Drive circuit for brushless motor and control method, device and apparatus thereof

Abstract

The present disclosure provides a drive circuit for a brushless motor and a control method, device, and apparatus thereof, relating to the field of motor drive technology. The brushless motor comprises: a stator core comprising Z tooth groups spaced apart in a circumferential direction; a rotor having a magnetic ring with a pole number of P; X phase conductors wound around the tooth groups to form coils, where X≥2 and Z=P×X; in the same phase conductor, the coils on two adjacent tooth groups have opposite winding directions along the circumference of the tooth groups and are spaced apart by X-1 tooth groups; and a drive circuit comprising: X full-bridge circuits, each full-bridge circuit comprising two half-bridge circuits connected in parallel between an input terminal of the drive circuit and a ground terminal, each half-bridge circuit comprising two switches connected via a node, the two half-bridge circuits comprising a first and a second half-bridge circuit, the node of the first half-bridge circuit in the i-th full-bridge circuit being connected to the first end of the i-th phase conductor, and the node of the second half-bridge circuit in the i-th full-bridge circuit being connected to the second end of the i-th phase conductor.

Description

Technical Field

[0001] The present disclosure relates to the field of motor drive technology, and in particular to a drive circuit for a brushless motor and a control method, device, and apparatus thereof. Background Art

[0002] Brushless DC motors (BLDCs) offer the advantages of traditional DC motors while eliminating carbon brushes and slip rings, enabling low-speed, high-power operation. They are not only compact and lightweight, but also offer excellent stability and high efficiency. Consequently, they are widely used in electrical servo drives, information processing, transportation, home appliances, consumer electronics, and national defense.

[0003] A more common brushless DC motor is a single-phase brushless DC motor, which has the characteristics of small size and simple control.

[0004] Another common type of brushless DC motor is the three-phase BLDC motor. These motors offer a long lifespan, low noise, flexible drive options, and a mature industrial chain. They are widely applicable in a variety of civilian and military products. Furthermore, three-phase BLDC motors offer advantages in speed regulation due to their wide speed range, compact size, high efficiency, and minimal steady-state speed error.

[0005] Three-phase brushless DC motors utilize a "UVW" three-phase winding design with corresponding magnetic ring layouts. The three-phase windings can be connected in two ways: star and delta. For example, a driver program switches power to the three-phase windings in a cross-connected fashion to create a rotating magnetic field, which in turn drives the rotor with the magnetic rings. Summary of the Invention

[0006] According to one aspect of an embodiment of the present disclosure, a drive circuit for a brushless motor is provided, the brushless motor comprising: a stator core comprising Z tooth groups spaced apart along a first circumferential direction; a rotor comprising a magnetic ring having a pole number P, where P is an even number; and X-phase conductors wound around the tooth groups to form coils, where X ≥ 2 and Z = P × X; wherein in the conductors of the same phase, the coils on two adjacent tooth groups have opposite winding directions along a second circumferential direction of the tooth groups and are spaced apart by X-1 tooth groups; and the drive circuit comprises: X full-bridge circuits, each full-bridge circuit comprising two half-bridge circuits connected in parallel between an input terminal and a ground terminal of the drive circuit, each half-bridge circuit comprising two switches connected via a node, the two half-bridge circuits comprising a first half-bridge circuit and a second half-bridge circuit, wherein: the node of the first half-bridge circuit in the i-th full-bridge circuit is configured to be connected to the first end of the i-th phase conductor, and the node of the second half-bridge circuit in the i-th full-bridge circuit is configured to be connected to the second end of the i-th phase conductor, where 1 ≤ i ≤ X.

[0007] In some embodiments, N of the X full-bridge circuits are configured to provide, within one control cycle, N periodically varying drive signals to the N-phase conductors through their respective independent first and second ends, where 1≤N≤X, and the waveform of each drive signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

[0008] In some embodiments, the intensities of the N driving signals are continuously non-zero during the first time period.

[0009] In some embodiments, the moment when the first waveform and the second waveform overlap is a first moment, and the intensity of each driving signal in any time period in a cycle except the first moment is continuously non-zero.

[0010] In some embodiments, the intensity of each driving signal during the second period in one cycle is continuously zero.

[0011] In some embodiments, the intensity of each driving signal is not 0 at any time in a cycle except the second time period.

[0012] In some embodiments, during a period in which the intensity of any one driving signal is not 0 in one cycle, the intensities of the other driving signals in the N driving signals are all 0.

[0013] In some embodiments, the N driving signals have the same amplitude.

[0014] In some embodiments, the first waveform is centrally symmetric to the second waveform.

[0015] In some embodiments, the waveforms of the N driving signals are all square waves; or the first waveform and the second waveform conform to a sine function.

[0016] In some embodiments, the brushless motor includes one or more stator cores, the X-phase conductors are sequentially wound around the tooth groups along the first circumferential direction in the order from the 1st phase to the Xth phase; the N-phase conductors include the i-th phase conductor and the k-th phase conductor, and the phase difference between the drive signal of the i-th phase conductor and the drive signal of the k-th phase conductor is Wherein, 1≤i<k≤X, in the same stator core, the tooth group of the x-th phase conductor and the adjacent tooth groups on both sides have a gap at the closest position, and the gap has a center position in the first circumferential direction. Among all the gaps formed by the Z tooth groups, the central angle corresponding to the arc between the center position of the x-th phase conductor and the adjacent center position in the first circumferential direction is β x , and the sector corresponding to the arc includes at least part of the tooth group of the x-th phase conductor.

[0017] In some embodiments, the two switches of each half-bridge circuit include a first switch connected to the input terminal of the drive circuit and a second switch connected to the ground terminal of the drive circuit, the first switch is one of an n-type metal oxide semiconductor MOSFET and a p-type MOSFET, and the second switch is an n-type MOSFET.

[0018] According to another aspect of the embodiments of the present disclosure, there is provided a method for controlling a drive circuit for a brushless motor as described in any one of the above embodiments, comprising: controlling, within a control cycle, one switch in a first half-bridge circuit and one switch in a second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits to be turned on, so that the N full-bridge circuits provide N periodically varying drive signals to the N-phase conductors through their respective independent first and second ends, wherein 1≤N≤X, and the waveform of each drive signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

[0019] In some embodiments, the method further includes: determining a first amplitude of the N-phase conductor and each drive signal according to a target torque of the rotor; and determining a first frequency of each drive signal according to a target rotational speed of the rotor.

[0020] In some embodiments, when the target torque is higher than the first preset torque, N=X.

[0021] In some embodiments, when the target torque is higher than the first preset torque, the first amplitudes of the N driving signals are the same.

[0022] In some embodiments, when the target torque is lower than the second preset torque: N<X, and the first amplitudes of the N drive signals are the same; or N=X, and the first amplitudes of at least two of the N drive signals are different.

[0023] In some embodiments, a set of parameters required to achieve the target speed and the target torque is called from multiple sets of parameters, wherein the set of parameters represents the second frequency and the second amplitude of each drive signal; and based on the set of parameters, the first frequency and the first amplitude of each drive signal are determined.

[0024] According to another aspect of the embodiments of the present disclosure, there is provided a control device for a drive circuit of a brushless motor as described in any one of the above embodiments, comprising: a control module configured to control, within a control cycle, one switch in a first half-bridge circuit and one switch in a second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits to be turned on, so that the N full-bridge circuits provide N periodically varying drive signals to the N-phase conductors through their respective independent first and second ends, wherein 1≤N≤X, and the waveform of each drive signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

[0025] According to another aspect of the embodiments of the present disclosure, a control device for a drive circuit for a brushless motor as described in any one of the above embodiments is provided, comprising: a memory; and a processor coupled to the memory, configured to execute the control method described in any one of the above embodiments based on instructions stored in the memory.

[0026] According to another aspect of the embodiments of the present disclosure, a drive system for a brushless motor is provided, comprising: the drive circuit for the brushless motor described in any one of the above embodiments; and the control device for the drive circuit for the brushless motor described in any one of the above embodiments.

[0027] In some embodiments, the X full-bridge circuits are packaged in one chip.

[0028] In some embodiments, the control device is packaged in the chip.

[0029] According to another aspect of the embodiments of the present disclosure, there is provided a device comprising: the drive system for a brushless motor according to any one of the above embodiments; and the brushless motor.

[0030] In a drive circuit for a brushless motor provided in some embodiments of the present disclosure, the nodes of the two half-bridge circuits of each of the X full-bridge circuits are connected to the first and second ends of the corresponding single-phase conductor. Thus, by controlling the state of each switch in the drive circuit, the drive circuit can provide N drive signals to the N phase conductors of the brushless motor according to the brushless motor driving method of any of the above-described embodiments, thereby driving the brushless motor to provide high torque using a simple control method.

[0031] The technical solution of the present disclosure is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1A A schematic diagram of the coordination between the stator core and the magnetic ring in a brushless motor according to some embodiments of the present disclosure is shown.

[0034] Figure 1B A schematic diagram of the structure of a brushless motor in which a wire is wound around a stator core according to some embodiments of the present disclosure is shown.

[0035] Figure 2 It is a flowchart of a driving method for a brushless motor according to some embodiments of the present disclosure.

[0036] Figure 3A 、 3B 3C and 3C are schematic diagrams of the working principles of the brushless motors of some embodiments of the present disclosure.

[0037] Figure 4A 3 is a waveform diagram of a driving signal under a cross-power driving mode according to some embodiments of the present disclosure.

[0038] Figure 4B 3 is a waveform diagram of a driving signal under a cross-power driving mode according to other embodiments of the present disclosure.

[0039] Figure 5 3 is a waveform diagram of a driving signal in a cross-current driving mode according to some other embodiments of the present disclosure.

[0040] Figure 6A 3 is a waveform diagram of a driving signal in an alternating power-on driving mode according to some embodiments of the present disclosure.

[0041] Figure 6B 3 is a waveform diagram of a driving signal under an alternating power-on driving mode according to other embodiments of the present disclosure.

[0042] Figure 6C and 6D 3 is a waveform diagram of a driving signal in a cross-power driving mode according to some embodiments of the present disclosure.

[0043] Figure 6E It is a schematic structural diagram of two stator cores superimposed along the axial direction in a brushless motor according to some embodiments of the present disclosure.

[0044] Figure 7It is a flowchart of a driving method for a brushless motor according to some other embodiments of the present disclosure.

[0045] Figure 8 3 is a schematic structural diagram of a drive device for a brushless motor according to some embodiments of the present disclosure.

[0046] Figure 9 2 is a schematic structural diagram of a drive device for a brushless motor according to other embodiments of the present disclosure.

[0047] Figure 10A 3 is a schematic structural diagram of a drive circuit for a brushless motor according to some embodiments of the present disclosure.

[0048] Figure 10B 2 is a schematic structural diagram of a drive circuit for a brushless motor according to other embodiments of the present disclosure.

[0049] Figure 11 1 is a flow chart of a control method for a drive circuit of a brushless motor according to some embodiments of the present disclosure.

[0050] Figure 12 It is a flowchart of a control method for a drive circuit of a brushless motor according to other embodiments of the present disclosure.

[0051] Figure 13 1 is a schematic structural diagram of a control device for a drive circuit of a brushless motor according to some embodiments of the present disclosure.

[0052] Figure 14 1 is a schematic structural diagram of a control device for a drive circuit of a brushless motor according to other embodiments of the present disclosure.

[0053] Figure 15A is a circuit diagram of a drive system for a brushless motor according to some embodiments of the present disclosure.

[0054] Figure 15B is a circuit diagram of a drive system for a brushless motor according to some other embodiments of the present disclosure.

[0055] Figure 16 2 is a schematic structural diagram of a drive circuit for a brushless motor according to some other embodiments of the present disclosure. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present disclosure in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0057] Unless specifically stated otherwise, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0058] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0059] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0060] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0061] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0062] However, single-phase brushless DC motors and three-phase brushless DC motors each have disadvantages.

[0063] The torque provided by single-phase brushless DC motors is small, which leads to limited application scenarios. They are usually used in low-power household appliances.

[0064] Although three-phase brushless DC motors can provide large torque, they need to regularly switch and energize two phases of the "UVW" three-phase winding in six ways during the driving process. The drive signal of each phase winding is related to the drive signal of each other phase winding, making the control complex.

[0065] In view of this, the present disclosure proposes the following solutions.

[0066] An embodiment of the present disclosure provides a driving method for a brushless motor.

[0067] To facilitate understanding, first combine Figure 1A and 1B The brushless motors according to some embodiments of the present disclosure are described. Figure 1A A schematic diagram of the coordination between the stator core and the magnetic ring in a brushless motor according to some embodiments of the present disclosure is shown. Figure 1B A schematic diagram of the structure of a brushless motor in which a wire is wound around a stator core according to some embodiments of the present disclosure is shown.

[0068] like Figure 1A and 1B As shown, the brushless motor includes a stator core 1 , a rotor 2 and multi-phase conductors 3 .

[0069] The stator core 1 includes Z tooth groups 11 spaced apart along the circumferential direction of the stator core 1 (hereinafter referred to as the first circumferential direction for distinction), where Z is an integer. Figure 1A and 1B The stator core 1 further includes a yoke 12 , and the tooth set 11 is connected to the yoke 12 .

[0070] The number of stator cores 1 can be one or more. It should be understood that, when the brushless motor includes multiple stator cores 1 , the total number Z of tooth sets 11 is the number of all tooth sets 11 provided on all stator cores 1 .

[0071] In some embodiments, the stator core 1 includes a plurality of stator cores stacked in the axial direction. In this case, the tooth groups of different stator cores are staggered.

[0072] Each tooth set 11 may include one or a plurality of teeth 11 ′ adjacent to each other along the first circumferential direction. Figure 1B It is schematically shown that each tooth set 11 in the brushless motor includes one tooth 11 ′.

[0073] The rotor 2 includes a magnetic ring 21 having a pole number P, where P is an even number greater than or equal to 2. The rotor 2 may be, for example, coaxial with the stator core 1 and rotatable relative to the stator core 1 .

[0074] The magnetic ring 21 includes an equal number of south poles (S) and north poles (N), and the south poles and north poles are alternately arranged along a first circumferential direction of the stator core 1 . Figure 1A In the brushless motor shown, the number P of poles of the magnetic ring 21 is equal to 4. In this case, the magnetic poles along the first circumference of the stator core 1 are arranged in the order NSNS.

[0075] The number of the multi-phase conductors 3 is represented by X, that is, X is an integer greater than or equal to 2. For example, X can be equal to 2, 3, or 5. Figure 1A and 1B The case where X=2 is schematically shown.

[0076] The X-phase conductor 3 is wound around the teeth 11 to form coils 31. The coils 31 on two adjacent teeth 11 of the same phase conductor 3 are wound in opposite directions along the circumference of the teeth 11 (hereinafter referred to as the second circumferential direction) and are separated by X-1 teeth 11. Each phase conductor 3 has two independent ends: a first end and a second end.

[0077] It can be understood that, in any one phase conductor 3 , the other X-1 phase conductors 3 are wound on the X-1 tooth groups 11 spaced between the coils 31 on two adjacent tooth groups 11 .

[0078] For example, the stator core 1 may include X stator cores stacked axially, with each stator core having only one phase conductor wound around its tooth group, and different stator cores having different phase conductors wound around their tooth groups. In this case, the X-1 tooth groups 11 between the coils 31 on two adjacent tooth groups 11 on the same phase conductor 3 may belong to the other X-1 stator cores outside the stator core where these two tooth groups 11 are located.

[0079] Because the coils 31 on two adjacent tooth groups 11 in the same phase conductor 3 are wound in opposite directions along the second circumferential direction of the tooth group 11, the magnetic fields generated at these two adjacent tooth groups 11 are directed in opposite directions. The coils 31 on two adjacent tooth groups 11 in the same phase conductor 3 can be connected, for example, via a connecting section 32.

[0080] It should be understood that the winding directions of the coils 31 on the same tooth set 11 along the second circumferential direction are the same. For example, each tooth set 11 may include multiple teeth 11', and the wire 3 may be wound around these multiple teeth 11' to form multiple coils. In this case, the multiple coils formed on a tooth set 11 have the same winding direction along the second circumferential direction.

[0081] In the brushless motor of the disclosed embodiment, the number P of poles in the magnetic ring 21, the number X of multi-phase conductors 3, and the number Z of tooth groups 11 satisfy the following relationship: Z = P × X. In other words, each phase conductor 3 is wound around P tooth groups 11, and each magnetic pole corresponds to X tooth groups 11 wound around a different phase conductor 3.

[0082] As some implementations, each tooth set 11 includes a neck portion 111 and a shoe portion 112 .

[0083] For example, see Figure 1B Each tooth group 11 includes a tooth 11', and this tooth 11' includes a neck 111 and a boot 112. For another example, each tooth group 11 includes multiple teeth 11', each tooth 11' includes an independent neck 111, and each also includes an independent boot 112. For another example, each tooth group 11 includes multiple teeth 11', each tooth 11' includes an independent neck 111, and multiple teeth 11' share a boot 112.

[0084] In these implementations, the wire 3 is wound around the neck portion 111 of the tooth set 11, and a magnetic field is generated when the wire 3 is energized (i.e., the intensity of the drive signal provided to the wire 3 is not zero). Because the coils 31 on two adjacent tooth sets 11 in the same phase wire 3 are wound in opposite directions along the second circumferential direction of the tooth set 11, when any phase wire 3 is energized, the magnetic fields generated at the two adjacent tooth sets 11 around which the phase wire 3 is wound are in opposite directions.

[0085] The following combination Figure 1A and1B The brushless motor shown is explained. Figure 1A and 1B In the brushless motor shown, the brushless motor includes two phase conductors 3, namely a first phase conductor X1 and a second phase conductor X2, and the number of poles of the magnetic ring 21 is 4, that is, X = 2 and P = 4. In this case, the number of tooth groups 11 (i.e., teeth 11') Z = 8.

[0086] The first phase conductor X1 and the second phase conductor X2 are each wound around four different teeth 11 ′ to form four coils 31 .

[0087] Among the four coils 31 formed by the first-phase conductor X1, the coils 31 on any two adjacent teeth 11' along the first circumferential direction of the stator core 1 are separated by one tooth 11', and the second-phase conductor X2 is wound around this tooth 11'. Furthermore, the coils 31 on these two adjacent teeth 11' are wound in opposite directions along the second circumferential direction of the tooth 11'.

[0088] Similarly, among the four coils 31 formed by the second phase conductor X2, the coils 31 on any two adjacent teeth 11' along the first circumferential direction are separated by one tooth 11', and the first phase conductor X1 is wound around this tooth 11'. In addition, the winding directions of the coils 31 on the two adjacent teeth 11' along the second circumferential direction are also opposite.

[0089] It should be understood that Figure 1A and 1B It is merely schematically shown that the brushless motor according to the embodiment of the present disclosure may be an outer rotor structure (ie, the magnetic ring 21 is disposed outside the stator core 1 ), but the present disclosure is not limited thereto.

[0090] For example, the brushless motor may also be an inner rotor structure in which the magnetic ring 21 is arranged inside the stator core 1 .

[0091] For another example, the brushless motor may also be a planar structure in which the magnetic ring 21 and the stator core 1 are axially superimposed. In some implementations, the brushless motor may include a magnetic ring and a stator core that are axially superimposed. In other implementations, the brushless motor may include a magnetic ring and two stator cores that are axially superimposed, with the magnetic ring located between the two stator cores. In yet other implementations, the brushless motor may include two magnetic rings and a stator core that are axially superimposed, with the stator core located between the two magnetic rings.

[0092] The driving method for the brushless motor provided by the present disclosure will be described below. Figure 2 It is a flowchart of a driving method for a brushless motor according to some embodiments of the present disclosure.

[0093] like Figure 2As shown, the driving method for a brushless motor includes step 210 .

[0094] In step 210, N periodically varying drive signals are provided to the N-phase conductors 3 in the X-phase conductor 3 via their respective independent first and second ends. N is any integer greater than or equal to 1 and less than or equal to X.

[0095] For example, when X=2, N may be equal to 1 or 2. For another example, when X=3, N may be equal to 1, 2, or 3. For another example, when X=5, N may be equal to 1, 3, or 5.

[0096] Here, the waveform of each of the N driving signals in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0. In other words, the intensity of each driving signal in one cycle changes positively and negatively.

[0097] In some embodiments, the frequencies of the N driving signals are the same.

[0098] In some embodiments, at least two of the N drive signals have different amplitudes. In other embodiments, the N drive signals have the same amplitude.

[0099] In some embodiments, the first waveform and the second waveform of each driving signal are centrosymmetric. It will be understood that within one cycle of the driving signal, if one of the first waveform and the second waveform can overlap with the other of the first waveform and the second waveform after flipping and translating along the horizontal axis, then the first waveform and the second waveform are centrosymmetric.

[0100] In some embodiments, the waveforms of the N drive signals are all square waves. In other embodiments, the first waveform and the second waveform of each of the N drive signals conform to a sine function. For example, the waveforms of the N drive signals are all sine waves. In still other embodiments, the waveforms of the N drive signals are not square waves, and the first waveform and the second waveform do not conform to a sine function. For example, the waveforms of the N drive signals are all bimodal waves or other waveforms.

[0101] The following combination Figure 3A 、 3B and 3C illustrate the working principle of the brushless motor provided by the present invention. Figure 3A 、 3B 3C and 3C are schematic diagrams of the working principle of the brushless motor in some embodiments of the present disclosure. For ease of understanding, Figure 3A 、 3B and 3C, Figure 1A and 1B The magnetic ring 21 and the teeth 11 ′ in the brushless motor are shown in a straight line expansion form.

[0102] Figure 3A 、 3B In FIG3 and FIG3C, N=X=2. That is, a drive signal is provided to the first phase conductor X1 through the first and second ends (X1-IN and X1-OUT) of the first phase conductor X1, and a drive signal is provided to the second phase conductor X2 through the first and second ends (X2-IN and X2-OUT) of the second phase conductor X2.

[0103] For ease of distinction, in these illustrations, the teeth 11' around which the first phase conductor X1 is wound are represented by X1(1), X1(2), X1(3) and X1(4) from left to right, and the teeth 11' around which the second phase conductor X2 is wound are represented by X2(1), X2(2), X2(3) and X2(4) from left to right.

[0104] As previously mentioned, since the coils 31 on two adjacent teeth 11' in the same phase conductor 3 are wound in opposite directions along the circumference of the tooth 11', when the intensity of the drive signal of the first phase conductor X1 is not zero (i.e., the first phase conductor X1 is energized), magnetic fields with opposite directions are generated at any two adjacent points among X1(1), X1(2), X1(3), and X1(4). Similarly, when the intensity of the drive signal of the second phase conductor X2 is not zero (i.e., the second phase conductor X2 is energized), magnetic fields with opposite directions are also generated at any two adjacent points among X2(1), X2(2), X2(3), and X2(4).

[0105] First, see Figure 3A , the critical point O of each of the four magnetic poles (i.e., the midpoint of each magnetic pole in the circumferential direction of the stator core 1) is directly opposite to the boot portion 112 of X1(1), X1(2), X1(3) and X1(4) respectively. At this time, the intensity of the drive signal provided to the first phase conductor X1 is one of positive and negative (assuming it is positive). In this case, NSNS magnetic fields are generated at X1(1), X1(2), X1(3) and X1(4) in turn. The intensity of the drive signal provided to the second phase conductor X2 is one of positive and negative (assuming it is also positive). In this case, NSNS magnetic fields are generated at X2(1), X2(2), X2(3) and X2(4) in turn. Under the action of magnetic force, the magnetic ring 21 moves along the Figure 3A Rotate in the direction of the arrow shown.

[0106] After rotating by a certain angle (for example, 90°), the relative position relationship between the magnetic ring 21 and the tooth 11 ′ is as follows: Figure 3BAs shown, the critical point O of each of the four magnetic poles is opposite to the boot portion 112 of X2(1), X2(2), X2(3) and X2(4) respectively. At this time, the intensity of the drive signal provided to the first phase conductor X1 remains positive, and the NSNS magnetic field is still generated at X1(1), X1(2), X1(3) and X1(4) in sequence. However, the intensity of the drive signal provided to the second phase conductor X2 switches from positive to negative, and the magnetic field generated at X2(1), X2(2), X2(3) and X2(4) in sequence changes from NSNS to SNSN. Under the action of the magnetic force, the magnetic ring 21 continues to rotate in the direction of the arrow.

[0107] After rotating again by a certain angle (for example, 90°), the relative position relationship between the magnetic ring 21 and the tooth 11 ′ is as follows: Figure 3C As shown, the critical point O of each of the four magnetic poles is again opposite to the boot portion 112 of X1(1), X1(2), X1(3) and X1(4). At this time, the intensity of the drive signal provided to the first phase conductor X1 switches from positive to negative. In this case, the magnetic field generated at X1(1), X1(2), X1(3) and X1(4) changes from NSNS to SNSN. The intensity of the drive signal provided to the second phase conductor X2 remains negative, and the magnetic field of SNSN is still generated at X2(1), X2(2), X2(3) and X2(4). Under the action of the magnetic force, the magnetic ring 21 continues to rotate in the direction of the arrow.

[0108] From the above description, it can be seen that by providing the first phase conductor X1 and the second phase conductor X2 with driving signals with positive and negative strength changes within a cycle, the magnetic ring 21 can be made to rotate continuously in the same direction.

[0109] It should be understood that the above description uses the example of commutating the drive signal provided to each phase conductor 3 (i.e., switching between positive and negative) when the boot 112 of the tooth group 11 around which the phase conductor 3 is wound is aligned with the critical point O of the magnetic pole. In this case, the efficiency of the brushless motor can be improved. However, in some embodiments, the drive signal can also be commutated when the boot 112 is not aligned with the critical point O of the magnetic pole.

[0110] In the brushless motor driving method provided by the present disclosure, N drive signals are provided to N phase conductors 3 via their respective independent first and second ends. In this manner, as N increases, the torque provided by the brushless motor increases. At the same time, because the N drive signals are independent of each other, control remains relatively simple. Thus, a brushless motor can be driven to provide greater torque using a simple control method.

[0111] Furthermore, the brushless motor driving method provided by the embodiment of the present disclosure can provide driving signals to different numbers of N-phase conductors 3 in different scenarios, so that the brushless motor can operate in different working conditions. This can improve the versatility of the brushless motor.

[0112] In the case of 2≤N≤X, the brushless motor driving method provided by the present disclosure can be further divided into two different modes: cross-energization and alternating energization, depending on whether the N-phase conductors 3 are continuously energized in the same period. These two modes will be described below.

[0113] First, the cross-current method will be described.

[0114] In this cross-energization mode, the N drive signals supplied to the N-phase conductors 3 maintain non-zero intensities during the first period. In other words, the N-phase conductors 3 are continuously energized during the same first period, meaning that the periods of continuous energization of the N-phase conductors 3 overlap with each other. This improves the utilization of the windings and core in the brushless motor.

[0115] Because two phase windings are energized while one phase winding is de-energized during the same time period, the utilization rate of the windings and core in a conventional three-phase brushless DC motor is only about 66%. For example, when N=X, the X-phase conductor 3 is continuously energized during the same first time period. That is, the utilization rate of the windings and core in the brushless motor during the first time period can reach the maximum utilization rate of 100%, which is superior to conventional three-phase brushless DC motors.

[0116] The following combination Figure 4A 、 4B and Figure 5 The following describes some embodiments of the cross-powering method. Figure 4A 3 is a waveform diagram of a driving signal under a cross-power driving mode according to some embodiments of the present disclosure. Figure 4B 3 is a waveform diagram of a driving signal under a cross-power driving mode according to other embodiments of the present disclosure. Figure 5 3 is a waveform diagram of a driving signal in a cross-current driving mode according to some other embodiments of the present disclosure.

[0117] In some embodiments, the moment when the first waveform with intensity greater than 0 and the second waveform with intensity less than 0 in each driving signal overlap is the first moment, and the intensity of each driving signal is continuously non-zero in any period of time in a cycle except the first moment.

[0118] In other words, in these embodiments, the waveform of each driving signal provided is continuous, that is, the intensity of each driving signal provided is not continuously 0 in any period of time, but is 0 only when switching between positive and negative (ie, the first moment).

[0119] For example, see Figure 4A and 4B The waveform of the drive signal provided to each phase conductor is a sine wave. At the first moment when the first waveform and the second waveform of the drive signal overlap, the intensity of the drive signal is 0. During any period other than the first moment, the intensity of the drive signal is continuously non-zero.

[0120] Figure 4A The schematic diagram shows the case where X=N=2. In this case, the phase difference between the driving signal of the first phase conductor and the driving signal of the second phase conductor is θ 12 .

[0121] Figure 4B The schematic diagram shows the case where X=N=3. In this case, the phase difference between the driving signal of the first phase conductor and the driving signal of the second phase conductor is θ 12 The phase difference between the driving signal of the second phase conductor and the driving signal of the third phase conductor is θ 23 , and the phase difference between the driving signal of the first phase conductor and the driving signal of the third phase conductor is θ 13 .

[0122] In these embodiments, the first period during which the N-phase conductors 3 are simultaneously energized is extended, thereby further improving the utilization of the windings and core of the brushless motor. For example, when N=X, the utilization of the windings and core of the brushless motor can reach the maximum utilization of 100% for a longer period of time.

[0123] In addition, when the N-phase conductor 3 is continuously energized, the jitter inside the stator core 1 is reduced, thereby reducing the electromagnetic noise generated when the brushless motor is running and extending the life of the bearings in the brushless motor.

[0124] As some implementations, such as Figure 4A and 4B As shown in the figure, in the cross-current mode, the N drive signals are all continuous sine waves. In this mode, each drive signal only needs two switching cycles to complete the rotation of a pair of magnetic rings. At the same speed and torque, a traditional three-phase brushless DC motor requires six switching cycles to complete the rotation of a pair of magnetic rings.

[0125] Therefore, in the cross-powered mode, using a drive signal with a sinusoidal waveform to drive the brushless motor can reduce the computing power requirements of the chip that provides the drive signal.

[0126] In some other embodiments, the intensity of each driving signal during the second period in one cycle is continuously 0. In other words, in these embodiments, the waveform of each driving signal provided is intermittent rather than continuous.

[0127] As some implementations, the intensity of each driving signal is not 0 at any time except the second time period in one cycle.

[0128] For example, see Figure 5 The driving signal provided to the first phase conductor and the driving signal provided to the second phase conductor are both discontinuous waveforms, and their respective first waveforms and second waveforms both conform to a sine function.

[0129] Specifically, the driving signal of the first phase conductor can be obtained by advancing the commutation position of the continuous sinusoidal wave signal by the phase angle f1' and lagging it by the phase angle f1", and the driving signal of the second phase conductor can be obtained by advancing the commutation position of the continuous sinusoidal wave signal by the phase angle f2' and lagging it by the phase angle f2".

[0130] In this case, the intensity of each driving signal is continuously 0 during the period of advance and lag of the commutation position, and the intensity is not 0 at any time except during this period.

[0131] As mentioned above, the drive signal provided to each phase conductor 3 preferably commutates when the boot portion 112 of the tooth set 11 around which the phase conductor 3 is wound is aligned with the critical point of the magnetic pole. However, in practice, due to various reasons (for example, errors in the average distribution angle of the magnetic ring of the brushless motor due to production; for example, errors in the drive detection of the brushless motor), it may not be possible to accurately control the commutation point to occur at the moment when it is aligned with the critical point of the magnetic pole, but rather to advance or lag this moment to a certain extent. This will cause the winding to perform useless work in the period before or after this moment, thereby reducing the efficiency of the brushless motor.

[0132] By providing a driving signal whose intensity is continuously 0 during the second period and whose intensity is not 0 at any time except the second period, the useless work done by the winding can be reduced, thereby improving the efficiency of the brushless motor.

[0133] Next, combine Figure 6A and 6B The driving method of alternating energization is described. Figure 6A 3 is a waveform diagram of a driving signal in an alternating power-on driving mode according to some embodiments of the present disclosure. Figure 6B 3 is a waveform diagram of a driving signal under an alternating power-on driving mode according to other embodiments of the present disclosure.

[0134] In the alternating power-on mode, during a period in which the intensity of any one driving signal is not 0 in one cycle, the intensities of the other driving signals in the N driving signals are all 0. 2≤N≤X.

[0135] In other words, in the alternating energization mode, each driving signal is intermittent and discontinuous, and any two phase conductors 3 will not be continuously energized at the same time in any period of time.

[0136] For example, see Figure 6A and 6B The waveform of the driving signal provided to each phase conductor is a square wave. During the period when the driving signal of any phase conductor is continuously non-zero, the intensity of the driving signal of the other phase conductors is zero. Figure 6A The case where X=N=2 is schematically shown. Figure 6B The case where X=N=3 is schematically shown.

[0137] Since the intensity of only one driving signal is continuously non-zero in the same period, driving the brushless motor by using an alternating power-on driving method can further simplify the control.

[0138] Compared to drive signals with other waveforms, providing a drive signal with a square waveform is simpler to control. Therefore, using a drive signal with a square waveform to drive a brushless motor in an alternating power supply mode can further simplify control.

[0139] So far, the two driving modes of cross-current and alternating current have been described.

[0140] It should be understood that the above merely schematically illustrates that the driving signal in the cross-energization driving mode conforms to a sine function, while the waveform of the driving signal in the alternating-energization driving mode is a square wave, and the embodiments of the present disclosure are not limited thereto.

[0141] In some embodiments, the brushless motor can be driven by one of two driving modes: cross-current and alternating current. In other embodiments, the brushless motor can be driven by a combination of cross-current and alternating current.

[0142] The following further describes some embodiments of the driving method for a brushless motor provided by the present disclosure. It should be understood that these embodiments are applicable to both the cross-energization driving mode and the alternating-energization driving mode.

[0143] In some embodiments, when N is greater than or equal to 2, the magnetic ring 21 can be driven to rotate in different directions by adjusting the order in which the driving signals are provided to the N-phase conductors 3 .

[0144] Below is Figure 6C and Figure 6D The situation shown is used as an example for explanation. Figure 6C and 6D 3 is a waveform diagram of a driving signal in a cross-power driving mode according to some embodiments of the present disclosure.

[0145] like Figure 6C As shown, the first-phase conductor is supplied with a first-phase drive signal starting at time t0, and the second-phase conductor is supplied with a second-phase drive signal starting at time t1 after time t0. That is, the first-phase conductor is supplied with the first-phase drive signal first, followed by the second-phase conductor. In this case, the magnetic ring 21 can rotate in a first direction (e.g., clockwise).

[0146] like Figure 6D As shown, the second-phase conductor drive signal is supplied to the second-phase conductor starting at time t0, and the first-phase conductor drive signal is supplied to the first-phase conductor starting at time t1 after time t0. That is, the second-phase conductor drive signal is supplied to the second-phase conductor first, followed by the first-phase conductor drive signal. In this case, the magnetic ring 21 can rotate in a second direction (e.g., counterclockwise) that is opposite to the first direction.

[0147] In this way, the magnetic ring 21 can be driven to rotate in different directions by adjusting the order of providing driving signals to the N-phase conductors 3, thereby improving the versatility of the brushless motor.

[0148] In some embodiments, the brushless motor includes one or more stator cores 1, and the X-phase conductors 3 are wound around the teeth 11 in order from the 1st to the Xth phase along the first circumference of the stator core 1. The N-phase conductors include the i-th phase conductor and the k-th phase conductor.

[0149] In this case, the phase difference between the driving signal of the i-th phase conductor and the driving signal of the k-th phase conductor is Wherein, 1≤i<k≤X. It should be understood that x in the formula is a variable, which takes any integer greater than or equal to i and less than or equal to k-1.

[0150] In some embodiments, θ ik The value range of is [1°, 180°). As some implementations, θ ik The value range of is [15°, 120°]. For example, θ ik It can be an integer multiple of 15°, such as 15°, 30°, 45°, 60°, etc.

[0151] In the same stator core 1 , there is a gap between the teeth group 11 of the x-phase conductor and the adjacent teeth groups 11 on both sides at the closest positions.

[0152] For example, if the brushless motor includes a single stator core 1, the tooth groups 11 adjacent to the tooth group 11 of the x-phase conductor are the tooth groups 11 of other phase conductors. For another example, if the brushless motor includes multiple stator cores 1 stacked axially, the tooth groups 11 adjacent to the tooth group 11 of the x-phase conductor are the tooth groups 11 of the same phase conductor.

[0153] Each gap has a center position in the first circumferential direction. In all gaps formed by the Z tooth groups 11, the central angle corresponding to the arc between the center position of the x-th phase conductor and the adjacent center position in the first circumferential direction is β x , and the sector corresponding to the arc includes at least part of the tooth group 11 of the x-th phase conductor.

[0154] For example, see Figure 6E A brushless motor can include two stator cores 1 stacked axially. The first stator core 1 is represented by a solid line, and the second stator core 1 is represented by a dashed line. In the first stator core 1, two adjacent tooth groups have a gap at their closest locations; in the second stator core 1, two adjacent tooth groups also have a gap at their closest locations. In this case, the central angle β1 of the first-phase conductor is the central angle corresponding to the arc between a center position of the first-phase conductor and a center position of the second-phase conductor adjacent to the first-phase conductor center position in the first circumferential direction.

[0155] For the sake of convenience, β x In short, it is the central angle of the x-phase conductor.

[0156] For example, in the case of X=2, i=1, k=2, that is, the phase difference θ between the driving signal of the first phase conductor and the driving signal of the second phase conductor is 12 =β1×P / 2.

[0157] For another example, when X=3, there are three possible values. In the first case, i=1, k=2, that is, the phase difference θ between the driving signal of the first phase conductor and the driving signal of the second phase conductor is 12 =β1×P / 2. In the second case, i=2, k=3, that is, the phase difference θ between the drive signal of the second phase conductor and the drive signal of the third phase conductor 23 =β2×P / 2. In the third case, i=1, k=3, that is, the phase difference θ between the driving signal of the first phase conductor and the driving signal of the third phase conductor 13 =(β1+β2)×P / 2.

[0158] Combine Figure 1A From the above, the central angle β1 of the first phase conductor X1 is 45°, the central angle β2 of the second phase conductor X2 is 45°, and the number of poles P of the magnetic ring 21 is 4.

[0159] In this case, see Figure 4A and Figure 6A , the phase difference θ between the driving signal of the first phase conductor and the driving signal of the second phase conductor 12 =2×45°=90°.

[0160] It should be understood that Figure 1A It is only schematically shown that the central angles of the different phase conductors 3 are equal, but the embodiment of the present disclosure is not limited thereto, as long as the sum of the central angles of the different phase conductors 3 is equal to β. Figure 1A , β is the central angle of a single magnetic pole on the magnetic ring 21 in the first circumferential direction, and its size is equal to 360° divided by the number of magnetic poles P.

[0161] by Figure 1A Taking the brushless motor shown in the figure as an example, X = 2 and P = 4. In this case, β = 90°. In other words, β1 and β2 can be any angle greater than 0° and less than 90°, as long as β1 + β2 = 90°.

[0162] In the above embodiment, the phase difference between the drive signals provided to any two phase conductors 3 is determined according to the number of poles of the magnetic ring 21 and the structural parameters of the stator core 1. In this way, the operation of the brushless motor can be accurately and stably controlled.

[0163] As mentioned above, the brushless motor can be driven to operate in different working conditions by providing driving signals to different numbers of N-phase conductors 3. In view of this, the present disclosure further provides a driving method for a brushless motor according to the following embodiment.

[0164] Figure 7 It is a flowchart of a driving method for a brushless motor according to some other embodiments of the present disclosure.

[0165] like Figure 7 As shown, the driving method for the brushless motor further includes step 220 and step 230. Step 220 and step 230 can be performed before step 210.

[0166] In step 220 , first amplitudes of the N-phase conductors and each driving signal are determined according to the target torque of the rotor.

[0167] In some implementations, when the target torque is greater, N is greater. In other implementations, when the target torque is greater, the first amplitude of each drive signal is greater. In still other implementations, when the target torque is greater, N is greater and the first amplitude of each drive signal is greater.

[0168] In step 230 , a first frequency of each driving signal is determined according to the target rotational speed of the rotor.

[0169] As some implementations, when the target rotation speed is greater, the first frequency of each driving signal is greater.

[0170] In this way, the N-phase conductor, the frequency and amplitude of the drive signal can be adjusted according to the target torque and target speed of the rotor to drive the brushless motor to operate under the working conditions with the target torque and target speed.

[0171] In some embodiments, when the target torque of the rotor is higher than the first preset torque, N = X. That is, when the target torque of the rotor is higher than the first preset torque, a drive signal is provided to each phase conductor 3 of the brushless motor. In this manner, by providing a drive signal to each phase conductor 3 of the brushless motor, the brushless motor can be driven to operate at a higher target torque.

[0172] In some implementations, when the target torque of the rotor is higher than the first preset torque, N=X, and the first amplitudes of the N drive signals are the same. In this manner, since the amplitudes provided to each phase conductor 3 are the same, the brushless motor can be driven to operate at a higher target torque using a simple control method.

[0173] In some embodiments, when the target torque of the rotor is lower than the second preset torque, N<X, and the first amplitudes of the N drive signals are the same. In this manner, since the amplitudes provided to the N-phase conductors 3 are the same, the brushless motor can be driven to operate at a lower target torque using a simple control method.

[0174] In other embodiments, when the target torque of the rotor is lower than the second preset torque, N=X, and the first amplitudes of at least two of the N drive signals are different. In this manner, by providing drive signals with larger amplitudes to some of the X-phase conductors 3 and drive signals with smaller amplitudes to other conductors 3, the brushless motor can be driven to operate at a lower target torque.

[0175] In some embodiments, the first frequency and the first amplitude of each of the N drive signals may be determined as follows.

[0176] First, a set of parameters required to achieve the target speed and target torque can be retrieved from multiple sets of parameters. This set of parameters represents the second frequency and second amplitude of each drive signal. Then, the first frequency and first amplitude of each drive signal can be determined based on the retrieved set of parameters.

[0177] For example, each of the multiple sets of parameters is used to enable the rotor to achieve a different speed and torque. These multiple sets of parameters can be pre-stored in a storage unit. The storage unit can be, for example, a read-only memory (ROM).

[0178] After obtaining the current target speed and target torque of the brushless motor rotor, a set of parameters that matches the target speed and target torque can be retrieved from the multiple sets of parameters. Then, the second frequency and second amplitude represented by this set of parameters can be fine-tuned based on the actual operating conditions of the brushless motor (e.g., friction) to obtain the first frequency and first amplitude of each drive signal.

[0179] In these embodiments, a set of parameters required to achieve the target rotor speed and target torque can be directly retrieved, and the first frequency and first amplitude of each drive signal can be determined based on this set of parameters. This approach can reduce the amount of real-time calculations required to drive the brushless motor.

[0180] The embodiment of the present disclosure also provides a driving device for a brushless motor.

[0181] Figure 8 1 is a schematic structural diagram of a drive device for a brushless motor according to some embodiments of the present disclosure. The brushless motor includes a stator core 1, a rotor 2, and an X-phase conductor 3, where X ≥ 2. The stator core 1 includes Z tooth groups 11 spaced apart along a first circumferential direction. The rotor 2 includes a magnetic ring 21 with a pole number P, where P is an even number. The X-phase conductor 3 is wound around the tooth group 11 to form a coil 31, where Z = P × X. In the same phase conductor 3, the coils 31 on two adjacent tooth groups 11 have opposite winding directions along the second circumferential direction of the tooth group 11 and are spaced apart by X-1 tooth groups 11.

[0182] like Figure 8 As shown, a driving device 800 for a brushless motor includes a providing module 801 .

[0183] The providing module 801 is configured to provide N periodically varying drive signals to the N-phase conductors 3 via the first and second independent ends of the N-phase conductors 3. Here, 1≤N≤X, and the waveform of each drive signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

[0184] In some embodiments, the intensities of the N driving signals in the first period are continuously not 0. That is, the driving apparatus 800 for the brushless motor can drive the brushless motor in a cross-powered manner.

[0185] In other embodiments, 2≤N≤X, and during a period in which the intensity of any one driving signal is not 0 in a cycle, the intensities of the other driving signals in the N driving signals are all 0. That is, the driving device 800 for a brushless motor can drive the brushless motor in an alternating energizing manner.

[0186] It should be understood that the driving device 800 for a brushless motor may further include various other modules to execute the driving method for a brushless motor of any of the above embodiments.

[0187] Figure 9 2 is a schematic structural diagram of a drive device for a brushless motor according to other embodiments of the present disclosure.

[0188] like Figure 9 As shown, a driving device 900 for a brushless motor includes a memory 901 and a processor 902 coupled to the memory 901 . The processor 902 is configured to execute the driving method for a brushless motor of any one of the above embodiments based on instructions stored in the memory 901 .

[0189] The memory 901 may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application program, a boot loader, and other programs.

[0190] The drive device 900 may further include an input / output interface 903, a network interface 904, a storage interface 905, and the like. These input / output interfaces 903, the network interface 904, and the storage interface 905, as well as the memory 901 and the processor 902, may be connected, for example, via a bus 906. The input / output interface 903 provides a connection interface for input / output devices such as a display, mouse, keyboard, and touch screen. The network interface 904 provides a connection interface for various networked devices. The storage interface 905 provides a connection interface for external storage devices such as SD cards and USB flash drives.

[0191] An embodiment of the present disclosure further provides a computer-readable storage medium comprising computer program instructions, which, when executed by a processor, implements the driving method for a brushless motor of any one of the above embodiments.

[0192] The present disclosure also provides a drive circuit for a brushless motor. The brushless motor includes a stator core 1, a rotor 2, and an X-phase conductor 3, where X≥2. The stator core 1 includes Z tooth groups 11 spaced apart along a first circumferential direction. The rotor 2 includes a magnetic ring 21 with a pole number P, where P is an even number. The X-phase conductor 3 is wound around the tooth group 11 to form a coil 31, where Z=P×X. In the same phase conductor 3, the coils 31 on two adjacent tooth groups 11 have opposite winding directions along the second circumferential direction of the tooth group 11 and are spaced apart by X-1 tooth groups 11.

[0193] Figure 10A 3 is a schematic structural diagram of a drive circuit for a brushless motor according to some embodiments of the present disclosure. Figure 10B2 is a schematic structural diagram of a drive circuit for a brushless motor according to other embodiments of the present disclosure.

[0194] Figure 10A The case of X=2 is shown. Figure 10B The case of X=3 is shown. Figure 10A and 10B The driving circuit for the brushless motor includes X full-bridge circuits 1010. Each full-bridge circuit 1010 includes two half-bridge circuits 1011 connected in parallel between an input terminal VIN and a ground terminal GND of the driving circuit.

[0195] Each half-bridge circuit 1011 includes two switches S1 and S2 connected via a node P. The switches S1 - S2 may be, for example, thyristors (also known as silicon controlled rectifiers), metal oxide semiconductors (MOSFETs), or insulated gate bipolar transistors (IGBTs).

[0196] The two half-bridge circuits 1011 in each full-bridge circuit 1010 include a first half-bridge circuit 1011a and a second half-bridge circuit 1011b. Here, the node P of the first half-bridge circuit 1011a in the i-th full-bridge circuit 1010 is configured to be connected to the first end of the i-th phase conductor, and the node P of the second half-bridge circuit 1011b in the i-th full-bridge circuit 1010 is configured to be connected to the second end of the i-th phase conductor 3. 1≤i≤X.

[0197] That is, the X full-bridge circuits 1010 correspond one-to-one to the X phase conductors 3 of the brushless motor BM. The node P of the first half-bridge circuit 1011a in each full-bridge circuit 1010 is connected to the first end of the corresponding phase conductor 3, and the node P of the second half-bridge circuit 1011b is connected to the second end of the corresponding phase conductor 3.

[0198] For example, see Figure 10A The nodes P of the two first half-bridge circuits 1011a are respectively connected to the first end X1-IN of the first phase conductor and the first end X2-IN of the second phase conductor, and the nodes P of the two second half-bridge circuits 1011b are respectively connected to the second end X1-OUT of the first phase conductor and the second end X2-OUT of the second phase conductor.

[0199] For example, see Figure 10B The nodes P of the three first half-bridge circuits 1011a are respectively connected to the first end X1-IN of the first phase conductor, the first end X2-IN of the second phase conductor, and the first end X3-IN of the third phase conductor, and the nodes P of the three second half-bridge circuits 1011b are respectively connected to the second end X1-OUT of the first phase conductor, the second end X2-OUT of the second phase conductor, and the second end X3-OUT of the third phase conductor.

[0200] By controlling the states of switches S1 and S2 in the driving circuit for a brushless motor of the above embodiment, the driving circuit can provide N driving signals to the N-phase conductors of the brushless motor according to the driving method for a brushless motor of any of the above embodiments.

[0201] In some embodiments, N of the X full-bridge circuits 1010 are configured to provide N periodically varying drive signals to the N-phase conductors 3 through their respective independent first and second ends within one control cycle, where 1≤N≤X.

[0202] Here, the waveform of each driving signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0. In some embodiments, the N driving signals provided by the driving circuit have the same frequency.

[0203] For example, of the two switches S1 and S2 of each half-bridge circuit 1011 , the first switch S1 is connected to the input terminal VIN of the driving circuit, and the second switch S2 is connected to the ground terminal GND of the driving circuit.

[0204] In this case, by controlling the first switch S1 in the first half-bridge circuit 1011a of the i-th full-bridge circuit 1010 to be turned on and the second switch S2 to be turned off, and controlling the second switch S2 in the second half-bridge circuit 1011b of the i-th full-bridge circuit 1010 to be turned on and the first switch S1 to be turned off, the i-th full-bridge circuit 1010 can be controlled to provide a first waveform with an intensity greater than 0 to the i-th phase conductor.

[0205] Conversely, by controlling the first switch S1 in the second half-bridge circuit 1011b of the i-th full-bridge circuit 1010 to be turned on and the second switch S2 to be turned off, and controlling the second switch S2 in the first half-bridge circuit 1011a of the i-th full-bridge circuit 1010 to be turned on and the first switch S1 to be turned off, the i-th full-bridge circuit 1010 can be controlled to provide a second waveform with an intensity less than 0 to the i-th phase conductor.

[0206] In some embodiments, the first switch S1 connected to the input terminal VIN of the driver circuit is one of an n-type MOSFET and a p-type MOSFET, and the second switch S2 connected to the ground terminal GND of the driver circuit is an n-type MOSFET. For example, the first switch S1 is an n-type MOSFET; for another example, the first switch S1 is a p-type MOSFET. This can improve driver stability.

[0207] In some embodiments, at least two of the N driving signals provided by the driving circuit have different amplitudes. In other embodiments, the N driving signals provided by the driving circuit have the same amplitude.

[0208] In some embodiments, the first waveform and the second waveform of each driving signal provided by the driving circuit are centrosymmetric.

[0209] In some embodiments, the waveforms of the N driving signals provided by the driving circuit are all square waves. In other embodiments, the first waveform and the second waveform conform to a sine function.

[0210] In some embodiments, the X-phase conductor 3 is wound around the teeth set 11 in sequence from the 1st phase to the Xth phase along the first circumferential direction. The N-phase conductor includes the i-th phase conductor and the k-th phase conductor.

[0211] The phase difference between the driving signal of the i-th phase conductor and the driving signal of the k-th phase conductor provided by the driving circuit Among them, 1≤i<k≤X.

[0212] In the same stator core 1 , a gap is present between the teeth group 11 of the x-phase conductor and the adjacent teeth groups 11 on both sides at their closest positions, and the gap has a central position in the first circumferential direction.

[0213] In all gaps formed by the Z tooth groups 11, the central angle of the arc between the center position of the x-th phase conductor and the adjacent center position in the first circumferential direction is β x , and the sector corresponding to the arc includes at least part of the tooth group 11 of the x-th phase conductor.

[0214] As some implementations, the drive circuit for the brushless motor provides N drive signals to the N-phase conductors 3 in a cross-current manner.

[0215] In these implementations, the intensities of the N driving signals in the first time period are continuously non-0. That is, the intensities of the N driving signals in the same time period are continuously non-0.

[0216] In some embodiments, the moment when the first waveform and the second waveform of each driving signal provided by the driving circuit overlap is the first moment, and the intensity of each driving signal in any period of time in a cycle except the first moment is continuously non-zero. That is, each driving signal is continuous and uninterrupted.

[0217] In other embodiments, the intensity of each drive signal provided by the drive circuit is continuously zero during the second time period of a cycle. That is, the drive signal is intermittent. As some implementations, the intensity of each drive signal provided by the drive circuit is not zero at any time during a cycle except the second time period.

[0218] As another implementation manner, the drive circuit for the brushless motor provides N drive signals to the N-phase conductors 3 in an alternating energization manner.

[0219] In these implementations, during a period in which the intensity of any one driving signal is not 0 in one cycle, the intensities of the other driving signals in the N driving signals are all 0. That is, the intensities of any two driving signals provided by the driving circuit are not continuously non-zero at the same time.

[0220] Figure 11 1 is a flow chart of a control method for a drive circuit of a brushless motor according to some embodiments of the present disclosure.

[0221] like Figure 11 As shown, the control method for the driving circuit of the brushless motor includes step 1110.

[0222] In step 1110, within a control cycle, one switch in the first half-bridge circuit and one switch in the second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits are controlled to be turned on, so that the N full-bridge circuits provide N periodically varying drive signals to the N-phase conductors through their respective independent first and second ends.

[0223] Here, 1≤N≤X, and the waveform of each driving signal in one period includes a first waveform having an intensity greater than 0 and a second waveform having an intensity less than 0.

[0224] In this way, the N full-bridge circuits in the brushless motor driving circuit of any of the above embodiments can be controlled to provide N periodically changing driving signals to the N-phase wires 3 through their respective independent first and second ends.

[0225] Figure 12 It is a flowchart of a control method for a drive circuit of a brushless motor according to other embodiments of the present disclosure.

[0226] like Figure 12 As shown, the control method for the driving circuit of the brushless motor further includes steps 1120 to 1130.

[0227] In step 1120 , first amplitudes of the N-phase conductor and each driving signal are determined according to the target torque of the rotor.

[0228] In step 1130 , a first frequency of each driving signal is determined according to the target rotational speed of the rotor.

[0229] Step 1120 and step 1130 may be performed before step 1110 .

[0230] In this way, the drive circuit can be controlled according to the target torque and target speed of the rotor, so that the drive circuit provides N drive signals capable of driving the brushless motor to operate at a working condition with the target torque and target speed.

[0231] In some embodiments, when the target torque is higher than the first preset torque, N = X. In some implementations, when the target torque is higher than the first preset torque, the first amplitudes of the N driving signals are the same.

[0232] In some embodiments, when the target torque is lower than the second preset torque, N<X, and the first amplitudes of the N drive signals are the same. In other embodiments, when the target torque is lower than the second preset torque, N=X, and the first amplitudes of at least two of the N drive signals are different.

[0233] In some embodiments, a set of parameters required to achieve the target speed and target torque is retrieved from a plurality of sets of parameters, where the set of parameters represents the second frequency and the second amplitude of each drive signal. The first frequency and the first amplitude of each drive signal are then determined based on the retrieved set of parameters.

[0234] Since the control method for the driving circuit of the brushless motor basically corresponds to the embodiment of the driving method for the brushless motor in the foregoing text, the description is relatively simple, and the relevant parts can be referred to the foregoing description.

[0235] The embodiment of the present disclosure also provides a control device for a drive circuit of a brushless motor.

[0236] Figure 13 1 is a schematic structural diagram of a control device for a drive circuit of a brushless motor according to some embodiments of the present disclosure.

[0237] like Figure 13 As shown, the control device 1300 for the driving circuit of the brushless motor includes a control module 1301 .

[0238] The control module 1301 is configured to control, within a control cycle, one switch in the first half-bridge circuit and one switch in the second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits to be turned on, so that the N full-bridge circuits provide N periodically varying drive signals to the N-phase conductors through their respective independent first and second ends.

[0239] Here, 1≤N≤X, and the waveform of each driving signal in one period includes a first waveform having an intensity greater than 0 and a second waveform having an intensity less than 0.

[0240] In some embodiments, the control module 1301 is configured to control the drive circuit so that the drive circuit provides the drive signal to the brushless motor in a cross-current manner. In other embodiments, the control module 1301 is configured to control the drive circuit so that the drive circuit provides the drive signal to the brushless motor in an alternating current manner.

[0241] It should be understood that the control device 1300 may further include various other modules to execute the control method for the drive circuit of the brushless motor of any of the above embodiments.

[0242] Figure 14 1 is a schematic structural diagram of a control device for a drive circuit of a brushless motor according to other embodiments of the present disclosure.

[0243] like Figure 14 As shown, the control device 1400 for the drive circuit of a brushless motor includes a memory 1401 and a processor 1402 coupled to the memory 1401, and the processor 1402 is configured to execute the control method for the drive circuit of a brushless motor of any one of the above embodiments based on instructions stored in the memory 901.

[0244] The memory 1401 may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, application programs, a boot loader, and other programs.

[0245] The control device 1400 may also include an input / output interface 1403, a network interface 1404, a storage interface 1405, and the like. These input / output interfaces 1403, network interface 1404, and storage interface 1405, as well as the memory 1401 and processor 1402, may be connected, for example, via a bus 1406. The input / output interface 1403 provides a connection interface for input / output devices such as a display, mouse, keyboard, and touch screen. The network interface 1404 provides a connection interface for various networked devices. The storage interface 1405 provides a connection interface for external storage devices such as SD cards and USB flash drives.

[0246] The present disclosure also provides a drive system for a brushless motor. The drive system includes a drive circuit for a brushless motor according to any of the aforementioned embodiments, and a control device for the drive circuit for a brushless motor according to any of the aforementioned embodiments (e.g., control device 1300 / 1400). The control device may be, for example, a microcontroller unit (MCU).

[0247] In some embodiments, X full-bridge circuits in a drive circuit for a brushless motor are packaged in X chips, that is, one full-bridge circuit is packaged in one chip. In other embodiments, X full-bridge circuits in a drive circuit for a brushless motor are packaged in one chip.

[0248] In some embodiments, the control device and the driving circuit for the brushless motor are packaged in different chips.

[0249] In other embodiments, the control device for the brushless motor drive circuit and the drive circuit are packaged in the same chip. For example, X full-bridge circuits are packaged in a one-to-one correspondence within X chips, and each chip may also package a sub-control device for controlling a full-bridge circuit within that chip. In this case, the control device for the brushless motor drive circuit includes all sub-control devices packaged within the X chips.

[0250] In some embodiments, the drive system further includes X Hall effect detectors. For example, the X Hall effect detectors may be packaged in the same chip as the X full-bridge circuits. For another example, each Hall effect detector may be packaged in the same chip as a corresponding full-bridge circuit.

[0251] Figure 15A is a circuit diagram of a drive system for a brushless motor according to some embodiments of the present disclosure.

[0252] like Figure 15A As shown, the driving system for the brushless motor includes a driving circuit 1501 for the brushless motor and a control device 1502 for the driving circuit of the brushless motor.

[0253] Figure 15A The driving circuit 1501 schematically shows that it includes two full-bridge circuits, each full-bridge circuit includes 4 switches, a total of 8 switches ( Figure 15A (All are shown as n-type MOSFETs.) The eight switches are represented by Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8, respectively.

[0254] The control device 1502 is configured to control the state of each switch Q1 - Q8 in the driving circuit 1501 .

[0255] Specifically, see Figure 15A The eight terminals PWM1_P, PWM2_P, PWM1_N, PWM2_N, PWM3_P, PWM4_P, PWM3_N, and PWM4_N of the control device 1502 are connected to the gates of switches Q1 through Q8, respectively. For example, the terminals PWM1_P, PWM2_P, PWM1_N, and PWM2_N are connected to the gates of switches Q1, Q2, Q5, and Q6 in the first full-bridge circuit, respectively, via one of the four resistors in the resistor array R1. Meanwhile, the terminals PWM3_P, PWM4_P, PWM3_N, and PWM4_N are connected to the gates of switches Q3, Q4, Q7, and Q8 in the second full-bridge circuit, respectively, via one of the four resistors in the resistor array R2. The control device 1502 can output pulse-width modulated (PWM) signals via these eight terminals to control the states of switches Q1 through Q8.

[0256] In some embodiments, the control device 1502 is further configured to control the state of each switch in the driving circuit 1501 according to the Hall detection signal.

[0257] For example, see Figure 15A The control device 1502 can be connected to the two Hall detection elements 1503 through terminals INT0 and INT1 respectively to obtain Hall detection signals from the Hall detection elements 1503. Each Hall detection element 1503 may include a power supply voltage terminal VCC, a ground terminal GND, and a Hall detection signal output terminal OUT.

[0258] In some embodiments, the control device 1502 is further configured to detect the current and voltage of the driving circuit 1501 to ensure that the driving circuit 1501 operates within a reliable voltage and current range, thereby improving the reliability of the driving circuit 1501.

[0259] For example, see Figure 15A , the control device 1502 can detect the current of the driving circuit 1501 through the terminal ACC_0 and detect the voltage of the driving circuit 1501 through the terminal ACC_1.

[0260] The driving system may further include a voltage divider circuit including two resistors R3 and R4 connected in series between the input terminal VIN and the ground terminal GND of the driving circuit 1501. Terminal ACC_1 is connected to the middle node between the resistors R3 and R4 to detect the voltage of the driving circuit 1501.

[0261] The drive system may also include Figure 15A The current detection circuit 1504 shown in FIG. 1 includes an operational amplifier OA and a plurality of resistors R5, R6, R7, R8, R9, and R10. The operational amplifier OA includes power supply terminals VDD and VSS, a positive input terminal IN+, a negative input terminal IN-, and an output terminal OUT.

[0262] Specifically, resistor R5 is connected to Figure 15A 1502 . A resistor R10 is connected between the output terminal OUT of the operational amplifier OA and the terminal ACC_0 of the control device 1502.

[0263] like Figure 15A As shown, the drive system may further include a plurality of capacitors C1, C2, C3, and C4, each with one end grounded. Specifically, the other end of capacitor C1 is connected to the intermediate node between one Hall detection element 1503 and the control device 1502. The other end of capacitor C2 is connected to the intermediate node between another Hall detection element 1503 and the control device 1502. The other end of capacitor C3 is connected to the intermediate node between the current detection circuit 1504 and the control device 1502. The other end of capacitor C4 is connected to the intermediate node between the voltage divider circuit and the control device 1502.

[0264] The control device 1502 may further include other terminals, such as a signal input terminal FGRD, a signal output terminal PWM_IN, a power supply voltage terminal VCC and a ground terminal GND, which will not be described in detail here.

[0265] Figure 15B is a circuit diagram of a drive system for a brushless motor according to some other embodiments of the present disclosure.

[0266] Figure 15B and Figure 15A The similar parts will not be described in detail. Figure 15A The difference is, Figure 15B The switches Q1 to Q4 in the circuit are p-type MOSFETs.

[0267] As mentioned above, in the alternating energization mode, the waveform of the driving signal provided to the wire is a square wave, which can further simplify the control. In this case, the internal circuit of the control device 1502 is relatively simple.

[0268] Specifically, if Figure 15B As shown, the control device 1502 includes four inverters INV1, INV2, INV3 and INV4. Each Hall detection element 1503 is connected to two resistors in the corresponding resistor array via two inverters, and each Hall detection element 1503 is also directly connected to the other two resistors in the corresponding resistor array.

[0269] In these implementations, a simple control device 1502 based on internal circuits can control the driving circuit 1501.

[0270] Figure 15A and 15B Some components are labeled with numbers indicating the serial number of the component's terminals. For example, the numbers 1, 2, and 3 next to the Hall effect sensor 1503 represent the first terminal (i.e., the power supply voltage terminal VCC), the second terminal (i.e., the output terminal OUT), and the third terminal (i.e., the ground terminal GND) of the Hall effect sensor 1503, respectively.

[0271] The present disclosure also provides a drive circuit for a brushless motor. The brushless motor includes a stator core 1, a rotor 2, and an X-phase conductor 3, where X≥2. The stator core 1 includes Z tooth groups 11 spaced apart along a first circumferential direction. The rotor 2 includes a magnetic ring 21 with a pole number P, where P is an even number. The X-phase conductor 3 is wound around the tooth group 11 to form a coil 31, where Z=P×X. In the same phase conductor 3, the coils 31 on two adjacent tooth groups 11 have opposite winding directions along the second circumferential direction of the tooth group 11 and are spaced apart by X-1 tooth groups 11.

[0272] Figure 16 2 is a schematic structural diagram of a drive circuit for a brushless motor according to some other embodiments of the present disclosure.

[0273] Figure 16 The case of X=2 is shown. Figure 16 The driving circuit for the brushless motor includes a first half-bridge circuit 1610 and X second half-bridge circuits 1620. The first half-bridge circuit 1610 and the X second half-bridge circuits 1620 are connected in parallel between an input terminal VIN and a ground terminal GND of the driving circuit.

[0274] Each of the first half-bridge circuit 1610 and the X second half-bridge circuits 1620 includes two switches S1' and S2' connected via a node P'. Switches S1' and S2' may be, for example, thyristors, MOSFETs, or IGBTs. For example, switch S1' may be either an n-type MOSFET or a p-type MOSFET; switch S2' is an n-type MOSFET.

[0275] In these embodiments, the nodes P′ of the first half-bridge circuits 1610 are configured to be connected to the first ends of the X-phase conductors 3, and the node P′ of the i-th second half-bridge circuit 1620 among the X second half-bridge circuits 1620 is configured to be connected to the second end of the i-th phase conductor 3. Here, 1≤i≤X.

[0276] For example, see Figure 16 Node P' of first half-bridge circuit 1610 is connected to the first end X1-IN of the first phase conductor and to the first end X2-IN of the second phase conductor. Node P' of the first second half-bridge circuit 1620 is connected to the second end X1-OUT of the first phase conductor, and node P' of the second second half-bridge circuit 1620 is connected to the second end X2-OUT of the second phase conductor.

[0277] The driving circuit is configured to provide N periodically varying driving signals to the N-phase conductors 3 through the first and second independent ends of the N-phase conductors 3 , where 2≤N≤X.

[0278] Here, the waveform of each driving signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0, and during a period in which the intensity of any driving signal is not 0 in one cycle, the intensities of the other driving signals in the N driving signals are all 0.

[0279] That is, the drive circuit is configured to supply N drive signals to the N-phase conductors 3 to drive the brushless motor in an alternating energizing manner.

[0280] For example, by controlling the switch S1' of a second half-bridge circuit 1620 to be turned on and the switch S2' to be turned off, and controlling the switch S1' of the first half-bridge circuit 1610 to be turned off and the switch S2' to be turned on, the driving circuit can provide a first waveform with an intensity greater than 0 to the single-phase conductor connected to the node P' of the second half-bridge circuit 1620.

[0281] Conversely, by controlling the switch S1' of a second half-bridge circuit 1620 to be off and the switch S2' to be on, and controlling the switch S1' of the first half-bridge circuit 1610 to be on and the switch S2' to be off, the driving circuit can provide a second waveform with an intensity less than 0 to the single-phase conductor connected to the node P' of the second half-bridge circuit 1620.

[0282] When the number of wires X in the brushless motor is equal, the number of half-bridge circuits in the drive circuit of these embodiments is relatively small. Using this drive circuit to drive the brushless motor in an alternating energization manner can reduce the cost and size of the drive circuit.

[0283] An embodiment of the present disclosure further provides a device comprising the driving device for a brushless motor according to any one of the above embodiments and the brushless motor according to any one of the above embodiments.

[0284] An embodiment of the present disclosure further provides a device comprising the drive circuit for a brushless motor according to any one of the above embodiments and the brushless motor according to any one of the above embodiments.

[0285] An embodiment of the present disclosure further provides a device comprising the drive system for a brushless motor according to any one of the above embodiments and the brushless motor according to any one of the above embodiments.

[0286] The device of any of the above embodiments may be, for example, a vehicle, an electrical device (such as a household electrical device), or the like, a device capable of converting electrical energy into mechanical energy.

[0287] An embodiment of the present disclosure also provides a computer program product, including a computer program, which, when executed by a processor, implements the driving method for a brushless motor of any of the above embodiments or the control method for a driving circuit for a brushless motor of any of the above embodiments.

[0288] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0289] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For device and circuit embodiments, since they essentially correspond to the method embodiments, their descriptions are relatively simple. For relevant parts, refer to the descriptions of the method embodiments.

[0290] Those skilled in the art will appreciate that embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0291] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0292] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0293] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0294] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A drive circuit for a brushless motor, the brushless motor comprising: A stator core (1) comprising Z tooth groups (11) spaced apart along a first circumferential direction; A rotor (2) comprising a magnetic ring (21) having a pole number P, where P is an even number; and An X-phase conductor (3) is wound around the tooth group (11) to form a coil (31), X≥2, Z=P×X; in the conductor (3) of the same phase, the coils (31) on two adjacent tooth groups (11) have opposite winding directions along the second circumferential direction of the tooth group (11) and are spaced apart by X-1 tooth groups (11); The driving circuit includes: X full-bridge circuits, each full-bridge circuit including two half-bridge circuits connected in parallel between an input terminal of the drive circuit and a ground terminal, each half-bridge circuit including two switches connected via a node, the two half-bridge circuits including a first half-bridge circuit and a second half-bridge circuit, wherein: The node of the first half-bridge circuit in the i-th full-bridge circuit is configured to be connected to the first end of the i-th phase conductor, and The node of the second half-bridge circuit in the i-th full-bridge circuit is configured to be connected to the second end of the i-th phase conductor, 1≤i≤X; N of the X full-bridge circuits are configured to provide N periodically varying drive signals to the N-phase conductors (3) through the first and second independent ends of the N-phase conductors (3) within a control cycle, wherein 1≤N≤X, and the waveform of each drive signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0; The brushless motor comprises one or more stator cores (1), and the X-phase conductors (3) are wound around the tooth groups (11) in sequence from the first phase to the X-phase along the first circumferential direction; The N-phase conductors include an i-th phase conductor and a k-th phase conductor, and the phase difference θ between the driving signal of the i-th phase conductor and the driving signal of the k-th phase conductor is ik = , where 1≤i<k≤X, In the same stator core (1), the tooth group (11) of the x-phase conductor and the adjacent tooth groups (11) on both sides have a gap at the closest position, and the gap has a center position in the first circumferential direction. In all gaps formed by the Z tooth groups (11), the central angle corresponding to the arc between the center position of the x-phase conductor and the adjacent center position in the first circumferential direction is β x , and the sector corresponding to the circular arc includes at least part of the tooth group (11) of the x-th phase conductor.

2. The circuit according to claim 1, wherein The intensities of the N driving signals are continuously not zero during the first time period.

3. The circuit according to claim 2, wherein The moment when the first waveform and the second waveform overlap is a first moment, and the intensity of each driving signal in any time period in one cycle except the first moment is continuously not 0.

4. The circuit according to claim 2, wherein The intensity of each driving signal in the second period of one cycle is continuously zero.

5. The circuit according to claim 4, wherein The intensity of each driving signal is not 0 at any time in a cycle except the second time period.

6. The circuit according to claim 1, wherein During a period in which the intensity of any one driving signal is not 0 in one cycle, the intensities of the other driving signals in the N driving signals are all 0.

7. The circuit according to claim 1, wherein The N driving signals have the same amplitude.

8. The circuit according to claim 1, wherein The first waveform is centrally symmetrical to the second waveform.

9. The circuit of claim 1 , wherein: The waveforms of the N driving signals are all square waves; or The first waveform and the second waveform conform to a sinusoidal function.

10. The circuit of claim 1, wherein The two switches of each half-bridge circuit include a first switch connected to the input terminal of the drive circuit and a second switch connected to the ground terminal of the drive circuit, the first switch is one of an n-type metal oxide semiconductor MOSFET and a p-type MOSFET, and the second switch is an n-type MOSFET.

11. A method for controlling a drive circuit for a brushless motor according to any one of claims 1 to 10, comprising: In one control cycle, one switch in the first half-bridge circuit and one switch in the second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits are controlled to be turned on, so that the N full-bridge circuits provide N periodically changing drive signals to the N phase conductors (3) through the first and second independent ends of the N phase conductors (3). Wherein, 1≤N≤X, the waveform of each driving signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

12. The method according to claim 11, further comprising: Determining a first amplitude of the N-phase conductor and each drive signal according to a target torque of the rotor (2); The first frequency of each driving signal is determined according to the target rotational speed of the rotor (2).

13. The method according to claim 12, wherein: When the target torque is higher than the first preset torque, N=X.

14. The method according to claim 13, wherein When the target torque is higher than the first preset torque, the first amplitudes of the N driving signals are the same.

15. The method according to claim 12, wherein: When the target torque is lower than the second preset torque: N<X, and the first amplitudes of the N driving signals are the same; or N=X, and the first amplitudes of at least two driving signals among the N driving signals are different.

16. The method of claim 12, wherein: Retrieving a set of parameters required to achieve the target speed and the target torque from a plurality of sets of parameters, wherein the set of parameters represents a second frequency and a second amplitude of each driving signal; and The first frequency and the first amplitude of each driving signal are determined according to the set of parameters.

17. A control device for a drive circuit of a brushless motor according to any one of claims 1 to 10, comprising: The control module is configured to control, within a control cycle, one switch in the first half-bridge circuit and one switch in the second half-bridge circuit of each of the N full-bridge circuits of the X full-bridge circuits to be turned on, so that the N full-bridge circuits provide N periodically changing drive signals to the N phase conductors (3) through the first and second ends of the N phase conductors (3). Wherein, 1≤N≤X, the waveform of each driving signal in one cycle includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0.

18. A control device for a drive circuit of a brushless motor according to any one of claims 1 to 10, comprising: Memory; as well as A processor coupled to the memory is configured to execute the control method according to any one of claims 11 to 16 based on instructions stored in the memory.

19. A drive system for a brushless motor, comprising: The drive circuit for a brushless motor according to any one of claims 1 to 10; as well as A control device for a drive circuit of a brushless motor according to claim 17 or 18.

20. The system of claim 19, wherein: The X full-bridge circuits are packaged in one chip.

21. The system of claim 20, wherein: The control device is packaged in the chip.

22. A device comprising: The drive system for a brushless motor according to any one of claims 19 to 21; and The brushless motor.

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