Modular bearingless electrically excited doubly salient electric machine

Abstract

This invention discloses a modular bearingless electrically excited doubly salient pole motor, relating to the field of bearingless electrically excited doubly salient pole motor technology, which can further improve the fault-tolerant performance of modular bearingless electrically excited doubly salient pole motors. The invention includes: the main body structure of the modular bearingless electrically excited doubly salient pole motor, and a ring DC winding control method for levitation control of the modular bearingless electrically excited doubly salient pole motor. This invention achieves structural optimization of traditional bearingless electrically excited doubly salient pole motors, reducing the inter-winding coupling of traditional bearingless electrically excited doubly salient pole motors. Simultaneously, the modular topology facilitates physical isolation of the motor windings as well as electrical, magnetic, and thermal isolation, resulting in high utilization of the remaining healthy windings in case of failure. This topology can be used for bearingless electrically excited doubly salient pole motors with other stator and rotor pole numbers.

Description

Technical Field

[0001] This invention relates to the field of bearingless electrically excited doubly salient pole motor technology, and in particular to a modular bearingless electrically excited doubly salient pole motor. Background Technology

[0002] With the development of technology, the types of motor topologies are increasing, and control methods are becoming more complex. Bearingless electrically excited doubly salient pole motors, as a type of reluctance motor, offer advantages such as no lubrication required, no friction, and high reliability, making them more suitable for high-speed operation. Bearingless electrically excited doubly salient pole motors not only have important applications in industrial fields that rely on lubrication-free and high-reliability systems, but also hold significant development potential in the aerospace field. Both of these applications place stringent requirements on the fault-tolerant performance of the motor.

[0003] Therefore, how to further improve the fault-tolerant performance of modular bearingless electrically excited doubly salient pole motors has become a research topic. Summary of the Invention

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

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

[0006] A modular bearingless electrically excited double salient pole motor, the topology of which includes: a rotor core (1), a stator core (2), an armature winding (3), and a ring DC winding (4); both the rotor core (1) and the stator core (2) are salient pole structures; the stator core (2) is evenly divided into 4 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 ring DC winding (4) is wound on the middle yoke of each stator module.

[0007] In one stator module, the armature winding terminals are labeled C in clockwise order. Mx-① A Mx-① B Mx-① C Mx-② A Mx-② B Mx-② The armature winding terminals in the stator module opposite to this stator module are labeled C in clockwise order. My-① A My-① B My-① C My-② A My-② B My-②x is a positive integer, and the maximum value of x is even. y = x + 2; the armature windings of two opposite stator modules are connected in series to form a three-phase armature winding, where Mx's A Mx-① With My's A My-① Series connection constitutes armature winding A MxMy-① For example: The stator core of a modular bearingless electrically excited doubly salient pole motor has four modules (labeled M1 to M4 respectively), and each stator pole is wound with an armature winding (the armature windings in module M1 are labeled C in clockwise direction). M1-① A M1-① B M1-① C M1-② A M1-② B M1-② The armature windings of the remaining modules follow the same principle.

[0008] In the preferred embodiment, M1 is opposite to M3, and M2 is opposite to M4; the armature winding (3) includes: armature windings A of the three phases ABC. M1M3 B M1M3 C M1M3 A M2M4 B M2M4 and C M2M4 , where A M1M3 B M1M3 and C M1M3 Wound onto M1 and M3 respectively, A M2M4 B M2M4 and C M2M4 They are wound separately on M2 and M4. To balance the back electromotive force, the spatially opposite armature windings of the same phase are connected in series to form four sets of three-phase armature windings (such as A). M1-① With A M3-① A is formed by series connection M1M3-① (winding).

[0009] Adjacent stator modules are not directly connected via a core; each stator module has a toroidal DC winding. Mz The generated magnetic flux forms a closed loop only through this stator module and the rotor core (1), where z is a positive integer and the maximum value of z is equal to the maximum value of x. The toroidal DC winding (4) includes: independent DC windings on the yokes of M1, M2, M3 and M4. M1 DC M2 DC M3 and DC M4 Adjacent stator modules are not directly connected via iron cores; each module's toroidal DC winding... M1 The generated magnetic flux forms a closed loop with the rotor core only through this module (such as DC). M1 The generated magnetic flux passes only through M1 and the rotor core without passing through the other stator modules.

[0010] The levitation control method applied to the above-mentioned modular bearingless electrically excited doubly salient pole motor includes: using a single-phase bridge inverter circuit, and through the control of the switching transistor, supplying a control current to the toroidal DC winding (4), thereby realizing the excitation and levitation control of the modular bearingless electrically excited doubly salient pole motor. The magnitude of the control current is the excitation current I. f With levitation control current I sx / sy The sum of I sx I sy They are respectively the levitation control current I sx / sy The levitation control current components are located in the x and y axes. During normal operation of the modular bearingless electrically excited doubly salient pole motor, the excitation current components of the four stator modules are identical, and the excitation magnetic field generated by the excitation current of each stator module simultaneously serves as the bias magnetic field required for rotor levitation. The levitation control current components of spatially opposite stator modules are equal in magnitude and opposite in polarity. In practical applications, the generated levitation control magnetic field is superimposed on the bias magnetic field (excitation magnetic field). By adjusting the levitation control current components, the levitation force in the x and y axes is controlled respectively. At different rotor angles, the direction of the levitation force on the rotor changes relatively little. Therefore, during high-speed rotor rotation, the levitation control current components do not require high-frequency commutation, making the motor more adaptable to high-speed operating environments.

[0011] The modular bearingless electrically excited doubly salient pole motor provided in this invention introduces a modular design into the bearingless electrically excited doubly salient pole motor. By using a single-layer concentrated winding and stator air gap magnetic barrier method, the motor is divided into modular combinations of the smallest unit motor. There are air gap magnetic barriers between modules to reduce magnetic coupling. The series and parallel combination of module windings is flexible and facilitates electrical isolation, thereby improving the fault tolerance performance of the modular bearingless electrically excited doubly salient pole motor, while its power density is not affected. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0014] Figure 2 This invention relates to a single-phase bridge inverter circuit for controlling the toroidal DC winding of a modular bearingless electrically excited doubly salient pole motor.

[0015] Figure 3This invention relates to a three-phase four-bridge inverter circuit for controlling the armature winding of a modular bearingless electrically excited doubly salient pole motor.

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

[0017] Figure 5 This is a schematic diagram of the rotor suspension principle of the modular bearingless electrically excited doubly salient pole motor of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of the present invention means the presence of the stated 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 groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0019] Figure 1 The topology of the modular bearingless electrically excited doubly salient pole motor provided in the embodiment of the present invention is shown. Figure 1 In the diagram, 1 represents the rotor with 16 poles. 2 represents the stator with 24 poles. 3 represents the armature winding, with each stator pole wound with an armature winding (the armature windings within module M1 are labeled C in clockwise order). M1-① A M1-① B M1-①C M1-② A M1-② B M1-② The armature windings within module M2 are labeled C in a clockwise direction. M2-① A M2-① B M2-① C M2-② A M2-② B M2-② The armature windings within the M3 module are labeled C in a clockwise direction. M3-① A M3-① B M3-① C M3-② A M3-② B M3-② The armature windings within the M4 module are labeled C in a clockwise direction. M4-① A M4-① B M4-① C M4-② A M4-② B M4-② To balance the back electromotive force, spatially opposite armature windings of the same phase are connected in series to form four sets of three-phase armature windings (such as A). M1-① With A M3-① A is formed by series connection M1M3-① Winding, A M1-② With A M3-② A is formed by series connection M1M3-② Winding, B M2-② With B M4-② Series connection constitutes B M2M4-② Each stator module has an independent power converter connected to its respective winding to achieve four-channel motoring and generating operation, or parallel operation. The levitation winding and excitation winding of each stator module share a common winding, called a toroidal DC winding, which is distributed in the middle yoke of each stator module. The magnitude of the current in this winding is controlled to make its amplitude equal to the excitation current component I. f and levitation control current component I sx / sy The sum of these two elements enables the reuse of excitation and levitation functions, such as... Figure 1 The DCM1, DCM2, DCM3, and DCM4 are listed in the table.

[0020] In this embodiment, as Figure 2This invention illustrates a three-phase four-bridge inverter circuit for controlling the armature winding of a modular bearingless electrically excited doubly salient pole motor. A single-phase bridge inverter circuit controls a toroidal DC winding. The single-phase bridge inverter circuit consists of upper and lower bridge arms, each with two switching transistors. The entire inverter circuit topology comprises four switching transistors T1, T2, T3, and T4, and one winding W, representing the toroidal DC windings DCM1, DCM2, DCM3, and DCM4. PWM control of the switching transistor gate voltages ensures that the amplitude of the toroidal DC winding current is equal to the excitation current component I. f and levitation control current component I sx / sy The sum of these two parameters enables the reuse of excitation and levitation functions.

[0021] In this embodiment, as Figure 3 This invention illustrates a three-phase four-arm inverter circuit for controlling the armature winding of a modular bearingless electrically excited doubly salient pole motor. The entire inverter circuit consists of eight switching transistors (T1, T2, T3, T4, T5, T6, T7, and T8), symmetrically distributed at the upper and lower arms. When the modular armature windings are used in series (e.g., A...),... M1-① With A M3-① A is formed by series connection M1M3-① A series winding uses a three-phase four-arm inverter circuit (hereinafter referred to as A). M1M3-① B M1M3-① C M1M3-① The armature windings of the inverters use the same three-phase four-arm inverter circuit. In the diagram, A, B, and C represent the armature windings of phases A, B, and C, respectively. TR is a bidirectional trigger diode, and E is the DC power supply. By using a three-phase four-arm inverter circuit, the problem of asymmetrical three-phase output voltage waveforms when the loads are unequal is solved.

[0022] In this embodiment, as Figure 4 A schematic diagram of the connection between the three-phase four-arm inverter circuit and the armature winding of the present invention is shown. Figure 4 The example shown is the series connection of the armature windings relative to the stator module. The left side shows the high-voltage DC busbar, used to provide the DC bus voltage. The modular bearingless electrically excited doubly salient pole motor of this invention can be used for motoring or generating. When the motor is generating, the DC load is connected to the high-voltage DC busbar shown in the figure. The figure contains four three-phase four-arm inverter circuits, used to control four sets of armature windings labeled ①, ②, ③, and ④. Each set of armature windings consists of A, B, and C phase armature windings and a neutral line. These four windings are respectively connected to the middle of each arm of the three-phase four-arm inverter circuit.

[0023] In this embodiment, as Figure 5This diagram illustrates the rotor levitation principle of the modular bearingless electrically excited doubly salient pole motor of the present invention. During normal operation, the excitation current components of the four modules are identical, and the resulting excitation magnetic field simultaneously serves as the bias magnetic field required for rotor levitation. The levitation control current components of the spatially relative modules are equal in magnitude but opposite in polarity, and the resulting levitation control magnetic field is superimposed on the bias magnetic field (excitation magnetic field). By adjusting the levitation control current components, the levitation force in the x-axis and y-axis directions is controlled respectively. At different rotor angles, the direction of the levitation force on the rotor changes relatively little. Therefore, during high-speed rotor rotation, the levitation control current components do not require high-frequency commutation, making the motor more adaptable to high-speed operating environments.

[0024] Furthermore, in Figure 5 The diagram only shows the levitation magnetic circuit when the rotor is centered in the x-direction. Figure a shows the magnetic circuit when the rotor's mechanical position angle is 0°. The red magnetic circuit in the figure represents the excitation flux component, which forms a closed loop along each stator module and passes through the toroidal DC winding. The blue magnetic circuit represents the levitation magnetic flux component in the y-axis direction, which forms a closed loop along each stator module and passes through the toroidal DC winding. Figure 5 Figure b shows a schematic diagram of the magnetic circuit when the rotor's mechanical position angle is 11.25°, similar to Figure a. In the figure, I... DCM1 I DCM2 I DCM3 I DCM4 Equations 1, 2, 3, and 4 are given respectively. f Indicates 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] Bearingless electrically excited doubly salient pole motors (ESPs) offer advantages such as no lubrication required, no friction, and high reliability, leading to their wide application. This embodiment optimizes the ESP motor body, improving its fault tolerance and power density. The modular motor topology offers the advantage of flexible winding series and parallel combinations. It facilitates physical isolation between windings, as well as electrical, magnetic, and thermal isolation, resulting in high utilization of remaining healthy windings in case of failure. Furthermore, the modular motor topology reduces coupling between windings in traditional ESPs, making levitation control more efficient. It should be noted that the control method in this embodiment can also be used for modular ESPs with other stator and rotor pole numbers.

[0030] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A modular bearingless electrically excited doubly salient pole motor, characterized in that, The topology of the modular bearingless electrically excited doubly salient pole motor includes: rotor core (1), stator core (2), armature winding (3) and toroidal DC winding (4); Both the rotor core (1) and the stator core (2) are salient pole structures; The stator core (2) is evenly divided into 4 stator modules including M1, M2, M3 and M4, and each stator module has the same shape; The armature winding (3) is wound around the stator pole of the stator core (2), and the toroidal DC winding (4) is wound around the middle yoke of each stator module; The terminals of the armature winding within a stator module are labeled C in clockwise order. Mx-① A Mx-① B Mx-① C Mx-② A Mx-② B Mx-② The armature winding terminals in the stator module opposite to this stator module are labeled C in clockwise order. 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, and y = x + 2; The armature windings of two opposing stator modules are connected in series to form a three-phase armature winding, wherein the A of Mx Mx-① With My's A My-① Series connection constitutes armature winding A MxMy-① ; Adjacent stator modules are not directly connected via a core; each stator module has a toroidal DC winding. Mz The generated magnetic flux forms a closed loop only through this stator module and the rotor core (1), where z is a positive integer and the maximum value of z is equal to the maximum value of x; The toroidal DC winding (4) includes: independent DC windings on the yokes of M1, M2, M3 and M4. M1 DC M2 DC M3 and DC M4 .

2. The modular bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, M1 is opposite to M3, and M2 is opposite to M4; The armature winding (3) includes: the armature winding A of the three phases ABC. M1M3 B M1M3 C M1M3 A M2M4 B M2M4 and C M2M4 , where A M1M3 B M1M3 and C M1M3 Wound onto M1 and M3 respectively, A M2M4 B M2M4 and C M2M4 They are wound onto M2 and M4 respectively.

3. The modular bearingless electrically excited doubly salient pole motor according to claim 1 or 2, characterized in that, The levitation control method applied to the modular bearingless electrically excited doubly salient pole motor includes: A single-phase bridge inverter circuit is used. By controlling the switching transistor, a control current is supplied to the toroidal DC winding (4), wherein the magnitude of the control current is equal to the excitation current I. f With levitation control current I sx / sy The sum of I sx I sy They are respectively the levitation control current I sx / sy Suspension control current components on the x and y axes.

4. The modular bearingless electrically excited doubly salient pole motor according to claim 3, characterized in that, When the modular bearingless electrically excited double salient pole motor is running 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 serves as the bias magnetic field required for rotor suspension. Among them, the levitation control current components of the spatially opposite stator modules are equal in magnitude and opposite in polarity.

5. The modular bearingless electrically excited doubly salient pole motor according to claim 4, 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 ,in, , , , I f This represents the excitation current.

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