Mixed magnetic core cylindrical magnetic flux switching permanent magnet linear motor applied to high-voltage circuit breaker

Abstract

The invention discloses a mixed magnetic core cylindrical magnetic flux switching permanent magnet linear motor applied to a high-voltage circuit breaker, and the cylindrical linear motor is a mixed material stator magnetic core formed by slotting a stator magnetic core prepared from a soft magnetic composite material and inserting silicon steel sheets laminated along the tangential direction. Compared with a traditional processing method of axial lamination of silicon steel sheets, magnetic resistance of a magnetic flux path is reduced, eddy-current loss caused by the fact that magnetic flux vertically penetrates through the silicon steel sheets is reduced, and output power and efficiency of the motor are improved. Compared with a magnetic core only made of a soft magnetic composite material, the silicon steel sheets laminated in the tangential direction are added, so that the overall magnetic conductivity of the motor is improved, and the output capacity of the motor is further improved. As the silicon steel sheet module does not penetrate through the whole stator and the soft magnetic composite material exists at the bottom, the magnetic flux deflection angle is reduced in the motor operation process, the tangential component of the flux density can be effectively reduced, and the motor performance is improved.

Description

Technical Field

[0001] The invention belongs to the field of high-voltage circuit breakers, and in particular relates to a hybrid magnetic core cylindrical flux switching permanent magnet linear motor used in a high-voltage circuit breaker. Background Art

[0002] As one of the core components of high-voltage circuit breakers, the operating mechanism drives the moving contacts to complete the opening and closing operations. The stability of the operating mechanism directly affects the reliability and mechanical characteristics of the high-voltage circuit breaker. Traditional operating mechanisms include hydraulic operating mechanisms, spring operating mechanisms, pneumatic operating mechanisms and permanent magnet operating mechanisms. The motor operating mechanism is an emerging operating mechanism. It adopts a high-performance permanent magnet linear motor to control the current of the linear motor winding to drive the motor mover to drive the operating rod of the high-voltage circuit breaker to open and close the contacts. It has the advantages of simple structure, high reliability, and controllable movement process. The motor operating mechanism has become a new development trend of the operating mechanism.

[0003] A linear motor is an electromagnetic device that performs linear motion. It can directly perform linear motion and provide thrust to the outside to complete the conversion of electrical energy and mechanical energy. The cylindrical flux switching permanent magnet linear motor has the advantages of both cylindrical linear motors and flux switching permanent magnet motors. Its magnetic core is closed along the circumferential direction and has no lateral end effect. The permanent magnet is located in the stator, which is beneficial to the heat dissipation of the permanent magnet and is not prone to high-temperature demagnetization. The winding utilization rate is high and has a strong magnetic concentration effect. It can provide high power and high thrust, which can not only meet the reliability of the circuit breaker contact action, but also control the movement of the contacts to achieve the adjustment of the contact position and speed during the opening and closing process of the circuit breaker.

[0004] Traditional cylindrical flux-switching permanent magnet linear motors are made of axially stacked silicon steel sheets. However, in actual operation, since the magnetic flux passes vertically through the silicon steel sheets, a large amount of eddy current loss is induced, reducing the operating efficiency. With the development of materials science, soft magnetic composites have been widely used in motor manufacturing. Soft magnetic composites are a type of metal particles wrapped with an insulating layer made by powder metallurgy technology. Relatively complex magnetic core structures can be processed by molding technology. The magnetic and thermal properties of soft magnetic composites are isotropic, and the eddy current loss is small. They are suitable for processing and manufacturing electromagnetic equipment with complex magnetic circuit structures, and can achieve low-cost mass production. However, the disadvantages of soft magnetic composites are low magnetic permeability and large hysteresis losses. The performance of motors made only of soft magnetic composites is subject to certain limitations. Summary of the invention

[0005] In order to further improve the performance of the linear motor of the high-voltage circuit breaker operating mechanism, the present invention provides a hybrid magnetic core cylindrical flux switching permanent magnet linear motor used in the high-voltage circuit breaker. The motor adopts tangentially stacked silicon steel sheet units and soft magnetic composite materials to make the stator magnetic core of the motor. The silicon steel sheet unit is embedded in the soft magnetic composite material unit along the axial direction. The magnetic conductivity direction of the silicon steel sheet is the same as the magnetic flux direction when the motor is running, which avoids the eddy current loss caused by the magnetic flux passing vertically through the silicon steel sheet, improves the performance of the motor, and improves the overall magnetic permeability of the motor. The soft magnetic composite material increases the path of the magnetic flux. The soft magnetic composite material at the bottom of the silicon steel sheet unit reduces the magnetic flux deflection angle during the operation of the motor, which can effectively reduce the tangential component of the magnetic density.

[0006] The present invention is implemented through the following technical solutions:

[0007] A hybrid magnetic core cylindrical flux switching permanent magnet linear motor used in a high-voltage circuit breaker, characterized in that the motor comprises a stator magnetic core, a mover magnetic core, a permanent magnet, and an armature winding, wherein the stator magnetic core is cylindrical and alternately arranged with the permanent magnet to form the stator part of the motor, and an annular groove is arranged inside each stator magnetic core, and a single-layer unipolar winding is built in the annular groove;

[0008] The mover core is a salient pole tooth slot structure, which is longer than the stator core. The mover core has no windings and permanent magnets and is only made of soft magnetic composite materials. The mover core is distributed with a number of annular salient pole teeth of the same shape. The radial cross section of the salient pole teeth is trapezoidal, and there is a certain air gap between the top of the salient pole teeth and the inner surface of the stator core.

[0009] The stator magnetic core is composed of silicon steel sheets and soft magnetic composite materials stacked in a tangential direction. Each stator magnetic core is composed of a soft magnetic composite material unit and eight silicon steel sheet units. The soft magnetic composite material unit is slotted at equal angles along the circumferential direction. The silicon steel sheet unit is formed by bonding a number of silicon steel sheets, which are then cut and formed, embedded in the slots of the soft magnetic composite material unit, bonded and fastened, and spliced ​​to form a complete stator magnetic core.

[0010] The outer surface of the silicon steel sheet unit is a curved surface, and the other surfaces are flat surfaces; the inner and outer surfaces of the soft magnetic composite material unit are curved surfaces, and the size of the notch on the surface of the soft magnetic composite material unit is the same as that of the silicon steel sheet unit; the silicon steel sheets, the silicon steel sheet units and the soft magnetic composite material units are bonded and fastened by adhesives;

[0011] The permanent magnet units are located in the stator part of the motor and are alternately distributed with the stator cores. The magnetization direction of the permanent magnets is axial magnetization. The polarities of adjacent permanent magnet units are opposite. The polarities of the permanent magnets at both ends of the stator are the same. The thickness is half of the internal permanent magnets. The permanent magnets are in the shape of a ring and are fastened to the adjacent stator cores by an adhesive.

[0012] Compared with the prior art, the beneficial effect of the present invention lies in that, by slotting the stator core made of soft magnetic composite materials and inserting silicon steel sheets stacked along the tangential direction, a hybrid material stator core of the motor is formed, and the magnetic conductivity direction of the silicon steel sheets is the same as the magnetic flux direction when the motor is running, which improves the overall magnetic permeability of the motor while avoiding eddy current losses caused by the magnetic flux passing vertically through the silicon steel sheets, thereby improving the performance of the motor. The soft magnetic composite material increases the path of the magnetic flux, and the soft magnetic composite material at the bottom of the silicon steel sheet unit reduces the magnetic flux deflection angle during the operation of the motor, which can effectively reduce the tangential component of the magnetic density. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0014] Figure 2 It is a schematic diagram of the stator structure of the hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0015] Figure 3 It is a schematic diagram of the structure of the hybrid magnetic core cylindrical flux switching permanent magnet linear motor mover of the present invention;

[0016] Figure 4 It is a schematic diagram of an axial cross-section of a stator core of a hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0017] Figure 5 It is a schematic diagram of the structure of a soft magnetic composite material unit of a hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0018] Figure 6 It is a schematic diagram of the structure of the silicon steel sheet unit of the hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0019] Figure 7 It is a schematic diagram of the stacking method of silicon steel sheet units of the hybrid magnetic core cylindrical flux switching permanent magnet linear motor of the present invention;

[0020] Figure 8 It is a schematic diagram comparing the working current and output thrust of a hybrid core cylindrical flux switching permanent magnet linear motor and a soft magnetic composite cylindrical flux switching permanent magnet linear motor;

[0021] Fig. 9 It is the magnetic flux vector distribution diagram of the motor stator core;

[0022] Markings in the figure: 1-silicon steel sheet unit; 2-soft magnetic composite material; 3-permanent magnet; 4-motor core. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific implementation methods to provide clear and specific guidance and reference for those skilled in the art to implement the relevant technical solutions, but this is not intended to limit the scope of protection of the present application.

[0024] The present invention proposes a hybrid magnetic core cylindrical flux switching permanent magnet linear motor used in a high-voltage circuit breaker. The motor structure consists of a stator magnetic core, a mover magnetic core, a permanent magnet, and an armature winding. The stator magnetic core is cylindrical and is alternately arranged with the permanent magnets to form the stator part of the motor. An annular groove is arranged inside each stator magnetic core, and a single-layer unipolar winding is built in the annular groove.

[0025] The mover core is a salient pole tooth structure, which is longer than the stator core. There are no windings, permanent magnets and other structures on the mover core. It is only composed of soft magnetic composite materials. There are several annular salient pole teeth of the same shape distributed on the mover core. The radial cross-section of the salient pole teeth is trapezoidal, and there is a certain air gap between the top of the salient pole teeth and the inner surface of the stator core.

[0026] The stator core is composed of silicon steel sheets and soft magnetic composite materials stacked along the tangent direction. Each stator core is composed of a soft magnetic composite material unit and eight silicon steel sheet units. The soft magnetic composite material unit is slotted at equal angles along the circumferential direction. The silicon steel sheet unit is formed by bonding several silicon steel sheets, which are then cut and formed, embedded in the slots of the soft magnetic composite material unit, bonded and fastened, and spliced ​​to form a complete stator core.

[0027] The outer surface of the silicon steel sheet unit is a curved surface, and the other surfaces are flat surfaces; the inner and outer surfaces of the soft magnetic composite material unit are curved surfaces, and the size of the surface groove of the soft magnetic composite material unit is the same as that of the silicon steel sheet unit; the silicon steel sheets and the silicon steel sheet units and the soft magnetic composite material units are fastened by adhesive.

[0028] Specifically, the soft magnetic composite material unit can be made in the following manner: after the insulation-wrapped soft magnetic composite material powder is placed in a vacuum drying oven and dried at 100°C for one hour, it is pressed and formed into the shapes of the stator core and the mover core at a pressure of 600MPa, wherein the soft magnetic composite material unit of the stator core is slotted at equal angles along the circumferential direction, and the inner mover core is a salient pole tooth structure. The pressed model is placed in a nitrogen environment and heat treated at 650°C for one hour. After naturally cooling to room temperature, the soft magnetic composite material unit required for the motor is obtained; the silicon steel sheet unit can be made in the following manner: take a number of silicon steel sheets, cut out annular grooves on the inner side of the stator core, insert the silicon steel sheets into the notches of the soft magnetic composite material along the tangent direction, and use an adhesive to bond the side and bottom surfaces of the silicon steel sheet unit to the soft magnetic composite material unit, and then use wire cutting to process the outer surface of the silicon steel sheet unit so that the outer side of the silicon steel sheet unit forms a curved surface.

[0029] The permanent magnet unit is located in the stator part of the motor and is alternately distributed with the stator core. The permanent magnet magnetization direction is axial magnetization. The polarities of adjacent permanent magnet units are opposite. The polarities of the permanent magnets at both ends of the stator are the same, and the thickness is half of the internal permanent magnet. The permanent magnet is in the shape of a ring and is fastened to the adjacent stator core by an adhesive.

[0030] The parameters of the cylindrical flux switching permanent magnet linear motor of this embodiment are shown in Table 1.

[0031] Table 1 Structural parameters of cylindrical flux switching permanent magnet linear motor

[0032] The cylindrical flux switching permanent magnet linear motor in this example is modeled and simulated in the finite element simulation software. The motor model is as follows: Figure 1 The motor stator structure is shown in Figure 2 As shown in FIG. 1 , the stator core and the permanent magnet are arranged alternately. The stator core includes a silicon steel sheet module stacked along the tangential direction and a soft magnetic composite material module slotted along the circumferential direction. Each stator core includes a soft magnetic composite material unit and eight silicon steel sheet units. The schematic diagram of the axial cross section of the stator core is shown in FIG. Figure 4 As shown, the soft magnetic composite material unit is slotted at equal angles along the circumferential direction, as shown in FIG. Figure 5 As shown, the silicon steel sheet unit structure and its stacking direction are as follows Figure 6 and Figure 7 shown.

[0033] Figure 8 This is a schematic diagram comparing the working current of the hybrid core cylindrical flux switching permanent magnet linear motor and the output thrust of the traditional cylindrical flux switching permanent magnet linear motor. It can be seen that the output thrust of the motor increases with the increase of input current. As the input current increases, the internal magnetic field of the motor reaches saturation, and the thrust increase decreases. The thrust can reach up to 5kN. Under the same input current, the output thrust of the hybrid core cylindrical flux switching permanent magnet linear motor is larger. This is because the addition of silicon steel sheet units increases the overall magnetic permeability of the motor and improves the performance of the motor.

[0034] Fig. 9 This is the stator core magnetic flux density vector distribution diagram of the hybrid core cylindrical flux switching permanent magnet linear motor. Since the soft magnetic composite material has isotropic material properties, the magnetic flux is distributed divergently in the soft magnetic composite material unit. Since the silicon steel sheet unit is stacked along the tangential direction, the magnetic resistance in the tangential direction is large, and the magnetic flux in the silicon steel sheet will flow in the axial plane. Since there is a soft magnetic composite material unit at the bottom of the silicon steel sheet unit, the magnetic flux in the air gap will first pass through the soft magnetic composite material unit and then enter the silicon steel sheet unit, which helps to reduce the component of the magnetic flux along the stacking direction of the silicon steel sheet when entering the silicon steel sheet unit, and reduce the eddy current loss caused by the magnetic flux vertically passing through the silicon steel sheet stack.

[0035] The hybrid magnetic core cylindrical flux switching permanent magnet linear motor adopts tangentially stacked silicon steel sheet units and soft magnetic composite materials to make the stator core of the motor. The silicon steel sheet unit is axially embedded in the soft magnetic composite material unit. The magnetic conductivity direction of the silicon steel sheet is the same as the magnetic flux direction when the motor is running, which avoids eddy current losses caused by the magnetic flux passing vertically through the silicon steel sheet, improves the performance of the motor, and improves the overall magnetic permeability of the motor. The soft magnetic composite material increases the path of the magnetic flux. The soft magnetic composite material at the bottom of the silicon steel sheet unit reduces the magnetic flux deflection angle during the operation of the motor, which can effectively reduce the tangential component of the magnetic density.

[0036] Although the present invention is described in conjunction with specific embodiments, it should be understood that the invention can be further modified. This application is intended to cover any modification, use or change made to the present invention in general according to the present invention, including those solutions different from the disclosure herein and such as those solutions that can be applied to the basic features proposed above, such as those falling into the known or customary practices in the technical field to which the present invention belongs.

[0037] Because the present invention can be implemented in several forms without departing from the spirit of the essential features of the present invention, it should be understood that, unless specifically stated, the embodiments described above are not intended to limit the present invention, but should be broadly understood within the spirit and scope of the present invention as defined in the appended claims. The described embodiments should be considered in all respects to be illustrative only and not restrictive.

[0038] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0039] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker, characterized in that: The motor comprises a stator core, a mover core, a permanent magnet and an armature winding. The stator core is cylindrical and is arranged alternately with the permanent magnet to form the stator part of the motor. An annular groove is arranged inside each stator core, and a single-layer unipolar winding is built in the annular groove. The mover core is a salient pole tooth slot structure, which is longer than the stator core. The mover core has no windings and permanent magnets and is only made of soft magnetic composite materials. The mover core is distributed with a number of annular salient pole teeth of the same shape. The radial cross section of the salient pole teeth is trapezoidal, and there is a certain air gap between the top of the salient pole teeth and the inner surface of the stator core. The stator magnetic core is composed of silicon steel sheets and soft magnetic composite materials stacked in a tangential direction. Each stator magnetic core is composed of a soft magnetic composite material unit and eight silicon steel sheet units. The soft magnetic composite material unit is slotted at equal angles along the circumferential direction. The silicon steel sheet unit is formed by bonding a number of silicon steel sheets, which are then cut and formed, embedded in the slots of the soft magnetic composite material unit, bonded and fastened, and spliced ​​to form a complete stator magnetic core. The outer surface of the silicon steel sheet unit is a curved surface, and the other surfaces are flat surfaces; the inner and outer surfaces of the soft magnetic composite material unit are curved surfaces, and the size of the notch on the surface of the soft magnetic composite material unit is the same as that of the silicon steel sheet unit; the silicon steel sheets, the silicon steel sheet units and the soft magnetic composite material units are bonded and fastened by adhesives; The permanent magnet unit is located in the stator part of the motor and is alternately distributed with the stator core. The permanent magnet magnetization direction is axial magnetization. The polarities of adjacent permanent magnet units are opposite. The polarities of the permanent magnets at both ends of the stator are the same, and the thickness is half of the internal permanent magnet. The permanent magnet is in the shape of a ring and is fastened to the adjacent stator core by an adhesive.

2. A hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The stator core consists of eight silicon steel sheet units and one soft magnetic composite material unit.

3. The hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The mover magnetic core and the annular salient pole teeth on the surface are made of soft magnetic composite materials.

4. The hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The soft magnetic composite material units of the stator magnetic core and the mover magnetic core are formed by compression molding of the soft magnetic composite material.

5. The hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The permanent magnet is made of neodymium iron boron material, and the magnetization method is axial magnetization.

6. A hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The armature winding is copper wire.

7. A hybrid core cylindrical flux switching permanent magnet linear motor used in a high voltage circuit breaker according to claim 1, characterized in that: The soft magnetic composite material model is 7005P, and the silicon steel sheet material model is M19_29G.

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