Under-actuated brushless direct current motor high-reliability position-free starting method

Abstract

The invention relates to the technical field of brushless direct current motors, in particular to a high-reliability positionless starting method for an under-actuated brushless direct current motor. The position-free starting method comprises the following steps: calculating a reference angular acceleration according to the rotational inertia of a motor rotor, a motor driving torque and an effective torque coefficient; according to the reference angular acceleration, the current beat angular position and the control period of each beat, the next beat angular position is estimated and calculated; carrying out fault diagnosis on a winding A, a winding B and a winding C of the motor, sequentially electrifying at least two normal windings according to a diagnosis result, completing rotor positioning, and obtaining an initial offset angle of a rotor magnetic pole relative to a stator winding; and calculating a rotor correction angle position according to the initial offset angle and the next beat angle position, and determining whether the winding is electrified or not according to the rotor correction angle position. The embodiment of the invention provides a high-reliability sensorless starting method and device for an under-actuated brushless direct current motor, electronic equipment and a storage medium. The sensorless starting can be realized when a phase winding is disconnected.

Description

Technical Field

[0001] The present invention relates to the technical field of brushless DC motors, and particularly to a high-reliability positionless starting method for an under-driven brushless DC motor. Background Art

[0002] Sensorless control has the advantages of high reliability and low cost, and is widely used in the drive control of brushless DC motors.

[0003] Sensorless control generally uses the back electromotive force of the winding to detect the commutation angle position of the rotor. However, at low speeds, the back electromotive force of the winding is small, and accurate rotor angle position information cannot be obtained. Therefore, the brushless DC motor uses a positionless starting method to drive at low speeds.

[0004] Traditional positionless starting methods require all three-phase windings of the motor and all three-phase drivers to be normal to work properly. When a certain phase winding or driver is open-circuited, the traditional method cannot be used to achieve positionless starting. Summary of the Invention

[0005] Embodiments of the present invention provide a high-reliability positionless starting method, device, electronic device, and storage medium for an under-driven brushless DC motor, which can achieve positionless starting when a phase winding or a phase driver is open-circuited.

[0006] In a first aspect, embodiments of the present invention provide a high-reliability positionless starting method for an under-driven brushless DC motor, including:

[0007] Calculating a reference angular acceleration according to the moment of inertia of the motor rotor, the motor driving torque, and the effective torque coefficient;

[0008] Predicting and calculating the next beat angular position according to the reference angular acceleration, the current beat angular position, and the control period of each beat;

[0009] Performing fault diagnosis on windings A, B, and C of the motor, and sequentially energizing at least two normal windings according to the diagnosis result to complete rotor positioning, and obtaining an initial offset angle of the rotor magnetic pole relative to the stator winding;

[0010] Calculating a rotor correction angular position according to the initial offset angle and the next beat angular position, and determining whether to energize the winding according to the rotor correction angular position.

[0011] In a possible design, after performing fault diagnosis on windings A, B, and C of the motor and obtaining the reference angular acceleration, it further includes:

[0012] Calculating the next beat angular velocity according to the reference angular acceleration and the current beat angular velocity;

[0013] Connect the normal winding to the current loop to energize it, and collect the average voltage output by the current loop controller at this time; wherein, the energizing current of the current loop is set to the current required for the motor driving torque M.

[0014] Calculate the compensation voltage according to the angular velocity of the next beat and the motor back electromotive force coefficient.

[0015] Calculate the control voltage according to the average voltage and the compensation voltage.

[0016] Calculate the control duty ratio of the buck chopper according to the motor supply voltage and the control voltage.

[0017] In a possible design, the fault diagnosis of windings A, B, and C of the motor is performed, and according to the diagnosis results, at least two normal windings are energized in sequence to complete rotor positioning, and the initial bias angle of the rotor magnetic pole relative to the stator winding is obtained, including:

[0018] Respectively determine whether windings A, B, and C in the three-phase windings are abnormal.

[0019] If at least two windings are normal, select two normal windings and determine the gating order of the two windings.

[0020] According to the gating order, sequentially conduct the two normal windings with the current loop. After the rotor oscillates and swings with decreasing amplitude until it stops under the action of the preset current, the rotor is at a known initial bias angle.

[0021] If at least two windings are abnormal, stop the pre-positioning.

[0022] In a possible design, the step of respectively determining whether windings A, B, and C in the three-phase windings are abnormal includes:

[0023] For each winding, the following operations are performed:

[0024] Connect the winding to be detected to the current loop.

[0025] After a preset time, calculate the average current of the winding to be detected within the preset time.

[0026] Determine the detection interval according to the reference current. If the average current does not exceed the detection interval, the winding to be detected is normal, otherwise it is abnormal; wherein, the detection interval is [Iref×0.8, Iref×1.2], where Iref is the reference current.

[0027] In a possible design, the step of if at least two windings are normal, select two normal windings and determine the gating order of the two windings includes:

[0028] If windings A and B are normal, regardless of whether winding C is normal or not, winding B is energized first, and then winding A is energized. Finally, the initial bias angle is 40 degrees.

[0029] If windings A and C are normal and winding B fails, winding A is energized first, and then winding C is energized. Finally, the initial bias angle is 280 degrees.

[0030] If windings B and C are normal and winding A fails, winding C is energized first, and then winding B is energized. Finally, the initial bias angle is 160 degrees.

[0031] In a possible design, determining whether to energize the windings according to the corrected angular position of the rotor includes:

[0032] Let θ be the corrected angular position of the rotor. If θ ∈ [0, 120), the commutation signal of winding A is 1 and winding A is energized; otherwise, the commutation signal of winding A is 0 and winding A is not energized.

[0033] If θ ∈ [120, 240), the commutation signal of winding B is 1 and winding B is energized; otherwise, the commutation signal of winding B is 0 and winding B is not energized.

[0034] If θ ∈ [240, 360), the commutation signal of winding C is 1 and winding C is energized; otherwise, the commutation signal of winding C is 0 and winding C is not energized.

[0035] In a possible design, conducting two normal windings in sequence with the current loop according to the gating order. After the rotor oscillates with decreasing amplitude under the action of a preset current until it stops, the rotor is in a known pre-positioning position, including:

[0036] According to the gating order, conduct the first-energized winding with the current loop, and set the current value to the first preset current.

[0037] After the rotor oscillates with decreasing amplitude under the action of the first preset current until it stops, according to the gating order, conduct the second-energized winding with the current loop, and set the current value to the second preset current, where the second preset current is greater than the first preset current.

[0038] In a second aspect, an underactuated brushless DC motor high-reliability positionless starting device provided by an embodiment of the present invention is used to implement any one of the above methods. The device includes:

[0039] A first calculation unit for calculating a reference angular acceleration according to the moment of inertia of the motor rotor, the driving torque of the motor, and the effective torque coefficient.

[0040] A second calculation unit for predicting and calculating the angular position of the next beat according to the reference angular acceleration, the current beat angular position, and the control period of each beat.

[0041] A third calculation unit is configured to perform fault diagnosis on windings A, B, and C of the motor, and sequentially energize at least two normal windings according to the diagnosis results to complete rotor positioning and obtain an initial bias angle of the rotor magnetic pole stator winding.

[0042] A fourth calculation unit is configured to calculate a rotor correction angle position according to the initial bias angle and the next beat angle position, and determine whether to energize the winding according to the rotor correction angle position.

[0043] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0044] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed on a computer, the computer is made to execute the method described in any embodiment of this specification.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] (1) The present invention uses a half-bridge drive circuit, and the three-phase windings can be energized separately, with strong fault tolerance.

[0047] (2) The present invention can achieve reliable positionless starting when any phase winding or drive circuit of the brushless DC motor fails.

[0048] (3) The fault diagnosis and positionless starting of the windings or drive circuits involved in the present invention are all automatically completed without manual participation, with high efficiency. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings 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.

[0050] Figure 1 It is a flowchart of a method for highly reliable positionless starting of an underactuated brushless DC motor provided by an embodiment of the present invention;

[0051] Figure 2 It is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;

[0052] Figure 3 It is a structural diagram of a device for highly reliable positionless starting of an underactuated brushless DC motor provided by an embodiment of the present invention;

[0053] Figure 4 It is a schematic structural diagram of a driving unit provided by an embodiment of the present invention;

[0054] Figure 5 It is a schematic structural diagram of a brushless DC motor provided by an embodiment of the present invention. Specific implementation manners

[0055] 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 of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0056] The following describes the specific implementation manners of the above concepts.

[0057] Please refer to Figure 1 , an embodiment of the present invention provides a high-reliability positionless starting method for an under-driven brushless DC motor. The method includes:

[0058] Calculating a reference angular acceleration according to the moment of inertia of the motor rotor, the motor driving torque and the effective torque coefficient;

[0059] Predicting and calculating the angular position of the next beat according to the reference angular acceleration, the current beat angular position and the control period of each beat;

[0060] Performing fault diagnosis on windings A, B and C of the motor, and sequentially energizing at least two normal windings according to the diagnosis result to complete rotor positioning and obtain an initial offset angle of the rotor magnetic pole relative to the stator winding;

[0061] Calculating a rotor correction angular position according to the initial offset angle and the angular position of the next beat, and determining whether to energize the winding according to the rotor correction angular position.

[0062] In the embodiment of the present invention, first, the reference angular acceleration is calculated according to the moment of inertia of the motor rotor, the driving torque of the motor, and the effective torque coefficient. Then, according to the reference angular acceleration, the current beat angle position, and the control period of each beat, the angular position of the next beat is estimated and calculated. After obtaining the angular position of the next beat, the fault condition of the winding is judged. If at least two windings are normal, the gating order of the two is determined according to the phases of the normal windings. According to the gating order, the normal windings are sequentially connected to the current loop. After the winding is connected to the current loop, the rotor will continuously oscillate back and forth under the action of the current towards the position associated with the winding. The oscillation of the rotor gradually weakens under the action of friction and finally stops. By sequentially energizing the two windings before and after, the position of the rotor is adjusted, and finally the rotor stops at the initial offset angle. After obtaining the initial offset angle, the corrected angular position of the rotor is obtained by combining the angular position of the next beat obtained before (calculated according to the non-offset initial position). After obtaining the corrected angular position of the rotor, according to the position of the rotor magnetic pole relative to the stator winding, the corresponding winding is energized to drive the rotor to rotate. The corrected angular position is calculated for each beat, and the nearby windings are energized according to the corrected angular position, so that the rotor continuously accelerates and rotates, and the motor completes startup.

[0063] Specifically, the reference angular acceleration is calculated according to the rotor moment of inertia J, the motor driving torque M, and the effective torque coefficient k where the value range of k is According to the current beat angle position θ N , and the control period T, the angular position θ of the next beat is estimated and calculated N+1 =θ N +Ω N+1 T. According to the angular position θ of the next beat N+1 and the initial offset angle θ bise , the sum is calculated to obtain the corrected angular position θ = θ N+1 +θ bise .

[0064] In an embodiment of the present invention, after diagnosing the faults of windings A, B, and C of the motor and obtaining the reference angular acceleration, it further includes:

[0065] Calculating the angular velocity of the next beat according to the reference angular acceleration and the current beat angular velocity;

[0066] Connect the normal windings to the current loop and energize them, and collect the average voltage output by the current loop controller at this time; wherein, the energizing current of the current loop is set to the current required by the motor driving torque M;

[0067] Calculating the compensation voltage according to the angular velocity of the next beat and the motor back electromotive force coefficient;

[0068] Calculating the control voltage according to the average voltage and the compensation voltage;

[0069] Calculate the control duty ratio of the buck chopper according to the motor supply voltage and the control voltage.

[0070] In this embodiment, the average voltage is calculated only once when initially powered on. When starting without position, to avoid the problem of integral saturation during the faulty winding period, open-loop control is performed, and the control duty ratio PWM_out calculated by the voltage control unit is directly used to control the buck chopper.

[0071] According to the current beat angular velocity Ω N , the reference angular acceleration α, and the control period T, predict and calculate the next beat angular velocity Ω N+1 = Ω N + αT. The compensation voltage is V comp = k v Ω N+1 , where k v is the motor back electromotive force coefficient, and the control power supply is V c = V + V comp , where V is the average voltage, and the control duty ratio is

[0072] In an embodiment of the present invention, the fault diagnosis of windings A, B, and C of the motor is performed, and according to the diagnosis result, at least two normal windings are sequentially powered on to complete rotor positioning and obtain the initial bias angle of the rotor magnetic pole relative to the stator winding, including:

[0073] Respectively determine whether windings A, B, and C in the three-phase windings are abnormal;

[0074] If at least two windings are normal, select two normal windings and determine the gating order of the two windings;

[0075] According to the gating order, sequentially conduct the two normal windings to the current loop. After the rotor oscillates with decreasing amplitude and swings until it stops under the action of a preset current, the rotor is at a known initial bias angle;

[0076] If at least two windings are abnormal, stop the pre-positioning.

[0077] In an embodiment of the present invention, the step of respectively determining whether windings A, B, and C in the three-phase windings are abnormal includes:

[0078] For each winding, the following operations are performed:

[0079] Connect the winding to be detected to the current loop;

[0080] After a preset time, calculate the average current of the winding to be detected within the preset time;

[0081] Determine the detection range according to the reference current. If the average current does not exceed the detection range, the winding to be detected is normal; otherwise, it is abnormal.

[0082] Specifically, the power-on instruction sending module sends a winding A selection instruction to the drive unit, and at the same time sends a current closed-loop control instruction to the drive unit. The reference current is Iref. After waiting for T0 time, the winding fault diagnosis module obtains the average value of the winding detection current of the drive unit in the time period [T0, T0 + T] as Iavg_A. Then it is judged whether Iavg_A is within the range [Iref×0.8, Iref×1.2]. If it is, it is considered that winding A is normal; otherwise, winding A is abnormal and Flag_A is set to 0.

[0083] Then, the power-on instruction sending module sends a clear instruction for the current loop integration of the drive unit. Then, the power-on instruction sending module sends a winding B selection instruction to the drive unit, and at the same time sends a current closed-loop control instruction to the drive unit. The reference current is Iref. After waiting for T0 time, the winding fault diagnosis module obtains the average value of the winding detection current of the drive unit in the time period [T0, T0 + T] as Iavg_B. Then it is judged whether Iavg_B is within the range [Iref×0.8, Iref×1.2]. If it is, it is considered that winding B is normal; otherwise, winding B is abnormal and Flag_B is set to 0.

[0084] Then, the power-on instruction sending module sends a clear instruction for the current loop integration of the drive unit. Then, the power-on instruction sending module sends a winding C selection instruction to the drive unit, and at the same time sends a current closed-loop control instruction to the drive unit. The reference current is Iref. After waiting for T0 time, the winding fault diagnosis module obtains the average value of the winding detection current of the drive unit in the time period [T0, T0 + T] as Iavg_C. Then it is judged whether Iavg_C is within the range [I_ref×0.8, I_ref×1.2]. If it is, it is considered that winding C is normal and Flag_C is set to 1; otherwise, winding C is abnormal and Flag_C is set to 0.

[0085] In an embodiment of the present invention, if at least two windings are normal, select two normal windings and determine the selection order of the two windings, including:

[0086] If winding A and winding B are normal, regardless of whether winding C is normal or not, winding B is powered on first, and winding A is powered on later. Finally, the initial bias angle is 40 degrees;

[0087] If winding A and winding C are normal and winding B is faulty, winding A is powered on first, and winding C is powered on later. Finally, the initial bias angle is 280 degrees;

[0088] If winding B and winding C are normal and winding A is faulty, winding C is powered on first, and winding B is powered on later. Finally, the initial bias angle is 160 degrees.

[0089] In one embodiment of the present invention, determining whether the winding is energized according to the rotor corrected angular position includes:

[0090] Let θ be the rotor corrected angular position. If θ ∈ [0, 120), the commutation signal of winding A is 1 and winding A is energized; otherwise, the commutation signal of winding A is 0 and winding A is not energized.

[0091] If θ ∈ [120, 240), the commutation signal of winding B is 1 and winding B is energized; otherwise, the commutation signal of winding B is 0 and winding B is not energized.

[0092] If θ ∈ [240, 360), the commutation signal of winding C is 1 and winding C is energized; otherwise, the commutation signal of winding C is 0 and winding C is not energized.

[0093] In this embodiment, since the positions of the windings are different, after detecting two normal windings, the energization sequence is determined according to the positions of the normal windings.

[0094] In one embodiment of the present invention, conducting the two anomaly-free windings with the current loop in sequence according to the gating sequence, and after the rotor undergoes damped oscillatory swinging until it stops under the action of a preset current, the rotor is in a known pre-positioning position, includes:

[0095] According to the gating sequence, conduct the first-energized winding with the current loop, and set the current value to the first preset current.

[0096] After the rotor undergoes damped oscillatory swinging until it stops under the action of the first preset current, according to the gating sequence, conduct the later-energized winding with the current loop, and set the current value to the second preset current, where the second preset current is greater than the first preset current.

[0097] Specifically, first, the pre-positioning control unit sends a gating instruction for the first-energized winding to the driving unit. At the same time, it sends a current closed-loop control instruction to the driving unit, with the reference current being I_pos and the energization time being T_pos1.

[0098] Then, the pre-positioning control unit sends a gating instruction for the later-energized winding to the driving unit. At the same time, it sends a current closed-loop control instruction to the driving unit, with the reference current being I_pos and the energization time being T_pos2.

[0099] Finally, the pre-positioning control unit sends a gating instruction for the later-energized winding to the driving unit. At the same time, it sends a current closed-loop control instruction to the driving unit, with the reference current being I_pos1 and the energization time being T_pos3.

[0100] In this embodiment, the windings with a later gating sequence need to be energized twice. The first preset current (reference current I pos) for the first energization is relatively small and can be the same as the current of the windings energized earlier. The second preset current (reference current I pos1) for the second energization of the later energized windings is relatively large. The larger the current, the larger the oscillation amplitude, the longer the oscillation stop time, and the more accurate the positioning. Therefore, to save time, the later windings are energized with a small current for the first time to achieve a quick initial positioning, and then with a large current for the second time. Based on the initial positioning during the first energization, the later windings can achieve a quick and accurate positioning.

[0101] In some embodiments of the present invention, before connecting the winding to be detected to the current loop, it further includes:

[0102] Resetting the current loop integration. Resetting the current loop integration can prevent excessive integration and burning out the circuit.

[0103] As Figure 2 、 Figure 3 shown, the embodiments of the present invention provide a high-reliability positionless starting device for an under-driven brushless DC motor. The device embodiments can be implemented through software, or through hardware or a combination of software and hardware. From the hardware level, as Figure 2 shown, it is a hardware architecture diagram of an electronic device where the high-reliability positionless starting device for an under-driven brushless DC motor provided by the embodiments of the present invention is located. In addition to Figure 2 the shown processor, memory, network interface, and non-volatile memory, the electronic device where the device is located in the embodiments usually may also include other hardware, such as a forwarding chip responsible for processing packets, etc. Taking software implementation as an example, as Figure 3 shown, as a logically meaningful device, it is formed by the CPU of its corresponding electronic device reading the corresponding computer program in the non-volatile memory into the memory for operation. Please refer to Figure 4 and Figure 5 , a high-reliability positionless starting device for an under-driven brushless DC motor provided by this embodiment includes:

[0104] A first calculation unit, configured to calculate a reference angular acceleration according to the moment of inertia of the motor rotor, the motor driving torque, and the effective torque coefficient;

[0105] A second calculation unit, configured to predict and calculate the angular position of the next beat according to the reference angular acceleration, the current beat angular position, and the control period of each beat;

[0106] A third calculation unit, configured to perform fault diagnosis on windings A, B, and C of the motor, and energize at least two normal windings in sequence according to the diagnosis result to complete rotor positioning and obtain the initial offset angle of the rotor magnetic pole relative to the stator winding;

[0107] A fourth calculation unit, configured to calculate a rotor correction angular position according to the initial bias angle and the angular position of the next beat, and determine whether the winding is energized according to the rotor correction angular position.

[0108] When initially powered on, the winding fault diagnosis unit performs three-phase winding fault diagnosis and the current loop controller is used when the voltage control unit calculates a constant voltage. The current loop controller calculates a control quantity according to the difference between the reference current sent by the winding fault diagnosis unit and the bus current detected by the current sensor according to a proportional-integral (PI) control method, and transmits it to the buck chopper to obtain a corresponding control voltage, which is applied to the selected motor winding through the motor neutral line O.

[0109] It can be understood that the structure schematically shown in the embodiments of the present invention does not constitute a specific limitation on a highly reliable positionless starting device for an underactuated brushless DC motor. In some other embodiments of the present invention, a highly reliable positionless starting device for an underactuated brushless DC motor may include more or fewer components than those shown in the figure, or combine certain components, or split certain components, or have different component arrangements. The components shown in the figure can be implemented in hardware, software, or a combination of software and hardware.

[0110] Regarding the information interaction, execution process, etc. between the various modules within the above-mentioned device, since they are based on the same concept as the method embodiments of the present invention, the specific content can be referred to the description in the method embodiments of the present invention, and will not be elaborated here.

[0111] An embodiment of the present invention further provides an electronic device, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, a highly reliable positionless starting method for an underactuated brushless DC motor in any embodiment of the present invention is implemented.

[0112] An embodiment of the present invention further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the processor is enabled to execute a highly reliable positionless starting method for an underactuated brushless DC motor in any embodiment of the present invention.

[0113] Specifically, a system or device equipped with a storage medium can be provided. Software program codes for implementing the functions in any one of the above embodiments are stored on the storage medium, and the computer (or CPU or MPU) of the system or device reads and executes the program codes stored in the storage medium.

[0114] In this case, the program code read from the storage medium itself can implement the functions in any one of the above embodiments. Therefore, the program code and the storage medium storing the program code constitute a part of the present invention.

[0115] Examples of storage media for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Optionally, the program code can be downloaded from a server computer via a communication network.

[0116] Furthermore, it should be clear that not only can the functions of any one of the above embodiments be realized by executing the program code read by a computer, but also by causing an operating system or the like operating on the computer to perform some or all of the actual operations based on the instructions of the program code.

[0117] In addition, it can be understood that the program code read from the storage medium is written into the memory provided in an expansion board inserted into the computer or into the memory provided in an expansion module connected to the computer, and then the CPU or the like installed on the expansion board or the expansion module is caused to perform some and all of the actual operations based on the instructions of the program code, thereby realizing the functions of any one of the above embodiments.

[0118] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0119] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including those of the above method embodiments; and the foregoing storage medium includes various media such as ROM, RAM, magnetic disks, or optical disks that can store program code.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-reliability non-position starting method for an underdriven brushless DC motor, characterized in that: include: Calculate the reference angular acceleration according to the rotational inertia of the motor rotor, the motor driving torque and the effective torque coefficient; Predicting and calculating the next beat angle position according to the reference angular acceleration, the current beat angle position and the control period of each beat; Perform fault diagnosis on winding A, winding B and winding C of the motor, and energize at least two normal windings in sequence according to the diagnosis result to complete the rotor positioning and obtain the initial offset angle of the rotor magnetic pole relative to the stator winding; A rotor correction angle position is calculated according to the initial offset angle and the next beat angle position, and whether the winding is energized is determined according to the rotor correction angle position.

2. The method for starting without position according to claim 1, characterized in that: After performing fault diagnosis on winding A, winding B and winding C of the motor and obtaining the reference angular acceleration, the method further includes: Calculating the next beat angular velocity according to the reference angular acceleration and the current beat angular velocity; Connect the normal winding to the current loop and energize it, and collect the average voltage output by the current loop controller at this time; wherein the current loop energization current is set to the current required by the motor driving torque M; Calculating a compensation voltage according to the next beat angular velocity and the motor back electromotive force coefficient; Calculating a control voltage according to the mean voltage and the compensation voltage; The control duty ratio of the step-down chopper is calculated according to the motor supply voltage and the control voltage.

3. The method for starting without position according to claim 1, characterized in that: The fault diagnosis is performed on winding A, winding B and winding C of the motor, and at least two normal windings are energized in sequence according to the diagnosis result to complete the rotor positioning and obtain the initial offset angle of the rotor magnetic pole relative to the stator winding, including: Determine whether winding A, winding B and winding C in the three-phase winding are abnormal; If at least two windings are normal, then the two windings without abnormalities are selected to determine the gating order of the two windings; According to the selection sequence, two windings without abnormalities are sequentially connected to the current loop, and after the rotor oscillates with reduced amplitude until it stops under the action of the preset current, the rotor is at a known initial offset angle; If at least two windings are abnormal, the pre-positioning is stopped.

4. The method according to claim 3, characterized in that The step of respectively judging whether winding A, winding B and winding C in the three-phase winding are abnormal comprises: For each winding, perform: Connect the winding to be tested to the current loop; After a preset time, calculating the average current of the winding to be detected within the preset time; The detection interval is determined according to the reference current. If the average current does not exceed the detection interval, the winding to be detected has no abnormality, otherwise it is abnormal; wherein the detection interval is [Iref×0.8, Iref×1.2], wherein Iref is the reference current.

5. The method according to claim 3, characterized in that: If at least two windings are normal, two windings without abnormalities are selected, and a gating order of the two windings is determined, including: If there is no abnormality in winding A and winding B, regardless of whether winding C is abnormal, winding B is energized first, and winding A is energized later, and the final initial bias angle is 40 degrees; If there is no abnormality in winding A and winding C, and winding B fails, winding A is energized first, and winding C is energized later, and the final initial bias angle is 280 degrees; If there is no abnormality in winding B and winding C and winding A fails, winding C will be energized first and winding B will be energized later, and the final initial bias angle will be 160 degrees.

6. The method according to claim 1, characterized in that The step of determining whether the winding is energized according to the rotor correction angular position comprises: θ is the rotor correction angular position. If θ∈[0,120), the commutation signal of winding A is 1 and winding A is energized. Otherwise, the commutation signal of winding A is 0 and winding A is not energized. If θ∈[120,240), the commutation signal of winding B is 1, and winding B is energized; otherwise, the commutation signal of winding B is 0, and winding B is not energized; If θ∈[240,360), the commutation signal of winding C is 1 and winding C is energized; otherwise, the commutation signal of winding C is 0 and winding C is not energized.

7. The method according to claim 3, characterized in that The two windings without abnormalities are sequentially connected to the current loop according to the selection sequence, and after the rotor oscillates with reduced amplitude until it stops under the action of the preset current, the rotor is in a known pre-positioned position, including: According to the gating sequence, the winding that is powered on first is connected to the current loop, and the current value is set to a first preset current; After the rotor oscillates with reduced amplitude until it stops under the action of the first preset current, the winding that is energized later is connected to the current loop according to the selection sequence, and the current value is set to a second preset current, which is greater than the first preset current.

8. A high-reliability non-position starting device for an under-driven brushless DC motor, characterized in that: For implementing the method described in any one of claims 1 to 7, the device comprises: A first calculation unit is used to calculate a reference angular acceleration according to the rotational inertia of the motor rotor, the motor driving torque and the effective torque coefficient; A second calculation unit, used for pre-estimating and calculating the next beat angle position according to the reference angular acceleration, the current beat angle position and the control period of each beat; A third calculation unit is used to perform fault diagnosis on winding A, winding B and winding C of the motor, and energize at least two normal windings in sequence according to the diagnosis result to complete the rotor positioning and obtain the initial offset angle of the rotor magnetic pole relative to the stator winding; The fourth calculation unit is used to calculate the rotor correction angle position according to the initial offset angle and the next beat angle position, and determine whether the winding is energized according to the rotor correction angle position.

9. An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 7.

Images