrical angular velocity of the rotor permanent magnet; Ψ f is the magnetic flux of the rotor permanent magnet; the induced electromotive force leads the magnetic flux by 90° electrical angle, I d , i q are respectively the stator excitation current and the torque current, which are two components of the motor current is; L d i d is the magnetic flux generated by the excitation current. Exemplarily, since the given current i d is negative, so l d i d generates a magnetic flux direction opposite to that of the rotor permanent magnet, playing a canceling role; jωL d i d , jωΨ d, jωΨ f , jωΨ s are respectively l d i d , Ψ d , Ψ f , Ψ s corresponding induced electromotive forces; Ψs is the synthetic magnetic flux linkage; Us is the synthetic stator voltage vector, that is, the motor output voltage vector.

[0154] In one example, when the motor is blocked, the position of the rotor permanent magnet no longer changes, that is, the dq axes of the rotating coordinate system stop rotating, the rotor angle no longer changes, which means the direction of the is current no longer changes; since es is proportional to the rotational speed, at this time es approaches 0, so the value of is increases sharply; due to the stator inductances l d and l q can be approximately considered unchanged. It can be seen from Figure 5 that l d i d and l q i q will both increase sharply. On the vector diagram, it shows that the direction of Ψ s is infinitely close to the q axis, and the direction of the induced electromotive force generated by Ψ s is also infinitely close to the negative half-axis of the d axis. Since ω approaches 0 infinitely, the induced electromotive force jωΨ s generated by Ψ also approaches 0 infinitely, and the value of us is basically in the same direction as jωΨ s , and the direction basically no longer changes. s

[0155] Please refer to Figure 6 , Figure 6 which shows a schematic diagram of space vector pulse width modulation (SVPWM) according to an embodiment of the present disclosure.

[0156] In one example, as Figure 6 shown, when the voltage vector Us is in a fixed direction, the duty ratios of the ABC three-phase outputs are in a fixed magnitude relationship. As the Us vector continuously increases, the non-zero vectors will also become larger and larger. When the voltage utilization rate is the highest, that is, when operating on the inscribed circle of the regular hexagon, the duty ratio of one of the three phases will approach 0 infinitely, the duty ratio of the other phase output will approach the maximum duty ratio infinitely, and the duty ratio of the middle phase is a fixed value.

[0157] As can be seen from the above analysis, when the brushless motor is blocked, the direction of the voltage output vector Us no longer changes. At this time, the output voltage of Us is the largest and is the bus voltage. In this case, by judging the duty cycle of the three-phase PWM output: Exemplarily, the maximum duty cycle is 100% of the maximum duty cycle value, and the minimum value is 0%. Set a threshold time (the first duration), for example, within 1 s, the maximum phase duty cycle within 1 s is 100% (or a threshold, such as greater than 98%), and the minimum phase is 0% (or a threshold, such as less than 2%). In this way, it can be determined that the maximum phase output (such as phase A) and the minimum phase output (such as phase C) are always a fixed phase, then it can be considered that the motor is blocked. When it is judged that the motor is blocked, the embodiments of the present disclosure can control the motor to stop running and perform maintenance to avoid damage to the motor.

[0158] It can be understood that the above-mentioned various method embodiments mentioned in the present disclosure can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, the present disclosure will not elaborate. Those skilled in the art can understand that in the above methods of the specific implementation manner, the specific execution order of each step should be determined according to its function and possible internal logic.

[0159] Please refer to Figure 7 , Figure 7 which shows a block diagram of a motor block detection device according to an embodiment of the present disclosure.

[0160] As Figure 7 shown, the device includes:

[0161] An acquisition module 70 for acquiring the three-phase current and the bus voltage of a three-phase motor;

[0162] A first determination module 80 for determining the space vector pulse width modulation SVPWM output voltage and the SVPWM three-phase duty cycle for driving the three-phase motor according to the three-phase current;

[0163] A second determination module 90 for: if within the first duration, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty cycle among the SVPWM three-phase duty cycles is within a first preset range and the fluctuation of the minimum duty cycle is within a second preset range, then determine that the three-phase motor is in a blocked state.

[0164] The motor stall detection device according to the embodiments of the present disclosure obtains the three-phase current and the bus voltage of a three-phase motor; determines the space vector pulse width modulation (SVPWM) output voltage and the SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current; if within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, it is determined that the three-phase motor is in a stalled state, and the stall detection can be performed quickly and accurately without relying on an angle observer.

[0165] In a possible implementation manner, the determining the space vector pulse width modulation (SVPWM) output voltage and the SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current includes:

[0166] Performing a Clarke transformation and then a Park transformation on the three-phase current in sequence to obtain the excitation current and the torque current;

[0167] Obtaining a first intermediate voltage by using the excitation current and a preset excitation current, and obtaining a second intermediate voltage by using the torque current and a preset torque current;

[0168] Determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage.

[0169] In a possible implementation manner, the determining the space vector pulse width modulation (SVPWM) output voltage and the SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current further includes:

[0170] Performing an inverse Park transformation on the first intermediate voltage and the second intermediate voltage in sequence to obtain a first voltage, a second voltage, and a third voltage;

[0171] Determining a target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage;

[0172] Determining a target operation equation according to the target SVPWM sector and a first correspondence relationship, where the first correspondence relationship includes the correspondence relationship between each sector and each operation equation, and the operation equation is used to determine the duty ratio according to the voltage;

[0173] Determining the maximum duty ratio and the minimum duty ratio of the SVPWM three-phase duty ratios according to the first voltage, the second voltage, the third voltage, and the target operation equation.

[0174] In a possible implementation manner, the determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage includes:

[0175] Determine the root mean square values of the first intermediate voltage and the second intermediate voltage;

[0176] Determine the SVPWM output voltage according to the root mean square values of the first intermediate voltage and the second intermediate voltage.

[0177] In a possible implementation, the determining the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage includes:

[0178] If the first voltage is positive, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the first sector;

[0179] If the first voltage is positive, the second voltage is negative, and the third voltage is negative, determine that the target SVPWM sector is the second sector;

[0180] If the first voltage is positive, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the third sector;

[0181] If the first voltage is negative, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the fourth sector;

[0182] If the first voltage is negative, the second voltage is positive, and the third voltage is positive, determine that the target SVPWM sector is the fifth sector;

[0183] If the first voltage is negative, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the sixth sector.

[0184] In a possible implementation, the determining the target operation equation according to the target SVPWM sector and the first correspondence includes any one of the following:

[0185] If the target SVPWM sector is the first sector, then determine the target operation equation according to the first correspondence as: Tmin = 50% - (U1 + U2) / 2, Tmax = 50% - (U1 + U2) / 2 + U1 + U2, where, Tmin represents the minimum duty cycle, Tmax represents the maximum duty cycle, U1 represents the first voltage, and U2 represents the second voltage;

[0186] If the target SVPWM sector is the second sector, then determine the target operation equation according to the first correspondence as: Tmin = 50% + (U2 + U3) / 2, Tmax = 50% + (U2 + U3) / 2 - U3 - U2, where, U3 represents the third voltage;

[0187] If the target SVPWM sector is the third sector, determine the target operation equation according to the first corresponding relationship as: Tmin = 50% - (U1 + U3) / 2, Tmax = 50% - (U1 + U3) / 2 + U3 + U1;

[0188] If the target SVPWM sector is the fourth sector, determine the target operation equation according to the first corresponding relationship as: Tmin = 50% + (U1 + U2) / 2, Tmax = 50% + (U1 + U2) / 2 - U2 - U1;

[0189] If the target SVPWM sector is the fifth sector, determine the target operation equation according to the first corresponding relationship as: Tmin = 50% - (U2 + U3) / 2, Tmax = 50% - (U2 + U3) / 2 + U2 + U3;

[0190] If the target SVPWM sector is the sixth sector, determine the target operation equation according to the first corresponding relationship as: Tmin = 50% + (U1 + U3) / 2, Tmax = 50% + (U1 + U3) / 2 - U1 - U3.

[0191] In a possible implementation manner, the three-phase motor is a three-phase brushless DC motor.

[0192] According to one aspect of the present disclosure, a driving component is provided, and the driving component includes the motor stall detection device described above.

[0193] According to one aspect of the present disclosure, a power tool is provided, and the power tool includes the driving component described above.

[0194] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0195] The embodiments of the present disclosure also propose a computer-readable storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the above methods are implemented. The computer-readable storage medium can be a non-volatile computer-readable storage medium.

[0196] The embodiments of the present disclosure also propose an electronic device, including: a processor; a memory for storing instructions executable by the processor; wherein, the processor is configured to call the instructions stored in the memory to execute the above methods.

[0197] Embodiments of the present disclosure also provide a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0198] The electronic device may be provided as a terminal, a server, or other forms of devices.

[0199] Please refer to Figure 8 , Figure 8 , which shows a block diagram of an electronic device according to an embodiment of the present disclosure.

[0200] For example, the electronic device 800 may be a terminal such as a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0201] Referring to Figure 8 , the electronic device 800 may include one or more of the following components: a processing component 802, a memory 804, a power component 806, a multimedia component 808, an audio component 810, an input / output (I / O) interface 812, a sensor component 814, and a communication component 816.

[0202] The processing component 802 generally controls the overall operation of the electronic device 800, such as operations associated with display, telephone calls, data communication, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the above method. In addition, the processing component 802 may include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0203] The memory 804 is configured to store various types of data to support the operation of the electronic device 800. Examples of these data include instructions for any application or method operating on the electronic device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disc.

[0204] The power supply component 806 provides power for various components of the electronic device 800. The power supply component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the electronic device 800.

[0205] The multimedia component 808 includes a screen that provides an output interface between the electronic device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen can be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors can not only sense the boundaries of the touch or swipe actions, but also detect the duration and pressure associated with the touch or swipe operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the electronic device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera can receive external multimedia data. Each of the front camera and the rear camera can be a fixed optical lens system or have focal length and optical zoom capabilities.

[0206] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC) that is configured to receive external audio signals when the electronic device 800 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 further includes a speaker for outputting audio signals.

[0207] The I / O interface 812 provides an interface between the processing component 802 and a peripheral interface module, and the peripheral interface module can be a keyboard, a click wheel, buttons, etc. These buttons can include, but are not limited to: a home button, a volume button, a power button, and a lock button.

[0208] The sensor assembly 814 includes one or more sensors for providing an assessment of the status of various aspects of the electronic device 800. For example, the sensor assembly 814 can detect the on / off state of the electronic device 800, the relative positioning of components, such as the display and keypad of the electronic device 800. The sensor assembly 814 can also detect a change in the position of the electronic device 800 or a component of the electronic device 800, the presence or absence of user contact with the electronic device 800, the orientation or acceleration / deceleration of the electronic device 800, and a change in the temperature of the electronic device 800. The sensor assembly 814 can include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor assembly 814 can also include a light sensor, such as a complementary metal oxide semiconductor (CMOS) or charge-coupled device (CCD) image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 can also include an acceleration sensor, a gyro sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0209] The communication component 816 is configured to facilitate communication between the electronic device 800 and other devices in a wired or wireless manner. The electronic device 800 can access a wireless network based on a communication standard, such as a wireless local area network (WiFi), a second-generation mobile communication technology (2G), or a third-generation mobile communication technology (3G), or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 further includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0210] In an exemplary embodiment, the electronic device 800 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components for performing the above-described methods.

[0211] In an exemplary embodiment, a non-transitory computer-readable storage medium is also provided, such as a memory 804 including computer program instructions that can be executed by a processor 820 of the electronic device 800 to complete the above-described methods.

[0212] Please refer to Figure 9 , Figure 9 which shows a block diagram of an electronic device according to an embodiment of the present disclosure.

[0213] For example, the electronic device 1900 can be provided as a server. Referring to Figure 9 , the electronic device 1900 includes a processing component 1922, which further includes one or more processors, and memory resources represented by a memory 1932 for storing instructions executable by the processing component 1922, such as application programs. The application programs stored in the memory 1932 can include one or more modules each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute instructions to perform the above-described method.

[0214] The electronic device 1900 may further include a power component 1926 configured to perform power management of the electronic device 1900, a wired or wireless network interface 1950 configured to connect the electronic device 1900 to a network, and an input / output (I / O) interface 1958. The electronic device 1900 can operate based on an operating system stored in the memory 1932, such as the Microsoft Server operating system (Windows Server TM ), the graphical user interface-based operating system launched by Apple Inc. (Mac OS X TM ), the multi-user and multi-process computer operating system (Unix TM ), the free and open-source Unix-like operating system (Linux TM ), the open-source Unix-like operating system (FreeBSD TM ) or the like.

[0215] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as the memory 1932 including computer program instructions, and the above computer program instructions can be executed by the processing component 1922 of the electronic device 1900 to complete the above method.

[0216] The present disclosure may be a system, a method, and / or a computer program product. The computer program product may include a computer-readable storage medium having thereon computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0217] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium may be, for example, (but is not limited to) an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device, such as a punched card or raised structures in grooves having instructions stored thereon, and any suitable combination of the foregoing. The computer-readable storage medium used herein is not construed as being a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., an optical pulse through an optical fiber cable), or an electrical signal transmitted through a wire.

[0218] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include a copper transmission cable, an optical fiber transmission, a wireless transmission, a router, a firewall, a switch, a gateway computer, and / or an edge server. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in each computing / processing device.

[0219] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine - related instructions, microcode, firmware instructions, state - setting data, or source code or object code written in any combination of one or more programming languages, including object - oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer - readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand - alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or alternatively, may be connected to an external computer (e.g., through the Internet using an Internet service provider). In some embodiments, by using the state information of the computer - readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field - programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer - readable program instructions to implement various aspects of the present disclosure.

[0220] Aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer - readable program instructions.

[0221] These computer - readable program instructions can be provided to a processor of a general - purpose computer, a special - purpose computer, or other programmable data - processing apparatus to produce a machine such that the instructions, when executed by the processor of the computer or other programmable data - processing apparatus, create a means for implementing the functions / acts specified in one or more blocks of the flowchart and / or block diagram. These computer - readable program instructions can also be stored in a computer - readable storage medium, which causes a computer, a programmable data - processing apparatus, and / or other devices to operate in a particular manner, so that the computer - readable medium storing the instructions comprises a manufacture, which includes instructions for implementing various aspects of the functions / acts specified in one or more blocks of the flowchart and / or block diagram.

[0222] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices, causing a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other devices to generate a computer-implemented process, such that the instructions executed on the computer, other programmable data processing apparatus, or other devices implement the functions / acts specified in one or more blocks of the flowchart and / or block diagram.

[0223] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of code, or a portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur in an order different from that noted in the figures. For example, two consecutive blocks may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or acts, or by a combination of dedicated hardware and computer instructions.

[0224] The computer program product may be implemented specifically in the form of hardware, software, or a combination thereof. In an alternative embodiment, the computer program product is embodied as a computer storage medium. In another alternative embodiment, the computer program product is embodied as a software product, such as a Software Development Kit (SDK), etc.

[0225] The various embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.

Claims

1. A method for detecting motor stall, characterized in that, the method includes: acquiring the three-phase current and bus voltage of a three-phase motor; determining the space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current; if, within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, then it is determined that the three-phase motor is in a motor stall state.

2. The method according to claim 1, characterized in that, the determining the space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current includes: successively performing Clarke transformation and Park transformation on the three-phase current to obtain the excitation current and torque current; obtaining a first intermediate voltage by using the excitation current and a preset excitation current, and obtaining a second intermediate voltage by using the torque current and a preset torque current, wherein, inputting the preset excitation current and the excitation current into a pre-configured first PI control loop to obtain the first intermediate voltage; inputting the preset torque current and the torque current into a pre-configured second PI control loop to obtain the second intermediate voltage; determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage.

3. The method according to claim 2, characterized in that, the determining the space vector pulse width modulation (SVPWM) output voltage and SVPWM three-phase duty ratios for driving the three-phase motor according to the three-phase current further includes: successively performing inverse Park transformation on the first intermediate voltage and the second intermediate voltage to obtain a first voltage, a second voltage, and a third voltage; determining the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage; determining a target operation equation according to the target SVPWM sector and a first correspondence relationship, wherein the first correspondence relationship includes the correspondence relationship between each sector and each target operation equation, and the target operation equation is used to determine the duty ratio according to the voltage; determining the maximum duty ratio and the minimum duty ratio of the SVPWM three-phase duty ratios according to the first voltage, the second voltage, the third voltage, and the target operation equation.

4. The method according to claim 2, characterized in that, the determining the SVPWM output voltage according to the first intermediate voltage and the second intermediate voltage includes: determining the root mean square of the first intermediate voltage and the second intermediate voltage; determining the SVPWM output voltage according to the root mean square of the first intermediate voltage and the second intermediate voltage.

5. The method according to claim 3, characterized in that, the determining the target SVPWM sector according to the positive and negative polarities of the first voltage, the second voltage, and the third voltage includes: If the first voltage is positive, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the first sector; If the first voltage is positive, the second voltage is negative, and the third voltage is negative, determine that the target SVPWM sector is the second sector; If the first voltage is positive, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the third sector; If the first voltage is negative, the second voltage is negative, and the third voltage is positive, determine that the target SVPWM sector is the fourth sector; If the first voltage is negative, the second voltage is positive, and the third voltage is positive, determine that the target SVPWM sector is the fifth sector; If the first voltage is negative, the second voltage is positive, and the third voltage is negative, determine that the target SVPWM sector is the sixth sector.

6. The method according to claim 3 or 5, characterized in that the determining the target operation equation according to the target SVPWM sector and the first correspondence relationship includes any one of the following: If the target SVPWM sector is the first sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% - (U1 + U2) / 2, Tmax = 50% - (U1 + U2) / 2 + U1 + U2, where Tmin represents the minimum duty cycle, Tmax represents the maximum duty cycle, U1 represents the first voltage, and U2 represents the second voltage; If the target SVPWM sector is the second sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% + (U2 + U3) / 2, Tmax = 50% + (U2 + U3) / 2 - U3 - U2, where U3 represents the third voltage; If the target SVPWM sector is the third sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% - (U1 + U3) / 2, Tmax = 50% - (U1 + U3) / 2 + U3 + U1; If the target SVPWM sector is the fourth sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% + (U1 + U2) / 2, Tmax = 50% + (U1 + U2) / 2 - U2 - U1; If the target SVPWM sector is the fifth sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% - (U2 + U3) / 2, Tmax = 50% - (U2 + U3) / 2 + U2 + U3; If the target SVPWM sector is the sixth sector, then determine the target operation equation according to the first correspondence relationship as: Tmin = 50% + (U1 + U3) / 2, Tmax = 50% + (U1 + U3) / 2 - U1 - U3.

7. The method according to claim 1, characterized in that the three-phase motor is a three-phase brushless DC motor.

8. A motor stall detection device, characterized in that the device includes: An acquisition module that acquires the three-phase current and the bus voltage of a three-phase motor; A first determination module for determining the space vector pulse width modulation (SVPWM) output voltage and the SVPWM three-phase duty ratios for driving the three-phase motor based on the three-phase current; A second determination module for: if within a first time period, the difference between the magnitude of the SVPWM output voltage and the magnitude of the bus voltage is less than a first preset value, and the fluctuation of the maximum duty ratio among the SVPWM three-phase duty ratios is within a first preset range and the fluctuation of the minimum duty ratio is within a second preset range, then determining that the three-phase motor is in a state of motor stalling.

9. A drive assembly, characterized in that, the drive assembly includes the motor stalling detection device according to claim 8.

10. A power tool, characterized in that, the power tool includes the drive assembly according to claim 9.

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