Voltage-controllable magnetic circuit parallel type permanent magnet motor

Abstract

This invention discloses a voltage-controllable parallel permanent magnet motor, comprising a rotor core; the rotor core surface is uniformly provided with a plurality of rotor slots, the number of slots being twice the number of motor poles; a permanent magnet is installed every other rotor slot, with the permanent magnets N, S alternating, and the magnetization direction of the permanent magnets being radial or parallel magnetization, the outer diameter of the permanent magnets being the same as the outer diameter of the rotor core; external excitation winding slots, the same number as the number of motor poles, are opened on the inner surface of the rotor slots where no permanent magnets are installed; and the rotor core is located near the shaft. An internal excitation winding slot with the same number of poles as the motor is formed. An excitation winding is wound on both the external excitation winding slot and the inner stator slot in the same radial direction, connected in series with the excitation winding coil of the same number of poles as the motor. Two mutually perpendicular magnetic isolation slots are formed on each side of the internal excitation winding slot, extending from one end of the internal excitation winding slot to near the inner ring of the permanent magnet to decouple the permanent magnet magnetic circuit and the electrically excited magnetic field. The end of the magnetic isolation slot near the inner ring of the permanent magnet is directly opposite the junction of the iron core and the permanent magnet, and the slotted part of the magnetic isolation slot is completely aligned with the permanent magnet. This invention effectively avoids competition between the two magnetic circuits and achieves efficient utilization of both magnetic fields.

Description

Technical Field

[0001] This invention belongs to the field of motors, specifically relating to a voltage-controllable parallel permanent magnet motor. Background Technology

[0002] Permanent magnet motors have the advantage of high power density, but rare earth elements are non-renewable resources and belong to national strategic resources, resulting in high operating costs. Furthermore, permanent magnet motors also suffer from the problem of unadjustable air gap magnetic fields. By combining permanent magnets and electromagnetic windings, two excitation sources jointly generate the motor's main magnetic field, enabling regulation and control of the main magnetic field, thereby improving the motor's speed regulation, drive performance, or voltage regulation characteristics.

[0003] However, existing adjustable magnetic field permanent magnet motors suffer from coupling issues between the permanent magnet circuit and the electrically excited magnetic circuit, sometimes even leading to competition between the two circuits. This prevents the permanent magnet circuit and the electrically excited magnetic circuit from working together to enhance the air gap magnetic field and achieve the basic function of regulation. To avoid this situation, the permanent magnet circuit and the ionizing magnetic circuit need to be designed to be completely decoupled. Summary of the Invention

[0004] Technical problem solved: In response to the problem of coupling between permanent magnet circuit and electrically excited magnetic circuit in existing magnetic field adjustable permanent magnet motors, this invention proposes a voltage-controllable parallel magnetic circuit permanent magnet motor. The magnetic circuits of the electrically excited magnetic circuit and the permanent magnet circuit in the rotor are completely different, which effectively avoids the competition between the two magnetic circuits and realizes the effective utilization of the two magnetic fields.

[0005] Technical solution:

[0006] A voltage-controllable parallel permanent magnet motor, the voltage-controllable parallel permanent magnet motor comprising a rotor core;

[0007] The rotor core surface is uniformly provided with a number of rotor slots, the number of slots being twice the number of motor poles; a permanent magnet is installed every other rotor slot, and the permanent magnets N, S are arranged alternately, with the magnetization direction of the permanent magnets being radial or parallel magnetization, and the outer diameter of the permanent magnets being the same as the outer diameter of the rotor core; an external excitation winding slot with the same number of motor poles is opened on the inner surface of the rotor slots where no permanent magnets are installed; an internal excitation winding slot with the same number of motor poles is opened inside the rotor core near the shaft; an excitation winding is wound on the external excitation winding slots and the internal stator slots in the same radial direction, and is connected in series with the excitation winding coil with the same number of motor poles;

[0008] Two mutually perpendicular magnetic isolation slots are respectively opened on both sides of the internal excitation winding slot. The magnetic isolation slots extend from one end of the internal excitation winding slot to near the inner circle of the permanent magnet to decouple the permanent magnet magnetic circuit and the electric excitation magnetic field. The end of the magnetic isolation slot near the inner circle of the permanent magnet is directly opposite the junction of the iron core and the permanent magnet, and the slot opening of the magnetic isolation slot is completely directly opposite the permanent magnet.

[0009] When current flows into the excitation winding, the electromagnetic field generated by the excitation winding starts from the region between the outer excitation winding slot and the inner excitation winding slot of the rotor core, passes through the region between the outer excitation winding slot and the magnetic isolation slot of the rotor core, passes through the rotor core region adjacent to the permanent magnet, enters the air gap, passes through the stator core, returns to the air gap, enters another rotor core region adjacent to the permanent magnet, and returns to the region between the outer excitation winding slot and the magnetic isolation slot of the rotor core. The direction of the electromagnetic field generated in the rotor core region adjacent to the permanent magnet is the same as the direction of the adjacent permanent magnet.

[0010] The permanent magnet magnetic field generated by the permanent magnet passes through the N-pole of the permanent magnet, through the air gap, through the stator core, back to the air gap, through the S-pole of the adjacent permanent magnet, through the rotor pole body of the rotor core, through the yoke of the rotor core, through the rotor pole body of the adjacent rotor core, and finally back to the S-pole of the permanent magnet.

[0011] Furthermore, the armature winding of the stator is single-phase.

[0012] Furthermore, the armature winding of the stator is multiphase.

[0013] Furthermore, the armature winding of the stator adopts a double-layer winding.

[0014] Furthermore, the armature winding of the stator adopts a single-layer winding.

[0015] Furthermore, an exciter is used to provide DC excitation current to the excitation winding.

[0016] Furthermore, a brush slip ring method is used to provide DC excitation current to the excitation winding.

[0017] Furthermore, the permanent magnet is made of rare earth permanent magnet or ferrite magnetic material.

[0018] Beneficial effects:

[0019] The voltage-controllable parallel permanent magnet motor of the present invention has completely different magnetic circuits in the rotor, namely the electrically excited magnetic circuit and the permanent magnet magnetic circuit, which effectively avoids the competition between the two magnetic circuits and realizes the effective utilization of the two magnetic fields. Attached Figure Description

[0020] Figure 1 The basic topology of the voltage-controllable parallel permanent magnet motor of the present invention is shown in the figure.

[0021] Figure 2 The diagram shows the topology of the voltage-controllable parallel permanent magnet motor of the present invention when there is an air gap between the permanent magnet and the core.

[0022] Figure 3The diagram shows the electromagnetic field path of the voltage-controllable parallel permanent magnet motor of the present invention.

[0023] Figure 4 The diagram shows the permanent magnet field path of the voltage-controllable parallel permanent magnet motor of the present invention.

[0024] Reference numerals in the attached figures: 1. Shaft, 2. Rotor slot, 3. Permanent magnet, 4. External excitation winding slot, 5. Internal excitation winding slot, 6. Excitation winding, 7. Magnetic isolation slot, 8. Rotor pole body, 9. Yoke of rotor core, 10. Stator core, 11. Armature winding, 12. Electrically excited magnetic field path, 13. Permanent magnet magnetic field path. Detailed Implementation

[0025] The following embodiments are provided to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.

[0026] This invention discloses a voltage-controllable parallel permanent magnet motor. Rotor core slots are cut on the surface of the rotor core, with a permanent magnet installed at every other slot. The permanent magnets are magnetized radially or parallelly. The outer diameter of the permanent magnet is the same as the outer diameter of the rotor core. The number of slots is twice the number of poles of the motor. External excitation winding slots, the same number as the number of poles, are cut on the inner surface of the slots where no permanent magnets are installed. Internal excitation winding slots, the same number as the number of poles, are also cut inside the rotor core near the shaft. Excitation windings are installed in the external excitation winding slots and the inner stator slots. Magnetic isolation slots are cut, extending from one end of the internal excitation winding slot to near the inner ring of the permanent magnet to decouple the permanent magnet magnetic circuit and the electrical excitation magnetic field. The end of the magnetic isolation slot near the inner ring of the permanent magnet is directly opposite the junction of the core and the permanent magnet. The opening of the magnetic isolation slot must be completely aligned with the permanent magnet to prevent severe leakage of the electrical excitation magnetic field.

[0027] When current flows through the excitation winding, the generated electromagnetic field starts from the region between the external and internal excitation winding slots of the rotor core, passes through the region between the external and internal excitation winding slots of the rotor core, passes through the rotor core region adjacent to the permanent magnet, enters the air gap, passes through the stator core, returns to the air gap, enters another rotor core region adjacent to the permanent magnet, and returns to the region between the external and internal excitation winding slots of the rotor core. The direction of the electromagnetic field generated in the rotor core region adjacent to the permanent magnet is the same as the direction of the adjacent permanent magnet.

[0028] The permanent magnets are arranged alternately as N and N poles. The permanent magnets generate a permanent magnetic field that passes through the N pole of the permanent magnet, through the air gap, through the stator core, back to the air gap, through the S pole of the adjacent permanent magnet, through the rotor pole of the rotor core, through the yoke of the rotor core, through the rotor pole of the adjacent rotor core, and finally back to the S pole of the permanent magnet.

[0029] The magnetic circuits of the electrically excited magnetic circuit and the permanent magnet magnetic circuit in the rotor are completely different, which effectively avoids the competition between the two magnetic circuits and realizes the effective utilization of the two magnetic fields.

[0030] Preferably, the stator armature winding can be designed as single-phase or multi-phase, and can be a double-layer winding or a single-layer winding. DC excitation current can be provided to the excitation winding using an exciter or by using brushes and slip rings.

[0031] like Figure 1 As shown, the stator core adopts a conventional structure, and the armature winding can be designed as single-phase or multi-phase, and can use either double-layer or single-layer windings. Taking a 2-pole motor as an example, the rotor core surface has 8 rotor slots. These rotor slots are used to install permanent magnets, or may not house any components. The slot angles can differ between the two uses. One permanent magnet is installed every other rotor slot. The permanent magnet can be rare-earth permanent magnets or other types of magnetic materials such as ferrite. The magnetization direction of the permanent magnet can be radial or parallel, as shown in the image. Figure 1 As indicated by the middle arrow. The outer diameter of the permanent magnet is the same as the outer diameter of the rotor core. The number of permanent magnets is exactly the same as the number of motor poles, which is 4. The permanent magnets are arranged alternately in the N-S direction. External excitation winding slots, the same number as the number of motor poles, are opened on the inner surface of the rotor slots where no permanent magnets are installed. Internal excitation winding slots, the same number as the number of motor poles, are also opened inside the rotor core near the shaft. Excitation windings are installed in the external excitation winding slots and the internal stator slots. One excitation winding is wound on the external excitation winding slot and the internal stator slot in the same radial direction, connected in series with the excitation winding coil of the same number of motor poles. A magnetic isolation slot is opened, extending from one end of the internal excitation winding slot to near the inner circle of the permanent magnet to decouple the permanent magnet magnetic circuit and the electrical excitation magnetic field. The end of the magnetic isolation slot near the inner circle of the permanent magnet is directly opposite the junction of the core and the permanent magnet, and the opening of the magnetic isolation slot must be completely aligned with the permanent magnet to prevent severe leakage of the electrical excitation magnetic field.

[0032] like Figure 2 This is a structural diagram of a voltage-controllable parallel permanent magnet motor with an air gap directly between the permanent magnet and the iron core, designed to further reduce magnetic leakage.

[0033] like Figure 3 When current flows through the excitation winding, the generated electromagnetic field starts from the region between the external and internal excitation winding slots of the rotor core, passes through the region between the external and internal excitation winding slots of the rotor core, passes through the rotor core region adjacent to the permanent magnet, enters the air gap, passes through the stator core, returns to the air gap, enters another rotor core region adjacent to the permanent magnet, and returns to the region between the external and internal excitation winding slots of the rotor core. The direction of the electromagnetic field generated in the rotor core region adjacent to the permanent magnet is the same as the direction of the adjacent permanent magnet.

[0034] like Figure 4 The permanent magnet generates a permanent magnetic field that passes through the N-stage of the permanent magnet, through the air gap, through the stator core, back to the air gap, through the S-stage of the adjacent permanent magnet, through the rotor pole body of the rotor core, through the yoke of the rotor core, through the rotor pole body of the adjacent rotor core, and finally back to the S-stage of the permanent magnet.

[0035] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A voltage-controllable parallel permanent magnet motor, characterized in that, The voltage-controllable parallel permanent magnet motor includes a rotor core; The rotor core surface is uniformly provided with a number of rotor slots, the number of slots being twice the number of motor poles; a permanent magnet is installed every other rotor slot, and the permanent magnets N, S are arranged alternately, with the magnetization direction of the permanent magnets being radial or parallel magnetization, and the outer diameter of the permanent magnets being the same as the outer diameter of the rotor core; an external excitation winding slot with the same number of motor poles is opened on the inner surface of the rotor slots where no permanent magnets are installed; an internal excitation winding slot with the same number of motor poles is opened inside the rotor core near the shaft; an excitation winding is wound on the external excitation winding slots and the internal stator slots in the same radial direction, and is connected in series with the excitation winding coil with the same number of motor poles; Two mutually perpendicular magnetic isolation slots are respectively opened on both sides of the internal excitation winding slot. The magnetic isolation slots extend from one end of the internal excitation winding slot to near the inner circle of the permanent magnet to decouple the permanent magnet magnetic circuit and the electric excitation magnetic field. The end of the magnetic isolation slot near the inner circle of the permanent magnet is directly opposite the junction of the iron core and the permanent magnet, and the slot opening of the magnetic isolation slot is completely directly opposite the permanent magnet. When current flows into the excitation winding, the electromagnetic field generated by the excitation winding starts from the region between the outer excitation winding slot and the inner excitation winding slot of the rotor core, passes through the region between the outer excitation winding slot and the magnetic isolation slot of the rotor core, passes through the rotor core region adjacent to the permanent magnet, enters the air gap, passes through the stator core, returns to the air gap, enters another rotor core region adjacent to the permanent magnet, and returns to the region between the outer excitation winding slot and the magnetic isolation slot of the rotor core. The direction of the electromagnetic field generated in the rotor core region adjacent to the permanent magnet is the same as the direction of the adjacent permanent magnet. The permanent magnet magnetic field generated by the permanent magnet passes through the N-pole of the permanent magnet, through the air gap, through the stator core, back to the air gap, through the S-pole of the adjacent permanent magnet, through the rotor pole body of the rotor core, through the yoke of the rotor core, through the rotor pole body of the adjacent rotor core, and finally back to the S-pole of the permanent magnet. Furthermore, the voltage-controllable parallel permanent magnet motor can provide DC excitation current to the excitation winding by using an exciter or by using brushes and slip rings.

2. The voltage-controllable parallel permanent magnet motor according to claim 1, characterized in that, The armature winding of the stator is single-phase.

3. The voltage-controllable parallel permanent magnet motor according to claim 1, characterized in that, The armature winding of the stator is multiphase.

4. The voltage-controllable parallel permanent magnet motor according to claim 1, characterized in that, The armature winding of the stator adopts a double-layer winding.

5. The voltage-controllable parallel permanent magnet motor according to claim 1, characterized in that, The armature winding of the stator adopts a single-layer winding.

6. The voltage-controllable parallel permanent magnet motor according to claim 1, characterized in that, The permanent magnets are made of rare earth permanent magnets or ferrite magnetic materials.

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