Motor starting method and device, electronic equipment and readable medium

Abstract

The invention relates to the technical field of motors, in particular to a motor starting method, device and equipment and a readable medium. According to the method, commutation control of a first stage is carried out by pre-defining rotor positioning time (namely first duration T1) in the first stage and detecting a counter electromotive force zero crossing point, so that it is ensured that a motor rotor can be stabilized at a preset position; and presetting a rotor acceleration curve in the second stage and detecting a counter electromotive force zero crossing point to carry out phase change control in the second stage so as to realize acceleration control. And finally, in the third stage, whether a stable position-free operation state is entered or not is determined by judging whether the frequency K of continuously detecting the zero crossing point of the counter electromotive force exceeds a corresponding frequency threshold value or not. Therefore, it can be ensured that the brushless direct current motor without the position sensor normally enters a stable position-free operation state, and the success rate of starting of the motor is increased.

Description

Technical Field

[0001] The present invention relates to the field of motor technology, and in particular to a motor starting method, a motor starting device, an electronic device and a readable medium. Background Art

[0002] Brushless motors can be divided into brushless DC motors (Brush Less Direct Current Motor, BLDCM) with trapezoidal wave back EMF and permanent magnet synchronous motors (PMSM) with sinusoidal back EMF according to the different back EMF (also known as back EMF) waveforms. Among them, brushless DC motors (BLDCM) generally use position sensors (such as Hall sensors) to detect the rotor position. However, since the position sensor is easily affected by the external environment, thus affecting the commutation operation, and even cannot work normally in certain environments (such as environments with excessively high temperatures), brushless DC motors without position sensors are becoming more and more widely used.

[0003] At present, in order to ensure the normal starting of the motor, a three-stage starting scheme is usually adopted for the brushless DC motor without position sensor. The scheme mainly includes three stages: rotor pre-positioning stage, rotor open-loop acceleration stage and position-free operation stage.

[0004] However, in each stage of the three-stage startup, the rotor positioning time in the first stage (i.e., the rotor pre-positioning stage) may be relatively long, the rotor acceleration curve setting in the second stage (i.e., the rotor open-loop acceleration stage) may be unreasonable, and the setting of the threshold for the number of consecutive zero crossings detected in the third stage (i.e., the position-free operation stage) may be unreasonable. These factors may cause the motor to fail to start, that is, it may not be able to enter the stable position-free operation state normally. Summary of the invention

[0005] The present application provides a motor starting method, which obtains a smooth second level signal by smoothing an output first level signal, thereby improving the accuracy of zero-crossing point detection and improving the success rate of commutation operation.

[0006] In a first aspect, the present application provides a motor starting method, which is applied to an electronic device with a position sensorless DC brushless motor, the method comprising: receiving a motor starting instruction; responding to the motor starting instruction and entering a first stage, wherein the first stage includes detecting the zero-crossing moment of the motor within a preset first time period, and switching the conduction phase of the motor according to the zero-crossing moment; when it is detected that the motor rotates into a predetermined position, entering a second stage, wherein the second stage includes detecting the zero-crossing moment of the motor within a second time period, and switching the conduction phase of the motor according to the zero-crossing moment, the second time period including the conduction time of the current phase of the motor; continuously detecting the zero-crossing moment a predetermined number of times and detecting that the motor speed is greater than a speed threshold, determining that the motor enters the third stage and completing the startup.

[0007] It can be understood that the first stage is, for example, a rotor pre-positioning stage, the second stage is, for example, a rotor open-loop acceleration stage, and the third stage is, for example, a position-free operation stage. Based on this, the motor starting scheme provided in the first aspect is to perform phase switching control by adding detection of the back electromotive force zero-crossing moment in the first and second stages, thereby realizing control of the time for the motor to rotate into a predetermined position and realizing acceleration control. In this way, it can be ensured that the position sensorless brushless DC motor normally enters a stable position-free operation state, thereby improving the success rate of motor starting.

[0008] In a possible implementation of the first aspect above, switching the conduction phase of the motor according to the zero-crossing moment includes: collecting a first voltage signal and a second voltage signal generated when the motor rotates; obtaining a first level signal according to the first voltage signal and the second voltage signal, wherein the first level signal is an abnormal signal, and the first level signal includes a low level signal and a high level signal; based on a comparison result of the number of times the stored first level signal is a high level signal and a low level signal, outputting a second level signal, wherein the second level signal is a low level signal or a high level signal; detecting the zero-crossing moment of the motor according to the second level signal; and, based on the zero-crossing moment, switching the first conduction phase of the motor to the second conduction phase.

[0009] It can be understood that the first voltage signal can be the three-phase terminal voltage when the motor rotates; the second voltage signal can be the neutral point voltage signal of the motor. The first level signal obtained based on the first voltage signal and the second voltage signal is a level signal with burrs. The second level signal is a smooth level signal. Therefore, when the zero crossing point is detected based on the second level signal, the detection result is more accurate, thereby improving the commutation success rate of the motor.

[0010] In a possible implementation of the first aspect above, the method also includes: collecting a first voltage signal and a second voltage signal generated when the motor rotates, including: detecting that the commutation sequence of the motor at a current moment is opposite to the predetermined commutation sequence, switching the first conduction phase of the motor to the third conduction phase, and collecting the first voltage signal and the second voltage signal of the motor; detecting that the commutation sequence of the motor at a current moment is the same as the predetermined commutation sequence, and collecting the first voltage signal and the second voltage signal of the motor.

[0011] In a possible implementation of the first aspect above, the method further includes: based on a comparison result of the number of times the stored first level signal is a high level signal and a low level signal, outputting a second level signal, including: determining that the number of times the stored first level signal is a high level signal is greater than the number of times the low level signal is output, and outputting the second level signal as a high level signal; determining that the number of times the stored first level signal is a high level signal is less than the number of times the low level signal is output, and outputting the second level signal as a low level signal.

[0012] In a possible implementation of the first aspect above, a method for determining the number of times that the stored first-level signal is a high-level signal and a low-level signal includes: when it is detected that the first-level signal is a high-level signal, shifting a numerical value stored in a first register in the electronic device to the left, and setting the last digit of the numerical value to a first identifier; when it is detected that the first-level signal is a low-level signal, shifting a numerical value stored in a first register in the electronic device to the left, and setting the last digit of the numerical value to a second identifier; determining a first number of numerical values ​​including the first identifier in the first register as the number of times the first-level signal is a high-level signal; and determining a second number of numerical values ​​including the second identifier in the first register as the number of times the first-level signal is a low-level signal.

[0013] In a possible implementation of the first aspect above, the method also includes: detecting the zero-crossing moment of the motor according to the second level signal, including: determining the first moment when the high-level signal is converted to a low-level signal, or the second moment when the low-level signal is converted to a high-level signal, in the detected second level signal as the zero-crossing moment of the motor.

[0014] In a possible implementation of the first aspect above, the method also includes: determining a first detection delay time based on the number of bits of the first register and the first detection frequency; wherein the first detection delay time is used to indicate the time interval between a third moment when a zero crossing occurs and a zero crossing moment when the zero crossing is detected.

[0015] In a possible implementation of the first aspect, the method further includes: the conduction time of the second conduction phase is less than the conduction time of the first conduction phase; or, the duty cycle of the second conduction phase is greater than the duty cycle of the first conduction phase.

[0016] In a possible implementation of the first aspect, the method further includes: determining when a zero-crossing point is detected consecutively for a predetermined number of times, delaying for a third time period, and switching a conduction phase of the motor.

[0017] In a possible implementation of the first aspect, the method further includes: the third duration is determined by:

[0018] The third duration is calculated according to the on-time of the current phase and the first detection delay time.

[0019] In a possible implementation of the first aspect above, the method further includes: collecting a first voltage signal and a second voltage signal generated when the motor rotates, including: starting the motor based on a first duty cycle, and causing the motor to rotate in a predetermined commutation sequence.

[0020] In the second aspect, the present application provides a motor starting device, including: a sampling module, a smoothing module, and a control module; wherein the sampling module is used to collect a first voltage signal and a second voltage signal generated when the motor rotates; the smoothing module is used to obtain a first level signal based on the first voltage signal and the second voltage signal, wherein the first level signal is a low level signal or a high level signal; and is used to output a second level signal based on a comparison result of the number of times the stored first level signal is a high level signal and a low level signal; the control module is used to detect the zero-crossing moment of the motor according to the second level signal; and is used to switch the first conduction phase of the motor to the second conduction phase based on the zero-crossing moment.

[0021] In a possible implementation of the second aspect, the device further includes: a reversal detection module; wherein the reversal detection module is used to make the motor rotate in a predetermined commutation sequence.

[0022] In a third aspect, the present application provides an electronic device comprising one or more processors; one or more memories; wherein the one or more memories store one or more programs, and when the one or more programs are executed by the one or more processors, the electronic device executes the motor starting method provided by the above-mentioned first aspect and various possible implementations of the first aspect.

[0023] In a fourth aspect, the present application provides a readable medium storing instructions, and when the instructions are executed by an electronic device, the electronic device executes the motor starting method provided by the first aspect and various possible implementations of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1a According to an embodiment of the present application, a flow chart of an implementation method of a motor starting method is shown.

[0025] Figure 1bAccording to an embodiment of the present application, a schematic diagram of a commutation detection process involved in a motor starting process is shown.

[0026] Figure 2a According to an embodiment of the present application, a schematic diagram of a commutation sequence when a motor rotates forward is shown.

[0027] Figure 2b According to an embodiment of the present application, a schematic diagram of a commutation sequence when a motor is reversed is shown.

[0028] Figure 3a According to an embodiment of the present application, a schematic diagram of a hardware zero-crossing detection structure is shown.

[0029] Figure 3b According to an embodiment of the present application, a schematic diagram of a software zero-crossing detection structure is shown.

[0030] Figure 4 According to an embodiment of the present application, a level signal with burrs is shown.

[0031] Figure 5a According to an embodiment of the present application, a first storage schematic diagram of a first register is shown.

[0032] Figure 5b According to an embodiment of the present application, a second storage schematic diagram of the first register is shown.

[0033] Figure 6 According to an embodiment of the present application, a smooth level signal is shown.

[0034] Figure 7 According to an embodiment of the present application, a schematic diagram of a smoothed zero-crossing point and an actual zero-crossing point is shown.

[0035] Figure 8a According to an embodiment of the present application, a flowchart for implementing the pre-positioning stage is shown.

[0036] Figure 8b According to an embodiment of the present application, another implementation flow chart of the pre-positioning stage is shown.

[0037] Fig. 9 According to an embodiment of the present application, a flowchart for implementing the rotor open-loop acceleration phase is shown.

[0038] Fig.10 According to an embodiment of the present application, another implementation flow chart of the rotor open-loop acceleration stage is shown.

[0039] Fig.11 According to an embodiment of the present application, a flowchart for implementing entering a position-free operation phase is shown.

[0040] Fig.12According to an embodiment of the present application, a module schematic diagram of a motor starting device is shown.

[0041] Fig.13 Shown is a schematic structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] As mentioned above, in each stage of the three-stage startup, the rotor positioning time in the first stage (i.e., the rotor pre-positioning stage) may be relatively long, the rotor acceleration curve setting in the second stage (i.e., the rotor open-loop acceleration stage) may be unreasonable, and the setting of the threshold for the number of consecutive zero crossings detected in the third stage (i.e., the position-free operation stage) may be unreasonable. These factors may cause the motor to fail to start, that is, it may not be able to enter the stable position-free operation state normally.

[0044] In order to solve the above problems, the present application provides a motor starting method, which is applied to a motor starting device or equipment of a brushless DC motor using a position sensorless motor. Specifically, the method predefines the rotor positioning time (recorded as the first duration T1) and detects the back electromotive force zero crossing point in the first stage to perform the first stage of phase change control, thereby ensuring that the motor rotor can be stabilized in a predetermined position; and predetermines the rotor acceleration curve in the second stage and detects the back electromotive force zero crossing point to perform the second stage of phase change control, thereby realizing acceleration control. Finally, in the third stage, it is determined whether to enter a stable positionless operation state by judging whether the number of times K of the back electromotive force zero crossing point is continuously detected exceeds the corresponding number threshold. In this way, it can be ensured that the position sensorless brushless DC motor normally enters a stable positionless operation state, thereby improving the success rate of motor starting.

[0045] As an example, Figure 1a According to an embodiment of the present application, a flow chart for implementing a motor starting method is shown. It can be understood that the execution subject of each step in the process can be a motor starting device that implements the motor starting method of the present application or an electronic device having the motor starting device. The structure of the specific starting device or device will be described in detail below and will not be repeated here.

[0046] like Figure 1a As shown, the implementation process may include:

[0047] a101: Receive motor start command.

[0048] The motor start command is used to instruct the start of the position sensorless brushless DC motor.

[0049] It can be understood that the motor start instruction may include a hardware control signal generated in an electronic device in the fields of automobiles, home appliances, industrial equipment, etc. where a position sensorless brushless DC motor is used, such as a control signal generated by a user triggering a switch of an electronic device, etc. It may also include a software control instruction generated by an electronic device running related software code, etc., without limitation here.

[0050] a102: Respond to the motor start command and enter the first stage, detect the zero-crossing moment of the motor within the preset first time period, and switch the conduction phase of the motor according to the zero-crossing moment.

[0051] Among them, the first stage (i.e., the rotor pre-positioning stage) can detect the zero crossing point within the pre-defined rotor positioning time (i.e., the first time length T1), which can eliminate the situation where the motor cannot stop in time after rotating to the predetermined position due to various factors such as the power supply voltage, load size, motor initial position, motor inertia size, etc., resulting in a long positioning time. That is, the rotor positioning time in the pre-positioning stage can be shortened, so that it can adapt to application scenarios that require rapid response. The specific implementation process of the first stage will be combined with Figure 8a and Figure 8b Describe in detail.

[0052] a103: When it is detected that the motor rotates into a predetermined position, the second stage is entered, the zero-crossing moment of the motor is detected within a preset second time period, and the conduction phase of the motor is switched according to the zero-crossing moment.

[0053] Among them, the second stage (i.e., the rotor open-loop acceleration stage) compensates for the risk of the motor losing step when the pre-set rotor acceleration curve is unreasonable by detecting the zero-crossing point of the back EMF to trigger the phase change. This allows the acceleration curve to be set relatively flexibly, that is, the open-loop acceleration range can be relatively wide, which can also avoid the tediousness of constant parameter adjustment and avoid the risk of the motor losing step due to unreasonable acceleration curve setting. The preset second duration can include the on-time of the current phase of the motor. After the phase is switched, the second duration can be updated to the updated on-time after the phase switch. For details, please refer to the following Fig. 9 The relevant descriptions in the implementation process shown will not be repeated here.

[0054] The specific implementation process of the second phase will be described below. Fig. 9 and Fig.10 Describe in detail.

[0055] a104: When the zero-crossing moment is detected for a predetermined number of times in succession and the motor speed is detected to be greater than the speed threshold, it is determined that the motor enters the third stage.

[0056] Complete startup.

[0057] For example, it can be determined whether the stable non-position operation stage, i.e., the third stage, has been entered by judging whether the number of times K of the back electromotive force zero crossings detected continuously exceeds the corresponding number threshold. When the motor enters the third stage and is in the non-position operation state, it means that the motor has been successfully started. The specific implementation process of entering the third stage will be described below in conjunction with Fig.10 Describe in detail.

[0058] However, it is worth noting that in the first stage, the rotor positioning time is predefined and the back EMF zero crossing point is detected to carry out the first stage of commutation control, and in the second stage of commutation control, the rotor acceleration curve is pre-set and the back EMF zero crossing point is detected. When detecting the commutation point for commutation, due to the presence of glitches in the output level signal, commutation point detection errors are prone to occur, resulting in incorrect commutation, which may also cause motor starting failure.

[0059] In this regard, the first voltage signal and the second voltage signal generated when the motor rotates in a predetermined commutation sequence can be collected; the first level signal is obtained according to the first voltage signal and the second voltage signal, and the first level signal is often a level signal with burrs, and the burr signal refers to a signal that switches from a low level to a high level, or from a high level to a low level in a short time, so it cannot be stabilized as a low level signal or a high level signal. At this time, based on the number of times the stored first level signal is a high level signal and a low level signal, the second level signal determined to be a high level or a low level can be output, and the second level signal is a smooth level signal. Then, according to the second level signal, the zero-crossing moment of the motor is detected more accurately; and based on the detected zero-crossing moment, the first conduction phase of the motor is switched to the second conduction phase. In this way, it is beneficial to improve the commutation success rate of the motor in the first stage (i.e., the pre-positioning stage) and avoid the situation where the motor fails to start due to incorrect commutation.

[0060] As an example, let's first combine Figure 1b The specific implementation process (ie, the commutation detection process) of switching the conduction phase of the motor according to the zero-crossing moment involved in the above-mentioned steps a102 and a103 is introduced.

[0061] Figure 1b According to an embodiment of the present application, a schematic diagram of a phase change detection process involved in a motor starting process is shown. It can be understood that the execution subject of each step in the process can be a motor starting device that implements the motor starting method of the present application or an electronic device having the motor starting device. The structure of the specific starting device or device will be described in detail below and will not be repeated here.

[0062] Specifically, Figure 1b The commutation detection process shown may include the following steps:

[0063] b101: Collect the first voltage signal and the second voltage signal generated when the motor rotates in a predetermined commutation sequence.

[0064] Exemplarily, the first voltage signal may be a three-phase terminal voltage when the motor rotates; and the second voltage signal may be a neutral point voltage signal when the motor rotates.

[0065] It can be understood that the commutation sequence after the motor starts may be as follows Figure 2a The rotation direction shown is in the forward order: AB→AC→BC→BA→CA→CB→AB, or it may be as follows Figure 2b The reversal order shown in is: AB→CB→CA→BA→BC→AC→AB. In order to determine the rotor position in the motor, the motor needs to rotate according to the predetermined commutation order. However, the corresponding commutation order when the motor is just started is not necessarily the same as the predetermined commutation order. Therefore, it is necessary to first determine whether the commutation order of the motor is the same as the predetermined commutation order. When it is detected that the commutation order of the motor at the current moment is opposite to the predetermined commutation order, a commutation signal corresponding to the predetermined commutation order can be generated first, and the conduction phase of the motor is switched from the current first conduction phase to the next phase (for distinction, hereinafter referred to as the third conduction phase) according to the commutation signal, and then the first voltage signal and the second voltage signal of the motor are collected. When it is detected that the commutation order of the motor at the current moment is the same as the predetermined commutation order, the first voltage signal and the second voltage signal of the motor are directly collected.

[0066] b102: obtaining a first level signal according to the first voltage signal and the second voltage signal, wherein the first level signal is an abnormal signal, and the first level signal includes a low level signal and a high level signal.

[0067] Exemplarily, the three-phase terminal voltage and the neutral point voltage during the rotation of the motor are collected, and the three-phase terminal voltage and the neutral point voltage are input into the comparator to obtain the first level signal. As mentioned above, the first level signal is often a level signal with burrs, and the signal cannot be stabilized as a high level signal or a low level signal.

[0068] It can be understood that the principle of the comparator is to compare the magnitude relationship between the input signals. When the value of the input at the "+" end is greater than the value of the input at the "-" end, the comparator outputs a high-level signal; when the value of the input at the "+" end is less than the value of the input at the "-" end, the comparator outputs a low-level signal. For example, when the value of the three-phase terminal voltage input at the "+" end is greater than the value of the neutral point voltage input at the "-" end, the comparator outputs a high-level signal, or when the value of the three-phase terminal voltage input at the "+" end is less than the value of the neutral point voltage input at the "-" end, the comparator outputs a low-level signal. Based on this, the first level signal can be obtained according to the first voltage signal and the second voltage signal.

[0069] The process of outputting the first level signal according to the comparator can be Figure 3a The hardware comparator circuit implementation shown.

[0070] like Figure 3a As shown in the figure, A, B and C represent the input A phase voltage, the input B phase voltage and the input C phase voltage respectively, and COM represents the neutral point voltage. Figure 3b The software comparator circuit shown is implemented, for example, the sampling module only needs to sample the three-phase voltages of A, B and C, and COM can be directly calculated by an algorithm executed by relevant software codes, and no limitation is made here.

[0071] b103: outputting a second level signal based on a comparison result of the number of times the first level signal is a high level signal and a low level signal.

[0072] Exemplarily, the output second level signal may be a smooth level signal, and the second level signal may be stably a low level signal or a high level signal.

[0073] It can be understood that when the motor is running at a low speed, the input signal has noise and the comparator has a hysteresis characteristic. Therefore, when the output edge of the comparator flips, it does not directly change from a low-level signal to a high-level signal or from a high-level signal to a low-level signal, but there are certain glitches, such as Figure 4 As shown, when the level signal output by the comparator changes from a low level signal to a high level signal, a glitch A will appear; when the level signal output by the comparator switches from a high level signal to a low level signal, a glitch B will appear.

[0074] Therefore, when detecting the zero-crossing point based on the first level signal output by the comparator, it is necessary to first smooth the first level signal to obtain a smooth second level signal, and then detect the zero-crossing point based on the second level signal. The zero-crossing point detected in this way can be more accurate. Among them, the specific processing process of the first level signal can be as follows: First, set a first register with a bit number of L to store the information of the zero-crossing signal. For example, it can be 32 bits. The digital circuit continuously detects the first level signal output by the comparator. When the detected first level information is a high level signal, the value stored in the first register is shifted one bit to the left, and the last bit of the value of the first register is set to the first mark, for example, set to "1". When the detected first level information is a low level signal, the value of the first register is shifted one bit to the left, and the last bit of the value of the first register is set to the second mark, for example, set to "0". Count the bit information on each bit in the first register. Figure 5a As shown in , when the number of bits with the last bit being 1 is greater than the number of bits with the last bit being 0, it indicates that the output second level signal is a high level signal. Figure 5b As shown in FIG. 1 , when the number of bits with the last bit being 0 is greater than the number of bits with the last bit being 1, it indicates that the output second level signal is a low level signal. The second level signal obtained according to the first level signal can be referred to as Figure 6 In other embodiments, the above-mentioned smoothing process can also be implemented by executing a counting algorithm in related software code instead of the first register. The specific smoothing process is the same as the principle of the above-mentioned hardware smoothing process, which will not be described in detail here.

[0075] Furthermore, the number of times that the stored first level signal is a high level signal and a low level signal and a comparison result of the number are continuously detected, and then a smooth second level signal is output based on the comparison result.

[0076] It can be understood that in the process of outputting the second level signal, if it is determined that the number of times the stored first level signal is a high level signal is greater than the number of times it is a low level signal, then the second level signal output is a high level signal; if it is determined that the number of times the stored first level signal is a high level signal is less than the number of times it is a low level signal, then the second level signal output is a low level signal.

[0077] b104: Detect the zero-crossing moment of the motor according to the second level signal.

[0078] It can be understood that the first moment when the second level signal is converted from a high level signal to a low level signal, or the second moment when the low level signal is converted from a high level signal, can be determined as the zero-crossing moment of the motor. However, since the first level signal needs to be processed to obtain the second level signal, there is a first detection delay time when detecting the zero-crossing point. Figure 7 As shown, the zero crossing point after filtering is delayed by a period of time T than the actual zero crossing point delay The first detection delay time is used to indicate the time interval between the third moment when the zero crossing occurs and the zero crossing moment when the zero crossing is detected. The first detection delay time can be obtained by:

[0079] The zero crossing point is detected at the first detection frequency. When the number of bits stored in the first register is an odd number, the first detection delay time is: When the number of bits stored in the first register is an even number, the first detection delay time is: Wherein, T is the first detection delay time, f is the first detection frequency, and L is the number of bits stored in the first register.

[0080] b105: Based on the zero-crossing moment, the first conduction phase of the motor is switched to the second conduction phase.

[0081] Exemplarily, based on the zero-crossing moment, the first conduction phase of the switching motor is changed to the second conduction phase. At this time, the conduction time of the second conduction phase is less than the conduction time of the first conduction phase, or the duty cycle of the second conduction phase is greater than the duty cycle of the first conduction phase. Furthermore, when the zero-crossing moment is detected a predetermined number of times in succession, the conduction phase of the switching motor is delayed for a third time length.

[0082] It can be understood that when the first conduction phase of the motor is switched to the second conduction phase based on the zero-crossing moment, and the conduction time of the second conduction phase is less than the conduction time of the first conduction phase, the motor is in the acceleration stage. Figures 9 and 10 The relevant description in is not repeated here.

[0083] At this time, continue to detect the zero crossing point of the motor, and determine whether the motor is in a state where the back electromotive force can be stably detected. In other embodiments, when a predetermined number of zero crossing moments are detected continuously, the third duration is delayed and the conduction phase of the motor is switched. Among them, the above-mentioned predetermined number of times is used to indicate the number of times the motor needs to detect the zero crossing point when it can stably detect the back electromotive force. In addition, the above-mentioned predetermined number of times can be reasonably set according to actual needs, or it can be an empirical value obtained based on a large number of experimental numbers.

[0084] Next, continue to combine Figure 8a The implementation process of the first stage (i.e. the rotor pre-positioning stage) is introduced in detail.

[0085] Figure 8a According to the embodiment of the present application, a flowchart for implementing the rotor pre-positioning stage is shown. It can be understood that the execution subject of each step in the process can be a motor starting device that implements the motor starting method of the present application or an electronic device having the motor starting device. The structure of the specific starting device or device will be described in detail below and will not be repeated here.

[0086] like Figure 8a As shown, the process includes the following steps:

[0087] a801: Start the motor and start timing.

[0088] a802: Determine whether the motor commutation sequence is consistent with the predetermined commutation sequence.

[0089] If the motor commutation sequence is consistent with the predetermined commutation sequence, that is, the judgment result is yes, then step a804 is executed.

[0090] If the motor commutation sequence is inconsistent with the predetermined commutation sequence, that is, the judgment result is no, then step a803 is executed.

[0091] a803: Generates a commutation signal and switches the first conduction phase to the third conduction phase according to a predetermined commutation sequence to drive the motor to rotate.

[0092] It can be understood that when the above motor commutation sequence is inconsistent with the predetermined commutation sequence, a commutation signal corresponding to the predetermined commutation sequence is generated, and the current phase is switched to the next phase corresponding to the predetermined commutation sequence, that is, the third conduction phase. Figure 2b The reverse order shown is: AB→CB→CA→BA→BC→AC→AB. The predetermined commutation order can be as above Figure 2a The forward rotation sequence shown is: AB→AC→BC→BA→CA→CB→AB. If the current phase of the above motor is AB, then the current phase is switched to the next phase corresponding to the predetermined commutation sequence, that is, the current phase AB is switched to the next phase AC corresponding to the predetermined commutation sequence.

[0093] It can be understood that when the level signal of the comparator is detected when the motor is just started, when the detected level signal is high, the motor commutation sequence is inconsistent with the predetermined commutation sequence; when the detected level signal is low, the motor commutation sequence is consistent with the predetermined commutation sequence. For example, the current conduction phase of the motor is AB, and the terminal voltage and neutral point voltage of phase C are detected at this time. When the motor is just started, the terminal voltage of phase C and the neutral point voltage have the following relationship:

[0094] U c =e c +U com

[0095] Among them, U c is the voltage at the phase C terminal, e c is the reverse potential of C, U com is the motor neutral point voltage.

[0096] When the motor commutation sequence is the forward rotation sequence, the next conduction vector is AC, so the reverse potential of C is e c Less than zero; when the motor commutation sequence is the reverse sequence, the next conduction vector is CB reverse e c When the predetermined commutation sequence is the forward sequence, the level signal of the comparator is detected when the motor is just started. c Greater than U com , the comparator outputs a high level, and the above motor commutation sequence is inconsistent with the predetermined commutation sequence; when the motor U c Less than U com , the comparator outputs a low level, and the motor commutation sequence is consistent with the predetermined commutation sequence. Therefore, after the motor is started, it is only necessary to detect the starting level of the comparator output to determine whether the motor commutation sequence is consistent with the predetermined commutation sequence.

[0097] a804: Determine whether a zero crossing is detected.

[0098] It can be understood that when the above motor commutation sequence is consistent with the predetermined commutation sequence, it is determined whether a zero crossing point is detected.

[0099] When a zero crossing is detected, that is, the judgment result is yes, the following step a806 is executed.

[0100] When no zero crossing point is detected, that is, when the judgment result is no, the following step a805 is executed.

[0101] a805: Determine whether the timing time is greater than the first time length T1.

[0102] It can be understood that when the zero crossing point is not detected, it is determined whether the timing time is greater than the first time length T1, that is, the predefined rotor positioning time.

[0103] When the timing time is greater than the first time length T1, step a804 is re-executed to continue detecting the zero-crossing point.

[0104] When the timing time is less than the first time length T1, step a806 is executed to switch the conduction phase of the motor.

[0105] a806: Switch the motor from the first conduction phase to the third conduction phase, and drive the motor to rotate.

[0106] It can be understood that when step a804 is executed and a zero crossing is detected, the motor is switched from the current first conduction phase to the third conduction phase and the motor is driven to rotate. When step a805 is executed and the timing time is greater than the first duration T1, the motor is switched from the current first conduction phase to the third conduction phase and the motor is driven to rotate.

[0107] In some other embodiments, the implementation process of the first stage (i.e., the rotor pre-positioning stage) can also refer to Figure 8b As shown, this is achieved by adding a pulse width modulation (PWM) modulation method.

[0108] Specifically, Figure 8b The implementation flow shown may include the following steps:

[0109] b801: Set the PWM duty cycle to the first duty cycle, start the motor, make the motor rotate in the predetermined commutation sequence, and start timing.

[0110] It can be understood that the first duty cycle D1 added to the PWM modulation at startup is generally selected reasonably according to the power supply voltage, motor rated current and motor winding equivalent resistance of the application. The first duty cycle D1 cannot be too small, otherwise the motor starting torque is insufficient, the startup is slow or it is difficult to overcome the load torque and friction torque to start. Generally, the first duty cycle does not exceed 50%.

[0111] b802: Determine whether the motor commutation sequence is consistent with the predetermined commutation sequence.

[0112] b803: Generates a commutation signal and switches the first conduction phase to the third conduction phase according to a predetermined commutation sequence to drive the motor to rotate.

[0113] b804: Determine whether a zero crossing is detected.

[0114] b805: Determine whether the timing time is greater than the first duration T1.

[0115] b806: Switch the motor from the first conduction phase to the third conduction phase and drive the motor to rotate.

[0116] Among them, the above steps b802 to b806 can refer to the above Figure 8a The relevant descriptions in steps a802 to a806 are not repeated here.

[0117] Next, continue to combine Fig. 9 The open-loop acceleration process of the motor entering the second stage in the above step a103 is described in detail.

[0118] Fig. 9 According to an embodiment of the present application, a flowchart for implementing the rotor open-loop acceleration phase is shown.

[0119] like Fig. 9 As shown, the specific steps of the implementation process are as follows:

[0120] 901: The motor enters the open-loop acceleration phase and starts timing.

[0121] It can be understood that after the motor is rotated in a predetermined commutation sequence, the motor enters an open-loop acceleration phase, at which time the timing is restarted.

[0122] 902: Determine whether a zero crossing point is detected.

[0123] When a zero-crossing point is detected, that is, the judgment result is yes, step 904b is executed.

[0124] When no zero-crossing point is detected, that is, the judgment result is no, step 903 is executed.

[0125] 903: Determine whether the timing time is greater than the second time length T2.

[0126] Exemplarily, when the zero crossing is not detected, the relationship between the timing time and the second time length T2 is determined. The second time length T2 may be a preset time threshold corresponding to the rotor open-loop acceleration stage, the size of T2 may be determined according to an acceleration curve preset in the open-loop acceleration stage, and the time threshold may be a statistical value based on the acceleration test result of the acceleration curve or a time threshold set based on the statistical value, which is not limited here.

[0127] When the timing time is greater than the second time length T2, that is, the judgment result is yes, execute step 905;

[0128] When the timing time is less than the second time length T2, that is, the judgment result is no, the above step 902 is executed.

[0129] 904a: Update the on-time ΔT value.

[0130] It can be understood that each time the phase is switched, the stored on-time ΔT of the previous phase is replaced with the on-time of the current phase.

[0131] 904b: Determine whether K zero-crossing points are detected consecutively.

[0132] When the zero crossing is detected K times (i.e., the predetermined number of times) continuously, step 906 is executed, the third time length is delayed, and the conduction phase of the motor is switched; when the zero crossing is not detected K times (i.e., the predetermined number of times) continuously, step 905 is executed.

[0133] 905: Switch the motor from the first conduction phase to the third conduction phase, update the conduction time T, and reset the timing time.

[0134] It can be understood that when the zero crossing is not detected continuously for K times, the motor is switched from the current first conduction phase to the third conduction phase, the conduction time T is updated, and the timing time is reset. In order to realize the acceleration control of the motor, the conduction time T after each phase change needs to be updated to T-Tacc, where Tacc is the conduction time acceleration. Among them, Tacc can be calculated based on the conduction angle of the motor, and parameters such as the moment of inertia, or set according to the statistical values ​​of a large amount of experimental data, and there is no restriction here. T=T–Tacc is called the rotor acceleration curve, which can be either a linear acceleration curve or a nonlinear acceleration curve. For example, T=T*xk is the latter, where x represents the number of accelerations in the acceleration stage, and k represents the nonlinearity of acceleration, which can be reasonably selected according to the moment of inertia of the motor.

[0135] 906: Delay for a third time period to switch the motor from the first conduction phase to the third conduction phase.

[0136] It can be understood that after the smoothing process from step b103 to step b104, the zero-crossing point detected based on the smoothed second level signal is delayed by the first detection delay time compared to the actual zero-crossing point. Therefore, according to the current phase conduction time and the detection delay time, the third duration can be calculated. For example, if the current conduction time is ΔT and the first detection delay time is T delay , then the third duration is ΔT / 2-T delay . Delay ΔT / 2-T delay The current first conduction phase of the motor is switched to the third conduction phase.

[0137] In other embodiments, when the first conduction phase of the motor is switched to the second conduction phase based on the zero-crossing moment, and the duty cycle of the second conduction phase is greater than the duty cycle of the first conduction phase, the motor is in the open-loop acceleration stage. Fig.10 As shown, another implementation flow chart of the rotor open-loop acceleration phase is provided.

[0138] Fig.10 The process shown may include the following steps:

[0139] 1001: The motor enters the open-loop acceleration phase and starts timing.

[0140] 1002: Determine whether a zero crossing point is detected.

[0141] 1003: Determine whether the timing time is greater than the second time length T2.

[0142] 1004a: Update the on-time ΔT value.

[0143] 1004b: Determine whether K zero crossings are detected consecutively.

[0144] It can be understood that the above steps 1001 to 1004b can refer to the relevant descriptions in steps 901 to 904b, and will not be repeated here.

[0145] 1005: Switch the motor from the first conduction phase to the third conduction phase, update the first duty cycle D1, and reset the timing time.

[0146] It can be understood that when the zero crossing point is not detected continuously for K times, the motor is switched from the first conduction phase to the third conduction phase, the first duty cycle D1 is updated, and the timing time is reset. In order to avoid excessive starting current of the motor, for the situation where PWM control is applied to the motor in the above step b801, the acceleration control of the motor can achieve motor acceleration by increasing the first duty cycle D1 of PWM, and the conduction time corresponding to each conduction phase can remain unchanged. Among them, the rotor acceleration curve is generally a linear acceleration curve T1=T1+Tacc, wherein Tacc can be calculated based on the conduction angle of the motor, and parameters such as the moment of inertia, or set according to the statistical value of a large amount of experimental data, and no limitation is made here. It can also be a nonlinear acceleration curve such as T1=T1*xk, where x represents the number of accelerations in the open-loop acceleration stage, and k represents the acceleration nonlinearity, which can be determined by experimental tests or reasonably set according to the moment of inertia of the motor.

[0147] 1006: Delay the third time period to switch the conduction phase of the motor.

[0148] It can be understood that the delay of the third time length in the above step 1006 to switch the conduction phase of the motor can be referred to the relevant description in step 906, and will not be repeated here.

[0149] In addition, after the motor is switched from the current first conduction phase to the third conduction phase, the motor device rotates according to the second duty cycle D2, wherein the second duty cycle D2 can be set according to the preset rotation speed of the motor and the motor rotation parameters.

[0150] It can be understood that after executing the above steps b101 to b105, the motor enters the non-position operation stage. At this time, after the motor enters the non-position operation stage, the electronic device can continue to execute Fig.11 The implementation process is shown.

[0151] like Fig.11 As shown, the implementation process after the motor enters the position-free operation stage may include the following steps:

[0152] 1101: The motor enters the non-position operation phase and starts timing.

[0153] It can be understood that by executing the above steps b101 to b105, the motor enters the position-free operation stage, and starts timing, and detects the zero-crossing point within the predetermined timing time.

[0154] It can be understood that there is a special stage in the starting process of the brushless DC motor, namely the acceleration stage in the "three-stage" starting. In this stage, the motor accelerates from a standstill until the speed is large enough, such as exceeding the preset speed threshold, and the zero crossing point can be detected by the back electromotive force, and then the motor switches to the normal operation state of the brushless DC motor. In this stage, since no position sensor is used to determine the position of the rotor pole, it is called the positionless operation stage.

[0155] In some embodiments, when the motor enters the position-free operation stage, a new PWM modulation is added to the motor, and the corresponding duty cycle is the second duty cycle D2.

[0156] 1102: Determine whether a zero crossing point is detected.

[0157] It can be understood that when a zero crossing is detected by the back electromotive force, step 1103 is executed to update the on-time ΔT value and reset the timing time; when no zero crossing is detected, step 1102 is repeatedly executed to determine whether a zero crossing is detected.

[0158] 1103: Update the on-time ΔT value and reset the timing time.

[0159] When the zero crossing point is detected, the stored on-time ΔT value is updated and the timing time is reset.

[0160] 1104: Delay the second time period to switch the conduction phase of the motor.

[0161] It can be understood that the above-mentioned back electromotive force zero-crossing detection method is consistent with the processing method of the opposite terminal voltage and the neutral point voltage in the above-mentioned step b103. Therefore, according to the updated conduction time ΔT value and the detection delay time, the second delay time can be calculated.

[0162] It can be understood that the above steps b101 to b105 can be performed as follows: Fig.12 The modules in are implemented.

[0163] Fig.12 According to an embodiment of the present application, a module schematic diagram of a motor starting device is shown.

[0164] like Fig.12 As shown, the motor starting device includes a sampling module, a smoothing module, a control module, and a reversal detection module.

[0165] The sampling module is used to collect the first voltage signal and the second voltage signal generated when the motor rotates.

[0166] A smoothing module is used to obtain a first level signal according to a first voltage signal and a second voltage signal; the first level signal is an abnormal signal, and the first level signal includes a low level signal and a high level signal; and is used to output a second level signal based on a comparison result of the number of times the first level signal is a high level signal and a low level signal stored. The second level signal is a low level signal or a high level signal.

[0167] The control module is used to detect the zero-crossing point of the motor according to the second level signal; and is used to switch the first conduction phase of the motor to the second conduction phase based on the zero-crossing point moment.

[0168] The reversal detection module is used to make the motor rotate in a predetermined commutation sequence.

[0169] The present application embodiment also provides an electronic device 100 for executing the above Figure 1a and Figure 1b The motor starting method shown.

[0170] As an example, Fig.13 According to an embodiment of the present application, a structural diagram of an electronic device 100 is provided.

[0171] Fig.13 According to an embodiment of the present application, a structural diagram of an electronic device 100 is provided.

[0172] like Fig.13 As shown, the electronic device 100 includes one or more processors 101, a system memory 102, a non-volatile memory (NVM) 103, a communication interface 104, an input / output (I / O) device 105, and a system control logic 106 for coupling the processor 101, the system memory 102, the non-volatile memory 103, the communication interface 104 and the input / output (I / O) device 105. Among them:

[0173] The processor 101 may include one or more processing units, for example, a central processing unit CPU (Central Processing Unit), an image processor GPU (Graphics Processing Unit), a digital signal processor DSP (Digital Signal Processor), a microprocessor MCU (Micro-Programmed Control Unit), artificial intelligence (Artificial Intelligence, AI), a processor or a programmable logic device FPGA (Field Programmable Gate Array), a neural network processor (Neural-Network Processing Unit, NPU), etc. The data processing unit or processing circuit may include one or more single-core or multi-core processors.

[0174] The system memory 102 is a volatile memory, such as a random-access memory (RAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), etc. The system memory is used to temporarily store data and / or instructions. For example, in some embodiments, the system memory 102 can be used to store operating data information of a motor to be started.

[0175] The non-volatile memory 103 may include one or more tangible, non-temporary computer-readable media for storing data and / or instructions. In some embodiments, the non-volatile memory 103 may include any suitable non-volatile memory such as flash memory and / or any suitable non-volatile storage device, such as a hard disk drive (HDD), a compact disc (CD), a digital versatile disc (DVD), a solid-state drive (SSD), etc. In some embodiments, the non-volatile memory 103 may also be a removable storage medium, such as a secure digital (SD) memory card, etc.

[0176] In particular, the system memory 102 and the non-volatile memory 103 may respectively include: a temporary copy and a permanent copy of the instruction 107. The instruction 107 may include: when executed by at least one of the processors 101, the electronic device 100 implements the motor starting method provided in various embodiments of the present application.

[0177] The communication interface 104 may include a transceiver for providing a wired or wireless communication interface for the electronic device 100, thereby communicating with any other suitable device through one or more networks. In some embodiments, the communication interface 104 may be integrated into other components of the electronic device 100, for example, the communication interface 104 may be integrated into the processor 101.

[0178] The input / output (I / O) device 105 may include input devices such as a keyboard, a mouse, etc., and output devices such as a display, etc. A user may interact with the electronic device 100 via the input / output (I / O) device 105 .

[0179] System control logic 106 may include any suitable interface controller to provide any suitable interface with other modules of electronic device 100. For example, in some embodiments, system control logic 106 may include one or more memory controllers to provide interfaces to system memory 102 and non-volatile memory 103.

[0180] In some embodiments, at least one of the processors 101 may be packaged together with the logic of one or more controllers for the system control logic 106 to form a system in package (System In Package, Sip). In other embodiments, at least one of the processors 101 may also be integrated with the logic of one or more controllers for the system control logic 106 on the same chip to form a system-on-chip (System-On-Chip, SOC).

[0181] Understandably, Fig.13 The structure of the electronic device 100 shown is only an example. In other embodiments, the electronic device 100 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware, which is not limited here.

[0182] The embodiments of the present application also provide a computer program product for implementing the motor starting methods provided in the above embodiments.

[0183] The various embodiments of the mechanism disclosed in the present application can be implemented in hardware, software, firmware or a combination of these implementation methods. The embodiments of the present application can be implemented as a computer module or module code executed on a programmable system, and the programmable system includes at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device and at least one output device.

[0184] The module code may be applied to input instructions to perform the functions described herein and generate output information. The output information may be applied to one or more output devices in a known manner. For purposes of this application, a processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), or a microprocessor.

[0185] Module code can be implemented with high-level modular language or object-oriented programming language to communicate with the processing system. When necessary, module code can also be implemented with assembly language or machine language. In fact, the mechanism described in this application is not limited to the scope of any specific programming language. In either case, the language can be a compiled language or an interpreted language.

[0186] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, instructions may be distributed over a network or by other computer-readable media. Therefore, machine-readable media may include any mechanism for storing or transmitting information in a machine (e.g., computer) readable form, including but not limited to, floppy disks, optical disks, optical disks, read-only memories (CD-Roms), magneto-optical disks, read-only memories (ROM), random access memories (RAM), erasable programmable read-only memories (EPROM), electrically erasable programmable read-only memories (EEPROM), magnetic cards or optical cards, flash memory, or tangible machine-readable memories for transmitting information (e.g., carrier waves, infrared signal digital signals, etc.) using the Internet in electrical, optical, acoustic, or other forms of propagation signals. Accordingly, machine-readable media include any type of machine-readable media suitable for storing or transmitting electronic instructions or information in a form readable by a machine (eg, a computer).

[0187] In the accompanying drawings, some structural or method features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. Instead, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a specific figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features. Reference to "one embodiment" or "embodiment" in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one exemplary embodiment or technology disclosed according to the embodiment of the present application. The appearance of the phrase "in one embodiment" in various places in the specification does not necessarily all refer to the same embodiment.

[0188] The disclosure of the embodiment of the present application also relates to an operating device for executing the text. The device can be specially constructed for the required purpose or it can include a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program can be stored in a computer-readable medium, such as, but not limited to any type of disk, including a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic or optical card, an application-specific integrated circuit (ASIC) or any type of medium suitable for storing electronic instructions, and each can be coupled to a computer system bus. In addition, the computer mentioned in the specification may include a single processor or may be an architecture involving multiple processors for increased computing power.

[0189] It should also be stated that the steps in the methods and processes in the embodiments of the present application are numbered for ease of reference, rather than to limit the order of precedence. If there is an order between the steps, the text description shall prevail.

[0190] In addition, the language used in this specification has been primarily selected for readability and instructional purposes and may not be selected to describe or limit the disclosed subject matter. Therefore, the present application embodiment disclosure is intended to illustrate rather than limit the scope of the concepts discussed herein.

Claims

1. A motor starting method, characterized in that: Applied to an electronic device having a position sensorless brushless DC motor, the method comprises: Receive motor start command; Responding to the motor start instruction and entering the first stage, wherein the first stage includes detecting the zero-crossing moment of the motor within a preset first time period, and switching the conduction phase of the motor according to the zero-crossing moment; When it is detected that the motor rotates into a predetermined position, the second stage is entered, wherein the second stage includes detecting the zero-crossing moment of the motor within a second time length, and switching the conduction phase of the motor according to the zero-crossing moment, and the second time length includes the conduction time of the current phase of the motor; The zero-crossing moments are detected a predetermined number of times in succession and the motor speed is detected to be greater than a speed threshold, and it is determined that the motor enters the third stage and the startup is completed.

2. The method according to claim 1, characterized in that: The switching of the conduction phase of the motor according to the zero-crossing point moment comprises: Collecting a first voltage signal and a second voltage signal generated when the motor rotates; Obtaining a first level signal according to the first voltage signal and the second voltage signal, wherein the first level signal is an abnormal signal, and the first level signal includes a low level signal and a high level signal; Outputting a second level signal based on a stored comparison result of the number of times the first level signal is a high level signal and a low level signal, wherein the second level signal is a low level signal or a high level signal; According to the second level signal, detecting the zero-crossing moment of the motor; and, Based on the zero-crossing moment, the first conduction phase of the motor is switched to the second conduction phase.

3. The method according to claim 2, characterized in that: The first voltage signal and the second voltage signal generated when the motor rotates are collected, including: Detecting that the current commutation sequence of the motor is opposite to the predetermined commutation sequence, switching the first conduction phase of the motor to the third conduction phase, and collecting the first voltage signal and the second voltage signal of the motor; It is detected that the commutation sequence of the motor at the current moment is the same as the predetermined commutation sequence, and the first voltage signal and the second voltage signal of the motor are collected.

4. The method according to claim 2, characterized in that: The outputting a second level signal based on the stored comparison result of the number of times the first level signal is a high level signal and a low level signal comprises: Determine that the number of times the stored first-level signal is a high-level signal is greater than the number of times the stored first-level signal is a low-level signal, and output a second-level signal that is a high-level signal; It is determined that the number of times the stored first level signal is a high level signal is less than the number of times the stored first level signal is a low level signal, and a second level signal which is a low level signal is output.

5. The method according to claim 4, characterized in that The method for determining the number of times that the stored first level signal is a high level signal and a low level signal includes: Upon detecting that the first level signal is a high level signal, shifting the value stored in the first register in the electronic device to the left, and setting the last bit of the value as a first flag; Upon detecting that the first level signal is a low level signal, shifting the value stored in the first register in the electronic device to the left, and setting the last bit of the value as a second flag; determining a first number of the values ​​of the first identifier in the first register as the number of times the first level signal is a high level signal; and The second number of the values ​​including the second identifier in the first register is determined as the number of times the first level signal is a low level signal.

6. The method according to any one of claims 2 to 5, characterized in that Detecting the zero-crossing moment of the motor according to the second level signal includes: The first moment when the detected second level signal is converted from a high level signal to a low level signal, or the second moment when the detected second level signal is converted from a low level signal to a high level signal, is determined as the zero-crossing moment of the motor.

7. The method according to claim 5, characterized in that Determining a first detection delay time based on the number of bits of the first register and a first detection frequency; The first detection delay time is used to indicate the time interval between the third moment when the zero crossing occurs and the zero crossing moment when the zero crossing is detected.

8. The method according to claim 7, characterized in that The conduction time of the second conduction phase is shorter than the conduction time of the first conduction phase; or, The duty cycle of the second conduction phase is greater than the duty cycle of the first conduction phase.

9. The method according to any one of claims 8, characterized in that The method further comprises: Determine when the zero-crossing point is detected continuously for a predetermined number of times, delay for a third time period, and switch the first conduction phase of the motor to a third conduction phase.

10. The method according to claim 9, characterized in that The third duration is determined by: The third duration is calculated according to the on-time of the current phase and the first detection delay time.

11. The method according to claim 2, characterized in that The first voltage signal and the second voltage signal generated when the motor rotates in a predetermined commutation sequence are collected, including: The motor is started based on a first duty cycle and is caused to rotate in a predetermined commutation sequence.

12. A motor starting device, characterized in that: include: Sampling module, smoothing module, control module; among them, The sampling module is used to collect the first voltage signal and the second voltage signal generated when the motor rotates; The smoothing module is used to obtain a first level signal according to the first voltage signal and the second voltage signal; the first level signal is a low level signal or a high level signal; and is used to output a second level signal based on the stored number of times that the first level signal is a high level signal and a low level signal; The control module is used to detect the zero-crossing moment of the motor according to the second level signal; and is used to switch the first conduction phase of the motor to the second conduction phase based on the zero-crossing moment.

13. The device according to claim 12, characterized in that The device also includes: a reversal detection module; Wherein, the reversal detection module is used to make the motor rotate in a predetermined commutation sequence.

14. An electronic device, characterized in that: include: One or more processors; one or more memories; wherein, The one or more memories store one or more programs, and when the one or more programs are executed by the one or more processors, the electronic device executes the motor starting method according to any one of claims 1 to 11.

15. A readable medium, characterized in that The readable medium stores instructions, and when the instructions are executed by an electronic device, the electronic device executes the motor starting method according to any one of claims 1 to 11.

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