A synchronous motor

Abstract

The present invention provides a synchronous motor, comprising: a housing; a rotating shaft connected to the housing and rotatable relative to the housing; a rotor assembly including a rotor core, a rotor main winding, a first rotor auxiliary winding, and a second rotor auxiliary winding arranged in rotor slots of the rotor core, the rotor core being fixedly arranged on the rotating shaft; a stator assembly including a stator core, a stator main winding, a first stator auxiliary winding, a second stator auxiliary winding, and a third stator auxiliary winding arranged in stator slots of the stator core, the stator core being sleeved outside the rotor core and fixedly arranged on the housing. The present invention establishes the no-load voltage of the motor through the electromagnetic coupling between the main and auxiliary windings, cancels the traditional AC exciter, reduces the manufacturing and operation costs of the motor, improves the operation reliability of the motor, and reduces the maintenance workload; at the same time, it also adjusts the stator auxiliary winding current through the AVR to realize the regulation of the motor terminal voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a synchronous motor. Background Art

[0002] The synchronous motor, like the induction motor (i.e., asynchronous motor), is a commonly used AC motor. The synchronous motor is the heart of the power system. It is an element that integrates rotation and rest, electromagnetic changes and mechanical motion to achieve the conversion between electrical energy and mechanical energy. The synchronous motor is divided into a synchronous generator and a synchronous motor. The AC machines in modern power plants are mainly synchronous generators.

[0003] In the prior art, currently, synchronous motors usually use an AC exciter and a pilot exciter for excitation, thus forming a synchronous motor with a three-structure form. Or some synchronous motors cancel the pilot exciter, forming a synchronous motor with a two-structure form, such as a third-harmonic excitation generator. However, for these two forms of synchronous motors, since they both rely on the AC exciter, the reliability of the motor operation is reduced, the maintenance workload is increased, and the manufacturing and operation costs are improved. Summary of the Invention

[0004] Based on this, the object of the present invention is to provide a synchronous motor to solve the problems of poor operation reliability, large maintenance workload, and high manufacturing and operation costs of the existing synchronous motors.

[0005] According to a synchronous motor in an embodiment of the present invention, the synchronous motor includes:

[0006] A housing;

[0007] A rotating shaft, connected to the housing and rotatable relative to the housing;

[0008] A rotor assembly, including a rotor core, a rotor main winding, a first rotor auxiliary winding, and a second rotor auxiliary winding. The rotor core is fixedly arranged on the rotating shaft, and the rotor main winding, the first rotor auxiliary winding, and the second rotor auxiliary winding are arranged in rotor slots circumferentially opened on the outer wall of the rotor core;

[0009] A stator assembly, including a stator core, a stator main winding, a first stator auxiliary winding, a second stator auxiliary winding, and a third stator auxiliary winding. The stator core is sleeved outside the rotor core and fixedly arranged on the housing, and the stator main winding, the first stator auxiliary winding, the second stator auxiliary winding, and the third stator auxiliary winding are arranged in stator slots circumferentially opened on the inner wall of the stator core;

[0010] Wherein, the first rotor auxiliary winding and the second rotor auxiliary winding are electrically connected to the rotor main winding through a rotor rectification module;

[0011] Among them, the first stator secondary winding and the second stator secondary winding are electrically connected to the third stator secondary winding through a stator rectification module, and the stator main winding is connected to the line connecting the stator rectification module and the third stator secondary winding.

[0012] Further, the rotor main winding, the first rotor secondary winding, and the second rotor secondary winding form a set of rotor windings, and the rotor assembly includes multiple sets of the rotor windings;

[0013] A plurality of sets of rotor slots are circumferentially formed on the outer wall of the rotor core, and each set of the rotor slots corresponds to and arranges a set of the rotor windings.

[0014] Further, each set of rotor slots includes two rotor slots, and the rotor slots extend radially along the rotor core;

[0015] One rotor main winding is arranged in each of the rotor slots, and the first rotor secondary winding and the second rotor secondary winding are arranged in different stator slots and on the side of the rotor main winding away from the rotating shaft.

[0016] Further, the stator main winding, the first stator secondary winding, the second stator secondary winding, and the third stator secondary winding form a set of stator windings, and the stator assembly includes multiple sets of the stator windings;

[0017] A plurality of sets of stator slots are circumferentially formed on the inner wall of the stator core, and each set of the stator slots corresponds to and arranges a set of the stator windings.

[0018] Further, each set of stator slots includes three stator slots, and the stator slots extend radially along the stator core;

[0019] One stator main winding is arranged in each of the stator slots, and the first stator secondary winding, the second stator secondary winding, and the third stator secondary winding are arranged in different stator slots and on the side of the stator main winding away from the rotating shaft.

[0020] Further, an automatic voltage regulator is provided on the line connecting the stator rectification module and the third stator secondary winding, and the stator main winding is connected to the automatic voltage regulator.

[0021] Further, the stator main winding is a three-phase winding, a single-phase winding, or a multi-phase winding, and the stator main winding is an integral-slot winding or a fractional-slot winding;

[0022] The first stator secondary winding and the second stator secondary winding are three-phase windings, single-phase windings, or multi-phase windings, and the third stator secondary winding is a single-phase winding.

[0023] Further, the first rotor secondary winding and the second rotor secondary winding are three-phase windings, single-phase windings or multi-phase windings.

[0024] Further, the pole pair number of the stator main winding and the pole pair number of the stator secondary winding are in an odd multiple relationship or an even multiple relationship. The stator secondary winding includes the first stator secondary winding, the second stator secondary winding and the third stator secondary winding;

[0025] The pole pair number of the rotor main winding and the pole pair number of the rotor secondary winding are in an odd multiple relationship or an even multiple relationship. The rotor secondary winding includes the first rotor secondary winding and the second rotor secondary winding.

[0026] Further, the synchronous motor is of salient pole structure or non-salient pole structure.

[0027] Compared with the prior art: by adding the stator secondary winding and the rotor secondary winding, the no-load voltage of the motor is established through the electromagnetic coupling between the stator main winding, the stator secondary winding and the rotor main winding, the rotor secondary winding, so that it is not necessary to rely on an AC exciter for excitation, and thus the AC exciter can be cancelled, reducing the manufacturing and operation costs of the motor, improving the operation reliability of the motor, and reducing the maintenance workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a cross-sectional view of a synchronous motor in an embodiment of the present invention;

[0029] Figure 2 is the electrical wiring schematic diagram of a synchronous motor in an embodiment of the present invention.

[0030] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention is thorough and complete.

[0032] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] Embodiment 1

[0035] Please refer to Figure 1 - Figure 2 , which shows a synchronous motor in Embodiment 1 of the present invention, including a housing (not shown in the figure), a rotating shaft 10 connected to the housing and rotatable relative to the housing, a rotor assembly fixedly connected to the rotating shaft 10 to rotate synchronously with the rotating shaft 10, and a stator assembly sleeved outside the rotor assembly and fixed to the housing.

[0036] Bearings (not shown in the figure) are provided at both ends of the housing. The rotating shaft 10 passes through the inside of the housing, and both ends of the rotating shaft 10 are rotatably connected to the housing through the bearings. The rotor assembly and the stator assembly are both arranged inside the housing to be protected by the housing. In specific implementation, the material, shape, etc. of the housing are not strictly limited, as long as the use requirements are met. For example, the housing can be arranged in a cylindrical shape.

[0037] Among them, the rotor assembly includes a rotor core 6, a rotor main winding 7, a first rotor secondary winding 8, and a second rotor secondary winding 9. The rotor core 6 is fixedly arranged on the rotating shaft 10, and the rotor main winding 7, the first rotor secondary winding 8, and the second rotor secondary winding 9 are arranged in the rotor slots axially opened on the outer wall of the rotor core 6.

[0038] In some cases of this embodiment, as Figure 1 shown, the rotor main winding 7, the first rotor secondary winding 8, and the second rotor secondary winding 9 form a set of rotor windings. The rotor assembly includes multiple sets of such rotor windings. Multiple sets of rotor slots are axially opened on the outer wall of the rotor core 6, and each set of rotor slots corresponds to a set of rotor windings. More specifically, each set of rotor slots includes two rotor slots. The rotor slots extend radially along the rotor core 6, and a rotor main winding 7 is arranged in each rotor slot. The first rotor secondary winding 8 and the second rotor secondary winding 9 are arranged in different stator slots and are located on the side of the rotor main winding 7 away from the rotating shaft 10.

[0039] Similarly, the stator assembly includes a stator core 1, a stator main winding 2, a first stator secondary winding 3, a second stator secondary winding 4, and a third stator secondary winding 5. The stator core 1 is sleeved outside the rotor core 6 and fixedly arranged on the housing. The stator main winding 2, the first stator secondary winding 3, the second stator secondary winding 4, and the third stator secondary winding 5 are arranged in the stator slots axially opened on the inner wall of the stator core 1.

[0040] In some cases of this embodiment, such as Figure 1 As shown, the main stator winding 2, the first auxiliary stator winding 3, the second auxiliary stator winding 4, and the third auxiliary stator winding 5 form a set of stator windings. The stator assembly includes multiple sets of such stator windings. The inner wall of the stator core 1 is provided with multiple sets of stator slots along the circumferential direction, and each set of stator slots corresponds to a set of stator windings. More specifically, each set of stator slots includes three stator slots. The stator slots extend radially along the stator core 1. A main stator winding 2 is arranged in each stator slot. The first auxiliary stator winding 3, the second auxiliary stator winding 4, and the third auxiliary stator winding 5 are arranged in different stator slots and on the side of the main stator winding 2 away from the rotating shaft 10.

[0041] In specific implementation, the main stator winding 2 is a three-phase winding, a single-phase winding, or a multi-phase winding, and the main stator winding 2 is an integral-slot winding or a fractional-slot winding. The first auxiliary stator winding 3 and the second auxiliary stator winding 4 are three-phase windings, single-phase windings, or multi-phase windings, and the third auxiliary stator winding 5 is a single-phase winding. The first rotor auxiliary winding 8 and the second rotor auxiliary winding 9 are three-phase windings, single-phase windings, or multi-phase windings. The pole number of the main stator winding 2 and the pole number of the auxiliary stator windings are in an odd multiple relationship or an even multiple relationship. The auxiliary stator windings include the first auxiliary stator winding 3, the second auxiliary stator winding 4, and the third auxiliary stator winding 5. The pole number of the main rotor winding 7 and the pole number of the rotor auxiliary windings are in an odd multiple relationship or an even multiple relationship. The rotor auxiliary windings include the first rotor auxiliary winding 8 and the second rotor auxiliary winding 9. The synchronous motor is a salient-pole structure or a non-salient-pole structure.

[0042] In addition, as Figure 2 shown, the first rotor auxiliary winding 8 and the second rotor auxiliary winding 9 are electrically connected to the main rotor winding 7 through a rotor rectification module. In addition, the first auxiliary stator winding 3 and the second auxiliary stator winding 4 are electrically connected to the third auxiliary stator winding 5 through a stator rectification module, and the main stator winding 2 is connected to the circuit connecting the stator rectification module and the third auxiliary stator winding 5. Among them, the rotor rectification module and the stator rectification module can specifically be rectifier diodes.

[0043] Furthermore, in some optional cases of this embodiment, an Automatic Voltage Regulator (AVR for short) is provided on the circuit connecting the stator rectification module and the third auxiliary stator winding 5. The main stator winding 2 is connected to the automatic voltage regulator, so as to control the excitation current of the main rotor winding 7, thereby achieving the purpose of regulating the terminal voltage of the motor.

[0044] The synchronous motor in this embodiment, when used as a generator, the main stator winding 2 is connected to a load, and when used as a motor, the main stator winding 2 is connected to an external power supply. Combining Figure 2, the specific working principle of the synchronous motor in this embodiment is as follows: When the motor runs without load, the rotor core 6 rotates at the synchronous speed. The residual magnetism in the motor will induce electromotive forces in the first stator secondary winding 3 and the second stator secondary winding 4. The current generated by this electromotive force is rectified by the stator rectification module to form direct current and supplied to the third stator secondary winding 5. The third stator secondary winding 5 provides a magnetic field to the air gap, so that electromotive forces are also induced in the first rotor secondary winding 8 and the second rotor secondary winding 9. The current generated by this induced electromotive force is rectified by the rotor rectification module and supplied to the rotor main winding 7, thereby establishing the no-load voltage of the motor and canceling the AC exciter;

[0045] In addition, in order to adjust the motor terminal voltage, the first stator secondary winding 3 and the second stator secondary winding 4 are adjusted by the AVR to adjust the current flowing through the third stator secondary winding 5, and then control the induced electromotive forces of the first rotor secondary winding 8 and the second rotor secondary winding 9, so as to control the current flowing through the rotor main winding 7, achieving the purpose of adjusting the generator terminal voltage.

[0046] Compared with the prior art, the synchronous motor of the present invention has at least the following advantages:

[0047] 1. By adding stator secondary windings and rotor secondary windings, the no-load voltage of the motor is established through the electromagnetic coupling between the stator main winding, stator secondary windings and rotor main winding, rotor secondary windings, so that it is not necessary to use an AC exciter for excitation, and then the AC exciter is canceled, forming a new type of synchronous motor with a single armature core structure, reducing the manufacturing and operation costs of the motor, improving the operation reliability of the motor, and reducing the maintenance workload;

[0048] 2. By adjusting the stator secondary winding current through the AVR, the adjustment of the motor terminal voltage is achieved.

[0049] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A synchronous motor, characterized in that, the synchronous motor comprises: a housing; a rotating shaft, connected to the housing and rotatable relative to the housing; a rotor assembly, including a rotor core, a main rotor winding, a first auxiliary rotor winding and a second auxiliary rotor winding, the rotor core is fixedly arranged on the rotating shaft, and the main rotor winding, the first auxiliary rotor winding and the second auxiliary rotor winding are arranged in rotor slots circumferentially formed on the outer wall of the rotor core; a stator assembly, including a stator core, a main stator winding, a first auxiliary stator winding, a second auxiliary stator winding and a third auxiliary stator winding, the stator core is sleeved outside the rotor core and fixedly arranged on the housing, and the main stator winding, the first auxiliary stator winding, the second auxiliary stator winding and the third auxiliary stator winding are arranged in stator slots circumferentially formed on the inner wall of the stator core; wherein, the first auxiliary rotor winding and the second auxiliary rotor winding are electrically connected to the main rotor winding through a rotor rectification module; wherein, the first auxiliary stator winding and the second auxiliary stator winding are electrically connected to the third auxiliary stator winding through a stator rectification module, and the main stator winding is connected to the line connecting the stator rectification module and the third auxiliary stator winding; the main rotor winding, the first auxiliary rotor winding and the second auxiliary rotor winding form a group of rotor windings, and the rotor assembly includes multiple groups of the rotor windings; multiple groups of rotor slots are circumferentially formed on the outer wall of the rotor core, and each group of rotor slots correspondingly arranges a group of the rotor windings; the main stator winding, the first auxiliary stator winding, the second auxiliary stator winding and the third auxiliary stator winding form a group of stator windings, and the stator assembly includes multiple groups of the stator windings; multiple groups of stator slots are circumferentially formed on the inner wall of the stator core, and each group of stator slots correspondingly arranges a group of the stator windings.

2. The synchronous motor according to claim 1, characterized in that, each group of rotor slots includes two rotor slots, and the rotor slots extend radially along the rotor core; one main rotor winding is arranged in each rotor slot, and the first auxiliary rotor winding and the second auxiliary rotor winding are arranged in different stator slots and on the side of the main rotor winding away from the rotating shaft.

3. The synchronous motor according to claim 1, characterized in that, each group of stator slots includes three stator slots, and the stator slots extend radially along the stator core; one main stator winding is arranged in each stator slot, and the first auxiliary stator winding, the second auxiliary stator winding and the third auxiliary stator winding are arranged in different stator slots and on the side of the main stator winding away from the rotating shaft.

4. The synchronous motor according to any one of claims 1-3, characterized in that, an automatic voltage regulator is provided on the line connecting the stator rectification module and the third auxiliary stator winding, and the main stator winding is connected to the automatic voltage regulator.

5. The synchronous motor according to any one of claims 1-3, characterized in that, The main stator winding is a single-phase winding or a polyphase winding, and the main stator winding is an integral-slot winding or a fractional-slot winding; The first and second auxiliary stator windings are single-phase windings or polyphase windings, and the third auxiliary stator winding is a single-phase winding.

6. The synchronous motor according to any one of claims 1-3, characterized in that, The first and second auxiliary rotor windings are single-phase windings or polyphase windings.

7. The synchronous motor according to any one of claims 1-3, characterized in that, The number of pole pairs of the main stator winding and the number of pole pairs of the auxiliary stator winding are in an odd multiple relationship or an even multiple relationship. The auxiliary stator winding includes the first auxiliary stator winding, the second auxiliary stator winding and the third auxiliary stator winding; The number of pole pairs of the main rotor winding and the number of pole pairs of the auxiliary rotor winding are in an odd multiple relationship or an even multiple relationship. The auxiliary rotor winding includes the first auxiliary rotor winding and the second auxiliary rotor winding.

8. The synchronous motor according to any one of claims 1-3, characterized in that, The synchronous motor is of salient-pole structure or non-salient-pole structure.

Images