A high-efficiency generator based on a split permanent magnet rotor

Abstract

This invention discloses a high-efficiency generator based on a split permanent magnet rotor. The core of this generator lies in dividing the traditional integral permanent magnet rotor into two parts: a stationary permanent magnet component and a rotating permanent magnet component. The stationary permanent magnet component is fixed to the housing and does not rotate with the motor shaft, while the rotating permanent magnet component rotates synchronously with the motor shaft. The magnetic fields generated by both components combine in the air gap to form a complete, approximately uniform rotating magnetic field, which induces electrical energy in the stator windings. This split design effectively halves the hysteresis, cogging effect, and back EMF resistance experienced by the rotating component, thereby significantly reducing the mechanical energy required to drive the generator and significantly improving power generation efficiency while outputting the same amount of electrical energy. Furthermore, the stator windings employ an innovative S-shaped arrangement, increasing the effective length of the windings and improving current output capability while maintaining voltage stability.

Description

Technical Field

[0001] This utility model relates to the field of mechanical technology, and more particularly to a permanent magnet synchronous generator, and more specifically, to a high-efficiency generator that reduces drive losses and improves power generation efficiency by optimizing the rotor structure. Background Technology

[0002] Permanent magnet synchronous generators are widely used in wind power generation, small hydropower generation, automotive generators, and backup power supplies due to their advantages such as simple structure, high efficiency, and high power density. However, traditional permanent magnet generators have some inherent loss problems, which limit further improvement in their efficiency.

[0003] In a traditional generator, the rotor is a single unit, with all permanent magnets rotating at high speed along the shaft. During rotation, it mainly faces the following resistances:

[0004] 1. Hysteresis loss: Ferromagnetic materials are repeatedly magnetized under an alternating magnetic field, consuming energy.

[0005] 2. Cogging torque: The periodic torque pulsation generated by the interaction between the magnetic field of the permanent magnet and the cogging of the stator core leads to unstable start-up and low-speed operation, and increases rotational resistance.

[0006] 3. Back EMF: When a generator generates electricity, the induced electromotive force generated in the windings will oppose the change in magnetic flux that produces it, which manifests as a kind of electromagnetic resistance.

[0007] The combined effect of these resistances means that the mechanical power required to drive the generator is usually greater than its rated electrical output, resulting in theoretical and technical bottlenecks in energy conversion efficiency. Typically, the ratio of traction energy consumption to generator output power is about 1:1.3 to 1.5, meaning that 1.3 to 1.5 units of mechanical energy are needed to generate 1 unit of electrical energy.

[0008] Therefore, how to effectively reduce the internal resistance of the generator during operation and reduce drive energy consumption has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0009] To address the aforementioned technical problems, the purpose of this utility model is to overcome the shortcomings of the prior art and provide a high-efficiency generator. Through a unique rotor split design, the losses of the rotating part are halved, thereby significantly reducing drive energy consumption and improving the overall power generation efficiency.

[0010] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0011] A high-efficiency generator based on a split permanent magnet rotor includes a housing, a motor shaft, a stator assembly, and a rotor assembly. The stator assembly is fixed inside the housing, and the rotor assembly includes a stationary permanent magnet component and a rotating permanent magnet component coaxially arranged. The stationary permanent magnet component is fixedly mounted on the housing or decoupled from the housing via bearings, so that the stationary permanent magnet component remains stationary relative to the housing in the working state. The housing is connected to the motor shaft via bearings and does not rotate with the motor shaft. The rotating permanent magnet component is fixedly mounted on the motor shaft and rotates synchronously with the motor shaft. The magnetic field polarities of the stationary permanent magnet component and the rotating permanent magnet component are alternately arranged along the circumferential direction, and together they synthesize a complete rotating magnetic field in the air gap for induction generation in the windings of the stator assembly.

[0012] Preferably, both the stationary permanent magnet component and the rotating permanent magnet component are composed of multiple permanent magnet blocks spliced ​​or embedded along the circumferential direction, and the permanent magnet blocks of the two are spatially corresponding one-to-one, with opposite or complementary polarities, together forming the magnetic circuit required for power generation.

[0013] Preferably, the stationary permanent magnet component is directly or indirectly connected to the housing via a fixed bracket to achieve stationarity.

[0014] Preferably, the stator assembly winding adopts an S-shaped waveform winding method, wherein the conductors of each phase winding are continuously arranged in an S-shape along the axial direction in the slot to increase the effective conductor length per unit volume.

[0015] Preferably, the S-shaped waveform winding method improves the output current capability of the winding with the same stator core volume.

[0016] By adopting the above technical solution, the beneficial effects of this utility model compared with the prior art are:

[0017] 1. Significantly reduced drive energy consumption: By dividing the rotor permanent magnet into stationary and rotating parts, the loss sources (hysteresis, cogging torque, back EMF) of the rotating part are halved, which greatly reduces the mechanical energy required to drive the generator and significantly improves the energy conversion efficiency. Under ideal conditions, traction energy consumption can be reduced by more than half.

[0018] 2. High power generation efficiency: Under the condition of outputting the same electrical power, this generator has a lower power requirement for the prime mover, thus achieving a higher energy utilization rate.

[0019] 3. Increased power density: Combined with the S-shaped winding design, the current output capability is improved while keeping the generator size basically unchanged, further enhancing the product's market competitiveness.

[0020] 4. Relatively simple structure and high reliability: This improvement is an optimization based on the traditional permanent magnet motor structure. It does not introduce complex electronic control or transmission mechanisms, making it highly feasible and reliable. Attached Figure Description

[0021] Figure 1 : A cross-sectional schematic diagram of the overall structure of the high-efficiency generator of this utility model.

[0022] Explanation of the labels in the diagram:

[0023] 1-Housing; 2-Stator assembly; 3-Motor shaft; 4-Static permanent magnet component; 5-Rotating permanent magnet component; 6-Bearing; 7-Fixed bracket; 21-Stator core; 22-S-shaped outer winding; 23-S-shaped inner winding. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0025] The high-efficiency generator based on a split permanent magnet rotor in this embodiment includes a housing 1, a motor shaft 3, a stator assembly 2, and a rotor assembly.

[0026] See Figure 1 This high-efficiency generator includes a cylindrical housing 1. A stator assembly 2 is fixedly installed inside the housing 1. The stator assembly 2 consists of a stator core 21 made of laminated silicon steel sheets and S-shaped windings 22 and 23 embedded in slots. The motor shaft 3 is supported at both ends of the housing 1 by bearings 6.

[0027] The core improvement of this embodiment lies in the rotor assembly. The rotor assembly includes a stationary permanent magnet component and a rotating permanent magnet component arranged coaxially.

[0028] The stationary permanent magnet component 4 is fixedly installed on the housing 1, such as Figure 1 As shown; or decoupled from the housing by a bearing, so that the stationary permanent magnet component remains stationary relative to the housing in the working state. The housing 1 is connected to the motor shaft by a bearing and does not rotate with the motor shaft.

[0029] The rotating permanent magnet component consists of an outer magnet assembly 51 and an inner magnet assembly 52. ​​The rotating permanent magnet component 5 of the rotor assembly is connected to the inner side of the rotating permanent magnet component 5 through two non-magnetic fixed brackets 7. The rotating permanent magnet component 5 is fixedly installed on the motor shaft 3 by means of key connection or other means, and rotates with the shaft.

[0030] Both the stationary permanent magnet component 4 and the rotating permanent magnet component 5 are composed of neodymium iron boron permanent magnet blocks, with the N and S poles arranged alternately along the circumference. During installation, it is necessary to ensure that the N pole of the rotating component 5 and the S pole of the stationary component 4 are spatially aligned (or matched according to a specific magnetic circuit design) so that the magnetic fields generated by the two can be effectively synthesized into a near-perfect rotating magnetic field in the air gap.

[0031] During operation, the prime mover (such as a wind turbine or diesel engine) drives the motor shaft 3 and the rotating permanent magnet component 5 to rotate. Since the stationary permanent magnet component 4 remains stationary, only half of the magnet rotates, thus significantly reducing the magnetic resistance experienced by the rotating part. The combined magnetic field cuts the stator windings 22 and 23 to generate three-phase alternating current. Simultaneously, the S-shaped winding method used in windings 22 and 23 increases the conductor cross-sectional area and effective length, which is beneficial for increasing the output current.

[0032] Since only half of the permanent magnets (the rotating part) are in motion, the hysteresis loss, cogging effect, and back EMF drag directly caused by the rotating part can theoretically be reduced by about half. This significantly reduces the torque required to drive the motor. Furthermore, the stator winding employs an optimized "S-shaped" waveform winding method. Compared to conventional winding methods, the S-shaped winding method allows the coil to be arranged axially within the stator slots, increasing the effective conductor length of the coil and enabling the generation of a larger current at the same voltage, thereby improving power density.

[0033] The embodiments described above are for illustrative purposes only and are not intended to limit the scope of this utility model. All equivalent changes and modifications made to this utility model by those skilled in the art should fall within the scope of the appended claims.

Claims

1. A high-efficiency generator based on a split permanent magnet rotor, comprising a housing, a motor shaft, a stator assembly, and a rotor assembly, wherein the stator assembly is fixed within the housing, characterized in that: The rotor assembly includes a stationary permanent magnet component and a rotating permanent magnet component arranged coaxially; The stationary permanent magnet component is fixedly mounted on the housing, or decoupled from the housing via a bearing, so that the stationary permanent magnet component remains stationary relative to the housing in the working state; the housing is connected to the motor shaft via a bearing and does not rotate with the motor shaft; The rotating permanent magnet component is fixedly mounted on the motor shaft and rotates synchronously with the motor shaft; The magnetic field polarities of the stationary permanent magnet component and the rotating permanent magnet component are arranged alternately along the circumferential direction, and together they synthesize a complete rotating magnetic field in the air gap, which is used to generate electricity in the windings of the stator assembly.

2. The high-efficiency generator according to claim 1, characterized in that, Both the stationary permanent magnet component and the rotating permanent magnet component are composed of multiple permanent magnet blocks spliced ​​or embedded along the circumferential direction. The permanent magnet blocks of the two are spatially corresponding one-to-one, with opposite or complementary polarities, and together they form the magnetic circuit required for power generation.

3. The high-efficiency generator according to claim 1 or 2, characterized in that, The stationary permanent magnet component is directly or indirectly connected to the housing via a fixed bracket to achieve stationarity.

4. The high-efficiency generator according to claim 1, characterized in that, The stator assembly uses an S-shaped waveform winding method, wherein the conductors of each phase of the winding are continuously arranged in an S-shape along the axial direction in the slot to increase the effective conductor length per unit volume.

5. The high-efficiency generator according to claim 4, characterized in that, The S-shaped waveform winding method improves the output current capability of the winding with the same stator core volume.

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