A multi-branch winding structure of an electric machine

Abstract

A multi-branch winding structure for a motor is disclosed. The stator core has N slots, and the winding coils are arranged in two parallel branches. Each branch has N / 6 coils per phase winding, which are embedded within the slots. Each phase winding consists of eight layers of coils, and connecting coils with different numbers of turns achieves eight different speeds. This multi-branch winding structure allows for speed regulation of the motor simply by changing the winding coil connections, eliminating the need for a frequency converter. This simplifies the structure, improves control accuracy, and reduces costs.

Description

Technical Field

[0001] This invention relates to the field of electric motor technology. Background Technology

[0002] A permanent magnet synchronous motor is a synchronous motor that uses permanent magnets as the rotor excitation source and a stator with three-phase AC windings. The stator houses the three-phase windings, and when three-phase AC current is applied, a rotating magnetic field is generated. The rotor is equipped with permanent magnets (permanent magnet poles), requiring no external excitation power supply and having no excitation windings. When the three-phase stator windings are connected to variable frequency AC current, a rotating magnetic field is formed. The magnetic coupling force between these magnetic fields pulls the rotor, which carries the permanent magnets, to rotate synchronously.

[0003] A three-phase permanent magnet motor consists of three phases: U, V, and W. Each phase is composed of multiple sets of coils connected in series or parallel to form a circuit. The number of independent parallel circuits = the number of branches (a): a=1 (single branch): All coils of the same phase are connected in series. Standard configuration for low-power motors, with the simplest wiring.

[0004] a=2 / a=4 (multiple branches in parallel): Commonly used in medium and high power motors. Its function is to shunt current, reduce the current carrying capacity of a single conductor, lower line losses, and improve heat dissipation. The number of turns, coil distribution, and induced electromotive force of all parallel branches must be exactly equal; otherwise, internal circulating current will occur, causing overheating and burning out the windings. A conventional permanent magnet motor is a 4-pole, 48-slot three-phase permanent magnet synchronous motor, with the total coil evenly distributed across the three phases, each phase having two parallel branches.

[0005] The windings typically employ a double-layer structure, with each slot divided into upper and lower layers, each layer belonging to a different coil. This results in a good magnetic field waveform, low torque ripple, and low operating noise. The vast majority of permanent magnet synchronous servo motors and drive motors use double-layer lap windings.

[0006] Whether the winding coils are connected in series (coil heads and tails are connected in sequence) or in parallel (multiple independent branch heads are connected to each other and tails are connected to each other, and then the phase lines are drawn out), the motor itself cannot achieve speed regulation. It needs to rely on frequency converters and mechanical gears to achieve speed regulation, which makes the structure complex, costly and has a high failure rate. Summary of the Invention

[0007] To address the issue that permanent magnet motors cannot achieve speed regulation on their own, this invention provides a multi-branch winding structure for the motor.

[0008] The technical solution adopted by the present invention to achieve the above objectives is: a multi-branch winding structure for an electric motor, wherein the stator core is provided with N slots, the winding coil is a branch with two parallel connections, each branch has N / 6 coils per phase winding, the coils are embedded in the slots, and each phase winding is divided into 8 layers of coils.

[0009] The winding coil has a double-layer structure.

[0010] The winding coil has a double-layer structure.

[0011] The number of turns per layer of the 8-layer coil in each winding is: 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 1 turn, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 3 turns, wire gauge: 8 strands of 1.25mm wire wound together. 5 turns, wire gauge: 8 strands of 1.25mm wire wound together; 7 turns, wire gauge: 8 strands of 1.25mm wire wound together. Eight different rotational speeds can be achieved by connecting coils with different numbers of turns.

[0012] The multi-branch winding structure of the motor of the present invention can realize the speed regulation of the motor by changing the connection of the winding coils, without the need for a frequency converter, thereby simplifying the structure, improving control accuracy, and reducing costs. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the multi-branch winding of the motor of the present invention.

[0014] Figure 2 This is a circular diagram of the multi-branch winding of the motor of the present invention.

[0015] Figure 3 This is an unfolded diagram of the multi-branch winding of the motor of the present invention.

[0016] Figure 4 This is a schematic diagram of the wiring principle of the multi-branch winding of the motor of the present invention. Detailed Implementation

[0017] The multi-branch winding of the motor of the present invention, as shown in the figure Figure 1-3 As shown, the natural numbers in each diagram represent slot numbers, and the windings are numbered according to the slot number of the next layer. The stator core has N slots, and the winding coils are divided into two parallel branches. Each branch has N / 6 coils per phase winding, which are embedded in the slots. Each phase winding consists of 8 layers of coils. In this embodiment, the stator core has 96 slots, and the winding coils are divided into two parallel branches. Each branch has 16 coils per phase winding, which are embedded in the slots. The double-layer lap windings are wound sequentially according to coil number, with coils bearing a negative sign wound in the reverse order. The coils are manufactured using a continuous winding method, with 16 coils continuously wound in each branch of each phase. Sufficient length of the continuous winding wire is provided, and there are 2 parallel branches.

[0018] Each winding consists of 8 layers of coils, with a winding span of 1-3, and the number of turns per layer is: 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 1 turn, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 3 turns, wire gauge: 8 strands of 1.25mm wire wound together. 5 turns, wire gauge: 8 strands of 1.25mm wire wound together; 7 turns, wire gauge: 8 strands of 1.25mm wire wound together. The 8-layer branch winding wiring is configured to meet different speed requirements. Each winding branch is connected to a relay switch, which switches the power supply to the windings for switching. Each section has 22 turns of coil, and connecting different numbers of turns achieves 8 different speeds, such as... Figure 4 As shown, fewer turns result in higher speed and lower torque; more turns result in higher torque.

[0019] This invention has been described through embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this invention.

Claims

1. A multi-branch winding structure of an electric machine, characterized in that: The stator core has N slots, and the winding coils are two parallel branches. Each branch has N / 6 coils per phase winding. The coils are embedded in the slots, and each phase winding is divided into 8 layers of coils.

2. The multi-branch winding structure of a motor according to claim 1, characterized in that: The winding coil has a double-layer structure.

3. The multi-branch winding structure of a motor according to claim 1, characterized in that: The winding span is 1-3.

4. The multi-branch winding structure of a motor according to claim 1, characterized in that: The number of turns per layer of the 8-layer coil in each winding is: 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 1 turn, wire gauge: 8 strands of 1.25mm wire wound together; 1 turn, wire gauge: 8 strands of 1.25mm wire wound together. 2 turns, wire gauge: 8 strands of 1.25mm wire wound together; 3 turns, wire gauge: 8 strands of 1.25mm wire wound together. 5 turns, wire gauge: 8 strands of 1.25mm wire wound together; 7 turns, wire gauge: 8 strands of 1.25mm wire wound together. Eight different rotational speeds can be achieved by connecting coils with different numbers of turns.

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