A rotating type permanent magnet motor with a field modulation ring for reactive compensation

Abstract

This invention relates to a rotary permanent magnet motor with a magnetic ring for reactive power compensation, comprising a permanent magnet rotor, a magnetic ring rotor, and a stator armature. The permanent magnet rotor and the magnetic ring rotor are located inside the stator armature. The magnetic ring rotor rotates synchronously with the permanent magnet rotor and is unloaded. The magnetic ring rotor has P salient poles. f Equal to the number of permanent magnet rotor pole pairs P m The number of pole pairs in the stator armature winding is twice the number of pole pairs in the permanent magnet rotor, P. m The magnetic field regulation structure is composed of a permanent magnet rotor, a magnetic ring rotor, and an armature stator, which has the advantages of simple structure, high power density, high efficiency, and high reliability.

Description

Technical Field

[0001] This invention belongs to the field of special motor device technology, specifically relating to a rotary permanent magnet motor with a magnetic adjusting ring for reactive power compensation. Background Technology

[0002] Permanent magnet motors (PMMs) have advantages such as high efficiency, high power density, high power factor, high starting torque, and wide speed range, and have gradually replaced induction motors and switched reluctance motors. Currently, the reactive power compensation phase-shifting motors used in power systems are generally electrically excited synchronous phase-shifting motors (EMS). The main disadvantages of EMS are: 1) Complex structure: Due to the presence of an electric excitation coil on the rotor side, the excitation coil requires a complex excitation system for power supply, leading to reduced system reliability; 2) Low efficiency: Because of the excitation coil in the EMS, excitation consumes some power, reducing system operating efficiency. However, there are also technologies that use intelligent system control to reduce reactive power losses through precise electronic control, such as the Chinese invention patent "An Intelligent Cooperative Control System and Method for Multi-Unit Permanent Magnet Synchronous Motors" (publication number not provided). CN105007014B employs a parallel structure of low-voltage multi-permanent magnet motor collaborative control units to achieve low-voltage high-power, low-speed high-torque control and system redundancy control. It utilizes a dual-parallel PWM rectifier circuit structure; when the system is in an unbalanced power supply network environment, the two sets of PWM rectifiers are used to control the positive and negative sequence currents respectively, reducing reactive power loss and harmonic loss. However, existing technologies for reducing reactive power loss and increasing power density are overly complex and costly. Developing a reactive power compensation motor with a simple structure, high power density, high efficiency, and high reliability suitable for power systems is one direction the industry is exploring. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a rotary permanent magnet motor with a magnetic ring for reactive power compensation, which employs a permanent magnet rotor, a magnetic ring rotor, and an armature stator to form a magnetic field regulation structure.

[0004] The specific technical solution is a rotary permanent magnet motor with a magnetic ring for reactive power compensation, comprising a permanent magnet rotor, a magnetic ring rotor, and a stator armature. The permanent magnet rotor and the magnetic ring rotor are located inside the stator armature. The magnetic ring rotor rotates synchronously with the permanent magnet rotor and is unloaded. The magnetic ring rotor has P salient poles. f Equal to the number of permanent magnet rotor pole pairs P m The number of pole pairs in the stator armature winding is twice the number of pole pairs in the permanent magnet rotor, P. m The magnetic field regulation structure is composed of a permanent magnet rotor, a magnetic ring rotor, and an armature stator, which has the advantages of simple structure, high power density, high efficiency, and high reliability.

[0005] Furthermore, the permanent magnet rotor is an inner rotor, and the adjusting ring rotor is located between the stator armature and the permanent magnet inner rotor.

[0006] Furthermore, the adjusting ring rotor is located on the inner side, and the permanent magnet rotor is located between the stator armature and the adjusting ring rotor.

[0007] Furthermore, the permanent magnet rotor includes a magnetic guide block and a permanent magnet, wherein the permanent magnet is magnetized tangentially.

[0008] The beneficial effects of this invention are as follows: By adjusting the relative angular position of the adjusting magnetic ring rotor and the permanent magnet rotor, the back electromotive force of the motor can be adjusted, so that the active power of the motor is zero, while the reactive power can be adjusted arbitrarily; compared with conventional electrically excited synchronous phase-adjusting motors, the motor has the advantages of simple structure, high power density, high efficiency and high reliability, and is very suitable for reactive power compensation in power systems. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the motor topology according to Embodiment 1 of the present invention;

[0010] Figure 2 This is a schematic diagram of the magnetic field lines distribution when the magnetic flux is at its maximum.

[0011] Figure 3 This is a schematic diagram of the magnetic field lines distribution when the magnetic flux is at its minimum.

[0012] Figure 4 The back EMF waveforms are shown at different positions;

[0013] Figure 5 This is a schematic diagram of the motor topology in Embodiment 2 of the present invention, which is a schematic diagram of the tangential magnetizing permanent magnet motor topology with built-in adjusting magnetic ring.

[0014] Figure 6 This is a schematic diagram of the motor topology in Embodiment 3 of the present invention. Figure 1 This is a schematic diagram of the topology of a radially magnetized permanent magnet motor with an externally mounted magnetic ring.

[0015] Figure 7 This is a schematic diagram of the motor topology in Embodiment 3 of the present invention. Figure 2 At this point, adjust the schematic diagram of the radial magnetized permanent magnet motor topology with built-in magnetic ring.

[0016] In the diagram: 1-magnetic block, 2-permanent magnet, 3-magnetic ring rotor, 4-stator core, 5-armature winding. Detailed Implementation

[0017] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0018] Example 1:

[0019] like Figure 1 As shown, a rotary permanent magnet motor with adjusting magnetic ring for reactive power compensation includes a permanent magnet rotor, an adjusting magnetic ring rotor 3, and a stator armature, wherein the permanent magnet rotor and the adjusting magnetic ring rotor 3 are located inside the stator armature.

[0020] In this embodiment, a permanent magnet rotor is used as the inner rotor, and the adjusting ring rotor 3 is located between the stator armature and the permanent magnet inner rotor. The permanent magnet rotor includes a magnetic guide block 1 and a permanent magnet 2. The permanent magnet 2 is magnetized in a tangential manner. Neither the adjusting ring rotor nor the permanent magnet rotor has an iron core yoke. That is, the permanent magnet 2 is magnetized in a tangential manner, and the magnetic guide block 1 is between adjacent magnets.

[0021] Adjusting the relative position of the adjusting ring rotor 3 and the permanent magnet 2 of the permanent magnet rotor can adjust the winding magnetic flux. When the magnetic flux is at its maximum, the magnetic field lines are distributed as follows: Figure 2 As shown; the distribution of magnetic field lines when the magnetic flux is at its minimum. Figure 3 As shown, the armature winding back EMF at different positions is as follows: Figure 4 As shown.

[0022] The stator armature includes the stator core 4 and the armature winding 5.

[0023] The adjusting magnetic ring rotor 3 rotates synchronously with the permanent magnet rotor and is unloaded. The number of salient poles P of the adjusting magnetic ring rotor 3 is... f Equal to the number of permanent magnet rotor pole pairs P m The number of pole pairs in the stator armature winding is twice the number of pole pairs in the permanent magnet rotor, P. m Since the output shaft is unloaded, and without considering motor losses and rotor mechanical transients, or when the motor speed reaches a steady state, the motor's input active power is always zero. The motor's armature three-phase windings are connected to the power grid. By mechanically adjusting the relative angle between the adjusting ring rotor and the permanent magnet rotor, the motor's back electromotive force can be adjusted, thus allowing for arbitrary adjustment of the motor's reactive power. Compared to conventional electrically excited synchronous phase-shifting motors, this motor lacks a complex excitation system for adjusting the motor's excitation current, resulting in advantages such as simple structure, low cost, high efficiency, and high reliability, making it highly suitable for use as a reactive power compensation motor in power systems.

[0024] Example 2:

[0025] like Figure 5As shown, the difference between this embodiment and the first embodiment is that in the motor topology, the adjusting magnetic ring rotor 3 is located on the inner side, and the permanent magnet rotor is located between the stator and the adjusting magnetic ring rotor. That is, the adjusting magnetic ring rotor 3 is located on the inner side, and the permanent magnet rotor is located between the stator armature and the adjusting magnetic ring rotor 3.

[0026] Example 3:

[0027] like Figure 6 , Figure 7 As shown, in this embodiment, the permanent magnet rotor and the adjusting ring rotor 3 have iron core yokes, and the magnetic guide block 1 and the permanent magnet 2 form a ring separately. The two are located between the stator armature and the adjusting ring rotor 3, and their positions can be interchanged.

[0028] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, 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 rotary permanent magnet motor with a magnetic adjusting ring for reactive power compensation, characterized in that, The system includes a permanent magnet rotor, a magnetic ring rotor (3), and a stator armature. The permanent magnet rotor and the magnetic ring rotor (3) are located inside the stator armature. The magnetic ring rotor (3) rotates synchronously with the permanent magnet rotor and is unloaded. The magnetic ring rotor (3) has P salient poles. f Equal to the number of permanent magnet rotor pole pairs P m The number of pole pairs in the stator armature winding is twice the number of pole pairs in the permanent magnet rotor, P. m ; The permanent magnet rotor is an inner rotor, and the adjusting ring rotor (3) is located between the stator armature and the permanent magnet inner rotor; Alternatively, the adjusting ring rotor (3) is located on the inner side, and the permanent magnet rotor is located between the stator armature and the adjusting ring rotor (3); By adjusting the relative angular position of the adjusting magnetic ring rotor and the permanent magnet rotor, the back electromotive force of the motor can be adjusted to compensate for reactive power.

2. A rotary permanent magnet motor with a magnetic adjusting ring for reactive power compensation according to claim 1, characterized in that, The permanent magnet rotor includes a magnetic block (1) and a permanent magnet (2), and the permanent magnet (2) is magnetized in a tangential manner.

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