Rotor wireless excitation type variable flux reluctance motor

Abstract

The application provides a rotor wireless excitation type variable magnetic flux reluctance motor, which comprises a DC input end, an inverter circuit, a resonance capacitor, a transmitting coil, a receiving coil, a rectification filter circuit and a motor DC winding; the inverter circuit is connected with an external DC power supply, and the DC power supply is inverted into high-frequency AC power of a set frequency through the inverter circuit, high-frequency current is generated in the transmitting coil and the resonance capacitor element, the high-frequency current generates a high-frequency magnetic field through the transmitting coil, then the high-frequency magnetic field transmits energy to the receiving coil and the resonance capacitor, and the DC winding of the backward motor is powered through the rectification filter circuit and the DC winding. The rotor wireless excitation type variable magnetic flux reluctance motor has the beneficial effects that the DC winding is placed on the rotor, the mutual interference of the magnetic fields in the motor is reduced, the core loss is lower, the heating and heat dissipation are more uniform, and when the number of rotor poles is odd, the electromagnetic force balance can be ensured and the torque density of the motor is increased by adjusting the rotor DC current according to the actual situation.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission technology, and in particular relates to a rotor wireless excitation type variable flux reluctance motor. Background Technology

[0002] In existing motor products, brushed motors, due to the presence of their brushes and slip rings, pose a risk of generating electrical sparks during operation. Furthermore, the long-term frictional operation necessitates periodic replacement of the brushes and slip rings to prevent performance degradation due to poor contact. Additionally, friction consumes energy, reducing energy efficiency.

[0003] In motors using permanent magnet excitation, the cost of the permanent magnet materials used inside accounts for more than half of the total cost of the motor. Furthermore, during operation, the permanent magnets may demagnetize due to temperature rise. When the motor malfunctions and needs to be stopped, it is difficult to demagnetize the permanent magnets.

[0004] Most existing motors that use wireless power transmission technology for excitation are synchronous motors. Their excitation devices are designed to be large in size. During operation, they consume some electrical energy and convert it into the kinetic energy of the rotating structure. At the same time, it is difficult for the device to ensure electromagnetic compatibility while ensuring that it can withstand rotational stress, which causes interference to the rotor magnetic field and stator magnetic field. The analysis of electrical parameters is more difficult, which increases the probability of step loss and causes a decrease in the stability of motor operation.

[0005] In traditional variable flux reluctance motors, both the DC and AC windings are located on the stator. Due to core losses and winding copper losses during operation, the stator temperature is relatively high, leading to a decrease in the motor's electromagnetic characteristics. While the number of stator and rotor poles in a variable flux reluctance motor can be flexibly matched, motors with an odd number of rotor poles suffer from magnetic imbalance and low torque density. Summary of the Invention

[0006] In view of this, the present invention aims to provide a rotor wireless excitation type variable flux reluctance motor to at least solve one of the problems in the background art.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] The rotor wireless excitation type variable flux reluctance motor includes a DC input terminal, an inverter circuit, a resonant capacitor, a transmitting coil, a receiving coil, a rectifier and filter circuit, and a motor DC winding;

[0009] The inverter circuit is connected to an external DC power supply and is converted into high-frequency AC power of a set frequency. This high-frequency current is generated in the transmitting coil and resonant capacitor. The high-frequency current then generates a high-frequency magnetic field through the transmitting coil. Subsequently, the high-frequency magnetic field transfers energy to the receiving coil and resonant capacitor, and then supplies power to the DC winding of the rear motor through the rectifier and filter circuit.

[0010] Furthermore, it also includes a packaging clamp, which is used to encapsulate the transmitting coil and the electromagnetic shielding material.

[0011] Furthermore, it also includes a packaging clamp, which is used to encapsulate the receiving coil.

[0012] Compared with the prior art, the rotor wireless excitation type variable flux reluctance motor of the present invention has the following advantages:

[0013] The rotor-based wireless excitation variable flux reluctance motor described in this invention places the DC winding on the rotor, reducing mutual interference of the internal magnetic fields, resulting in lower core losses, more uniform heat generation and dissipation. Furthermore, when the rotor has an odd number of poles, the rotor DC current can be adjusted to ensure electromagnetic force balance, increasing the motor's torque density. Simultaneously, the wireless excitation device designed in this patent has a simple structure, high transmission efficiency, and low stray loss, ensuring stable motor performance and promoting the development of motor technology. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0015] Figure 1 This is a schematic diagram of a motor circuit system according to an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the motor circuit system of embodiment two according to the present invention;

[0017] Figure 3 This is a schematic diagram of the motor winding distribution according to an embodiment of the present invention;

[0018] Figure 4 This is a schematic cross-sectional view of the motor described in an embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of the coil style of the wireless power transmission device according to an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of coil style two of the wireless power transmission device according to an embodiment of the present invention. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] like Figures 1 to 3 As shown in the diagram, after all parts of the motor are assembled, its internal structure is as shown in the cross-sectional view. At the rear end of the motor, the wireless excitation circuit is encapsulated and fixed with shielding material. The transmitter remains stationary, while the receiver is connected to the motor rotor and can rotate with it. The shielding material shown in the diagram can be made of materials such as ferrite or nanocrystals, and the selection and amount of material can be determined according to the power of the motor and the coupling structure.

[0024] like Figure 4 and Figure 5 As shown, Figure 1 The diagram shows the packaging effect of the wireless excitation circuit device, which is installed on the fixed plate together with the shielding material to meet the working state of the motor rotation within a limited space. Figure 4 The coil in the image is a flat, disc-shaped coil. Figure 5 The coils are designed with coaxial sleeves, which can meet the requirements of the motor's rotation state.

[0025] This solution belongs to the field of combining wireless power transfer technology with electric motors. It supplies power to the rotor of a variable flux reluctance motor in a non-contact manner, eliminating the need for brushes and slip rings found in some traditional motors and reducing the use of rare-earth materials in some permanent magnet synchronous motors. Compared to traditional variable flux reluctance motors, the DC winding located on the rotor increases the rotational speed, and the magnetic imbalance caused by an odd number of rotor poles can be overcome by adjusting the current. The device in this patent uses a compact package and incorporates novel electromagnetic shielding materials to reduce energy loss, thereby improving the motor's performance. The novel motor manufactured using this patent can replace brushed motors, permanent magnet motors, or variable flux reluctance motors currently used in electric drive equipment, demonstrating strong adaptability and promising application prospects.

[0026] The objective of this solution is to utilize wireless power transfer technology to power the rotor of a variable flux reluctance motor, replacing methods such as brush excitation, permanent magnet excitation, or stator DC excitation. The wireless excitation device employs an encapsulated design, fixing the inductor coil, coil mounting plate, and electromagnetic shielding material within a multi-layered clamp. Non-metallic materials are used for fixation around the clamp, ensuring advantages such as electromagnetic compatibility, high-speed rotation, low energy loss, ample rotational space, and strong coupling. Transferring the DC winding to the rotor reduces motor torque ripple and, by adjusting the DC winding, overcomes the magnetic imbalance caused by an odd number of rotor poles, thereby improving motor performance.

[0027] In existing motor products, brushed motors pose a risk of generating electrical sparks during operation due to the presence of their brushes and slip rings. Furthermore, the long-term frictional operation necessitates periodic replacement of the brushes and slip rings to prevent performance degradation caused by poor contact. Additionally, friction consumes energy, reducing energy efficiency.

[0028] In motors using permanent magnet excitation, the cost of the permanent magnet materials used inside accounts for more than half of the total cost of the motor. Furthermore, during operation, the permanent magnets may demagnetize due to temperature rise. When the motor malfunctions and needs to be stopped, it is difficult to demagnetize the permanent magnets.

[0029] Existing motors that use wireless power transmission technology for excitation are mostly synchronous motors. Their excitation devices are designed to be large in size, and during operation, they consume some electrical energy to convert it into the kinetic energy of the rotating structure. At the same time, it is difficult for the device to ensure electromagnetic compatibility while ensuring that it can withstand rotational stress, which causes interference to the rotor magnetic field and stator magnetic field. The analysis of electrical parameters is more difficult, which increases the probability of step loss and causes a decrease in the stability of motor operation.

[0030] In traditional variable flux reluctance motors, both the DC and AC windings are located on the stator. Due to core losses and winding copper losses during operation, the stator temperature is relatively high, leading to a decrease in the motor's electromagnetic characteristics. While the number of stator and rotor poles in a variable flux reluctance motor can be flexibly matched, motors with an odd number of rotor poles suffer from magnetic imbalance and low torque density.

[0031] The main problem this solution aims to address is that in existing variable flux reluctance motors, the DC and AC windings are located on the stator, resulting in excessive stator core losses, concentrated heat generation, and unbalanced electromagnetic forces and low torque density when the rotor has an odd number of poles. To address this, a rotor-wireless excitation type variable flux reluctance motor is designed.

[0032] The technical solution adopted in this project is to move the DC winding of a traditional variable flux reluctance motor to the rotor and use wireless excitation to transmit electrical energy to the DC winding of the rotor. The circuitry and materials required for the excitation device are encapsulated and installed on the motor and its tail section. The coupling mechanism uses a rotating disc or coaxial sleeve-shaped structure, placed parallel to each other within the motor. In this patent, the stator and rotor structure of the motor can be 6 slots and 4 poles. In addition, the number of rotor poles can be determined based on 6N±1, where N is a positive integer; simultaneously, the number of stator and rotor poles can also be M times 6 slots and 6N±1 poles, where M is a positive integer. The wireless excitation device for the motor includes a DC input terminal, an inverter circuit, a resonant capacitor, a transmitting coil, a receiving coil, electromagnetic shielding material, a coupling mechanism fixing plate, a rectifier and filter circuit, and the motor's DC winding.

[0033] First, an external DC power supply is input, which is then inverted into a high-frequency AC power of a specific frequency by an inverter circuit. A high-frequency current is generated in the transmitting coil and resonant capacitor, which in turn generates a high-frequency magnetic field. This magnetic field then transfers energy to the receiving coil and resonant capacitor, and finally supplies power to the DC windings of the motor via a rectifier and filter circuit. The transmitting coil and electromagnetic shielding material are encapsulated together using a sealing plate. The receiving coil is encapsulated in the same way. Once a magnetic field is established in the three-phase stator windings and the rotor DC windings of the motor, electrical energy is converted into mechanical energy, enabling the motor to operate.

[0034] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0035] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of units described above is merely a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. The aforementioned units may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotor-wireless excitation type variable flux reluctance motor, characterized in that: It includes a DC input terminal, inverter circuit, resonant capacitor, transmitting coil, receiving coil, rectifier filter circuit, and motor DC winding; The inverter circuit is connected to an external DC power supply. The inverter circuit converts the DC power to a high-frequency AC power of a set frequency. The high-frequency current is generated in the transmitting coil and resonant capacitor. The high-frequency current then generates a high-frequency magnetic field through the transmitting coil. The high-frequency magnetic field then transfers energy to the receiving coil and resonant capacitor. The rectifier and filter circuit then supplies power to the DC winding of the rear motor. By placing the DC winding on the rotor, and when the number of rotor poles is odd, the rotor DC current is adjusted to ensure electromagnetic force balance, thereby increasing the torque density of the motor. At the rear end of the motor, the wireless excitation circuit is encapsulated and fixed with shielding material. The transmitter remains stationary, while the receiver is connected to the motor rotor and can rotate with it. The circuits and materials required for the excitation device are encapsulated and installed on the motor and tail section. The coupling mechanism is a disc-shaped or coaxial sleeve-shaped device suitable for rotation, which is placed parallel to the motor. The stator and rotor structure of the motor can adopt 6 slots and 4 poles. In addition, the number of rotor poles can also be determined according to 6N±1, where N is a positive integer. At the same time, the number of stator and rotor can also be M times 6 slots and 6N±1 poles, where M is a positive integer.

2. The rotor wireless excitation type variable flux reluctance motor according to claim 1, characterized in that: It also includes a packaging clamp, which is used to encapsulate the transmitting coil and the electromagnetic shielding material.

3. The rotor wireless excitation type variable flux reluctance motor according to claim 1 or 2, characterized in that: It also includes a packaging clamp, which is used to encapsulate the receiving coil.

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