Modularized bearingless electro-magnetic doubly salient motor

Abstract

The embodiment of the invention discloses a modular bearingless doubly salient electro-magnetic motor, relates to the technical field of bearingless doubly salient electro-magnetic motors, and can further improve the fault tolerance performance of the modular bearingless doubly salient electro-magnetic motor. The invention comprises a body structure of the modular bearingless electro-magnetic doubly salient motor and an annular direct current winding control method for suspension control of the modular bearingless electro-magnetic doubly salient motor. Structural optimization of a traditional bearingless electro-magnetic doubly salient motor is achieved, coupling between windings of the traditional bearingless electro-magnetic doubly salient motor is reduced, meanwhile, the modular topology is beneficial to physical isolation and electric, magnetic and thermal isolation of the motor windings, and the utilization rate of residual healthy windings is high when a fault occurs. The topological structure can be used for bearingless electro-magnetic doubly salient motors with other stator and rotor pole numbers.

Description

Technical Field

[0001] The present invention relates to the technical field of bearingless electrically excited double-pole motors, and in particular to a modular bearingless electrically excited double-pole motor. Background Art

[0002] With the development of science and technology, there are more and more types of motor topologies, and the control methods are becoming more and more complex. As one of the reluctance motors, the bearingless electrically excited double-pole motor has the advantages of no lubrication, no friction, high reliability, etc., and is more suitable for high-speed operation. The bearingless electrically excited double-pole motor not only has important applications in industrial fields that rely on no lubrication and high reliability, but also has important development potential in the aviation field. In the above application scenarios, strict requirements are placed on the fault tolerance performance of the motor.

[0003] Therefore, how to further improve the fault tolerance performance of modular bearingless electrically excited double-pole motor has become a topic that needs to be studied. Summary of the invention

[0004] Embodiments of the present invention provide a modular bearingless electrically excited double-pole motor and a suspension control method, which can further improve the fault tolerance performance of the modular bearingless electrically excited double-pole motor.

[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0006] A modular bearingless electrically excited double-salient pole motor, wherein the topological structure of the modular bearingless electrically excited double-salient pole motor comprises: a rotor core (1), a stator core (2), an armature winding (3) and an annular DC winding (4); the rotor core (1) and the stator core (2) are both salient pole structures; the stator core (2) is evenly divided into four stator modules, including: M1, M2, M3 and M4, and each stator module has the same shape; the armature winding (3) is wound on the stator pole of the stator core (2), and the annular DC winding (4) is wound on the middle yoke of each stator module.

[0007] The wire ends of the armature winding in a stator module are marked as C in clockwise direction. Mx-① , A Mx-① , B Mx-① , C Mx-② , A Mx-② , B Mx-② The wire ends of the armature winding in the other stator module opposite to the stator module are marked as C in clockwise direction. My-① , A My-① , B My-① , C My-② , A My-② , B My-②, x is a positive integer, the maximum value of x is an even number, y=x+2; the armature windings of the two opposite stator modules are connected in series to form a three-phase armature winding, where A of Mx Mx-① With My A My-① The armature winding A is formed in series MxMy-① For example, the stator core of a modular bearingless electrically excited double-pole motor has four modules (labeled as M1 to M4), and each stator pole is wound with an armature winding (the armature winding in the M1 module is labeled C in clockwise direction). M1-① , A M1-① , B M1-① , C M1-② , A M1-② , B M1-② , and the armature windings of the remaining modules are similarly calculated).

[0008] In the preferred embodiment, M1 is opposite to M3, and M2 is opposite to M4; the armature winding (3) comprises: an armature winding A of three phases ABC M1M3 , B M1M3 , C M1M3 , A M2M4 , B M2M4 and C M2M4 , where A M1M3 , B M1M3 and C M1M3 Wound on M1 and M3 respectively, A M2M4 , B M2M4 and C M2M4 In order to balance the back electromotive force, the same-phase armature windings that are relatively spaced are connected in series to form four sets of three-phase armature windings (such as A M1-① With A M3-① Series A M1M3-① winding).

[0009] Adjacent stator modules are not directly connected through the core, and the annular DC winding DC of each stator module Mz The generated magnetic flux only passes through the stator module and the rotor core (1) to form a closed loop, z is a positive integer, and the maximum value of z is equal to the maximum value of x. The annular DC winding (4) includes: M1, M2, M3 and M4, each of which has an independent winding DC on its yoke. M1 、DC M2 、DC M3 and DC M4 Adjacent stator modules are not directly connected through the core, and the annular DC winding DC of each module M1 The generated magnetic flux only passes through this module and the rotor core to form a closed loop (such as DC M1 The generated magnetic flux only passes through M1 and the rotor core without passing through the other stator modules).

[0010] The suspension control method applied to the above modular bearingless electrically excited double-pole motor comprises: using a single-phase bridge inverter circuit, and passing a control current to the annular DC winding (4) by controlling the switch tube, thereby realizing the excitation and suspension control of the modular bearingless electrically excited double-pole motor. The control current is the excitation current I f With suspension control current I sx / sy The sum of I sx ,I sy They are suspension control current I sx / sy The suspension control current components on the x-axis and y-axis. Among them, when the modular bearingless electrically excited double-pole motor is operating normally, the excitation current components of the four stator modules are the same, and the excitation magnetic field generated by the excitation current of each stator module is also used as the bias magnetic field required for rotor suspension; the suspension control current components of the stator modules relative to each other in space are equal in magnitude and opposite in polarity. In practical applications, the generated suspension control magnetic field is superimposed on the bias magnetic field (excitation magnetic field), and the suspension forces in the x-axis and y-axis directions are controlled respectively by adjusting the suspension control current components. At different rotor angles, the direction of the suspension force on the rotor changes little. Therefore, during the high-speed rotation of the rotor, the suspension control current component does not need to be commutated at high frequency, so the motor is more adaptable to high-speed working environments.

[0011] The modular bearingless electrically excited double-pole motor provided in an embodiment of the present invention introduces modular design into the bearingless electrically excited double-pole motor, adopts a single-layer concentrated winding and a stator air gap magnetic barrier method, and divides the motor into a module combination of the smallest unit motor. There are air gap magnetic barriers between the modules to reduce magnetic coupling. The series and parallel combination of the module windings is flexible, which is convenient for achieving electrical isolation, thereby improving the fault tolerance performance of the modular bearingless electrically excited double-pole motor, and its power density is also unaffected. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a simplified topological diagram of the modular bearingless electrically excited double-salient-pole motor structure of the present invention;

[0014] Figure 2 The single-phase bridge inverter circuit of the present invention is used to control the ring-shaped DC winding of a modular bearingless electrically excited double-salient-pole motor;

[0015] Figure 3The invention discloses a three-phase four-bridge-arm inverter circuit for controlling the armature winding of a modular bearingless electrically excited double-salient-pole motor;

[0016] Figure 4 It is a schematic diagram of the connection mode between the three-phase four-bridge-arm inverter circuit and the armature winding of the present invention;

[0017] Figure 5 It is a schematic diagram of the rotor suspension principle of the modular bearingless electrically excited double-salient pole motor of the present invention. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0019] Figure 1 The topological structure of the modular bearingless electrically excited double-salient-pole motor provided by the embodiment of the present invention is shown. Figure 1 In the figure, 1 is the rotor with 16 poles. 2 is the stator with 24 poles. 3 is the armature winding, and each stator pole is wound with an armature winding (the armature windings in the M1 module are marked as C in clockwise direction). M1-① , A M1-① , B M1-①, C M1-② , A M1-② , B M1-② The armature windings in the M2 module are marked as C in clockwise direction. M2-① , A M2-① , B M2-① , C M2-② , A M2-② , B M2-② The armature windings in the M3 module are marked as C in clockwise direction. M3-① , A M3-① , B M3-① , C M3-② , A M3-② , B M3-② The armature windings in the M4 module are marked as C in clockwise direction. M4-① , A M4-① , B M4-① , C M4-② , A M4-② , B M4-② ), in order to balance the back electromotive force, the spatially opposite same-phase armature windings are connected in series to form four sets of three-phase armature windings (such as A M1-① With A M3-① Series A M1M3-① Winding, A M1-② With A M3-② Series A M1M3-② Winding, B M2-② With B M4-② Series connection B M2M4-② Windings), connected to independent power converters to realize four-channel motoring and generating operation, or parallel operation. The suspension winding and excitation winding of each stator module share a set of windings, called annular DC windings, which are distributed in the middle yoke of each stator module. By controlling the current in the winding, its amplitude is equal to the excitation current component I f and suspension control current component I sx / sy The sum of the excitation and suspension functions is realized, such as Figure 1 DCM1, DCM2, DCM3, and DCM4 in the system.

[0020] In this embodiment, Figure 2The present invention shows a three-phase four-bridge-arm inverter circuit for controlling the armature winding of a modular bearingless electrically excited double-pole motor. A single-phase bridge inverter circuit is used to control a toroidal DC winding. The single-phase bridge inverter circuit consists of two upper and lower bridge arms, each of which has two switching tubes. The entire inverter circuit topology consists of four switching tubes T1, T2, T3, T4 and a winding W, where W represents the toroidal DC windings DCM1, DCM2, DCM3, and DCM4. The gate voltage of the switching tube is controlled by PWM so that the current amplitude of the toroidal DC winding is the excitation current component I f and suspension control current component I sx / sy The sum of the two realizes the multiplexing function of excitation and suspension.

[0021] In this embodiment, Figure 3 The three-phase four-bridge-arm inverter circuit for controlling the armature winding of a modular bearingless electric excitation double-salient-pole motor of the present invention is shown. The switch devices of the entire inverter circuit are composed of eight switch tubes, T1, T2, T3, T4, T5, T6, T7, and T8, which are symmetrically distributed at the upper and lower bridge arms. When the modular armature windings are used in series (such as A M1-① With A M3-① Series A M1M3-① Winding), a set of series windings uses a three-phase four-bridge inverter circuit (hereinafter referred to as A M1M3-① , B M1M3-① , C M1M3-① The armature windings of the inverter circuit use the same three-phase four-bridge-arm inverter circuit). In the figure, A, B, and C represent the armature windings of phases A, B, and C respectively. TR is a bidirectional trigger diode, and E is a DC power supply. By using a three-phase four-bridge-arm inverter circuit, the problem of asymmetric output three-phase voltage waveform when the loads are unequal is solved.

[0022] In this embodiment, Figure 4 A schematic diagram showing the connection between the three-phase four-bridge-arm inverter circuit and the armature winding of the present invention is shown. Figure 4 The series connection of the armature winding relative to the stator module is taken as an example. On the left is a high-voltage DC busbar for providing DC bus voltage. The modular bearingless electrically excited double-pole motor of the present invention can be used for motoring or generating operation. When the motor is used for generating operation, the DC load is connected to the high-voltage DC busbar shown in the figure. There are four three-phase four-bridge arm inverter circuits in the figure, which are used to control four groups of armature windings with subscripts ①, ②, ③, and ④, wherein each group of armature windings is composed of A, B, and C phase armature windings and a neutral line, and these four windings are respectively connected to the middle of each bridge arm of the three-phase four-bridge arm inverter circuit.

[0023] In this embodiment, Figure 5The schematic diagram of the rotor suspension principle of the modular bearingless electrically excited double-salient pole motor of the present invention is shown. During normal operation, the excitation current components of the four modules are the same, and the excitation magnetic field generated by them also serves as the bias magnetic field required for rotor suspension; the suspension control current components of the spatially relative modules are equal in magnitude and opposite in polarity, and the generated suspension control magnetic field is superimposed on the bias magnetic field (excitation magnetic field). By adjusting the suspension control current components, the suspension forces in the x-axis and y-axis directions are controlled respectively. At different rotor angles, the direction of the suspension force on the rotor changes little. Therefore, during the high-speed rotation of the rotor, the suspension control current components do not need to undergo high-frequency commutation, so the motor is more adaptable to high-speed working environments.

[0024] Further, in Figure 5 In the figure, only the schematic diagram of the suspension magnetic circuit is shown when the rotor is located at the center of the x-direction. Figure a is a schematic diagram of the magnetic circuit when the rotor mechanical position angle is 0°. The red magnetic circuit in the figure is the excitation magnetic flux component, which forms a closed loop along each stator module itself and passes through the toroidal DC winding. The blue magnetic circuit is the suspension magnetic flux component in the y-axis direction, which forms a closed loop along each stator module itself and passes through the toroidal DC winding. Figure 5 In the diagram, Figure b is a schematic diagram of the magnetic circuit when the rotor mechanical position angle is 11.25°, which is similar to Figure a. DCM1 ,I DCM2 ,I DCM3 ,I DCM4 There are formula 1, formula 2, formula 3 and formula 4 respectively. f represents the excitation current,

[0025] I DCM1 =I f +I sy

[0026] I DCM2 =I f

[0027] I DCM3 =I f -I sy

[0028] I DCM4 =I f

[0029] The bearingless electrically excited double-pole motor has the advantages of no need for lubrication, no friction, and high reliability, and has a wide range of applications. In this embodiment, the bearingless electrically excited double-pole motor body is optimized to improve the fault tolerance and power density of the modular bearingless electrically excited double-pole motor. The modular motor topology has the advantage of flexible series and parallel combinations of windings. It is conducive to achieving physical isolation between windings, as well as electrical, magnetic, and thermal isolation, and has a high utilization rate of the remaining healthy windings in the event of a fault. In addition, the modular motor topology also reduces the coupling between the windings of the traditional bearingless electrically excited double-pole motor, which is more conducive to suspension control. It should be noted that the control method in this embodiment can also be used for modular bearingless electrically excited double-pole motors with other stator and rotor pole numbers.

[0030] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A modular bearingless electrically excited double-salient-pole motor, characterized in that: The topological structure of the modular bearingless electrically excited double-pole motor comprises: a rotor core (1), a stator core (2), an armature winding (3) and a ring-shaped DC winding (4); The rotor core (1) and the stator core (2) are both salient pole structures; The stator core (2) is evenly divided into four stator modules including: M1, M2, M3 and M4, and each stator module has the same shape; The armature winding (3) is wound on the stator poles of the stator core (2), and the annular DC winding (4) is wound on the middle yoke of each stator module.

2. The modular bearingless electrically excited double-salient-pole motor according to claim 1, characterized in that: The wire ends of the armature winding in a stator module are marked in clockwise direction as C Mx-① , A Mx-① , B Mx-① , C Mx-② , A Mx-② , B Mx-② The wire ends of the armature winding in the other stator module opposite to the stator module are marked as C in clockwise direction. My-① , A My-① , B My-① , C My-② , A My-② , B My-② , x is a positive integer, the maximum value of x is an even number, y=x+2; The armature windings of the two opposite stator modules are connected in series to form a three-phase armature winding, where A of Mx Mx-① With My A My-① The armature winding A is formed in series MxMy-① .

3. The modular bearingless electrically excited double-salient-pole motor according to claim 2, characterized in that: M1 is opposite to M3, M2 is opposite to M4; The armature winding (3) includes: an armature winding A of three phases ABC M1M3 , B M1M3 , C M1M3 , A M2M4 , B M2M4 and C M2M4 , where A M1M3 , B M1M3 and C M1M3 Wound on M1 and M3 respectively, A M2M4 , B M2M4 and C M2M4 Wound on M2 and M4 respectively.

4. The modular bearingless electrically excited double-salient-pole motor according to claim 2, characterized in that: Adjacent stator modules are not directly connected through the core, and the annular DC winding DC of each stator module Mz The generated magnetic flux only passes through the stator module and the rotor core (1) to form a closed loop, z is a positive integer, and the maximum value of z is equal to the maximum value of x.

5. The modular bearingless electrically excited double-salient-pole motor according to claim 4, characterized in that: The annular DC winding (4) comprises: independent windings DC on the yokes of M1, M2, M3 and M4 respectively. M1 、DC M2 、DC M3 and DC M4 .

6. The modular bearingless electrically excited double-salient-pole motor according to any one of claims 1 to 5, characterized in that: The suspension control method applied to the modular bearingless electrically excited double-salient-pole motor comprises: A single-phase bridge inverter circuit is used to control the switch tube to pass a control current into the annular DC winding (4), wherein the control current is equal to the excitation current I f With suspension control current I sx / sy The sum of I sx ,I sy They are suspension control current I sx / sy Suspension control current components in the x-axis and y-axis.

7. The modular bearingless electrically excited double-salient-pole motor according to claim 6, characterized in that: When the modular bearingless electrically excited double-salient-pole motor operates normally, the excitation current components of the four stator modules are the same, and the excitation magnetic field generated by the excitation current of each stator module also serves as the bias magnetic field required for rotor suspension; The suspension control current components of the stator modules that are spatially opposite to each other are equal in magnitude and opposite in polarity.

8. The modular bearingless electrically excited double-salient-pole motor according to claim 7, characterized in that: During normal operation of the modular bearingless electrically excited doubly salient pole motor, the independent winding DC M1 、DC M2 、DC M3 and DC M4 The current is I DCM1 ,I DCM2 ,I DCM3 ,I DCM4 , where I DCM1 =I f +I sy , I DCM2 =I f , I DCM3 =I f -I sy , I DCM4 =I f , I f Indicates the excitation current.

Images