EP-4738687-A1 - DRIVING METHOD AND APPARATUS FOR BRUSHLESS ELECTRIC MOTOR, AND DEVICE

EP4738687A1EP 4738687 A1EP4738687 A1EP 4738687A1EP-4738687-A1

Abstract

The present disclosure relates to the technical field of driving of electric motors. Provided are a driving method and apparatus for a brushless electric motor, and a device. The brushless electric motor comprises: a stator core, which comprises Z tooth groups spaced apart from each other in a first circumferential direction; a rotor, which comprises a magnetic ring having P poles, P being an even number; and X phase conductors, which are wound on the tooth groups to form coils, where X ≥ 2, and Z=P×X, wherein in the same phase conductor, the coils on two adjacent tooth groups have opposite winding directions in a second circumferential direction of the tooth groups, and are spaced apart by X-1 tooth groups. The driving method comprises: by means of first ends and second ends, which are independent of each other, of N phase conductors, providing N periodically changing drive signals for the N phase conductors, wherein the waveform of each drive signal in one period comprises a first waveform, the intensity of which is greater than 0, and a second waveform, the intensity of which is less than 0, where 1 ≤ N ≤ X. In this way, by means of a simple control mode, a brushless electric motor can be driven to provide a relatively large torque.

Inventors

ZHANG, PING
WU, Sin Hin
SUN, Xinglin
ZHOU, Huizhu
SUN, Yelin
LUO, Lanying

Assignees

Xuxin Technology (Shenzhen) Group Co., Ltd

Dates

Publication Date: 20260506
Application Date: 20240511

Claims (18)

A driving method for a brushless motor, wherein the brushless motor comprises: a stator core (1), comprising Z tooth groups (11) spaced apart from each other in a first circumferential direction; a rotor (2), comprising a magnetic ring (21) having a pole number P, P being an even number; and X phase wires (3), wound on the tooth groups (11) to form coils (31), X≥2, and Z=P×X, wherein in each of the phase wires (3), the coils (31) on two neighboring tooth groups (11) have opposite winding directions in a second circumferential direction of the tooth groups (11), and are spaced apart by X-1 tooth groups (11), the driving method comprises: providing N periodically varying drive signals to N phase wires (3) through first ends and second ends, which are independent of each other, of the N phase wires (3), wherein a waveform of each drive signal in one period comprises a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0, and 1≤N≤X.
The method of claim 1, wherein 2≤N≤X, and intensities of the N drive signals are always not 0 in a first time interval.
The method of claim 1, wherein a moment at which the first waveform and the second waveform overlap is a first moment, and an intensity of each drive signal is always not 0 in any time interval other than the first moment in one period.
The method of claim 1, wherein an intensity of each drive signal is always 0 in a second time interval in one period.
The method of claim 4, wherein the intensity of each drive signal is not 0 at any moment in one period except for the second time interval.
The method of claim 1, wherein the N drive signals have the same amplitude.
The method of claim 1, wherein the first waveform is centrosymmetric to the second waveform.
The method of claim 1, wherein: waveforms of the N drive signals are square waves; or the first waveform and the second waveform conform to a sine function.
The method of any one of claims 1 to 8, wherein the brushless motor comprises one or more stator cores (1), and the X phase wires (3) are wound on the tooth groups (11) in the first circumferential direction in an order from a 1 st phase wire to an X th phase wire; the N phase wires comprise an i th phase wire and a k th phase wire, and a phase difference between a drive signal of the i th phase wire and a drive signal of the k th phase wire is θ ik = P 2 ∑ i k − 1 β X , wherein 1≤i<k≤X; and in each of the one or more stator cores (1), a spacing exists between the tooth group (11) of an x th phase wire and each of neighboring tooth groups (11) on two sides of the tooth group (11) of the x th phase wire, the spacing has a center position in the first circumferential direction, and among all the spacings formed between the Z tooth groups (11), a central angle corresponding to an arc between the center position of the x th phase wire and each of the center positions neighboring to the center position of the x th phase wire in the first circumferential direction is β X , and a sector corresponding to the arc comprises at least a part of the tooth group (11) of the x th phase wire.
The method of any one of claims 1 to 8, further comprising: determining the N phase wires and a first amplitude of each of the drive signals according to a target torque of the rotor (2); and determining a first frequency of each of the drive signals according to a target rotational speed of the rotor (2).
The method of claim 10, wherein when the target torque is higher than a first preset torque, N=X.
The method of claim 11, wherein when the target torque is higher than the first preset torque, the first amplitudes of the N drive signals are the same.
The method of claim 10, wherein when the target torque is lower than a second preset torque, N<X, and the first amplitudes of the N drive signals are the same; or N=X, and at least two of the N drive signals have different first amplitudes.
The method of claim 10, wherein the method further comprises: calling a set of parameters required to achieve the target rotational 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 of the drive signals; and determining the first frequency and the first amplitude of each of the drive signals according to the set of parameters.
A driving apparatus for a brushless motor, wherein the brushless motor comprises: a stator core (1), comprising Z tooth groups (11) spaced apart from each other in a first circumferential direction; a rotor (2), comprising a magnetic ring (21) having a pole number P, P being an even number; and X phase wires (3), wound on the tooth groups (11) to form coils (31), X≥2, and Z=P×X, wherein in each of the phase wires (3), the coils (31) on two neighboring tooth groups (11) have opposite winding directions in a second circumferential direction of the tooth groups (11), and are spaced apart by X-1 tooth groups (11), the driving apparatus comprises: a providing module configured for providing N periodically varying drive signals to N phase wires (3) through first ends and second ends, which are independent of each other, of the N phase wires (3), wherein a waveform of each drive signal in one period comprises a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0, and 1≤N≤X.
A driving apparatus for a brushless motor, comprising: a memory; and a processor coupled to the memory and configured for running instructions stored in the memory to execute the driving method for a brushless motor of any one of claims 1 to 14.
A device, comprising: the driving apparatus for a brushless motor of claim 15 or 16; and the brushless motor.
A computer-readable storage medium, having computer program instructions stored therein, wherein the computer program instructions, when executed by a processor, cause the processor to implement the driving method for a brushless motor of any one of claims 1 to 14.

Description

TECHNICAL FIELD The present disclosure relates to the technical field of motor driving, and in particular to a driving method, and apparatus for a brushless motor, and a device. BACKGROUND Brushless direct current (DC) motors have the advantages of conventional DC motors while eliminating the carbon brush and slip ring structures, and can run at low speed and high power. Brushless DC motors have been widely used in the fields such as electrical servo drive, information processing, transportation, household appliances, consumer electronics, and national defense due to small size, light weight, good stability, and high efficiency. A commonly used brushless DC motor is single-phase brushless DC motor, which has the characteristics of small size and simple control. Another commonly used brushless DC motor is three-phase brushless DC motor, which has the characteristics of long service life, low noise, flexible driving modes, and mature industrial chain technology and can be applied to a wide range of scenarios including various civilian products and military products. In addition, due to wide speed regulation range, small size, high efficiency, and small steady-state speed error, three-phase brushless DC motors also have advantages in the field of speed regulation. Three-phase brushless DC motors adopt a UVW three-phase winding and a corresponding magnetic ring layout design. There are two wiring modes for the three-phase winding: star configuration and delta configuration. Using an electric motor as an example, a driver program is used to sequentially energize the phases of a three-phase winding to produce a rotating magnetic field to drive a rotor provided with a magnetic ring to rotate. However, single-phase brushless DC motors and three-phase brushless DC motors have their respective disadvantages. Single-phase brushless DC motors produce a small torque and therefore can be applied to only a limited range of application scenarios such as low-power household appliances. Three-phase brushless DC motors, although capable of providing greater torque, require six distinct methods to regularly switch and energize two phases among the "UVW" three-phase windings during the driving process. The drive signal for each phase is interrelated with those of the other phases, making control complex. SUMMARY In view of the above, the present disclosure provides the following schemes for driving a brushless motor by simple control to provide a large torque. In accordance with one aspect of the present disclosure, an embodiment provides a driving method for a brushless motor. The brushless motor includes: a stator core, including Z tooth groups spaced apart from each other in a first circumferential direction; a rotor, including a magnetic ring having a pole number P, P being an even number; and X phase wires, wound on the tooth groups to form coils, X≥2, and Z=P×X, where in each of the phase wires, the coils on two neighboring tooth groups have opposite winding directions in a second circumferential direction of the tooth groups, and are spaced apart by X-1 tooth groups; the driving method includes: providing N periodically varying drive signals to N phase wires through first ends and second ends, which are independent of each other, of the N phase wires, where a waveform of each drive signal in one period includes a first waveform with an intensity greater than 0 and a second waveform with an intensity less than 0, 1≤N≤X. In some embodiments, 2≤N≤X, and intensities of the N drive signals are always not 0 in a first time interval. In some embodiments, a moment at which the first waveform and the second waveform overlap is a first moment, and an intensity of each drive signal is always not 0 in any time interval other than the first moment in one period. In some embodiments, an intensity of each drive signal is always 0 in a second time interval in one period. In some embodiments, the intensity of each drive signal is not 0 at any moment in one period except for the second time interval. In some embodiments, the N drive signals have the same amplitude. In some embodiments, the first waveform is centrosymmetric to the second waveform. In some embodiments, waveforms of the N drive signals are square waves; or the first waveform and the second waveform conform to a sine function. In some embodiments, the brushless motor includes one or more stator cores, and the X phase wires are wound on the tooth groups in the first circumferential direction in an order from a 1st phase wire to an Xth phase wire; the N phase wires include an ith phase wire and a kth phase wire, and a phase difference between a drive signal of the ith phase wire and a drive signal of the kth phase wire is θik=P2∑ik−1βX, where 1≤i<k≤X; and in each of the one or more stator cores, a spacing exists between the tooth group of an xth phase wire and each of neighboring tooth groups on two sides of the tooth group of the xth phase wire, the spacing has a center positi