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CN-121051894-B - Hexagonal hollow cup winding optimal design method for brushless direct current motor

CN121051894BCN 121051894 BCN121051894 BCN 121051894BCN-121051894-B

Abstract

The invention discloses an optimal design method of a hexagonal hollow cup winding of a brushless direct current motor, which obtains constraint conditions of no structural interference of adjacent coil wire arrangement under different wire diameters and hexagonal coil size parameters by establishing a coil geometric model, deduces coil design parameters for maximizing the flux of a winding turn chain, and converts the coil design parameters into control parameters in the process of coil winding. The oblique line segments of the hollow cup winding optimally designed by the invention are in a compact arrangement state, so that the space between the wires is physically restrained, the space positions of the wires are effectively limited, the wires are prevented from being randomly shifted, the torque output performance of the motor can be optimized, the electrical parameter symmetry of the three-phase winding is effectively improved, and the hexagonal hollow cup winding is scientifically and normalized by the auxiliary design.

Inventors

  • ZHANG ZHEN
  • HU PEIDONG
  • WANG JIAN

Assignees

  • 杭州曦诺未来科技有限公司

Dates

Publication Date
20260508
Application Date
20250818

Claims (8)

  1. 1. The method for optimally designing the hexagonal hollow cup winding of the brushless direct current motor is characterized by comprising the following steps of: (1) Modeling the close arrangement mode of the winding wires along the circumferential direction and the radial direction respectively, wherein the close arrangement mode along the circumferential direction is seamless close arrangement along the oblique line section; (2) According to the winding geometric mathematical model obtained by modeling in the step (1), the functional relation between the motor equivalent slot filling rate and the winding shape is established as follows: K is the equivalent slot filling rate of the motor, h is the available thickness of the winding, d h is the winding process margin, r is the distribution radius of the innermost element of the winding, and θ is the included angle between the inclined line section of the winding and the horizontal direction; (3) Modeling the winding turn chain magnetic flux to obtain a functional relation between the winding turn chain magnetic flux and a winding shape, wherein the calculation expression of the winding turn chain magnetic flux is as follows: wherein phi is the chain magnetic flux of winding turns, p is the pole pair number of the motor, The magnetic flux is the turn chain magnetic flux of a single-turn coil, N c is the number of turns of the winding, K w is the distribution coefficient of the winding, and beta is the continuous distribution coverage electrical angle of the single-phase winding; (4) Determining the functional relation between the electromagnetic torque of the motor and the shape of the winding according to the functional relation obtained in the steps (2) and (3) and the fact that the electromagnetic torque of the motor is proportional to the product of the winding turn chain magnetic flux phi and the equivalent slot filling rate K of the motor; (5) According to the functional relation between the electromagnetic torque of the motor and the winding shape, the optimal solution of the winding shape is calculated under the design target of improving the electromagnetic torque, namely, as the included angle theta is increased, the motor equivalent slot fullness rate K is gradually increased, but the winding turn chain magnetic flux phi is reduced in a nonlinear manner, the product of the two products can have a maximum value in the theta change process, the value theta corresponding to the maximum value is obtained through a numerical method to enable the electromagnetic torque T of the motor to reach the maximum value, the value theta is the optimal solution of the winding shape, and then the overall design parameter of the winding is calculated according to the value theta.
  2. 2. The method for optimizing the design of the hexagonal hollow cup winding of the brushless direct current motor according to claim 1, wherein the step (1) models the compact arrangement mode of winding wires along the circumferential direction, specifically, analyzes the spatial arrangement of winding elements belonging to the same layer as the upper layer side, when the straight line segments of adjacent coils are compact arranged, the center distance between the two coils along the circumferential direction is d, when the oblique line segments of the adjacent coils are compact arranged, the center distance between the two coils along the circumferential direction is d/sin theta, therefore, the center distance between the adjacent coils when the oblique line segments are compact arranged is larger than the center distance between the straight line segments when the straight line segments are compact arranged, the winding oblique line segments can not be orderly arranged due to insufficient space when the straight line segments are compact arranged, and the closest arrangement mode of the winding wires along the circumferential direction is compact arrangement of the oblique line segments according to the analysis, and the expression of a geometrical model of the winding is as follows: Wherein n is the number of single-layer elements of the winding, and d is the wire diameter.
  3. 3. The method for optimizing the design of the hexagonal hollow cup winding of the brushless direct current motor according to claim 1, wherein the step (1) is characterized in that the winding wires are modeled in a compact arrangement mode along the radial direction, specifically, after the size of the main magnetic circuit is determined, the available thickness of the winding in the radial direction is a fixed value, the conductor is required to fill the space along the radial direction as much as possible, the number of the element arrangement layers of the winding is usually 2 or 6, and the expression of a geometric mathematical model of the winding is as follows in order to enable the winding to be compactly arranged along the radial direction: Wherein n is the number of single-layer elements of the winding, q is the number of element arrangement layers of the winding, and d is the wire diameter.
  4. 4. The method for optimizing the design of the hexagonal coreless winding of the brushless DC motor as set forth in claim 1, wherein the step (3) is specifically implemented by first recognizing that the flux of the winding turn chain varies sinusoidally when the rotor rotates at a constant speed, the flux linkage amplitude being the value of the flux linkage when the N pole faces the positive direction of the winding, the circumferential distribution of the radial component of the exciting magnetic field of the permanent magnet of the rotor being approximately sinusoidal, and when the N pole of the rotor is aligned with the central axis of the single-turn coil, the flux linkage of the single-turn coil The calculated expression of (2) is as follows: l is the axial length of the winding, x is the length of a straight line segment of the winding, alpha is half of the electric angle of a span of the winding, and B n is the effective value of the radial component of the air gap flux density; The dimensions of the windings satisfy the following relation: 。
  5. 5. The method of claim 1, wherein in the step (4), according to the functional relationship between the motor equivalent slot filling rate and the winding turn chain magnetic flux and the winding shape, the product of the motor electromagnetic torque proportional to the winding turn chain magnetic flux Φ and the motor equivalent slot filling rate K is obtained by calculation, and the functional relationship between the motor electromagnetic torque and the winding shape is obtained as follows: wherein L is the axial length of the winding, alpha is half of the electrical angle of the span of the winding, and oc is proportional to the electrical angle.
  6. 6. The method for optimizing design of hexagonal hollow cup windings of a brushless DC motor as set forth in claim 1, wherein the overall design parameters of the windings include an axial length of the windings, an inner diameter of the windings, an outer diameter of the windings, a span of the windings, a length of a straight line segment of the windings, a wire diameter, a number of layers of component arrangement, and a number of turns of the windings.
  7. 7. A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor is used for executing the computer program to realize the method for optimizing the design of the hexagonal hollow cup winding of the brushless direct current motor according to any one of claims 1-6.
  8. 8. A computer readable storage medium storing a computer program, wherein the computer program is executed by a processor to implement the method for optimizing the design of the hexagonal coreless winding of the brushless DC motor according to any one of claims 1 to 6.

Description

Hexagonal hollow cup winding optimal design method for brushless direct current motor Technical Field The invention belongs to the technical field of motor design, and particularly relates to an optimized design method for a hexagonal hollow cup winding of a brushless direct current motor. Background The hexagonal winding type coreless winding is one of the mainstream coreless winding structures at present, and space arrangement constraint exists among the turns, the wire diameter and the hexagonal winding shape of each turn of the coreless winding, and the electromagnetic performance of the motor can be influenced. The Chinese patent technology with publication number of CN222750222U provides a hollow cup winding structure, a micro motor and a power device, which take the hollow cup motor structure as main invention content, but lack the discussion of a design method for parameters such as specific turns, layers, wire diameters and the like of the hollow cup winding. The chinese patent application with publication No. CN120185261a provides a method for designing a rhombic winding with hollow cups, which describes a method for deriving layout design parameters of the rhombic winding with hollow cups based on physical structure relation of the winding, and can make predictive design for the winding parameters, but does not establish theoretical connection between the winding parameters and electromagnetic torque of the motor, does not involve calculation of magnetic flux of winding turn chains, and is difficult to make reasonable optimization for the shape of the winding. Therefore, the existing design theory of the hollow cup winding is imperfect, a clear theoretical model is lacking to deduce the relation between the shape of the hexagonal winding, the number of turns, the wire diameter and the flux of the winding turn chain and the equivalent slot filling rate, so that the electromagnetic design scheme and the scheme which can be achieved in the actual winding processing are difficult to achieve unification, the motor performance is difficult to achieve the optimum, and the motor design process is complex and lengthy. Therefore, constructing a theoretical model between the geometry of the hexagonal coil and the windings of the hollow cup and the electromagnetic performance of the motor and forming an accurate and efficient design method become urgent demands in the field of hollow cup motors. Disclosure of Invention In view of the above, the invention provides an optimized design method for the hexagonal hollow cup winding of the brushless direct current motor, which can assist in optimizing the electromagnetic performance of the motor and accelerate the iterative speed of design and manufacture. A method for optimally designing a hexagonal hollow cup winding of a brushless direct current motor comprises the following steps: (1) Modeling the close arrangement mode of the winding wires along the circumferential direction and the radial direction respectively; (2) Establishing a functional relation between the motor equivalent slot filling rate and the winding shape according to the winding geometric mathematical model obtained by modeling in the step (1); (3) Modeling the winding turn chain magnetic flux to obtain a functional relationship between the winding turn chain magnetic flux and the winding shape; (4) Determining the functional relation between the electromagnetic torque of the motor and the winding shape according to the functional relation obtained in the steps (2) and (3); (5) And (3) calculating to obtain an optimal solution of the winding shape under the condition of improving the design target of the electromagnetic torque according to the functional relation obtained in the step (4), so as to calculate the overall design parameter of the winding. For a single-turn coil, the shape of the single-turn coil is an axisymmetric hexagon with sharp corners facing the vertical direction, two sides of the left side and the right side, which are parallel to symmetry axes, are called straight line sections, the lengths of the two straight line sections are equal, four inclined sides of the left upper side, the right upper side, the left lower side and the right lower side are called inclined line sections, the lengths of the four inclined line sections are equal, the left winding and the right winding are divided into an upper layer side and a lower layer side along the central axis of the hexagon, the upper layer side and the lower layer side in winding arrangement are respectively positioned in different wire distribution layers, the upper layer side is positioned at a relatively inner layer close to a central axis of the motor, the lower layer side is positioned at a relatively outer layer of the central axis of the motor, the upper layer side is only in physical arrangement constraint with the upper layer sides of other turn coils, the lower layer side is only in physical arrangement constraint wit