Rotor position detection method, and downwind starting method and device

Abstract

The invention relates to the technical field of motor driving, discloses a rotor position detection method, and a downwind starting method and device, and solves the problems of current interference and signal confusion possibly generated by multi-phase simultaneous driving by adopting a mode of sequentially performing pulse driving on each phase of power tube and only driving one phase of lower tube to be switched on and switched off each time. According to the time-sharing driving strategy, the characteristics of each phase of current can be clearer and distinguishable, the detection difficulty is effectively reduced, the accuracy of negative bus current sampling is improved, and a reliable data foundation is laid for subsequent rotor position calculation. Meanwhile, under the condition that a back electromotive force detection device is not arranged, the position of the rotor can be calculated based on the sum value of the lasting time when the three-phase negative bus current is larger than the preset threshold value, and therefore the complexity and cost of hardware design are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motor drive, and particularly to a rotor position detection method, a downwind starting method and device. Background Art

[0002] In the context of the continuous development of motor drive and control technologies, accurately obtaining the rotor position and speed of a motor is crucial for achieving efficient and stable operation of the motor. Currently, a relatively common technical solution is to use a back electromotive force sampling circuit. By detecting the back electromotive force generated during the operation of the motor and calculating, the rotor position and speed information of the motor can be obtained, thereby providing a basis for precise control of the motor.

[0003] However, the existing motor control solutions based on back electromotive force sampling still have significant limitations. On the one hand, since the terminal voltage of the motor during operation can be as high as hundreds of volts, while the sampling signal input range of the microcontroller unit (MCU) is usually limited to 3.3V. To meet the requirements of electrical safety regulations (safety regulations), special processing must be carried out in the hardware design. This not only requires additional complex circuit modules such as level conversion and isolation for back electromotive force sampling, but also greatly increases the difficulty of printed circuit board (PCB) wiring design, increases the design cycle and development cost, and at the same time reduces the reliability and maintainability of the circuit. On the other hand, the additional back electromotive force sampling circuit module and related special processing hardware significantly increase the hardware cost of the entire motor control system, weaken the competitiveness of this technical solution in cost-sensitive application scenarios, and limit its further promotion and application. Therefore, it is urgent to explore new technical means or optimization schemes to solve the problems existing in the hardware complexity and cost of the existing back electromotive force sampling technology and promote the continuous progress of motor control technology. Summary of the Invention

[0004] In view of this, the present invention provides a rotor position detection method, a downwind starting method and device to solve the problem of how to achieve rotor position detection.

[0005] In a first aspect, the present invention provides a rotor position detection method. The motor is driven by a three-phase converter. The method includes: sequentially performing pulse driving on each phase power tube, driving only one phase of the lower tube to conduct and close each time, and keeping the remaining power tubes in the off state; based on the negative bus current during each pulse driving period, obtaining the duration when the negative bus current of each phase is greater than a preset threshold; calculating the rotor position based on the sum value of the durations when the negative bus currents of the three phases are greater than the preset threshold.

[0006] The present invention adopts a method of sequentially performing pulse driving on each phase of power tubes, driving only one phase of the lower tube to conduct and turn off each time, which avoids the problems of current interference and signal confusion that may occur during simultaneous driving of multiple phases. This time-sharing driving strategy can make the current characteristics of each phase clearer and more distinguishable, effectively reducing the detection difficulty, improving the accuracy of negative bus current sampling, and laying a reliable data foundation for subsequent rotor position calculation. At the same time, in the case where no back electromotive force detection device is provided, based on the sum of the durations when the negative bus currents of the three phases are greater than a preset threshold, the rotor position can be calculated, thereby reducing the complexity and cost of hardware design.

[0007] In an alternative embodiment, the process of sequentially performing pulse driving on each phase of power tubes includes: performing pulse driving on the lower tube of the U phase, and keeping the other power tubes in the off state; determining whether the negative bus current is greater than a preset threshold; if the negative bus current is greater than the preset threshold, recording the duration when the negative bus current is greater than the preset threshold; performing pulse driving on the lower tube of the V phase, and returning to the step of "determining whether the negative bus current is greater than a preset threshold" until the duration when the negative bus current is greater than the preset threshold is obtained; performing pulse driving on the lower tube of the W phase, and returning to the step of "determining whether the negative bus current is greater than a preset threshold" until the duration when the negative bus current is greater than the preset threshold is obtained.

[0008] In an alternative embodiment, the frequency of the pulse driving is 1k, and the duty cycle is 50%.

[0009] In an alternative embodiment, the process of calculating the rotor position includes: taking the sum of the durations when the negative bus currents of the three phases are greater than a preset threshold as an electrical cycle; calculating the electrical frequency based on the electrical cycle; and calculating the rotor position according to the electrical frequency.

[0010] In an alternative embodiment, before calculating the rotor position, it further includes: determining whether the deviation between the durations when the negative bus current of each phase is greater than a preset threshold is less than a preset difference; when the deviation between the durations when the negative bus current of each phase is greater than a preset threshold is less than the preset difference, calculating the rotor position based on the sum of the durations when the negative bus currents of the three phases are greater than a preset threshold.

[0011] In a second aspect, the present invention provides a downwind starting method, including: calculating the rotor position based on the rotor position detection method of the first aspect and any of its alternative embodiments; and achieving downwind starting based on the rotor position.

[0012] In a third aspect, the present invention provides a rotor position detection device, including: a pulse driving module, configured to sequentially perform pulse driving on each phase of power tubes, driving only one lower tube of one phase to conduct and turn off each time, and keeping the remaining power tubes in a turned-off state; a time calculation module, configured to obtain the duration when the negative bus current of each phase is greater than a preset threshold based on the negative bus current during each pulse driving; a position calculation module, configured to calculate the rotor position based on the sum of the durations when the negative bus currents of three phases are greater than the preset threshold.

[0013] In a fourth aspect, a downwind starting device of the present invention includes: a calculation module, configured to calculate the rotor position based on the rotor position detection method of the first aspect and any one of its optional embodiments; a starting module, configured to achieve downwind starting based on the rotor position.

[0014] In a fifth aspect, the present invention provides a computer device, including: a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the rotor position detection method of the first aspect or any one of its corresponding embodiments, or execute the downwind starting method of the second aspect.

[0015] In a sixth aspect, the present invention provides a computer-readable storage medium, on which computer instructions are stored. The computer instructions are used to cause a computer to execute the rotor position detection method of the first aspect or any one of its corresponding embodiments, or execute the downwind starting method of the second aspect.

[0016] In a seventh aspect, the present invention provides a computer program product, including computer instructions, which are used to cause a computer to execute the rotor position detection method of the first aspect or any one of its corresponding embodiments, or execute the downwind starting method of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 is a schematic diagram of a motor drive circuit according to an embodiment of the present invention;

[0019] Figure 2 is a flowchart of a rotor position detection method according to an embodiment of the present invention;

[0020] Figure 3It is the back electromotive force waveform diagram according to an embodiment of the present invention;

[0021] Figure 4 , Figure 5 They are all schematic diagrams of current flow directions according to an embodiment of the present invention;

[0022] Figure 6 It is a schematic flow chart of another rotor position detection method according to an embodiment of the present invention;

[0023] Figure 7 It is a schematic flow chart of another rotor position detection method according to an embodiment of the present invention;

[0024] Figure 8 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed implementation manners

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] According to an embodiment of the present invention, an embodiment of a rotor position detection method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0027] In this embodiment, a rotor position detection method is provided, which can be used in the above-mentioned mobile terminals, such as mobile phones, tablet computers, etc. As Figure 1 shown, the motor is driven by a three-phase converter. As Figure 2 shown, the rotor position detection method includes the following steps:

[0028] Step S1: Pulse drive each phase power tube in sequence, each time only driving one phase lower tube to conduct and close, and the remaining power tubes remain in the off state.

[0029] In a motor control system, to accurately detect the rotor position, it is necessary to orderly control the three-phase power transistors. During specific operations, pulse driving is sequentially applied to the power transistors of each phase in the order of phase A, B, and C. During each driving process, only the lower transistor of one phase is activated to conduct and turn off according to the set pulse signal pattern, while the power transistors of the other two phases (including the upper and lower transistors) remain in the off state. This time-sharing driving method can ensure that during the driving of each phase, the system can independently collect the electrical parameters related to that phase, avoid interference between phases, and provide an accurate data basis for subsequent data analysis and rotor position calculation.

[0030] Step S2: Based on the negative bus current during each pulse driving, obtain the duration when the negative bus current of each phase is greater than a preset threshold.

[0031] After the pulse driving of the power transistors of each phase in step S1 is completed, monitor and analyze the negative bus current during each pulse driving. The negative bus current is one of the key parameters reflecting the operating state of the motor, and there is a certain correlation between its magnitude and variation and the rotor position. By real-time collecting the negative bus current data and comparing it with the preset threshold, record the time period when the negative bus current of each phase is greater than the preset threshold. Specifically, within the pulse period of the lower transistor of the power transistor of each phase conducting and turning off, once the negative bus current exceeds the preset threshold, start timing; when the negative bus current drops below the preset threshold, stop timing, and this timing duration is the duration when the negative bus current of this phase is greater than the preset threshold. In this way, the durations when the negative bus currents of phases A, B, and C are greater than the preset threshold are respectively obtained, and these data will be used as important bases for calculating the rotor position.

[0032] Step S3: Calculate the rotor position based on the sum of the durations when the negative bus currents of the three phases are greater than the preset threshold.

[0033] After obtaining the durations when the negative bus currents of the three phases are greater than the preset threshold, perform a summation operation on the durations of phases A, B, and C to obtain a comprehensive time sum value. This sum value contains information related to the operating states of the three phases of the motor and has a specific functional relationship with the position of the rotor inside the motor. Based on motor control theory and the pre-established mathematical model, using this three-phase duration sum value, through corresponding algorithms and formulas for calculation, finally obtain the accurate position of the motor rotor at the current moment. This calculation result will be fed back to the motor control system to adjust the driving strategy of the power transistors, achieve precise control of parameters such as the motor speed and torque, and ensure the stable and efficient operation of the motor.

[0034] Specifically, Figure 3 For the three-phase back electromotive force waveforms of a permanent magnet synchronous motor during free operation. Based on Figure 3, a pulse drive strategy is adopted to control the lower transistors of the three-phase bridge arm, where the pulse frequency is set to 1000 Hz and the duty cycle is configured to 50%. Based on the operating characteristics of the brushless DC motor, at any given moment, only the back electromotive force of one phase winding in the three-phase windings is at the minimum value. Taking the angle range of 0° to 120° as an example, at this time, the back electromotive force of the U-phase winding is the lowest, and the system drives the lower transistor Q2 of the U-phase to conduct, while keeping the upper and lower transistors of the V-phase and the upper and lower transistors of the W-phase in the off state. Due to the unidirectional conduction characteristics of the antiparallel diodes of the lower transistors of the V and W phases, the reverse flow of current is blocked, so there is no current flowing in the three-phase windings during this stage.

[0035] When the motor rotor rotates and the electrical angle exceeds 120°, the U-phase is no longer the phase with the minimum back electromotive force. However, due to the continuous application of the pulse drive signal, when the drive pulse is at the high level, a positive current is generated in the U-phase winding, and the current path is as Figure 4 shown; when the drive pulse switches to the low level, a freewheeling circuit is formed through the negative bus, and the freewheeling current path is as Figure 5 shown.

[0036] Based on the above working mechanism, the system can accurately judge whether the motor rotor runs to the intersection point of the three-phase back electromotive forces by real-time detecting the negative bus current signal. By recording the time interval of this key event and combining with the sampling period, the operating speed of the motor can be calculated. At the same time, based on the corresponding relationship between the current generation moment and the motor operating cycle, the real-time position angle of the motor rotor can be further deduced.

[0037] In some alternative embodiments, as Figure 6 shown, the process of sequentially performing pulse drive on each phase power transistor includes:

[0038] Step S11: Perform pulse drive on the lower transistor of the U-phase, and keep the other power transistors in the off state.

[0039] Step S12: Judge whether the negative bus current is greater than a preset threshold.

[0040] Step S13: If the negative bus current is greater than the preset threshold, record the duration during which the negative bus current is greater than the preset threshold.

[0041] Step S14: Perform pulse drive on the lower transistor of the V-phase, and return to the step of "judging whether the negative bus current is greater than the preset threshold" until the duration during which the negative bus current is greater than the preset threshold is obtained.

[0042] Step S15: Perform pulse drive on the lower transistor of the W-phase, and return to the step of "judging whether the negative bus current is greater than the preset threshold" until the duration during which the negative bus current is greater than the preset threshold is obtained.

[0043] Optionally, determine whether the deviation between the durations when the negative busbar current of each phase is greater than a preset threshold is less than a preset difference; when the deviation between the durations when the negative busbar current of each phase is greater than the preset threshold is less than the preset difference, calculate the rotor position based on the sum of the durations when the negative busbar current of the three phases is greater than the preset threshold.

[0044] In some alternative embodiments, the process of calculating the rotor position includes:

[0045] Take the sum of the durations when the negative busbar current of the three phases is greater than the preset threshold as one electrical cycle; based on the electrical cycle, calculate the electrical frequency; according to the electrical frequency, calculate the rotor position.

[0046] Specifically, in a motor drive control system, to achieve precise monitoring of the motor rotor position, a calculation method based on the characteristics of the negative busbar current is introduced. Specifically, the system continuously monitors the negative busbar current corresponding to the three-phase windings. When the negative busbar current of a certain phase is greater than a preset threshold, the timing starts; when the current drops below the threshold, the timing stops, and this period of time is the duration when the current of this phase is greater than the threshold. Summing up such durations of the three phases, the obtained sum value is defined as a complete electrical cycle. The basis for this setting is that within one electrical cycle of the motor, the current changes of the three-phase windings show specific patterns. By integrating the effective durations of the three-phase currents, the operating cycle characteristics of the motor can be comprehensively and accurately reflected.

[0047] After obtaining the electrical cycle, there is a reliable basis for calculating the electrical frequency. The electrical frequency, as a key indicator to measure the speed of change of the motor electrical signal, is calculated by the formula: electrical frequency = 1 / electrical cycle. This formula is based on the reciprocal relationship between the cycle and the frequency. By converting the time cycle into a frequency value, it can intuitively show the dynamic change of the motor operation. For example, if the electrical cycle is 0.02 seconds, through calculation, the electrical frequency is 50 Hz, indicating that the motor completes 50 electrical cycles of operation per unit time.

[0048] Based on the calculated electrical frequency, further deduce the motor rotor position. The determination of the motor rotor position is closely related to the electrical frequency. During the actual operation of the motor, there is a specific correspondence between the electrical frequency and the mechanical position of the rotor. By establishing a mathematical model between the electrical frequency and the rotor position and combining parameters such as the number of pole pairs of the motor, an accurate conversion from the electrical frequency to the rotor position can be achieved. Generally, the formula: rotor position angle = electrical frequency × 360° / (number of pole pairs × 2) can be used to calculate the rotor position angle.

[0049] Exemplarily, Figure 7 is a flowchart for rotor position detection. As Figure 7 shown, the specific process is as follows:

[0050] (1) U-phase Drive and Current Sampling

[0051] The MCU first outputs a pulse drive signal with a frequency of 1 kHz and a duty cycle of 50% to control the periodic on and off operations of the lower U-phase transistor, while keeping the other power transistors in the off state. During this process, the MCU continuously samples the negative bus current. When the sampled negative bus current value exceeds a pre-set threshold, the next step is executed; if it does not exceed the threshold, the current pulse drive strategy is maintained, and the lower U-phase transistor continues to be driven until the current meets the conditions.

[0052] In terms of the working principle, when the lower U-phase transistor is on, if the back electromotive force of the U-phase winding is the minimum among the three phases, no current will be generated in the motor phase wire loop; conversely, if current is generated in the U-phase, when the drive pulse becomes low level and the lower U-phase transistor turns off, the current will form a freewheeling loop through the negative bus, and at this time, the freewheeling current can be sampled and detected through the bus resistance. After completing the above operations, the current time is recorded as Tu.

[0053] (2) V-phase Drive and Current Sampling

[0054] The MCU adjusts the drive strategy, sends a pulse drive signal with a frequency of 1 kHz and a duty cycle of 50% to control the periodic on and off of the lower V-phase transistor, while keeping the other power transistors in the off state. Continuously sample the negative bus current. If the negative bus current is greater than the set threshold, go to the next step; otherwise, continue to maintain the current pulse to drive the lower V-phase transistor. Similarly, when the lower V-phase transistor is on, if the back electromotive force of the V-phase is the minimum among the three phases, there is no current in the motor phase wire; if current is generated, there will be a phase current in the V-phase during the high level of the drive pulse, and a freewheeling current will be generated in the negative bus during the low level. Record the current time when the conditions are met as Tv.

[0055] (3) W-phase Drive and Current Sampling

[0056] The MCU outputs a pulse drive signal with a frequency of 1 kHz and a duty cycle of 50% to drive the periodic on and off of the lower W-phase transistor, and the other power transistors remain off. Continuously sample the negative bus current. When the negative bus current is greater than the set threshold, execute the next step; otherwise, continue to drive the lower W-phase transistor in the current pulse form. During the on period of the lower W-phase transistor, if the back electromotive force of the W-phase is the minimum among the three phases, there is no current in the motor phase wire; if current is generated, there is a W-phase phase current when the drive pulse is high level and the lower W-phase transistor is on, and a freewheeling current is generated in the negative bus when the pulse is low level and the lower W-phase transistor is off. Record this time as Tw.

[0057] (4) Data Verification and Parameter Calculation

[0058] Verify the three time data of Tu, Tv, and Tw recorded, and determine whether the difference among them is within the normal range. The judgment basis is whether the deviation values of the three are less than a preset threshold. If the condition is met, the data is considered valid. Add the three time values of Tu, Tv, and Tw, and the obtained result is the time of a complete electrical cycle. Based on this electrical cycle time, the electrical frequency of the current motor can be calculated through the formula "electrical frequency = 1 / electrical cycle".

[0059] In this embodiment, a downwind starting method is provided, including:

[0060] Drive the power tubes of each phase in sequence by pulses. Each time, only drive the lower tube of one phase to conduct and turn off, and the other power tubes remain in the off state; based on the negative bus current during each pulse drive, obtain the duration when the negative bus current of each phase is greater than a preset threshold; based on the sum of the durations when the negative bus currents of the three phases are greater than the preset threshold, calculate the rotor position; based on the rotor position, achieve downwind starting.

[0061] Exemplarily, compare and analyze the detected rotor position with the wind direction. For example, when there is a certain angular relationship between the magnetic pole position of the rotor and the wind direction, select an appropriate starting time. If the wind direction is close to the same as the magnetic field direction generated by a certain phase winding of the motor, it can be considered to start from this phase, so as to utilize the wind power to assist the motor starting and reduce the resistance during starting.

[0062] In this embodiment, a rotor position detection device and a downwind starting device are also provided. This device is used to implement the above embodiments and preferred implementation manners, and those that have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0063] This embodiment provides a rotor position detection device, including:

[0064] A pulse drive module for driving the power tubes of each phase in sequence by pulses. Each time, only drive the lower tube of one phase to conduct and turn off, and the other power tubes remain in the off state;

[0065] A time calculation module for obtaining the duration when the negative bus current of each phase is greater than a preset threshold based on the negative bus current during each pulse drive;

[0066] A position calculation module for calculating the rotor position based on the sum of the durations when the negative bus currents of the three phases are greater than the preset threshold.

[0067] This embodiment provides a downwind starting device, including:

[0068] A calculation module, configured to calculate the rotor position based on a rotor position detection method;

[0069] A starting module, configured to implement downwind starting based on the rotor position.

[0070] The further function descriptions of the above-mentioned various modules and units are the same as those in the corresponding foregoing embodiments, and will not be elaborated herein.

[0071] The rotor position detection device and the downwind starting device in this embodiment are presented in the form of functional units. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0072] An embodiment of the present invention further provides a computer device having the above-mentioned Figure 8 shown rotor position detection device and downwind starting device.

[0073] Please refer to Figure 8 , Figure 8 which is a schematic structural diagram of a computer device provided by an optional embodiment of the present invention. As Figure 8 shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including a high-speed interface and a low-speed interface. Each component communicates with each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a set of blade servers, or a multi-processor system). Figure 8 In

[0074] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Among them, processor 10 may further include a hardware chip. The above-mentioned hardware chip may be an application specific integrated circuit, a programmable logic device, or a combination thereof. The above-mentioned programmable logic device may be a complex programmable logic device, a field programmable gate array, a general array logic, or any combination thereof.

[0075] Among them, the memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiments.

[0076] The memory 20 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some alternative embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0077] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk, or a solid-state drive; the memory 20 may also include a combination of the above types of memories.

[0078] The computer device further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30, and the output device 40 may be connected through a bus or other means. Figure 8 Taking the connection through the bus as an example.

[0079] The input device 30 may receive input digital or character information, and generate key signal inputs related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touchpad, a pointing stick, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (such as an LED), and a tactile feedback device (such as a vibration motor), etc. The above display device includes but is not limited to a liquid crystal display, a light-emitting diode, a display, and a plasma display. In some alternative embodiments, the display device may be a touch screen.

[0080] Embodiments of the present invention also provide a computer-readable storage medium. The method according to the embodiments of the present invention can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented as computer code that is originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored as such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0081] A part of the present invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should be able to understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Herein, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible by the computer.

[0082] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A rotor position detection method, characterized in that: The motor is driven by a three-phase converter, and the method comprises: Pulse drive is performed on each phase power tube in turn, and only one phase tube is driven on and off each time, while the other power tubes remain off. Based on the negative bus current during each pulse driving period, obtaining the duration when the negative bus current of each phase is greater than a preset threshold; The rotor position is calculated based on the sum of the durations when the negative bus currents of the three phases are greater than a preset threshold.

2. The rotor position detection method according to claim 1, characterized in that: The process of pulse driving each phase power tube in turn includes: The U-phase lower tube is pulse driven, and the other power tubes remain off; Determine whether the negative bus current is greater than a preset threshold; If the negative bus current is greater than the preset threshold, then the duration of the negative bus current being greater than the preset threshold is recorded; Pulse drive is performed on the lower tube of the V phase, and the process returns to the step of "determining whether the negative bus current is greater than the preset threshold value" until the duration of the negative bus current being greater than the preset threshold value is obtained; The W-phase lower tube is pulse-driven, and the process returns to the step of "determining whether the negative bus current is greater than the preset threshold value" until the duration of the negative bus current being greater than the preset threshold value is obtained.

3. The rotor position detection method according to claim 1, characterized in that: The frequency of the pulse drive is 1k and the duty cycle is 50%.

4. The rotor position detection method according to claim 1, characterized in that: The process of calculating the rotor position includes: The sum of the durations when the negative bus currents of the three phases are greater than a preset threshold is regarded as an electrical cycle; calculating an electrical frequency based on the electrical period; From the electrical frequency, the rotor position is calculated.

5. The rotor position detection method according to claim 1, characterized in that: Before calculating the rotor position, it also includes: Determine whether a deviation between the durations when the negative bus current of each phase is greater than a preset threshold is less than a preset difference; When the deviation between the durations when the negative bus current of each phase is greater than the preset threshold is less than the preset difference, the rotor position is calculated based on the sum of the durations when the negative bus current of the three phases is greater than the preset threshold.

6. A downwind starting method, characterized in that: include: Calculating the rotor position based on the rotor position detection method according to any one of claims 1 to 5; Based on the rotor position, a downwind start is achieved.

7. A rotor position detection device, characterized in that: include: The pulse drive module is used to drive the power tubes of each phase in turn, driving only one phase of the lower tube to turn on and off each time, and the other power tubes remain in the off state; A time calculation module, used for obtaining a duration when the negative bus current of each phase is greater than a preset threshold based on the negative bus current during each pulse driving period; The position calculation module is used to calculate the rotor position based on the sum of the durations when the negative bus currents of the three phases are greater than a preset threshold.

8. A downwind starting device, characterized in that: include: A calculation module, used for calculating the rotor position based on the rotor position detection method according to any one of claims 1 to 5; A starting module is used to achieve downwind starting based on the rotor position.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the rotor position detection method described in any one of claims 1 to 5 and the downwind starting method described in claim 6 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the rotor position detection method described in any one of claims 1 to 6, and to execute the downwind starting method described in claim 6.

11. A computer program product, characterized in that It comprises computer instructions, and the computer instructions are used to make a computer execute the rotor position detection method described in any one of claims 1 to 5, and execute the downwind starting method described in claim 6.

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