CN113991957B - A kind of single-phase double magnetic circuit permanent magnet motor and its driving method - Google Patents

Abstract

The present invention relates to the field of new energy automobile motors, in particular to a single-phase double magnetic circuit permanent magnet motor and a driving method. The permanent magnet motor includes a stator assembly, a rotor assembly and a rotating shaft assembly; An iron core on the disk, and a winding wound around the iron core, the winding is connected to a single-phase AC power supply; the rotor assembly includes a rotor disk and a first permanent magnet; the first permanent magnet is installed on the rotor disk; the rotating shaft The assembly includes a rotating shaft and a second permanent magnet; the rotating shaft passes through the shaft center of the rotor disc and the stator disc, is fixedly connected with the rotor disc, and is rotatably connected with the stator disc; the second permanent magnet is installed in the rotating shaft; the The polarity directions of the first permanent magnet and the second permanent magnet are opposite, and the magnetic field strengths are different. The invention can realize the self-starting of the permanent magnet motor, avoiding setting complicated starting circuits and auxiliary equipment.

Description

A kind of single-phase double magnetic circuit permanent magnet motor and its driving method

technical field

The invention relates to the field of new energy vehicle motors, in particular to a single-phase dual-magnetic circuit permanent magnet motor and a driving method.

Background technique

With the widespread popularization of new energy vehicles, the performance requirements for new energy vehicles are getting higher and higher. Permanent magnet motors are widely used in new energy vehicles due to their high efficiency and high power factor. In the general permanent magnet motor structure, the electromagnetic torque of the permanent magnet motor is generated by the interaction between the rotating magnetic field generated by the stator current and the magnetic field of the permanent magnet rotor. When a single-phase alternating current is applied to the permanent magnet motor, its torque The average value of is zero, and the permanent magnet motor cannot be self-started. In the prior art, in order to realize the starting of the permanent magnet motor, the following three methods are generally included, one is to use the asynchronous motor with the same magnetic pole logarithm to drive the start, the other is to add a starting capacitor or drive the auxiliary winding for asynchronous starting, The third is to use the frequency converter to gradually increase the power supply frequency at both ends of the stator to start with frequency conversion.

The above start-up methods all require the design of complex circuits and additional auxiliary structures to realize the start-up of the single-phase permanent magnet motor, which will inevitably affect the cost and volume of the single-phase permanent magnet motor.

Contents of the invention

In order to solve the above-mentioned problem that the single-phase permanent magnet motor cannot be self-started, the present invention provides a single-phase dual-magnetic circuit permanent magnet motor on the one hand, and on the other hand provides a method for driving the single-phase dual-magnetic circuit permanent magnet motor The driving method, its concrete technical scheme is as follows.

On the one hand, a single-phase double magnetic circuit permanent magnet motor provided by the present invention includes a stator assembly and a rotor assembly, and also includes a rotating shaft assembly;

The stator assembly includes a stator plate, an iron core installed on the stator plate, and a winding wound around the iron core, and the winding is connected to a single-phase AC power supply;

The rotor assembly includes a rotor disk and a first permanent magnet; the first permanent magnet is mounted on the rotor disk;

The rotating shaft assembly includes a rotating shaft and a second permanent magnet; the rotating shaft passes through the shaft center of the rotor disc and the stator disc, is fixedly connected with the rotor disc, and is rotatably connected with the stator disc; the second permanent magnet is installed in the rotating shaft ;

The polarity directions of the first permanent magnet and the second permanent magnet are opposite, and the magnetic field strengths are different.

Further, it includes two rotor assemblies, and the two rotor assemblies are arranged symmetrically along the stator disk;

Iron cores are respectively arranged symmetrically on both sides of the stator disk, and windings are respectively wound on each iron core.

Further, the side of the rotor disk close to the stator disk is installed with a magnetic conduction assembly;

The magnetic permeable component includes a first magnetic permeable component and a second magnetic permeable component; the first magnetic permeable component includes a first magnetic permeable rod arranged along the circumference of the rotor disk; the first permanent magnet is installed on the first magnetic permeable Inside the rod; the second magnetic conducting assembly includes a second magnetic conducting rod arranged along the circumference of the rotor disk, and a magnetic conducting block connected to the second magnetic conducting rod;

The first magnetic conduction assembly and the second magnetic conduction assembly are arranged at intervals along the circumferential direction of the rotor disk.

Further, the magnetically permeable components include four first magnetically permeable components and four second magnetically permeable components; four iron cores are respectively arranged on each side of the stator disk;

The four first magnetic permeable components are arranged at 90° intervals, the four second magnetic permeable components are arranged at 90° intervals, and the adjacent first magnetic permeable components are arranged at 45° intervals from the second magnetic permeable components; located in the stator The four iron cores on the same side of the disk are arranged at 90° intervals.

Further, before the permanent magnet motor is started, the iron core is located between the first magnetically permeable assembly and the second magnetically permeable assembly in the circumferential direction.

Further, the second magnetically conductive rod is in contact with the rotating shaft.

Further, the iron core is triangular in shape, and the shape and size of the magnetic permeable block are the same as those of the iron core.

Further, the stator disk includes a stator disk body and a stator disk outer layer surrounding the stator disk body; the magnetic resistance of the stator disk outer layer is smaller than that of the stator disk body; the first permanent magnet The magnetic field axis passes through the outer circular layer of the stator disk.

Further, the first magnetically conductive rod is provided with a protrusion protruding toward the direction of the iron core; the side of the iron core facing the first magnetically conductive rod is pasted with a magnetically attracting sheet.

On the other hand, the present invention provides a driving method for driving the above-mentioned permanent magnet motor, comprising applying single-phase alternating current to the permanent magnet motor, so that every 90° rotation of the rotor assembly corresponds to one current cycle.

Beneficial effects: In the single-phase dual-magnetic circuit permanent magnet motor provided by the present invention, by setting the first permanent magnet on the rotor disk and the second permanent magnet on the rotating shaft, when the motor is started, when the single-phase alternating current The positive and negative currents form two magnetic circuits respectively, and apply two torques in opposite directions to the rotor assembly respectively. By designing the first permanent magnet and the second permanent magnet to be of different sizes, the magnetic field strengths of the two magnetic circuits are different. , so that the magnitudes of the two torques are different, the self-starting of the permanent magnet motor is realized, the design of complex circuits and additional auxiliary structures is avoided, and the cost and volume of the single-phase permanent magnet motor are reduced.

Description of drawings

Fig. 1 is the overall structure schematic diagram of single-phase permanent magnet motor in the embodiment of the present invention;

Fig. 2 is a schematic structural view of a rotor assembly in an embodiment of the present invention;

Fig. 3 is a schematic structural view of a stator assembly in an embodiment of the present invention;

Fig. 4 is the schematic diagram of the electromagnetic circuit when the single-phase permanent magnet motor starts in the embodiment of the present invention;

Fig. 5 is a schematic diagram of the electromagnetic circuit of the single-phase permanent magnet motor after the rotor assembly rotates by 45° in the embodiment of the present invention.

Reference signs: 1. first rotor assembly; 2. stator assembly; 3. second rotor assembly; 4. shaft assembly; 11. first permanent magnet; 12. rotor disc; 13. first magnetically conductive rod; 14. Bump; 15, second magnetic guide rod; 16, magnetic guide block; 21, iron core; 22, winding; 23, magnetic lead piece; 24, stator disc body; 42. The second permanent magnet; 100. The first closed magnetic circuit; 200. The second closed magnetic circuit; 300. The third closed magnetic circuit.

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

Example 1

Referring to FIG. 1 , in this embodiment, a single-phase dual-magnetic circuit permanent magnet motor is disclosed. The single-phase dual-magnetic circuit permanent magnet motor includes a stator assembly 2 , two rotor assemblies and a shaft assembly 4 .

Referring to Fig. 3, the stator assembly 2 includes a stator plate and iron cores 21 installed on the stator plate, a total of 8 iron cores 21 are installed on the stator plate, and 4 iron cores 21 are respectively installed on each side of the stator plate , the iron cores 21 on each side of the stator disk are respectively arranged around the axis of the stator disk, and the interval between adjacent iron cores 21 is 90°; windings 22 are respectively wound on each iron core 21, and each winding 22 is respectively connected in parallel The method is connected with a single-phase AC power supply, and each winding 22 generates a magnetic field in the same direction when a current in the same direction is passed through.

1 and 2, in this embodiment, the two rotor assemblies are the first rotor assembly 1 and the second rotor assembly 3 respectively, and the first rotor assembly 1 and the second rotor assembly 3 are symmetrically arranged along the stator disk, Their structure is the same, so only the first rotor assembly 1 will be described in detail.

Referring to Fig. 2, the first rotor assembly 1 includes a rotor disk 12, a magnetically permeable assembly and a first permanent magnet 11; wherein the magnetically permeable assembly includes a first magnetically permeable assembly and a second magnetically permeable assembly, and the first magnetically permeable assembly There are 4 groups in total, and each group includes 1 magnetic guide rod, one end of each magnetic conduction rod is connected to the rotor disk 12, and the other end extends toward the stator disk, and an embedding cavity is opened, each embedding cavity is respectively embedded with a first permanent magnet 11. Moreover, four groups of first magnetic permeable components are distributed on the outer circle of the rotor disk 12 and arranged at intervals of 90°. The second magnetic conducting assembly also has 4 groups in total, and each group includes a second magnetic conducting rod 15 and a magnetic conducting block 16; one end of each second magnetic conducting rod 15 is adjacent to the magnetic conducting block 16, and the other end faces The axis of the rotor disk 12 extends; 4 sets of second magnetic permeable components are respectively mounted on the rotor disk 12 and arranged at intervals of 90°. The interval between the first magnetically permeable component and the second magnetically permeable component is 45°.

1-3, the rotating shaft assembly 4 includes a rotating shaft 41 and a second permanent magnet 42, and the two ends of the rotating shaft 41 are respectively connected with the rotor discs 12 of the first rotor assembly 1 and the second rotor assembly 3, and It rotates accordingly; the axis of the stator disk is provided with a through hole for receiving the passage of the rotating shaft 41, and the rotating shaft 41 passes through the stator disk along the passage, does not contact the stator disk, and forms a relative rotation with the stator disk. The second permanent magnet 42 is embedded in the rotating shaft 41 and is exactly located at the center of the rotating shaft 41 , that is, at the center of the stator disk; and the second permanent magnet 42 is parallel to the magnetic field axis of the first permanent magnet, but opposite in polarity. The first rotor assembly 1 , the stator assembly 2 , the second rotor assembly 3 , and the rotating shaft assembly 4 are coaxially arranged.

In this embodiment, each winding 22 is connected to a single-phase AC power supply, and the current passing through the winding 22 in the first half cycle is set as a positive current, and the current passing through the winding 22 in the second half cycle is set as a negative current.

Taking the permanent magnet motor in the state shown in Figure 4 as an example, the magnetic field direction of the first permanent magnet 11 is set to be from left to right, and the magnetic field direction of the second permanent magnet 42 is from right to left; When a positive current is applied, each iron core 21 generates a magnetic field from left to right, and when a negative current is applied to the winding 22, each iron core 21 generates a magnetic field from right to left.

When the permanent magnet motor is started, each iron core 21 is respectively located between two adjacent first and second magnetization attracting assemblies. When the coil passes a positive current, a magnetic field from left to right is generated in each iron core 21 at this time, and the magnetic field will pass through the air gap and reach the second magnetic conduction assembly, then pass through the rotating shaft 41 to the second permanent magnet 42, and finally It passes through the air gap again to reach the iron core 21 , thereby forming a first closed magnetic circuit 100 . Since the reluctance of the air gap is very large, much greater than the reluctance of the second magnetic permeable component, based on the principle of the minimum reluctance path flow of the magnetic field, the air gap between the magnetic field passing through the iron core 21 and the second magnetic permeable component will be reduced, so The second magnetically permeable assembly moves closer to the nearest iron core 21 . Viewed from left to right in FIG. 4 , the rotor assembly generates counterclockwise torque. When the coil passes a negative current, a magnetic field from right to left is generated in the iron core 21 at this time, and the magnetic field will pass through the air gap and reach the first magnetically conductive component and the first permanent magnet 11 on the first rotor assembly 1, Then pass through the air gap and the stator disk to reach the first permanent magnet assembly and the first permanent magnet 11 on the second rotor assembly 3 , and finally pass through the air gap and return to the iron core 21 to form the second closed magnetic circuit 200 . Since the reluctance of the air gap is very large, much greater than the reluctance of the first magnetic permeable component, based on the principle of the minimum reluctance path flow of the magnetic field, the air gap between the magnetic field passing through the iron core 21 and the first magnetic permeable component will be reduced, so The first magnetically permeable assembly moves closer to the nearest iron core 21 , and when viewed from left to right in FIG. 4 , the rotor assembly generates a clockwise torque. Since the first permanent magnet 11 and the second permanent magnet 42 have different sizes, resulting in different magnetic field strengths, the magnetic field strengths of the first closed magnetic circuit 100 and the second closed magnetic circuit 200 are different, resulting in different torques. When the magnetic field strength of the first closed magnetic circuit 100 is greater than that of the second closed magnetic circuit 200 , the torque in the counterclockwise direction is always greater than the torque in the clockwise direction, so that the rotor assembly starts in the counterclockwise direction. When the magnetic field strength of the first closed magnetic circuit 100 is smaller than that of the second closed magnetic circuit 200 , the counterclockwise torque is always smaller than the clockwise torque, so that the rotor assembly rotates clockwise.

In this embodiment, in order to ensure smooth magnetic conduction according to the first closed magnetic circuit 100 and the second closed magnetic circuit 200 when the permanent magnet motor is energized, it is necessary to minimize the reluctance in each closed magnetic circuit. Therefore, the stator disk includes a stator disk body 24 and a stator disk outer circle layer 25 surrounding the stator disk body 24; the magnetic resistance of the stator disk outer circle layer 25 is smaller than that of the stator disk body 24, the first The magnetic field axis of the permanent magnet 11 passes through the outer circular layer 25 of the stator disk, so that the second closed magnetic circuit 200 does not leak magnetic flux to the main body 24 of the stator disk when passing through the outer circular layer 25 of the stator disk. The end of the second magnetically conductive rod 15 away from the magnetically conductive block 16 is connected to the rotating shaft 41 to reduce the unnecessary air gap in the first closed magnetic circuit 100 and further maintain the smooth conduction of the first closed magnetic circuit 100 . In addition, the shape of the iron core 21 is designed to be triangular, the shape and size of the magnetically conductive block 16 are designed to be the same as the shape and size of the iron core 21, and the iron core 21 faces one side of the first magnetically conductive rod 13. A magnetically attracting piece 23 is attached to the side, and the first magnetically conducting rod 13 is provided with a bump 14 protruding toward the direction of the iron core 21 to further ensure the smooth conduction of the second closed magnetic circuit 200 .

In this embodiment, in order to avoid loss of the rotor assembly due to friction during rotation, there is a gap between the first magnetic conducting rod 13 and the stator disk.

Example 2

This embodiment provides a driving method for driving the permanent magnet motor in Embodiment 1. The method specifically includes applying a single-phase alternating current to the permanent magnet motor to drive the permanent magnet motor to start; when the permanent magnet motor starts smoothly, Each rotation of the rotor assembly by 90° corresponds to one current cycle, that is, the direction of the current is switched every time the rotor rotates by 45°.

Specifically, after the permanent magnet motor is successfully started, as shown in FIG. 4 , it is set that the winding 22 is passed into the negative current of the second half cycle at this time. At this time, the iron core 21 produces a magnetic field from right to left, which is the same as the nearest The first magnetic conductive assembly and the first permanent magnet 11 form a second closed magnetic circuit 200. Viewed from left to right in FIG. 4, the rotor assembly generates a clockwise torque, and the torque and inertia make the The rotor assembly rotates 45° to the state shown in Figure 5. At this time, the current enters the positive current of the first half cycle again, and the iron core 21 generates a magnetic field from left to right, forming a third closed magnetic circuit 300 with the nearest second magnetically conductive component and the second permanent magnet 42. At this time, Viewed from left to right in FIG. 5 , based on the principle of the minimum reluctance path flow of the magnetic field, the rotor assembly will still generate a clockwise torque, thereby continuing to drive the rotor to move in the clockwise direction.

In the same current cycle, the magnetic field forms a closed loop through two different paths successively, making the rotor assembly rotate 90°. After entering the next current cycle, the motor rotor switches the magnetic flux path every 45°, so that the motor continues to run.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (7)

1. The utility model provides a single-phase dual magnetic circuit permanent-magnet machine, includes stator module and rotor subassembly, its characterized in that: the rotating shaft assembly is also included;

the stator assembly comprises a stator disc, an iron core arranged on the stator disc and a winding wound on the iron core, and the winding is connected with a single-phase alternating-current power supply;

the rotor assembly comprises a rotor disc and a first permanent magnet; the first permanent magnet is arranged on the rotor disc;

the rotating shaft assembly comprises a rotating shaft and a second permanent magnet; the rotating shaft penetrates through the axes of the rotor disc and the stator disc, is fixedly connected with the rotor disc and is rotationally connected with the stator disc; the second permanent magnet is arranged in the rotating shaft;

the first permanent magnet and the second permanent magnet are opposite in polarity direction, and different in magnetic field intensity;

the stator comprises two rotor assemblies which are symmetrically arranged along a stator disc;

iron cores are symmetrically arranged on two sides of the stator disc respectively, and each iron core is wound with a winding;

a magnetic conduction assembly is arranged on one side, close to the stator disc, of the rotor disc;

the magnetic conduction assembly comprises a first magnetic conduction assembly and a second magnetic conduction assembly; the first magnetic conducting assembly comprises a first magnetic conducting rod arranged along the circumference of the rotor disc; the first permanent magnet is arranged in the first magnetic conduction rod; the second magnetic conduction assembly comprises a second magnetic conduction rod arranged along the circumference of the rotor disc and a magnetic conduction block connected with the second magnetic conduction rod;

the first magnetic conduction assembly and the second magnetic conduction assembly are arranged at intervals along the circumferential direction of the rotor disc;

before the permanent magnet motor is started, the iron core is located between the first magnetic conduction assembly and the second magnetic conduction assembly in the circumferential direction.

2. A single-phase dual-magnetic circuit permanent magnet machine according to claim 1, wherein: the magnetic conduction assembly comprises four first magnetic conduction assemblies and four second magnetic conduction assemblies; four iron cores are respectively arranged on each side of the stator disc;

the four first magnetic conduction assemblies are arranged at intervals of 90 degrees, the four second magnetic conduction assemblies are arranged at intervals of 90 degrees, and the adjacent first magnetic conduction assemblies and the adjacent second magnetic conduction assemblies are arranged at intervals of 45 degrees; the four iron cores positioned on the same side of the stator disc are arranged at intervals of 90 degrees.

3. A single-phase dual-magnetic circuit permanent magnet machine according to claim 1, wherein: the second magnetic conducting rod is in contact with the rotating shaft.

4. A single-phase dual-magnetic circuit permanent magnet machine according to claim 1, wherein: the iron core is triangular, and the shape and the size of the magnetic conduction block are the same as those of the iron core.

5. A single-phase dual-magnetic circuit permanent magnet motor according to any of claims 1 to 4, characterized in that: the stator disc comprises a stator disc body and a stator disc outer circle layer surrounding the stator disc body; the magnetic resistance of the outer circle layer of the stator disc is smaller than that of the stator disc body; the magnetic field axis of the first permanent magnet penetrates through the outer circle layer of the stator disc.

6. A single-phase dual-magnetic circuit permanent magnet machine according to claim 5, characterized in that: the first magnetic conducting rod is provided with a convex block protruding towards the direction of the iron core; one side of the iron core, which faces the first magnetic conducting rod, is attached with a magnetic guiding sheet.

7. A method of driving the permanent magnet electric machine of claim 2, comprising applying a single phase alternating current to the permanent magnet electric machine for one current cycle for each 90 ° rotation of the rotor assembly.

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