Pre-charging control method, device, equipment and storage medium for a fan motor

Abstract

The present application relates to a pre-charging control method, apparatus, computer equipment, storage medium, and computer program product for a fan motor. The method comprises: obtaining first sampled current data collected when a lower bridge arm switch in any one of the three-phase circuits of the fan motor is turned on; determining the current operating state of the fan based on the first sampled current data; if the operating state is rotational, determining the target phase corresponding to the lowest potential in the three-phase circuit based on the first sampled current data; and controlling the bootstrap capacitor of the circuit corresponding to the target phase to initiate pre-charging. This method can effectively improve the safety of the fan motor during pre-charging.

Description

Technical Field

[0001] The present application relates to the field of air conditioning control technology, and in particular to a pre-charging control method, device, computer equipment, storage medium and computer program product for a fan motor. Background Art

[0002] A fan motor is an electromagnetic device that uses the law of electromagnetic induction to achieve electrical energy conversion or transmission. Due to its excellent control performance and ability to realize various circuit functions, fan motors are widely used in air-conditioning outdoor fans.

[0003] In traditional technology, before the air-conditioning fan starts, the three bootstrap capacitors on the upper arm of the IPM module need to be pre-charged before the six-channel PWM modulation waveform is output to form a voltage difference. Since the air-conditioning fan is generally located outdoors, under the action of external wind, the fan motor rotor is likely to not be fixed and stationary at startup, and the fan will rotate under the action of the wind. At this time, if the bootstrap capacitor of the fan motor is pre-charged, it is easy for a braking current to be generated inside the fan motor due to the rotation of the fan. After charging is completed, the generated voltage generated by the rapid discharge of the inductor will be backflowed to the bus, causing false triggering of overvoltage protection and even loss of the fan drive power module. Summary of the Invention

[0004] Based on this, it is necessary to provide a pre-charging control method, device, computer equipment, computer-readable storage medium and computer program product for a fan motor that can improve the safety of the fan motor operation in order to address the above technical problems.

[0005] In a first aspect, the present application provides a pre-charging control method for a fan motor. The method comprises:

[0006] Acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on;

[0007] determining a current operating state of the wind turbine according to the first sampled current data;

[0008] If the operating state is a rotating state, determining a target phase corresponding to a lowest potential in the three-phase circuit according to the first sampled current data;

[0009] The bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging.

[0010] In one embodiment,

[0011] The determining, according to the first sampled current data, a target phase corresponding to the lowest potential in the three-phase circuit includes:

[0012] determining a rotation direction of the fan and a reference phase corresponding to a highest potential in the three-phase circuit according to the first sampled current data;

[0013] Based on the rotation direction and the reference phase, a target phase corresponding to the lowest potential in the three-phase circuit is determined.

[0014] In one embodiment, the method further comprises:

[0015] Acquiring second sampled current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged;

[0016] monitoring a potential change of each phase in the three-phase circuit according to the second sampled current data;

[0017] When it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

[0018] In one embodiment, the method further comprises:

[0019] determining, according to the second sampled current data, a phase corresponding to a lowest potential after the potential of the three-phase circuit changes;

[0020] Updating the phase corresponding to the lowest potential after the potential change of the three-phase circuit as the target phase;

[0021] The bootstrap capacitor of the target phase corresponding circuit is controlled to be pre-charged.

[0022] In one embodiment, determining the current operating state of the wind turbine according to the first sampled current data includes:

[0023] Determine a sampling current value corresponding to the three-phase circuit within a preset time period according to the first sampling current data;

[0024] If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the fan is a rotating state;

[0025] If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

[0026] In one embodiment, the method further comprises:

[0027] If the operating state is a stationary state, the three lower bridge arm switches of the three-phase circuit are controlled to be turned on simultaneously to pre-charge the bootstrap capacitor corresponding to the three-phase circuit.

[0028] In one embodiment, the method further comprises:

[0029] Recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit;

[0030] When the accumulated pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

[0031] In a second aspect, the present application further provides a pre-charging control device for a fan motor. The device comprises:

[0032] A data acquisition module, configured to acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on;

[0033] An operating state determining module, configured to determine a current operating state of the wind turbine according to the first sampled current data;

[0034] a target phase determination module, configured to determine, if the operating state is a rotational state, a target phase corresponding to a lowest potential in the three-phase circuit according to the first sampled current data;

[0035] The pre-charging module is used to control the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging.

[0036] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0037] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor.

[0038] In a fifth aspect, the present application further provides a computer program product, which includes a computer program that implements the steps of the above method when executed by a processor.

[0039] The above-mentioned pre-charging control method, device, computer equipment, storage medium and computer program product of the fan motor obtains the first sampled current data of the three-phase circuit when any lower bridge arm switch in the three-phase circuit of the fan motor is turned on, and determines the operating state of the fan loaded by the fan motor based on the first sampled current data. When the operating state of the fan is the rotation state, if the bootstrap capacitor of the three-phase circuit is directly pre-charged, it is easy to affect the operating safety of the fan motor. The target phase corresponding to the lowest potential in the three-phase circuit is determined based on the first sampled current data. Since current can only flow from high potential to low potential, when the potential of the target phase is the lowest, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging, which can ensure that the fan motor always maintains a zero current state during the pre-charging process, avoiding the formation of braking current inside the fan motor. After charging is completed, it will not cause the generated voltage to flow back into the bus, effectively improving the operating safety of the fan motor during pre-charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 FIG. 1 is an application environment diagram of a pre-charging control method for a fan motor according to an embodiment;

[0041] Figure 2 1 is a flow chart of a pre-charging control method for a fan motor according to an embodiment;

[0042] Figure 3 1 is a three-phase current phase diagram when the fan rotates with the wind in one embodiment;

[0043] Figure 4 A three-phase current phase diagram when the fan rotates against the wind in one embodiment;

[0044] Figure 5 A schematic diagram of the current flow inside the motor in one embodiment;

[0045] Figure 6 Another schematic diagram of the current flow inside a motor according to an embodiment;

[0046] Figure 7 Another schematic diagram of the current flow inside a motor according to an embodiment;

[0047] Figure 8 1 is a flow chart of a pre-charging control method for a fan motor in another embodiment;

[0048] Figure 9 1 is a flow chart of a pre-charging control method for a fan motor in another embodiment;

[0049] Figure 10 1 is a flow chart of the steps of determining the current operating state of the wind turbine according to the first sampled current data in one embodiment;

[0050] Figure 11 1 is a flow chart of a pre-charging control method for a fan motor in another embodiment;

[0051] Figure 12 PWM input waveform diagram of three-way switch tubes in the lower bridge arm in one embodiment;

[0052] Figure 13 is a structural block diagram of a pre-charging control device for a fan motor in one embodiment;

[0053] Figure 14 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0055] Three-resistor sampling motor inverter control circuit Figure 1 As shown in the figure, the circuit contains three phases, with each phase divided into an upper bridge arm and a lower bridge arm. For example, V1 and V4 in the figure correspond to the upper and lower bridge arms of the U-phase circuit, V3 and V6 correspond to the upper and lower bridge arms of the V-phase circuit, and V5 and V2 correspond to the upper and lower bridge arms of the W-phase circuit. The upper and lower arms of the same phase (i.e., the same half-bridge) conduct electricity alternately, with the conduction angle of each phase differing by 120°. Resistors R1, R2, and R3 are sampling resistors in the lower bridge arm of the three-phase circuit.

[0056] Taking the fan motor of an air conditioner as an example, before the air conditioner fan starts, the upper bridge arm of the circuit cannot be directly turned on. The three bootstrap capacitors of the upper bridge arm need to be pre-charged before the six-way PWM modulation waveform is output. The voltage is raised by pre-charging the bootstrap capacitors, causing a voltage difference, and then the circuit is turned on. The traditional pre-charging method is to control the three switching tubes of the lower bridge arm of the IPM module to be turned on at the same time for a certain period of time, or to pre-charge the three tubes in sequence for a certain period of time. However, if the fan rotates with or without wind under the action of external wind, the traditional pre-charging method will form a braking current inside the motor. The higher the speed, the greater the current, and a certain amount of heat will be generated inside the motor. After charging is completed, the generated voltage will be backflowed to the busbar. The higher the speed of the forward and backward wind, the greater the backflow voltage, which will mistakenly trigger the overvoltage protection and even cause damage to the fan drive power module.

[0057] Based on this, the pre-charging control method of the fan motor provided in the embodiment of the present application can be applied to Figure 1In the three-resistance sampling motor inverter control circuit shown in the figure. The controller in the circuit (not shown in the figure) obtains the first sampled current data collected when the lower bridge arm switch of any one of the three-phase circuits of the fan motor is turned on through the acquisition circuit (not shown in the figure), determines the current operating state of the fan based on the first sampled current data, and if the operating state is the rotation state, determines the target phase corresponding to the lowest potential in the three-phase circuit based on the first sampled current data, and controls the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging. Among them, the controller can be a single-chip microcomputer or any control chip that can perform data processing.

[0058] In one embodiment, Figure 2 As shown, a pre-charge control method for a fan motor is provided, and the method is applied to Figure 1 The three-resistor sampling motor inverter control circuit in the example is used to illustrate, including the following steps:

[0059] Step 202 : obtaining first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on.

[0060] The first sampled current data is current data flowing through each phase circuit collected by the sampling circuit when any lower arm switch in the three-phase circuit is turned on.

[0061] Specifically, when the fan rotates under external force, it becomes a power source. When the controller turns on any lower bridge arm in the three-phase circuit, a circuit is formed inside the motor, generating current. The voltage and current waveforms generated inside the motor are 120° out of phase. The controller obtains the current data flowing through each phase of the three-phase circuit obtained by the acquisition circuit at this time, generating first sampled current data.

[0062] Step 204: Determine the current operating state of the wind turbine according to the first sampled current data.

[0063] Specifically, because the first sampled current data is collected by the acquisition circuit when any lower bridge arm in the three-phase circuit is conducting, if the first sampled current data indicates that current is flowing through each phase circuit in the three-phase circuit, the current operating state of the fan can be determined based on the current flowing through each phase circuit. It will be understood that the operating state of the fan includes a rotating state and a stationary state.

[0064] Step 206: If the operating state is the rotation state, determine the target phase corresponding to the lowest potential in the three-phase circuit according to the first sampled current data.

[0065] Among them, when the fan is in the rotating state, a current loop is formed inside the motor, and the highest potential in the three-phase circuit inside the motor changes periodically. Taking the phase corresponding to the initial highest potential as the U phase as an example, the order of change of the highest potential of the three phases inside the motor is UVWUV, or UWVUW. Correspondingly, the lowest potential inside the circuit will also change periodically. According to the sampled current of each phase circuit in the three-phase circuit, the phase circuit corresponding to the lowest potential in the three-phase circuit can be determined.

[0066] Specifically, the controller determines the absolute value and polarity of the current in each phase circuit based on the collected first sampled current data, and determines the target phase corresponding to the lowest potential in the three-phase circuit based on the absolute value and polarity of the current in each phase current.

[0067] Step 208 : Control the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging.

[0068] Specifically, when the target phase corresponding to the lowest potential in the three-phase circuit is determined, the controller controls the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging.

[0069] In the above-mentioned pre-charging control method of the fan motor, when any lower bridge arm switch in the three-phase circuit of the fan motor is turned on, the first sampled current data of the three-phase circuit is obtained, and the operating state of the fan of the load fan motor is determined based on the first sampled current data. When the operating state of the fan is the rotation state, if the bootstrap capacitor of the three-phase circuit is directly pre-charged, it is easy to affect the operating safety of the fan motor. The target phase corresponding to the lowest potential in the three-phase circuit is determined based on the first sampled current data. Since the current can only flow from high potential to low potential, when the potential of the target phase is the lowest, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging, which can ensure that the fan motor always maintains a zero current state during the pre-charging process, avoiding the formation of braking current inside the fan motor. After charging is completed, it will not cause the generated voltage to flow back into the bus, effectively improving the operating safety of the fan motor during pre-charging.

[0070] Since there are two orders of changes in the highest three-phase potential inside the motor, in one embodiment, the target phase corresponding to the lowest potential in the three-phase circuit is determined based on the first sampled current data, including: determining the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit based on the first sampled current data; and determining the target phase corresponding to the lowest potential in the three-phase circuit based on the rotation direction and the reference phase.

[0071] The fan has two rotation directions: with the wind and against the wind. The fan's rotation direction can be determined based on the magnitude and polarity of the current flowing through each phase circuit.

[0072] by Figure 1 Take the middle lower arm switch V4 as an example. When the lower arm switch V4 is turned on, if the fan rotates forward or reverse due to changes in the external airflow, a loop will be formed inside the motor to generate current. The voltage / current waveforms generated inside the motor have a phase difference of 120 degrees. The three-phase current phase diagram when the fan rotates with the wind is as follows: Figure 3 As shown, the three-phase current phase diagram when rotating against the wind is as follows Figure 4 As shown. The internal current of the motor will have the following three situations:

[0073] The first one, such as Figure 5 As shown, the internal current of the motor flows out from the U phase and flows into the V and W phases. At this time, the U phase potential is the highest, and the V and W phase potentials are at medium and low levels.

[0074] The second type, such as Figure 6 As shown, the internal current of the motor flows out from the U phase and flows into the V phase. At this time, the U phase is at a medium potential, the V phase is at a low potential, and the W phase is at a high potential. If the W phase is at a low potential and the V phase is at a high potential, the situation is similar.

[0075] The third is the ideal situation, such as Figure 7 As shown, the U phase is at a low potential, no potential difference can be formed, and no current is generated inside the motor.

[0076] Therefore, the controller can determine the potential of phase U based on the first sampled current data. If it is at a medium potential, the controller waits for phase U to enter the medium potential and then determines whether phase V is at a high potential. If so, the fan is considered to be rotating with the wind, and the potential change sequence is UVWUV. If not, the fan is considered to be rotating against the wind, and the potential change sequence is UWVUW.

[0077] Based on the reference phase corresponding to the highest potential and the fan's rotation direction, the phase corresponding to the lowest potential in the three-phase circuit can be determined. For example, when the fan rotates with the wind and phase U is the highest phase, the lowest potential is phase W. When the fan rotates against the wind and phase U is the highest phase, the lowest potential is phase V.

[0078] Specifically, the controller determines the absolute value and polarity of the sampled current of each phase in the three-phase circuit based on the first sampled current data. The controller then determines the reference phase corresponding to the highest potential in the three-phase circuit and the direction of fan rotation based on the absolute value and polarity of the sampled current of each phase. The controller also determines the order of potential changes based on the fan rotation direction. Based on the order of potential changes and the reference phase, the controller determines the target phase corresponding to the lowest potential in the three-phase circuit.

[0079] In this embodiment, the motor controller determines the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit based on the first sampled current data, and determines the target phase corresponding to the lowest potential in the three-phase circuit based on the rotation direction and the reference phase. The entire judgment process does not require the use of redundant hardware facilities. Instead, a simple software judgment logic is designed in advance on the controller. According to the judgment logic and the collected sampled current data, the rotation direction of the fan and the phase corresponding to the highest potential can be determined, and based on this, the target phase corresponding to the lowest potential can be obtained, which effectively reduces the cost required to determine the target phase corresponding to the lowest potential and improves the accuracy of the target phase determination.

[0080] Since the potential of the internal circuit changes periodically when the motor forms a loop, the potential of the bootstrap capacitor of the target phase corresponding circuit is very likely to change during pre-charging. Based on this, in one embodiment, Figure 8 As shown, the pre-charging control method of the fan motor also includes the following steps:

[0081] Step 802 : Acquire second sampled current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged.

[0082] The second sampled current data is current data flowing through each phase circuit, which is collected by the sampling circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged.

[0083] Specifically, the motor controller obtains the current data flowing through each phase circuit in the three-phase circuit collected by the sampling circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged, thereby obtaining the second sampled current data.

[0084] Step 804 : monitor the potential change of each phase in the three-phase circuit according to the second sampled current data.

[0085] Specifically, the motor controller determines the potential change of each phase in the three-phase circuit based on the second sampled current data. The potential determination scheme of each phase is basically consistent with the method of determining the reference phase corresponding to the highest potential in the previous embodiment, and will not be repeated here.

[0086] Step 806 : When it is detected that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

[0087] Specifically, when the motor controller detects a change in the potential in the three-phase circuit based on the second sampled current data, it indicates that the potential corresponding to the target phase has changed and is no longer at the lowest potential. Current will flow through the circuit. Continuing to pre-charge the bootstrap capacitor in the circuit corresponding to the target phase can easily generate excessive braking current and heat, exposing the motor to a higher risk of operational failure. Therefore, when the motor controller detects a change in the potential in the three-phase circuit, it controls the bootstrap capacitor in the circuit corresponding to the target phase to stop pre-charging, preventing the formation of braking current within the fan motor and effectively improving the safety of the fan motor during pre-charging.

[0088] When the potential changes, the motor controller needs to find the phase corresponding to the current lowest potential as the target phase and perform pre-charging. Figure 9 As shown, the pre-charging control method of the fan motor also includes the following steps:

[0089] Step 902: Determine the phase corresponding to the lowest potential after the potential of the three-phase circuit changes based on the second sampled current data.

[0090] Specifically, the motor controller determines the absolute value and polarity of the sampling current of each phase circuit during pre-charging of the three-phase circuit based on the second sampling current, determines the second reference phase corresponding to the highest potential in the three-phase circuit and the current rotation direction of the fan based on the absolute value and polarity of the sampling current of each phase circuit, and determines the phase corresponding to the lowest potential after the three-phase potential changes based on the second reference phase and the rotation direction of the fan.

[0091] Step 904: Update the phase corresponding to the lowest potential after the potential change of the three-phase circuit as the target phase.

[0092] Specifically, after the motor controller determines the phase corresponding to the lowest potential after the three-phase potential changes, it updates the phase corresponding to the current lowest potential to the target phase.

[0093] Step 906 , controlling the bootstrap capacitor of the circuit corresponding to the target phase to pre-charge.

[0094] Specifically, since the target phase has been updated to the phase corresponding to the lowest potential in the current three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to be pre-charged, which can ensure that the fan motor always maintains a zero current state during the pre-charging process, avoiding the formation of braking current inside the fan motor. After charging is completed, the generated voltage will not be backflowed into the bus, which effectively improves the safety of the fan motor during pre-charging.

[0095] In order to avoid interference of noise signals in the circuit or signals generated by slow rotation of the fan on the judgment of the fan operation status, in one embodiment, as Figure 10As shown, determining the current operating state of the wind turbine according to the first sampled current data includes:

[0096] Step 1002: Determine a sampled current value corresponding to a three-phase circuit within a preset time period according to the first sampled current data.

[0097] The preset time period is a time range pre-set according to the voltage / current generation cycle. It is understood that the specific value of the preset time period is related to the speed range of the fan in the wind direction or the wind direction. For example, the preset time period can be 100ms.

[0098] Specifically, the motor controller determines the sampled current values corresponding to the three-phase circuit within a preset time period based on the first sampled current data, and the sampled current values corresponding to the three-phase current within the preset time period include the current values of the entire cycle of generating voltage / current.

[0099] Step 1004: If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the wind turbine is a rotating state.

[0100] The preset current threshold is the minimum current threshold that indicates whether the fan is rotating. The preset current threshold is obtained by designers based on empirical data. For example, the preset current threshold may be 50 mA.

[0101] Specifically, if the controller determines that the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it means that the current value collected by the sampling circuit at this time is not generated by noise in the circuit or the fan rotating at a slower speed, but is generated by the fan rotating under the action of external wind force. The controller determines that the current operating state of the fan is the rotating state.

[0102] Step 1006: If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

[0103] Specifically, if the controller determines that the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it means that the current value collected by the sampling circuit at this time is generated by the noise in the circuit or the fan rotating at a slower speed, but is not generated by the fan rotating under the action of external wind force. The controller determines that the current operating state of the fan is stationary.

[0104] In this embodiment, the controller determines the operating status of the fan by judging whether the sampled current collected by the sampling circuit within a preset time period reaches a preset current threshold, effectively avoiding the interference of the noise signal in the circuit or the signal generated by the slow rotation of the fan on the judgment of the fan operating status, thereby improving the accuracy of the judgment of the fan operating status.

[0105] When the fan is in a stationary state, in one embodiment, the pre-charging control method of the fan motor further includes: if the operating state is a stationary state, controlling the three lower bridge arm switches of the three-phase circuit to be turned on at the same time to pre-charge the bootstrap capacitor corresponding to the three-phase circuit.

[0106] Specifically, when the controller determines that the fan is in a stationary state, the fan itself will not form a power supply, that is, no circuit will be formed inside the motor. At this time, it is safe to pre-charge the bootstrap capacitor corresponding to any phase circuit in the three-phase circuit. Therefore, the controller controls the three lower bridge arm switches in the three-phase circuit to be turned on at the same time to pre-charge the bootstrap capacitor corresponding to the three-phase circuit.

[0107] In this embodiment, by pre-judging that the fan is in a stationary state and then pre-charging the bootstrap capacitors corresponding to the three-phase circuits, it can be ensured that the fan motor always maintains a zero current state during the pre-charging process, avoiding the formation of braking current inside the fan motor. After charging is completed, the generated voltage will not flow back into the bus, effectively improving the safety of the fan motor during pre-charging.

[0108] Since the pre-charging time of the bootstrap capacitor cannot be too long, it is necessary to stop the pre-charging immediately after the pre-charging is completed. Therefore, in one embodiment, the pre-charging control method for the fan motor further includes: recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit; when the accumulated pre-charging time of each phase circuit reaches a preset time threshold, controlling the bootstrap capacitor corresponding to each phase circuit to stop pre-charging.

[0109] The preset time threshold is a time threshold for indicating the completion of precharging the bootstrap capacitor. It is understood that the specific value of the preset time threshold is determined based on the actual situation of the circuit, and the preset time threshold is pre-stored in the controller's database for easy access at any time.

[0110] Specifically, when the controller controls the pre-charging of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit, it needs to record the pre-charging time corresponding to each phase circuit in real time, determine the cumulative pre-charging time of the bootstrap capacitor corresponding to each phase circuit based on the recorded pre-charging time corresponding to each phase circuit, and compare the cumulative pre-charging time with the preset time threshold. When the cumulative pre-charging time of each phase circuit reaches the preset time threshold, it means that the pre-charging of the bootstrap capacitor corresponding to the phase circuit is completed, and the controller controls the bootstrap capacitor to end pre-charging.

[0111] In one of the embodiments, if the controller is controlling the pre-charging of the bootstrap capacitor corresponding to any one of the three-phase circuits, and the pre-charging process stops due to a change in potential, the controller will record the charging time of the bootstrap capacitor corresponding to the circuit for this pre-charging. When the bootstrap capacitor corresponding to the circuit is pre-charged next time, the recorded charging time will be superimposed with the charging time recorded this time to obtain the cumulative pre-charging time of the bootstrap capacitor corresponding to the phase circuit. When the cumulative pre-charging time of the bootstrap capacitor corresponding to the phase circuit reaches a preset time threshold, the controller controls the bootstrap capacitor to end pre-charging.

[0112] In the above embodiment, by comparing the cumulative pre-charging time recorded when the bootstrap capacitor corresponding to each phase circuit is pre-charged with the preset time threshold, when the cumulative pre-charging time of each phase circuit reaches the preset time threshold, the controller controls the bootstrap capacitor to end pre-charging, which can effectively ensure the safety of the bootstrap capacitor during pre-charging and avoid malfunction of the bootstrap capacitor or the charging circuit due to too long pre-charging time.

[0113] In one embodiment, Figure 11 As shown, a control method for pre-charging a fan motor is provided, and the method is applied to Figure 1 The three-resistor sampling motor inverter control circuit is used as an example to illustrate.

[0114] First, the motor controller receives the fan start command, controls the U-phase lower bridge V4 to open, and obtains the first sampling current data through the sampling circuit. The first sampling current data includes the three-phase current I corresponding to the three-phase circuit. u , I v and I w .

[0115] The controller determines whether the three-phase currents have reached the preset current threshold value I according to the first sampling current data. min If the time is not reached, the fan is determined to be in a stationary state. The controller controls the three lower bridge arm switches of the three-phase circuit to turn on simultaneously to pre-charge the corresponding bootstrap capacitors of the three-phase circuit. The pre-charge time corresponding to each bootstrap capacitor is recorded. When the pre-charge time corresponding to each bootstrap capacitor reaches the preset time threshold, the pre-charge of each bootstrap capacitor is determined to be complete, and the pre-charge of each bootstrap capacitor is controlled to end, and the fan enters the pre-start state.

[0116] If the three-phase currents all reach the preset current threshold, the current state of the fan is determined to be the rotation state. The controller determines the current polarity and absolute value of each of the three-phase currents based on the first sampled current data, and determines the phase corresponding to the lowest potential point in the three-phase circuit based on the respective current polarity and absolute value. If the U phase is the lowest potential point, V4 is kept open and the pre-charge time T of the bootstrap capacitor of this circuit is recorded. uIf the V phase is at the lowest potential point, keep V6 open and record the pre-charge time T of the bootstrap capacitor. v If the W phase is at the lowest potential point, keep V2 open and record the pre-charge time T of the bootstrap capacitor. w The PWM input waveform of the three-way switch tube of the lower bridge arm is as follows Figure 12 shown.

[0117] The controller simultaneously monitors whether the charging time of the bootstrap capacitors corresponding to the three-phase circuits has reached the set time value T. If so, charging is complete, the pre-charging of each bootstrap capacitor ends, and the wind turbine enters the pre-start state. If not, the controller continues to evaluate the three-phase circuit, determining the target phase corresponding to the lowest potential in the circuit, controlling the bootstrap capacitor corresponding to the target phase to pre-charge and recording the pre-charge time.

[0118] The control method for pre-charging the fan motor in this embodiment can effectively avoid the situation where the speed of the wind and headwind is too high during the pre-charging process, resulting in excessive energy feedback to the bus. At the same time, it can ensure that the pre-charging process always maintains zero current inside the motor, and will not generate excessive braking current and heat, thereby effectively improving the safety of the fan motor during pre-charging.

[0119] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0120] Based on the same inventive concept, embodiments of the present application further provide a pre-charging control device for a fan motor for implementing the aforementioned pre-charging control method for a fan motor. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the pre-charging control device for a fan motor provided below can be found in the above-described limitations of the pre-charging control method for a fan motor, and will not be further elaborated here.

[0121] In one embodiment, Figure 13As shown, a pre-charging control device 1300 for a fan motor is provided, comprising: a data acquisition module 1301, an operating state determination module 1302, a target phase determination module 1303 and a pre-charging module 1304, wherein:

[0122] The data acquisition module 1301 is used to acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on.

[0123] The operating state determining module 1302 is configured to determine the current operating state of the wind turbine according to the first sampled current data.

[0124] The target phase determination module 1303 is configured to determine the target phase corresponding to the lowest potential in the three-phase circuit according to the first sampled current data if the operating state is the rotation state.

[0125] The pre-charging module 1304 controls the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging.

[0126] The above-mentioned pre-charging control device of the fan motor obtains the first sampled current data of the three-phase circuit when any lower bridge arm switch in the three-phase circuit of the fan motor is turned on, and determines the operating state of the fan of the load fan motor based on the first sampled current data. When the operating state of the fan is the rotation state, if the bootstrap capacitor of the three-phase circuit is directly pre-charged, it is easy to affect the operating safety of the fan motor. The target phase corresponding to the lowest potential in the three-phase circuit is determined based on the first sampled current data. Since the current can only flow from high potential to low potential, when the potential of the target phase is the lowest, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging, which can ensure that the fan motor always maintains a zero current state during the pre-charging process, avoiding the formation of braking current inside the fan motor. After charging is completed, it will not cause the generated voltage to flow back into the bus, effectively improving the operating safety of the fan motor during pre-charging.

[0127] In one embodiment, the target phase determination module is also used to determine the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit based on the first sampled current data; based on the rotation direction and the reference phase, determine the target phase corresponding to the lowest potential in the three-phase circuit.

[0128] In one embodiment, the pre-charging control device of the fan motor also includes: a potential change monitoring module, which is used to obtain the second sampling current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged; monitor the potential changes of each phase in the three-phase circuit according to the second sampling current data; when it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, control the bootstrap capacitor of the circuit corresponding to the target phase to stop pre-charging.

[0129] In one embodiment, the pre-charging control device of the fan motor also includes: a target phase update module, which is used to determine the phase corresponding to the lowest potential after the three-phase circuit potential changes based on the second sampling current data; update the phase corresponding to the lowest potential after the three-phase circuit potential changes to the target phase; and control the bootstrap capacitor of the circuit corresponding to the target phase to pre-charge.

[0130] In one embodiment, the operating status determination module is also used to determine the sampling current values corresponding to the three-phase circuit within a preset time period based on the first sampling current data; if the sampling current values corresponding to the three-phase circuit all reach the preset current threshold, it is determined that the current operating status of the fan is a rotating state; if the sampling current values corresponding to the three-phase circuit do not reach the preset current threshold, it is determined that the current operating status of the fan is a stationary state.

[0131] In one embodiment, the pre-charging control device of the fan motor also includes: a static pre-charging module, which is used to control the three lower bridge arm switches of the three-phase circuit to be turned on at the same time if the operating state is a static state, so as to pre-charge the bootstrap capacitor corresponding to the three-phase circuit.

[0132] In one embodiment, the pre-charging control device of the fan motor also includes: a pre-charging time recording module, which is used to record the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit; when the cumulative pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

[0133] Each module in the aforementioned pre-charging control device for a fan motor may be implemented in whole or in part via software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor in a computer device in hardware form, or may be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0134] In one embodiment, a computer device is provided. The computer device may be a motor controller, and its internal structure diagram may be as follows: Figure 14 As shown. The computer device includes a processor, a memory and a network interface connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data such as the first sampled current and the operating status of the fan. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a pre-charging control method for a fan motor is implemented.

[0135] Those skilled in the art will understand that Figure 14 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0136] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0137] Acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on;

[0138] Determining a current operating state of the wind turbine according to the first sampled current data;

[0139] If the operating state is the rotation state, determining the target phase corresponding to the lowest potential in the three-phase circuit according to the first sampled current data;

[0140] The bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging.

[0141] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0142] Determining the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit according to the first sampled current data;

[0143] Based on the rotation direction and the reference phase, the target phase corresponding to the lowest potential in the three-phase circuit is determined.

[0144] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0145] Acquire second sampling current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged;

[0146] monitoring a potential change of each phase in the three-phase circuit according to the second sampled current data;

[0147] When it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

[0148] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0149] determining the phase corresponding to the lowest potential after the potential of the three-phase circuit changes according to the second sampled current data;

[0150] The phase corresponding to the lowest potential after the potential change of the three-phase circuit is updated as the target phase;

[0151] The bootstrap capacitor of the target phase corresponding circuit is pre-charged.

[0152] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0153] Determine a sampling current value corresponding to the three-phase circuit within a preset time period according to the first sampling current data;

[0154] If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the fan is the rotation state;

[0155] If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

[0156] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0157] If the operating state is a stationary state, the three lower bridge arm switches of the three-phase circuit are controlled to be turned on at the same time to pre-charge the bootstrap capacitors corresponding to the three-phase circuit.

[0158] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0159] Recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit;

[0160] When the accumulated pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

[0161] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0162] Acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on;

[0163] Determining a current operating state of the wind turbine according to the first sampled current data;

[0164] If the operating state is the rotation state, determining the target phase corresponding to the lowest potential in the three-phase circuit according to the first sampled current data;

[0165] The bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging.

[0166] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0167] Determining the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit according to the first sampled current data;

[0168] Based on the rotation direction and the reference phase, the target phase corresponding to the lowest potential in the three-phase circuit is determined.

[0169] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0170] Acquire second sampling current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged;

[0171] monitoring a potential change of each phase in the three-phase circuit according to the second sampled current data;

[0172] When it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

[0173] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0174] determining the phase corresponding to the lowest potential after the potential of the three-phase circuit changes according to the second sampled current data;

[0175] The phase corresponding to the lowest potential after the potential change of the three-phase circuit is updated as the target phase;

[0176] The bootstrap capacitor of the target phase corresponding circuit is pre-charged.

[0177] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0178] Determine a sampling current value corresponding to the three-phase circuit within a preset time period according to the first sampling current data;

[0179] If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the fan is the rotation state;

[0180] If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

[0181] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0182] If the operating state is a stationary state, the three lower bridge arm switches of the three-phase circuit are controlled to be turned on at the same time to pre-charge the bootstrap capacitors corresponding to the three-phase circuit.

[0183] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0184] Recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit;

[0185] When the accumulated pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

[0186] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0187] Acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on;

[0188] Determining a current operating state of the wind turbine according to the first sampled current data;

[0189] If the operating state is the rotation state, determining the target phase corresponding to the lowest potential in the three-phase circuit according to the first sampled current data;

[0190] The bootstrap capacitor of the circuit corresponding to the target phase is controlled to start pre-charging.

[0191] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0192] Determining the rotation direction of the fan and the reference phase corresponding to the highest potential in the three-phase circuit according to the first sampled current data;

[0193] Based on the rotation direction and the reference phase, the target phase corresponding to the lowest potential in the three-phase circuit is determined.

[0194] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0195] Acquire second sampling current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged;

[0196] monitoring a potential change of each phase in the three-phase circuit according to the second sampled current data;

[0197] When it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

[0198] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0199] determining the phase corresponding to the lowest potential after the potential of the three-phase circuit changes according to the second sampled current data;

[0200] The phase corresponding to the lowest potential after the potential change of the three-phase circuit is updated as the target phase;

[0201] The bootstrap capacitor of the target phase corresponding circuit is pre-charged.

[0202] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0203] Determine a sampling current value corresponding to the three-phase circuit within a preset time period according to the first sampling current data;

[0204] If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the fan is the rotation state;

[0205] If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

[0206] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0207] If the operating state is a stationary state, the three lower bridge arm switches of the three-phase circuit are controlled to be turned on at the same time to pre-charge the bootstrap capacitors corresponding to the three-phase circuit.

[0208] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0209] Recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit;

[0210] When the accumulated pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

[0211] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0212] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0213] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0214] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A pre-charging control method for a fan motor, characterized in that: The method comprises: Acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on; determining a current operating state of the wind turbine according to the first sampled current data; If the operating state is a rotating state, determining a target phase corresponding to a lowest potential in the three-phase circuit according to the first sampled current data; Controlling the bootstrap capacitor of the target phase corresponding circuit to start pre-charging; the target phase corresponding circuit is the phase circuit corresponding to the lowest potential in the three-phase circuit.

2. The method according to claim 1, characterized in that The determining, according to the first sampled current data, a target phase corresponding to the lowest potential in the three-phase circuit includes: determining a rotation direction of the fan and a reference phase corresponding to a highest potential in the three-phase circuit according to the first sampled current data; Based on the rotation direction and the reference phase, a target phase corresponding to the lowest potential in the three-phase circuit is determined.

3. The method according to claim 1, characterized in that The method further comprises: Acquiring second sampled current data of the three-phase circuit when the bootstrap capacitor of the circuit corresponding to the target phase is pre-charged; monitoring a potential change of each phase in the three-phase circuit according to the second sampled current data; When it is monitored that the potential corresponding to the target phase is not the lowest potential in the three-phase circuit, the bootstrap capacitor of the circuit corresponding to the target phase is controlled to stop pre-charging.

4. The method according to claim 3, characterized in that The method further comprises: determining, according to the second sampled current data, a phase corresponding to a lowest potential after the potential of the three-phase circuit changes; Updating the phase corresponding to the lowest potential after the potential change of the three-phase circuit as the target phase; The bootstrap capacitor of the target phase corresponding circuit is controlled to be pre-charged.

5. The method according to claim 1, characterized in that The determining the current operating state of the wind turbine according to the first sampled current data includes: Determine a sampling current value corresponding to the three-phase circuit within a preset time period according to the first sampling current data; If the sampled current values corresponding to the three-phase circuits all reach the preset current threshold, it is determined that the current operating state of the fan is a rotating state; If the sampled current value corresponding to the three-phase circuit does not reach the preset current threshold, it is determined that the current operating state of the wind turbine is a stationary state.

6. The method according to claim 5, characterized in that The method further comprises: If the operating state is a stationary state, the three lower bridge arm switches of the three-phase circuit are controlled to be turned on simultaneously to pre-charge the bootstrap capacitor corresponding to the three-phase circuit.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: Recording the pre-charging time of the bootstrap capacitor corresponding to each phase circuit in the three-phase circuit; When the accumulated pre-charging time of each phase circuit reaches a preset time threshold, the bootstrap capacitor corresponding to each phase circuit is controlled to end pre-charging.

8. A pre-charging control device for a fan motor, characterized in that: The device comprises: A data acquisition module, configured to acquire first sampled current data collected when a lower arm switch of any one of the three-phase circuits of the fan motor is turned on; An operating state determining module, configured to determine a current operating state of the wind turbine according to the first sampled current data; a target phase determination module, configured to determine, if the operating state is a rotational state, a target phase corresponding to a lowest potential in the three-phase circuit according to the first sampled current data; A pre-charging module is used to control the bootstrap capacitor of the circuit corresponding to the target phase to start pre-charging; the circuit corresponding to the target phase is the phase circuit corresponding to the lowest potential in the three-phase circuit.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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