Reluctance motor and control method thereof

Abstract

The invention provides a reluctance motor and a control method thereof, and the reluctance motor comprises a rotor which comprises n permanent magnets which are uniformly distributed around the axis of the rotor at intervals in the circumferential direction, n is an even number and is greater than or equal to 4, and n is an integer greater than or equal to 2 on the cross section perpendicular to the axis of the rotor; one of the permanent magnet field direction of each permanent magnet and the permanent magnet field direction of the circumferentially adjacent permanent magnet points to the rotor axis along the radial direction, and the other one is back to the rotor axis along the radial direction; the stator comprises a * n stator windings which are uniformly distributed at intervals along the circumferential direction around the axis of the stator, the n stator windings spaced by a-1 stator windings form a stator winding combination, and a is an integer and is greater than or equal to 2; on a cross section perpendicular to the axis of the rotor, the electromagnetic field direction of each stator winding is the same as the electromagnetic field direction of the radially opposite stator winding; a magnetic pole detection device, an eccentricity detection device and a controller. According to the reluctance motor and the control method thereof provided by the invention, the motor is simple in structure, small in size and low in heat productivity, and the power density of the motor can be improved.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a reluctance motor and a control method thereof. Background Art

[0002] With the advancement of science and technology, high-speed motors are increasingly used in energy, medical, industrial, etc. Especially in the fields of aviation and new energy, the design power density of motors is increasingly required, and the resulting complex motor structure, large size, and high bearing heat generation have become bottlenecks restricting the development of high-speed motors. Summary of the invention

[0003] Based on this, the present application provides a reluctance motor and a control method thereof to solve the problems existing in the prior art such as complex motor structure, large size and high bearing heat generation.

[0004] To achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0005] On the one hand, an embodiment of the present application provides a reluctance motor, comprising:

[0006] A rotor, the rotor comprising n permanent magnets uniformly spaced around the rotor axis in the circumferential direction, n being an even number and n≥4, and in a cross section perpendicular to the rotor axis, the permanent magnetic field direction of each permanent magnet and the permanent magnetic field direction of the circumferentially adjacent permanent magnet are one radially pointing to the rotor axis and the other radially facing away from the rotor axis;

[0007] A stator, the stator comprising a×n stator windings uniformly spaced in a circumferential direction around a stator axis, wherein n stator windings spaced at intervals of a-1 stator windings form a stator winding combination, wherein a is an integer and a≥2;

[0008] On a cross section perpendicular to the rotor axis, the electromagnetic field direction of each stator winding is the same as the electromagnetic field direction of the radially opposite stator winding, and radially points to the stator axis or radially faces away from the stator axis;

[0009] A magnetic pole detection device, used to detect the direction of the permanent magnetic field of the rotor located at the magnetic pole detection device to obtain a magnetic pole detection result;

[0010] An eccentricity detection device, used to detect the position of the rotor axis relative to the stator axis to obtain a position detection result;

[0011] a controller, electrically connected to the stator winding, the rotor magnetic pole detection device and the eccentricity detection device, and configured to control the stator winding according to the received magnetic pole detection result and the position detection result;

[0012] Wherein, the controller is configured to, in accordance with the received external instructions: adjust the current direction and magnitude of the stator winding in at least one of the stator winding combinations so that the rotor axis coincides with the stator axis; adjust the current direction and magnitude of the stator winding in each of the stator winding combinations so that the rotor axis coincides with the stator axis and the rotor rotates relative to the stator.

[0013] In one embodiment, the stator windings are configured such that: energizing only one set of the stator windings can move the rotor until the rotor axis coincides with the stator axis.

[0014] In one embodiment, the reluctance motor further includes a motor housing, which is a cylindrical shell, the stator winding is evenly distributed along the inner wall of the motor housing, and a cavity for accommodating the rotor is formed around the stator axis in the core of the motor housing.

[0015] In one of the embodiments, a plurality of grooves recessed toward the inside of the rotor are provided on the outer circumferential surface of the rotor.

[0016] In one of the embodiments, the number of the permanent magnets is 4, the number of the stator windings is 8, and the magnetic pole detection device is fixed on the motor housing; in one of the stator winding combinations, the four stator windings are respectively located on the vertical inner wall and the horizontal inner wall of the motor housing.

[0017] In one of the embodiments, the eccentricity detection device is fixed on the motor housing, and includes a first position detector and a second position detector. The first position detector is arranged corresponding to the position of one of the stator windings, and the second position detector is arranged corresponding to the position of the other stator winding. The angle between the center lines of the two stator windings corresponding to the two position detectors is a right angle.

[0018] On the other hand, an embodiment of the present application provides a control method of a reluctance motor, which is used to control the above-mentioned reluctance motor, comprising the following steps:

[0019] S1, the magnetic pole detection device detects the permanent magnetic field direction of the rotor located at the magnetic pole detection device, obtains a magnetic pole detection structure, and sends the magnetic pole detection result to the controller; the controller receives the magnetic pole detection result, and determines the current direction and magnitude of the stator winding of at least one stator winding combination according to the magnetic pole detection result, so that the rotor is subjected to a vertical upward force to counteract the gravity of the rotor;

[0020] S2. The eccentricity detection device detects the position of the rotor axis relative to the stator axis in real time, obtains and sends the position detection result to the controller; the controller receives the position detection result, compares the position detection result with the preset position information, and adjusts the current of the stator winding according to the comparison result.

[0021] In one embodiment, the step S2 further includes the following steps:

[0022] S3, determining the current direction and magnitude of the stator winding according to the external command received by the controller, so that the rotor rotates relative to the stator according to the rotation direction and rotation speed in the external command;

[0023] S4. The magnetic pole detection device obtains the magnetic pole detection result by real-time detection, and the eccentricity detection device obtains the position detection result by real-time detection, and sends the magnetic pole detection result and the position detection result to the controller; the controller compares the position detection result with the preset position information, adjusts the current size of the stator winding according to the comparison result, and adjusts the current direction of the stator winding according to the magnetic pole detection result.

[0024] In one embodiment, in step S1, the current direction of the stator winding of at least one stator winding combination is determined according to the magnetic pole detection result, specifically:

[0025] The current direction of the stator winding located at the magnetic pole detection device is controlled so that the electromagnetic field direction of the stator winding and the permanent magnetic field direction of the magnetic pole detection result are set oppositely.

[0026] In one embodiment, in step S3, the following steps are also included:

[0027] Based on the current direction in the stator winding combination in step S1, the next adjacent stator winding combination is energized in sequence along the rotation direction, and its current direction is controlled so that the current direction of each stator winding is the same as that of the previous adjacent stator winding.

[0028] In one embodiment, in step S2 and step S4, the current of the stator winding is adjusted according to the comparison result, specifically:

[0029] A comparison result of radially outward displacement is defined as a positive deviation, otherwise defined as a negative deviation; when the comparison result is a positive deviation, the current of the stator winding corresponding to the eccentricity detection device is controlled to decrease; when the comparison result is a negative deviation, the current of the stator winding corresponding to the eccentricity detection device is controlled to increase.

[0030] The present application has at least the following beneficial effects: the reluctance motor provided in the embodiment of the present application has a simple overall structure, and the rotor can be rotated in a suspended state through the corresponding arrangement of the stator winding and the rotor permanent magnet, and almost no friction is generated between the rotor and the stator, which greatly reduces the heat generated by the reluctance motor. The control method of the reluctance motor in the embodiment of the present application can integrate the suspension system and the drive system by controlling the current magnitude and direction of the stator winding respectively through the controller, simplifying the motor structure and control steps, and facilitating the increase of the speed of the reluctance motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the structure of the reluctance motor according to an embodiment of the present application.

[0032] Figure 2 for Figure 1 Schematic diagram of the main structure of the reluctance motor.

[0033] Figure 3 for Figure 1 Schematic diagram of the rear view structure of the reluctance motor.

[0034] Figure 4 for Figure 1 Schematic diagram of the front view (or rear view) of the reluctance motor with some components removed.

[0035] Figure 5 for Figure 1 Schematic diagram of the structure of the rotor and output shaft.

[0036] Figure 6 Schematic diagram of the direction of the permanent magnetic field of the stator winding and permanent magnet of the reluctance motor of an embodiment of the present application when the rotor is in a suspended state after starting (the shadow in the first stator winding combination represents the S pole, and the shadow in the second stator winding combination represents the non-powered state).

[0037] Figure 7 for Figure 6 Schematic diagram of the permanent magnetic field direction when the rotor rotates 22.5° clockwise.

[0038] Figure 8 for Figure 7 Schematic diagram of the permanent magnetic field direction when the rotor rotates 45° clockwise.

[0039] The meanings of the symbols in the accompanying drawings are as follows:

[0040] 1. Motor housing; 11. Cavity; 2. Rotor; 21. Permanent magnet; 211. Magnet A; 212. Magnet B; 213. Magnet C; 214. Magnet D; 22. Groove; 3. Stator; 31. Stator winding; 311. 1st stator winding; 312. 2nd stator winding; 313. 3rd stator winding; 314. 4th stator winding; 315. 5th stator winding; 316. 6th stator winding; 317. 7th stator winding; 318. 8th stator winding; 4. Output shaft; 5. Magnetic pole detection device; 6. Eccentricity detection device; 61. First position detector; 62. Second position detector. DETAILED DESCRIPTION

[0041] The technical solution of the present application is further elaborated in detail below in conjunction with the accompanying drawings and specific embodiments of the specification.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the implementation of this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0043] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating positions or positional relationships, are based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0044] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] See also Figures 1 to 3 The reluctance motor of the embodiment of the present application includes a motor housing 1, a stator 3, a rotor 2, an output shaft 4, a magnetic pole detection device 5, an eccentricity detection device 6 and a controller (not shown).

[0046] like Figure 1 and Figure 4 As shown, in this embodiment, the motor housing 1 is a cylindrical housing, and the rotor 2 is also a cylindrical structure, including n permanent magnets 21 uniformly distributed along the circumferential direction around the axis direction of the stator 2, n is an even number and n≥4; the stator 3 includes a×n stator windings 31, where a is an integer and a≥2. The output shaft 4 is arranged on the axis of the rotor 2, and the rotor 2 is extended at both ends to provide support and connect with the driving component to output the power of the rotor 2 to the driving component. The stator windings 31 are uniformly and spacedly distributed along the circumferential direction of the inner wall of the motor housing 1, and a cavity 11 for accommodating the rotor 2 is formed in the core of the motor housing 1, and the rotor 2 is penetrated in the cavity 11. The direction of the electromagnetic field generated by each stator winding 31 after power is applied is distributed along the radial direction of the distribution circle of the stator winding 31, that is, along the radial direction of the motor housing 1 (stator 2). The direction of the permanent magnetic field of each permanent magnet 21 is respectively distributed along the radial direction of the distribution circle of the permanent magnet 21. When the rotor 2 is suspended in the center (the rotor 2 is coaxial with the stator 3), the direction of the permanent magnetic field of each permanent magnet 21 is also respectively distributed along the radial direction of the motor housing 1. On the cross section perpendicular to the axis, the direction of the permanent magnetic field of each permanent magnet 21 and the direction of the permanent magnetic field of the permanent magnet 21 opposite to the radial direction are both radially pointing to the axis or radially away from the axis (the permanent magnetic field directions are the same), and the direction of the permanent magnetic field of each permanent magnet 21 and the direction of the permanent magnetic field of the circumferentially adjacent permanent magnet 21 are one radially pointing to the axis and the other radially away from the axis (the permanent magnetic field directions are opposite); when power is turned on, the direction of the electromagnetic field of each stator winding 31 and the direction of the electromagnetic field of the stator winding 31 opposite to the radial direction are both radially pointing to the axis or radially away from the axis (the electromagnetic field directions are the same).

[0047] n stator windings 31 spaced a-1 apart form a stator winding combination. When energized, in each stator winding combination, the directions of the electromagnetic fields of every two radially opposite stator windings 31 are the same, and the directions of the electromagnetic fields of every two adjacent stator windings 31 in the circumferential direction are opposite.

[0048] like Figure 1 and Figure 2 As shown, the magnetic pole detection device 5 is fixed on the motor housing 1 and is arranged corresponding to the position of a stator winding 31, and is used to detect the direction of the permanent magnetic field of the rotor 2 corresponding to the position of the stator winding 31, and determine the magnetic pole detection result. The magnetic pole detection device 5 in this embodiment can use a Hall sensor to detect the magnetic field change at the position of the stator winding 31, and send the magnetic pole detection result to the controller. The magnetic pole detection device 5 can also detect other information such as the rotation speed and rotation angle of the rotor 2.

[0049] like Figure 3As shown, the stator winding 31 corresponding to the position of the magnetic pole detection device 5 is defined as the first stator winding 311, and the other stator windings 31 are numbered in sequence, namely the second stator winding 312, the third stator winding 313, the fourth stator winding 314, the fifth stator winding 315, the sixth stator winding 316, the seventh stator winding 317, and the eighth stator winding 318; the stator windings 31 are grouped according to their numbers, and the first stator winding combination is the first stator winding 311, the third stator winding 313, the fifth stator winding 315, the seventh stator winding 317, and the eighth stator winding 318. 17. The second stator winding combination is the second stator winding 312, the fourth stator winding 314, the sixth stator winding 316, and the eighth stator winding 318; when the first stator winding combination is powered on, the current on and off of each stator winding 31 is synchronously controlled, and when powered on, the magnetic poles of each adjacent two stator windings 31 in the first stator winding combination are oppositely arranged; similarly, when the second stator winding combination is powered on, the current on and off and the current direction of each stator winding 31 are synchronously controlled, and when powered on, the magnetic poles of each adjacent two stator windings 31 in the second stator winding combination are oppositely arranged. Current on and off synchronous control means simultaneous power on or simultaneous power off, and current direction synchronous control means simultaneous conversion of current direction.

[0050] The stator 3 and the rotor 2 in this embodiment are an outer stator and inner rotor structure. In other embodiments, an inner stator and outer rotor structure may also be adopted. The specific structural form is not limited. In this embodiment, the specific structure of 8 stator windings 31 and 4 permanent magnets 21 is taken as an example for description.

[0051] like Figure 3 and Figure 5As shown, the eccentricity detection device 6 is used to detect the position information of the output shaft 4, is fixed on the motor housing 1, and includes a first position detector 61 and a second position detector 62. The first position detector 61 is set corresponding to the position of one of the stator windings 31, and the second position detector 62 is set corresponding to the position of the other stator winding 31. The angle between the center lines of the two stator windings 31 corresponding to the two position detectors is a right angle. For the convenience of control, the first position detector 61 can be set corresponding to the position of the first stator winding 311, and the second position detector 62 can be set corresponding to the position of the third stator winding 313. The first position detector 61 and the second position detector 62 in this embodiment are both position sensors. The eccentricity detection device 6 can detect the position of the rotor 2 in two directions perpendicular to each other, and send the position detection result to the controller. The controller controls the position of the rotor 2 so that it is kept in the center of the cavity 11 for accommodating the rotor 2 in real time, that is, the rotor 2 is controlled to be suspended relative to the stator 3 to form a suspended bearing structure, reduce the friction between the rotor 2 and the stator 3, reduce the heat generated by the friction, and help to further increase the speed of the motor. In order to further reduce the heat generated when the motor is running, a groove 22 that is recessed toward the inside of the rotor 2 can be provided on the cylindrical outer surface of the rotor 2. For example, the shape of the groove 22 can be designed to be spiral. When the rotor 2 rotates, the groove 22 on the surface of the rotor 2 can increase the air flow speed, enhance the heat dissipation function of the motor, and reduce the heat generated by the motor.

[0052] The controller is used to receive the detection results sent by the magnetic pole detection device 5 and the eccentricity detection device 6, and control the current magnitude and direction of the stator winding 31 according to the detection results, so that the rotor 2 can suspend and rotate relative to the stator 3. Specifically, the control method executed by the controller is as follows:

[0053] S1, the magnetic pole detection device 5 detects the permanent magnetic field direction of the corresponding permanent magnet 21, obtains and sends the magnetic pole result to the controller; the controller receives the magnetic pole detection result, and determines the magnetic pole of the first stator winding 311 according to the magnetic pole detection result, determines the current direction of each stator winding 31 in the first stator winding combination according to the magnetic pole of the first stator winding 311, determines the current size of each stator winding 31 according to the dead weight of the rotor 2, controls the first stator winding combination to be energized, and makes the rotor 2 levitate relative to the stator 3.

[0054] S2. The eccentricity detection device 6 detects the position of the rotor axis relative to the stator axis in real time, obtains and sends the position detection result to the controller; the controller receives the position detection result, compares the position detection result with the preset position information, and controls the current of each stator winding 31 in the first stator 3 combination according to the comparison result.

[0055] S3. According to the external command received by the controller, the current direction and magnitude of the stator winding 31 are determined so that the rotor 2 rotates relative to the stator 3 according to the rotation direction and rotation speed in the external command. Based on the current direction in the stator winding combination in step S1, the next adjacent stator winding combination is energized in sequence along the rotation direction, and its current direction is controlled so that each stator winding has the same current direction as the previous adjacent stator winding. For example, there are three groups of stator winding combinations, which are arranged in sequence along the rotation direction as a first stator winding combination, a second stator winding combination and a third stator winding combination. In step S1, the current direction of each stator winding in the first stator winding combination has been determined. First, the second stator winding combination is energized, and the current direction of each stator winding in the second stator winding combination is made the same as the current direction of the stator winding in the first stator winding combination adjacent to it; then, the third stator winding combination is energized, and the current direction of each stator winding in the third stator winding combination is made the same as the current direction of the stator winding in the second stator winding combination adjacent to it.

[0056] S31. Specifically, according to the rotation direction requirement of the output shaft 4, the magnetic poles of the two stator windings 31 adjacent to the first stator winding 311 are determined, and the current direction of each stator winding 31 in the second stator winding combination is determined according to the magnetic poles of the two stator windings 31, and the second stator winding combination is controlled to be energized so that the output shaft 4 generates torque.

[0057] S32, changing the current direction of each stator winding 31 in the first stator winding combination.

[0058] S33, changing the current direction of each stator winding 31 in the second stator winding combination.

[0059] S34. Loop steps S32 and S33.

[0060] S4, the magnetic pole detection device obtains the magnetic pole detection result by real-time detection, the eccentricity detection device 6 obtains the position detection result by real-time detection, and sends the magnetic pole detection result and the position detection result to the controller; the controller receives the position detection result, and compares the position detection result with the preset position information, and controls the current size and direction of each stator winding 31 in the first stator 3 combination according to the comparison result and the magnetic pole detection result.

[0061] Specifically, the rotor 2 structure with eight stator windings 31 and four permanent magnets 21 is used as an example for explanation. The eight stator windings 31 are defined as the first stator winding 311, the second stator winding 312, the third stator winding 313, the fourth stator winding 314, the fifth stator winding 315, the sixth stator winding 316, the seventh stator winding 317, and the eighth stator winding 318 in the clockwise direction. The first stator winding 311 is provided with a magnetic pole detection device 5 on one side along the length direction of the output shaft 4, and the first position detector 61 is provided on the other side. The third stator winding 313 is provided with a second position detector 62. The first position detector 61 and the second position detector 62 are located on the same side of the stator 3. The four permanent magnets 21 are defined as A magnet 211, B magnet 212, C magnet 213, and D magnet 214 in the clockwise direction. The direction of the permanent magnetic field pointing to the center of the distribution circle is defined as the first magnetic field direction, denoted by N; the direction of the permanent magnetic field away from the center of the distribution circle is defined as the second magnetic field direction, denoted by S.

[0062] S1. The magnetic pole detection device 5 detects the permanent magnetic field direction of the permanent magnet 21 (A magnet 211) located at the position of the first stator winding 311, and sends the magnetic pole detection result to the controller.

[0063] If the magnetic pole detection result of the A magnet 211 is N, the controller controls the current direction to make the electromagnetic field direction of the first stator winding 311 S, which is opposite to N. Based on the fact that the magnetic poles of each two adjacent stator windings 31 in the first stator winding combination are set opposite to each other, the electromagnetic field direction of the third stator winding 313 can be controlled to be N, the electromagnetic field direction of the fifth stator winding 315 to be S, and the electromagnetic field direction of the seventh stator winding 317 to be N. The controller controls the magnitude of the energizing current according to the preset program and the force analysis result of the rotor 2, and performs the energizing operation on the first stator winding combination, such as Figure 6 As shown, according to the principle of opposite poles attract each other, the center lines of the four permanent magnets 21 coincide with the center lines of the four stator windings 31 of the first stator 3 combination, and the forces in four directions of the rotor 2 are balanced. Therefore, the rotor 2 can be suspended relative to the stator 3. At this time, the second stator winding combination is in a power-off state, and the first stator winding combination is used as a suspension system.

[0064] If the magnetic pole detection result of the A magnet 211 is S, the controller controls the current direction to make the electromagnetic field direction of the first stator winding 311 N which is opposite to S. The principle is the same and will not be repeated.

[0065] S2. When the rotor 2 is suspended, the first position detector 61 and the second position detector 62 detect the position information of the output shaft 4 at the A magnet 211 and the B magnet 212 in real time, and send the position detection result to the controller. The controller receives the position detection result, compares the position detection result with the preset position information, and controls the current of each stator winding 31 in the first stator winding combination according to the comparison result. The preset position refers to the central axis of the cavity 11 (that is, the central axis of the stator 2), and the first position detector 61 and the second position detector 62 respectively detect the distance of the measured point relative to the central axis of the cavity 11.

[0066] When the detection point of the output shaft 4 is radially offset outward relative to the preset position, it is defined as a positive deviation, otherwise it is defined as a negative deviation. When the comparison result of the position detection result of the first position detector 61 and the preset position information is a positive deviation, that is, the output shaft 4 is offset in the vertically upward direction in the direction shown in the figure, at this time, the current of the first stator winding 311 is controlled to decrease or the current of the fifth stator winding 315 is controlled to increase; when the above comparison result is a negative deviation, that is, the output shaft 4 is offset in the vertically downward direction in the direction shown in the figure, at this time, the current of the first stator winding 311 is controlled to increase (increase the magnetic field strength) or the current of the fifth stator winding 315 is controlled to decrease (reduce the magnetic field strength).

[0067] When the comparison result between the position detection result of the second position detector 62 and the preset position information is a positive deviation, that is, the output shaft 4 is offset in the horizontal right direction in the direction shown in the figure, at this time, the current of the third stator winding 313 is controlled to decrease or the current of the seventh stator winding 317 is controlled to increase; when the above comparison result is a negative deviation, that is, the output shaft 4 is offset in the horizontal left direction in the direction shown in the figure, at this time, the current of the third stator winding 313 is controlled to increase or the current of the seventh stator winding 317 is controlled to decrease. The specific degree of current increase or decrease is calculated based on the comparison result.

[0068] When the position detection result of the eccentricity detection device 6 is that the rotor axis coincides with the stator axis, the current current is kept unchanged.

[0069] S3. According to the external command received by the controller, the current direction and magnitude of the stator winding 31 are determined so that the rotor 2 rotates relative to the stator 3 according to the rotation direction and rotation speed in the external command.

[0070] If the rotation direction of the output shaft 4 is required to be clockwise and the magnetic pole detection result of the A magnet 211 is N, the following steps are performed:

[0071] S310. After the rotor 2 is suspended, the magnetic poles of the two stator windings 31 adjacent to the first stator winding 311 are determined according to the rotation direction requirement of the output shaft 4. The current direction of each stator winding 31 in the second stator winding combination is determined according to the magnetic poles of the two stator windings 31. The second stator winding combination is controlled to be energized so that the output shaft 4 generates torque.

[0072] The electromagnetic field direction of the second stator winding 312 is determined to be the same as the electromagnetic field direction of the first stator winding 311, which is S. The electromagnetic field direction of the fourth stator winding 314 is N, the electromagnetic field direction of the sixth stator winding 316 is S, and the electromagnetic field direction of the eighth stator winding 318 is N. According to the electromagnetic field direction determined above, the current direction of the second stator winding combination is controlled, and the second stator winding combination is powered on. At this time, the first stator winding combination is used as a suspension system, and the second stator winding combination is used as a drive system. Figure 7 As shown, based on the principle of minimum magnetic resistance, magnet A 211 is deflected 22.5° clockwise. At this time, magnet A 211 corresponds to the first stator winding 311 and the second stator winding 312 , and the center line of magnet A 211 is located between the first stator winding 311 and the second stator winding 312 .

[0073] S320, changing the current direction of each stator winding 31 in the first stator winding combination, that is, the electromagnetic field direction of the first stator winding 311 and the fifth stator winding 315 is N, and the electromagnetic field direction of the third stator winding 313 and the seventh stator winding 317 is S, such as Figure 8 As shown, based on the principle of minimum magnetic resistance, magnet A 211 continues to rotate 45° clockwise. At this time, the current direction of the second stator winding combination remains unchanged, the second stator 3 combination is used as a suspension system, and the first stator winding combination is used as a drive system.

[0074] S330, change the current direction of each stator winding 31 in the second stator winding combination, that is, the electromagnetic field direction of the second stator winding 312 and the sixth stator winding 316 is N, and the electromagnetic field direction of the fourth stator winding 314 and the eighth stator winding 318 is S. Based on the principle of minimum magnetic resistance, the A magnet 211 continues to rotate clockwise by 45°. At this time, the current direction of the first stator winding combination remains unchanged, the first stator winding combination is used as a suspension system, and the second stator winding combination is used as a drive system.

[0075] S340, and looping steps S320 and S330 can realize continuous rotation of the rotor 2.

[0076] S40, when the rotor 2 rotates, the first position detector 61 and the second position detector 62 detect the position information of the output shaft 4 at the first stator winding 311 and the third stator winding 313 in real time, and send the position information detection result to the controller. The controller receives the position detection result, compares the position detection result with the preset position information, and controls the current size of each stator winding 31 in the first stator 3 combination according to the comparison result. This step is the same as step S2 and will not be repeated.

[0077] If the rotation direction of the output shaft 4 is required to be counterclockwise, and the permanent magnetic field direction detection result of the A magnet 211 is N, perform the following steps:

[0078] S311. When the rotor 2 is suspended, the magnetic poles of the two stator windings 31 adjacent to the first stator winding 311 are determined according to the rotation direction requirement of the output shaft 4, and the current direction of each stator winding 31 in the second stator winding combination is determined according to the magnetic poles of the two stator windings 31, and the second stator winding combination is controlled to be energized so that the output shaft 4 generates torque.

[0079] It is determined that the electromagnetic field direction of the second stator winding 312 is opposite to the electromagnetic field direction of the first stator winding 311, which is N. The electromagnetic field direction of the fourth stator winding 314 is S, the electromagnetic field direction of the sixth stator winding 316 is N, and the electromagnetic field direction of the eighth stator winding 318 is S. The current direction of the second stator winding combination is controlled according to the electromagnetic field direction determined above, and the second stator winding combination is powered on. At this time, the first stator winding combination is used as a suspension system, and the second stator winding combination is used as a drive system. Based on the principle of minimum magnetic resistance, the A magnet 211 is deflected 22.5° counterclockwise. At this time, the A magnet 211 corresponds to the first stator winding 311 and the eighth stator winding 318, and the center line of the A magnet 211 is located between the first stator winding 311 and the eighth stator winding 318.

[0080] S321. Change the current direction of each stator winding 31 in the first stator winding combination, that is, the electromagnetic field direction of the first stator winding 311 and the fifth stator winding 315 is N, and the electromagnetic field direction of the third stator winding 313 and the seventh stator winding 317 is S. Based on the principle of minimum magnetic resistance, the A magnet 211 continues to rotate counterclockwise by 45°. At this time, the current direction of the second stator winding combination remains unchanged. The second stator winding combination is used as a suspension system, and the first stator winding combination is used as a drive system.

[0081] S331. Change the current direction of each stator winding 31 in the second stator winding combination, that is, the electromagnetic field direction of the second stator winding 312 and the sixth stator winding 316 is S, and the electromagnetic field direction of the fourth stator winding 314 and the eighth stator winding 318 is N. Based on the principle of minimum magnetic resistance, the A magnet 211 continues to rotate counterclockwise by 45°. At this time, the current direction of the first stator winding combination remains unchanged. The first stator winding combination is used as a suspension system, and the second stator winding combination is used as a drive system.

[0082] S341, looping steps S321 and S331 can realize continuous rotation of the rotor 2.

[0083] S41, when the rotor 2 rotates, the first position detector 61 and the second position detector 62 detect the position information of the output shaft 4 at the first stator winding 311 and the third stator winding 313 in real time, and send the position detection result to the controller. The controller receives the position detection result, compares the position detection result with the preset position information, and controls the current of each stator winding 31 in the first stator 3 combination according to the comparison result. This step is the same as S2 and will not be repeated.

[0084] The reluctance motor provided by the present application has a simple structure, does not require an additional bearing structure, is small in size, light in weight, and generates almost no friction, which effectively reduces the heat generated by the motor, and is beneficial to further increase the speed of the motor. The rotor and the stator are lubricated by air, and no other lubrication accessories are required, which can make the power density of the motor higher. The surface of the rotor is provided with grooves, which can increase the circulation speed of the air and force air cooling, and no heat dissipation accessories are required, thereby further improving the power density of the motor. The control method of the present application is simple. By designing the stator windings in groups, the two groups of stator windings are alternately used as the suspension system and the drive system in turn, so that the suspension system and the drive system are integrated, the structure of the device is simplified, and the volume of the reluctance motor is reduced, which is beneficial to expand the application field of the reluctance motor.

[0085] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0086] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A reluctance motor, characterized in that: include: A rotor, the rotor comprising n permanent magnets uniformly spaced around the rotor axis in the circumferential direction, n being an even number and n≥4, and in a cross section perpendicular to the rotor axis, the permanent magnetic field direction of each permanent magnet and the permanent magnetic field direction of the circumferentially adjacent permanent magnet are one radially pointing to the rotor axis and the other radially facing away from the rotor axis; A stator, the stator comprising a×n stator windings uniformly spaced in a circumferential direction around a stator axis, wherein n stator windings spaced at intervals of a-1 stator windings form a stator winding combination, wherein a is an integer and a≥2; On a cross section perpendicular to the rotor axis, the electromagnetic field direction of each stator winding is the same as the electromagnetic field direction of the radially opposite stator winding, and radially points to the stator axis or radially faces away from the stator axis; A magnetic pole detection device, used to detect the direction of the permanent magnetic field of the rotor located at the magnetic pole detection device to obtain a magnetic pole detection result; An eccentricity detection device, used to detect the position of the rotor axis relative to the stator axis to obtain a position detection result; a controller, electrically connected to the stator winding, the rotor magnetic pole detection device and the eccentricity detection device, and configured to control the stator winding according to the received magnetic pole detection result and the position detection result; Wherein, the controller is configured to: adjust the current direction and magnitude of the stator winding in at least one of the stator winding combinations according to the received external instruction, so that the rotor axis coincides with the stator axis; The current direction and magnitude of the stator winding in each stator winding combination are adjusted so that the rotor axis coincides with the stator axis and the rotor rotates relative to the stator.

2. The reluctance motor according to claim 1, characterized in that The stator windings are configured such that: when only one set of the stator windings is energized, the rotor can be moved until the rotor axis coincides with the stator axis.

3. The reluctance motor according to claim 2, characterized in that: It also includes a motor housing, which is a cylindrical shell. The stator winding is evenly distributed along the inner wall of the motor housing, and a cavity for accommodating the rotor is formed around the stator axis at the core of the motor housing.

4. The reluctance motor according to claim 3, characterized in that: A plurality of grooves recessed toward the inside of the rotor are arranged on the outer circumferential surface of the rotor.

5. The reluctance motor according to claim 3, characterized in that: The number of the permanent magnets is 4, the number of the stator windings is 8, and the magnetic pole detection device is fixed on the motor housing; in one of the stator winding combinations, the four stator windings are respectively located on the vertical inner wall and the horizontal inner wall of the motor housing.

6. The reluctance motor according to claim 3, characterized in that: The eccentricity detection device is fixed on the motor housing, and includes a first position detector and a second position detector. The first position detector is arranged corresponding to the position of one of the stator windings, and the second position detector is arranged corresponding to the position of the other stator winding. The angle between the center lines of the two stator windings corresponding to the two position detectors is a right angle.

7. A control method for a reluctance motor, characterized in that: For controlling a reluctance motor as claimed in any one of claims 1 to 6, comprising the following steps: S1, the magnetic pole detection device detects the permanent magnetic field direction of the rotor located at the magnetic pole detection device, obtains a magnetic pole detection structure, and sends the magnetic pole detection result to the controller; the controller receives the magnetic pole detection result, and determines the current direction and magnitude of the stator winding of at least one stator winding combination according to the magnetic pole detection result, so that the rotor is subjected to a vertical upward force to counteract the gravity of the rotor; S2. The eccentricity detection device detects the position of the rotor axis relative to the stator axis in real time, obtains and sends the position detection result to the controller; the controller receives the position detection result, compares the position detection result with the preset position information, and adjusts the current of the stator winding according to the comparison result.

8. The control method of the reluctance motor according to claim 7, characterized in that: After step S2, the method further includes the following steps: S3, determining the current direction and magnitude of the stator winding according to the external command received by the controller, so that the rotor rotates relative to the stator according to the rotation direction and rotation speed in the external command; S4. The magnetic pole detection device obtains the magnetic pole detection result by real-time detection, and the eccentricity detection device obtains the position detection result by real-time detection, and sends the magnetic pole detection result and the position detection result to the controller; the controller compares the position detection result with the preset position information, adjusts the current size of the stator winding according to the comparison result, and adjusts the current direction of the stator winding according to the magnetic pole detection result.

9. The control method of the reluctance motor according to claim 7, characterized in that: In the step S1, the current direction of the stator winding of at least one stator winding combination is determined according to the magnetic pole detection result, specifically: The current direction of the stator winding located at the magnetic pole detection device is controlled so that the electromagnetic field direction of the stator winding and the permanent magnetic field direction of the magnetic pole detection result are set oppositely.

10. The control method of the reluctance motor according to claim 7, characterized in that: In step S3, the following steps are also included: Based on the current direction of the stator winding combination in step S1, the next adjacent stator winding combination is energized in sequence along the rotation direction, and the current direction is controlled so that the current direction of each stator winding is the same as that of the previous adjacent stator winding; And / or, in step S2 and step S4, the current of the stator winding is adjusted according to the comparison result, specifically: A comparison result of radially outward displacement is defined as a positive deviation, otherwise defined as a negative deviation; when the comparison result is a positive deviation, the current of the stator winding corresponding to the eccentricity detection device is controlled to decrease; when the comparison result is a negative deviation, the current of the stator winding corresponding to the eccentricity detection device is controlled to increase.

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