Demagnetization fault simulation device for permanent magnet linear motor

Abstract

The invention belongs to the field of linear motor fault simulation, and particularly relates to a permanent magnet linear motor demagnetization fault simulation device which comprises a base and a combined secondary structure detachably arranged on the base. The combined secondary structure comprises an adjustable permanent magnet array and a plurality of limiting blocks, the adjustable permanent magnet array comprises a plurality of sub permanent magnets which are arranged at intervals, and the sub permanent magnets are attached to the back iron; at least one limiting block is arranged between the back irons of two adjacent sub permanent magnets, and the back irons are next to the limiting blocks; the sub permanent magnets are normal permanent magnets or fault permanent magnets; by flexibly adjusting the adjustable permanent magnet array and the limiting block, demagnetization simulation of the permanent magnet in multiple scenes is realized, and the experiment efficiency is greatly improved under the condition that the experiment cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of linear motor fault simulation technology, specifically relating to a device for simulating demagnetization faults in permanent magnet linear motors. Background Technology

[0002] Permanent magnet synchronous linear motors (PMLSMs) are widely used in high-end equipment fields such as direct-drive elevators, precision machine tools, and rail transportation due to their advantages such as high thrust density, high efficiency, and fast dynamic response. However, the secondary-side permanent magnets operate in complex and harsh environments for extended periods, making them susceptible to irreversible demagnetization faults due to factors such as armature reaction, high temperature, and mechanical vibration. This leads to motor performance degradation, increased thrust fluctuations, and seriously threatens the reliability of the entire drive system. Therefore, in-depth research into the mechanism of permanent magnet demagnetization faults and the development of effective online diagnostic technologies have significant engineering value.

[0003] Currently, research in this field heavily relies on finite element simulation and theoretical modeling, while experimental verification methods have significant shortcomings. Existing experimental methods mainly employ a structure where the permanent magnet is fixed as a whole to the back iron. To simulate local demagnetization faults at different locations, ranges, or combinations, researchers often need to customize the entire fault sub-module or use forceful methods to disassemble and replace individual permanent magnets. This method has inherent drawbacks such as high experimental costs, cumbersome and time-consuming operations, and a high risk of damaging the permanent magnet and back iron. Furthermore, existing simulation devices have limited functionality and cannot flexibly simulate complex fault modes such as skewed pole demagnetization and eccentric demagnetization.

[0004] In summary, there is an urgent need in this field for an experimental device that can flexibly, conveniently, and cost-effectively simulate various demagnetization fault scenarios. An ideal device should support rapid replacement of faulty permanent magnets, flexible adjustment of fault location and severity, and the ability to simulate complex fault modes and mixed operating conditions, thereby filling the gap in experimental research methods and providing a reliable experimental platform for the characteristic analysis, diagnostic algorithm verification, and system optimization of PMLSM demagnetization faults. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a permanent magnet linear motor demagnetization fault simulation device. This device is modular, flexibly reconfigurable, and capable of simulating various demagnetization faults, providing support for fault analysis and optimization design of permanent magnet linear motors.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A device for simulating demagnetization faults of a permanent magnet linear motor includes a base and a detachable combined secondary structure mounted on the base. The combined secondary structure includes an adjustable permanent magnet array and several limiting blocks. The adjustable permanent magnet array includes several sub-permanent magnets arranged at intervals, and the sub-permanent magnets are attached to a back iron. At least one limiting block is provided between the back irons of two adjacent sub-permanent magnets, and the back iron is adjacent to the limiting block. The sub-permanent magnets are normal permanent magnets or faulty permanent magnets.

[0007] Furthermore, the demagnetization of the faulty permanent magnet can be one or more of the following: demagnetization along the length magnetization direction, demagnetization along the height magnetization direction, demagnetization along the width magnetization direction, demagnetization along a random magnetization direction, and complete demagnetization of the permanent magnet.

[0008] Furthermore, the adjustable permanent magnet array includes at least one faulty permanent magnet array, and one faulty permanent magnet array includes four to six sub-permanent magnets, wherein the sub-permanent magnets in the faulty permanent magnet array are arranged in a combination to set the permanent magnet fault.

[0009] Furthermore, the widths of the limit blocks in different faulty permanent magnet arrays may be the same or different; the widths of the limit blocks in the same faulty permanent magnet array may be the same or different.

[0010] Furthermore, when a fault permanent magnet array composed of four sub-permanent magnets is used to simulate whole-piece demagnetization faults or partial demagnetization faults, the sub-permanent magnets of the fault permanent magnet array can be arranged and combined into 15 fault types; when a fault permanent magnet array composed of five sub-permanent magnets is used to simulate mixed demagnetization faults, the sub-permanent magnets of the fault permanent magnet array can be arranged and combined into 30 fault types.

[0011] Furthermore, the surface of the base is provided with at least two parallel slots, and a plurality of slides are provided in the slots. The back iron is fixed to the slides by fasteners.

[0012] Furthermore, the slot extends through the base along the arrangement direction of the sub-permanent magnets.

[0013] In an optional embodiment, the length of the limiting block is not less than the center distance between the two slots, and the lower surface of the limiting block is provided with a protrusion that can extend into the slot, the protrusion abutting against the slide block.

[0014] In an optional embodiment, the length direction of the back iron is inclined to the length direction of the base.

[0015] Furthermore, a V-shaped positioning protrusion is provided on one side of the back iron and the limiting block, and a V-shaped positioning recess is provided on the other side of the back iron to cooperate with the V-shaped positioning protrusion.

[0016] The beneficial effects of this invention are: The permanent magnet linear motor demagnetization fault simulation device provided by this invention realizes permanent magnet demagnetization simulation in multiple scenarios by flexibly adjusting the adjustable permanent magnet array, which greatly improves experimental efficiency while reducing experimental costs.

[0017] The permanent magnet linear motor demagnetization fault simulation device provided by this invention uses an adjustable permanent magnet array in its secondary permanent magnet structure. By adding limiting blocks between the back irons, the distance between the permanent magnet arrays can be manually adjusted while ensuring the continuity of the magnetic circuit. When simulating new demagnetization conditions, only specific faulty permanent magnets need to be fabricated, and then the existing sub-permanent magnets can be replaced at designated locations. The operation is very convenient, eliminating the need to repeatedly fabricate the entire permanent magnet array, greatly reducing manufacturing costs and difficulty.

[0018] The adjustable permanent magnet array of this invention can be set to demagnetization under different scenarios, such as random demagnetization of a single permanent magnet and multiple permanent magnets according to their length, width and height, as well as non-uniform demagnetization of a single permanent magnet and multiple permanent magnets. Compared with traditional permanent magnet demagnetization simulation devices that only consider uniform demagnetization and local demagnetization and rely solely on simulation models to simulate demagnetization, this invention can more accurately simulate the actual operation of a motor after demagnetization. In addition, by tilting the back iron and limiting block at a certain angle, it is possible to simulate the situation of different angled poles and non-equidistant pole pitches, providing a good experimental basis for subsequent motor fault detection.

[0019] The permanent magnet linear motor demagnetization fault simulation device of the present invention can be combined with any primary structure to simulate demagnetization faults. The device can not only simulate demagnetization fault conditions, but also provide normal operation conditions as a reference. It is particularly suitable for engineering applications of demagnetization fault simulation of high thrust and high power linear motors. It can flexibly adjust the secondary structure and overcome a series of limitations such as layout and installation space. It can be used for research on demagnetization fault simulation of linear permanent magnet motors. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0021] Figure 2 This is an exploded view diagram of an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the base structure according to an embodiment of the present invention.

[0023] Figure 4 This is an exploded structural diagram of an adjustable permanent magnet array according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the installation of a sub-permanent magnet demagnetized in the direction of length magnetization according to an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the installation of a sub-permanent magnet demagnetized in the width magnetization direction according to an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the installation of a sub-permanent magnet demagnetized in the direction of high magnetization according to an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the installation of a non-uniformly demagnetized sub-permanent magnet according to an embodiment of the present invention.

[0028] Figure 9 This is a schematic diagram illustrating the installation of limit blocks with different width specifications according to an embodiment of the present invention.

[0029] Figure 10 Schematic diagrams illustrating different angled pole implementations in embodiments of the present invention.

[0030] Figure 11 This is a schematic diagram of the fit between the V-shaped positioning protrusion and the V-shaped positioning recess in one embodiment of the present invention.

[0031] Figure 12 This is a schematic diagram of the cooperation between the V-shaped positioning protrusion and the V-shaped positioning recess in another embodiment of the present invention.

[0032] Figure 13 yes Figure 12 A schematic diagram of the structure of the back iron and permanent magnet set at different angles of the inclined poles.

[0033] Figure 14 yes Figure 12 A schematic diagram of the limiting block that is adapted to the back iron of the middle and oblique poles.

[0034] In the diagram: 1-base, 2-slide, 3-bolt, 4-adjustable permanent magnet array, 5-limit block, 6-normal permanent magnet array, 7-faulty permanent magnet array, 8-normal permanent magnet, 9-back iron, 10-faulty permanent magnet, 11-V-shaped positioning recess, 12-slot. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art are within the scope of protection of the present invention.

[0036] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0038] like Figures 1 to 9 As shown, a permanent magnet linear motor demagnetization fault simulation device includes a primary component and a secondary component, with an air gap between them. The primary component includes multiple unit cores, windings, and a non-magnetic backplate. The windings are wound on each unit core and mounted on the non-magnetic backplate. The primary component can adopt the primary structure of a conventional linear motor suitable for the secondary component of this application. The secondary component includes a base 1 and a detachable combined secondary structure mounted on the base 1. The combined secondary structure includes an adjustable permanent magnet array 4 and several limiting blocks 5. The adjustable permanent magnet array 4 includes several spaced sub-permanent magnets, which are glued to a back iron 9. At least one limiting block 5 is provided between the back irons 9 of two adjacent sub-permanent magnets, with the back iron 9 adjacent to the limiting block 5. The sub-permanent magnets can be selected as normal permanent magnets 8 or faulty permanent magnets 10 according to the test requirements. Normal permanent magnets 8 are used to simulate healthy operating conditions, and faulty permanent magnets 10 are used to simulate demagnetization conditions. This application adopts a modular design, with the back iron 9 of a secondary component having the same shape and size, which facilitates the quick disassembly or replacement of the sub-permanent magnet; a sub-permanent magnet is bonded and fixed on a back iron 9.

[0039] Optional, such as Figure 1 As shown, two rows of threaded holes are directly opened on the upper surface of the base 1 to fix the back iron 9 with bolts 3. The limiting block 5 is placed on the upper surface of the base 1 and sandwiched between two adjacent back irons 9. This type of base 1 can adjust the fault simulation of the adjustable permanent magnet array 4 by adjusting the position and fault type of the faulty permanent magnet 10. Preferably, as Figure 1 , Figure 2 , Figure 9 As shown, the limiting block 5 has different width specifications, and different width specifications of the limiting block 5 can be selected according to experimental requirements.

[0040] Preferred, such as Figures 1 to 3 As shown, the surface of the base 1 has at least two parallel slots 12, both slots 12 being the same size. The slots 12 can not only support and position the secondary structure, but also fix and replace the adjustable permanent magnet array 4 and the limiting block 5 in the secondary structure. A slide 2 is provided inside the slot 12, and the back iron 9 is fixed to the slide 2 by fasteners, facilitating the assembly and disassembly of the modular secondary structure. The slot 12 is preferably located on the upper surface of the base 1, but it can also be located on the side of the base 1 to accommodate irregularly shaped bases. The slide 2 must not be able to come out from the top of the slot 12. The shape of the slot 12 can be L-shaped, T-shaped, trapezoidal, dovetail, etc., and the shape of the slide 2 is adapted to the shape of the slot 12, such as an L-shaped, T-shaped nut, trapezoidal block, or dovetail block. The slide 2 can only enter and exit from both ends of the slot 12. The slide 2 is placed in the slot 12 of the base 1 and is close to both sides of the slot 12, and can move flexibly along the slot direction, facilitating the positioning and fixing of the detachable secondary structure. The back iron 9 has end holes at both ends, which are either round or elongated. Preferably, the end of the elongated hole away from the permanent magnet extends to the edge of the back iron 9 to form an opening (i.e., the elongated hole is U-shaped). In one embodiment, the fastener is a bolt 3, and the slide 2 has threaded holes that mate with the bolt 3. The back iron 9 is fixed by the bolt 3. After the bolt 3 is tightened, the slide 2 and the back iron 9 can be clamped and fixed at the edge of the top opening of the slot 12. Therefore, in this application, it is not necessary to provide plugs at the openings at both ends of the slot 12. Preferably, in this embodiment, the bolt 3 is a hexagonal bolt 3, which is convenient for manual installation and disassembly. It cooperates with the slide 2 to firmly fix the secondary structure to the base 1 with the slot 12, making it less likely for the secondary structure to shift. In another embodiment, a fixing post is provided on the slide 2. The fixing post has external threads. The back iron 9 is fixed by being fitted onto the fixing post through the end hole. Then, the back iron 9 is pressed and fixed onto the base 1 by a nut or clamp that matches the fixing post. The base 1 is made of a plate with a certain strength, such as an aluminum alloy profile.

[0041] Preferred, such as Figures 1 to 3 As shown, the slot 12 extends through the base 1 along the arrangement direction of the sub-permanent magnets, facilitating the slide 2 to enter and exit from both ends of the slot 12; before the back iron 9 is installed on the slide 2, the slide 2 can flexibly slide and adjust its position within the slot 12.

[0042] Preferred, such as Figures 1 to 2 , Figures 4 to 9 As shown, the length of the limiting block 5 is not less than the center distance between the two slots 12. The surface of the limiting block 5 is provided with a protrusion that can extend into the slot 12, so that one limiting block 5 can be inserted into two slots 12 at the same time, which is convenient for use.

[0043] The adjustability of the adjustable permanent magnet array 4 is reflected in: (1) The spacing between the sub-permanent magnets is adjustable; specifically, the spacing between the sub-permanent magnets can be adjusted by using different numbers of limiting blocks 5 or limiting blocks 5 of different widths, or by adjusting the tilt angle of the limiting blocks 5. (2) Whether the sub-permanent magnets are faulty and the type of fault are adjustable; the demagnetization of the faulty permanent magnet 10 is demagnetization along the length magnetization direction ( Figure 5 Demagnetization in the direction of high magnetization ( Figure 7 ), width magnetization direction demagnetization ( Figure 6 Demagnetize according to the magnetization direction at random positions ( Figure 8 ) and the permanent magnet is completely demagnetized. The faulty permanent magnet 10 is demagnetized by using demagnetizing coil magnetic field technology, dynamic magnetic field attenuation technology, pulse magnetic field and AC attenuation technology, temperature induction technology and current overload technology to set a demagnetization fault in the permanent magnet, and to precisely control the size and position of the demagnetization area. (3) The number of adjustable permanent magnet arrays 4 installed on the base 1 and the number of sub-permanent magnets in each adjustable permanent magnet array 4 are adjustable.

[0044] This application achieves simulation of permanent magnet demagnetization in multiple scenarios by flexibly adjusting the adjustable permanent magnet array 4, which greatly improves experimental efficiency while reducing experimental costs. Figures 4-12 The sub-permanent magnet with the patterned design is the faulty permanent magnet 10. The patterned area in the diagram schematically represents the demagnetized region. Figure 4 As shown, the adjustable permanent magnet array 4 in the combined secondary structure is composed of multiple normal permanent magnet arrays 6 and faulty permanent magnet arrays 7. The sub-permanent magnets in the normal permanent magnet array 6 and the faulty permanent magnet array 7 are arranged sequentially with a spacing of the width of the limiting block 5 sandwiched between the two back irons 9 (or the total width of the limiting blocks 5 if there are multiple limiting blocks 5). The permanent magnet array adopts a modular design. The normal permanent magnet array 6 is used to simulate the healthy working condition, and the faulty permanent magnet array 7 is used to simulate the demagnetization working condition. They can be flexibly replaced according to experimental needs.

[0045] According to experimental requirements, the normal permanent magnet 8 and the faulty permanent magnet 10 can be arranged in a linear arrangement with equal spacing or a non-equal spacing linear arrangement; it is preferred to be arranged with equal spacing to ensure the continuity of the magnetic field distribution and the repeatability of the experiment; the non-equal spacing linear arrangement can be used for special working conditions, such as high-performance servo systems to achieve ultra-low torque fluctuation through harmonic suppression, and adaptive magnetic field modulation for electric vehicles and wind power generation.

[0046] like Figure 9 As shown, the limiting block 5 includes at least a horizontal bar portion, which, when installed on the base 1, is positioned to the left and right of the horizontal bar portion (according to...). Figure 1The back iron 9 is clamped in the orientation of the T-shaped slot 12. In a preferred embodiment, taking the T-shaped slot 12 as an example, the limiting block 5 is designed as a Π-shaped block. The limiting block 5 includes a horizontal bar and a protrusion fixed to the lower surface of the horizontal bar. The protrusion can be stably embedded in the T-shaped slot 12, and the limiting block 5 can be installed and removed manually. By increasing the volume of the Π-shaped limiting block 5 or increasing the number of Π-shaped limiting blocks 5, the distance between permanent magnets can be quickly adjusted, thereby meeting the demagnetization simulation requirements of unequal spacing and studying the fault effects of uneven magnetic field distribution or magnetic force weakening. During the adjustment process, the size and contact surface of the limiting block 5 ensure the continuity of the magnetic circuit, thereby avoiding magnetic circuit loss caused by adjustment. The material of the limiting block 5 is the same as that of the back iron 9, both being soft magnetic materials, such as silicon steel sheets, soft magnetic composite materials, and cast iron. The thickness of the back iron 9 is 5mm-8mm, which is easy to process by wire cutting. The thickness of the horizontal bar of the limiting block 5 is the same as that of the back iron 9. If the limiting block 5 is provided with protrusions, the overall thickness of the limiting block 5 should be greater than that of the back iron 9 so that the protrusions can be processed by wire cutting.

[0047] The faulty permanent magnet array 7 can be configured with demagnetization faults in three directions: length, width, and height of the sub-permanent magnets. Normal permanent magnets 8 can also be replaced by faulty permanent magnets 10 of different sizes, such as reducing their length, width, or thickness. The faulty permanent magnet array 7 is coupled with the limiting block 5 to ensure the consistency of the magnetic field distribution, thereby simulating scenarios of partial magnetic performance failure. Demagnetization of some permanent magnets can also be selectively performed as needed, with demagnetization levels ranging from complete demagnetization to partial demagnetization and weakening, to achieve refined fault simulation. Alternatively, certain permanent magnets can be removed to simulate demagnetization at specific locations. Furthermore, the magnetization direction can be changed as required, altering the orientation of some or all permanent magnets to study the impact of abnormal magnetic field distribution on overall performance. You can adjust a single permanent magnet to simulate single-stage demagnetization, or adjust multiple permanent magnets to simulate large-area demagnetization faults (simulating multi-stage demagnetization faults), or combine multiple demagnetization simulation scenarios and adjust the position, orientation, and magnetic strength of the permanent magnets to change the arrangement of the fault permanent magnet array 7, in order to simulate large-scale or uneven demagnetization fault scenarios.

[0048] The adjustable permanent magnet array 4 includes at least one fault permanent magnet array 7. Each fault permanent magnet array 7 includes four to six sub-permanent magnets, and the sub-permanent magnets in the fault permanent magnet array 7 are arranged in a combination to simulate permanent magnet faults. The secondary permanent magnets of the permanent magnet synchronous linear motor are also arranged in an NSNS pattern. Generally, one cycle contains two permanent magnets. However, since it is a linear motor, its periodicity is not as pronounced as that of a rotating motor. Therefore, setting four or more permanent magnets to simulate faults can simulate more demagnetization conditions. For a rotating motor, the magnetic fields of the stator and rotor form a closed loop, and the magnetic field is uniformly distributed in the circumferential direction, repeating periodically without interruption. For a linear motor, the magnetic field is distributed along a straight line, and the end magnetic circuits of the primary or secondary are not closed, resulting in end effects. The magnetic field distribution of the first and last magnetic poles is different from that of the middle magnetic poles, and the periodicity has a certain difference. Therefore, in this invention, the fault permanent magnet array 7 needs to be set with a number of fault permanent magnets 10 covering one cycle.

[0049] Specifically, the faulty permanent magnet array 7 is composed of faulty magnetic units of different numbers and forms. Now, the faulty permanent magnets 10 in the faulty magnetic units are arranged and combined to set permanent magnet faults, enabling various types of simulations. The first example is the faulty permanent magnet array 7 composed of four sub-permanent magnets, which studies the demagnetization fault of the entire permanent magnet in the four sub-permanent magnets. The four permanent magnets are numbered 1, 2, 3, and 4. There are 15 fault types in the arrangement and combination of the four permanent magnets, as detailed in Table 1.

[0050] Table 1. Complete demagnetization combinations in a faulty permanent magnet array consisting of four permanent magnets.

[0051] The second approach takes a faulty permanent magnet array composed of four sub-permanent magnets as an example. It studies the local demagnetization faults that occur in the four sub-permanent magnets. The four permanent magnets have demagnetization faults in the length magnetization direction, height magnetization direction, width magnetization direction, and random position magnetization direction, which are numbered A, B, C, and D respectively. There are 15 fault types in the arrangement and combination of the four permanent magnets, as detailed in Table 2.

[0052] Table 2. Combinations of local demagnetization faults in a faulty permanent magnet array composed of four permanent magnets.

[0053] The third approach combines the study of complete demagnetization of permanent magnets with the study of localized demagnetization. Taking a faulty permanent magnet array composed of five sub-permanent magnets as an example, the demagnetization scenarios of the five permanent magnets are: demagnetization along the length magnetization direction, demagnetization along the height magnetization direction, demagnetization along the width magnetization direction, demagnetization along a random position magnetization direction, and complete demagnetization, numbered A, B, C, D, and E respectively. There are 30 possible fault types in the arrangement of the five permanent magnets, as detailed in Table 3. The first four demagnetization scenarios refer to localized demagnetization in a certain direction, while the complete demagnetization scenario refers to demagnetizing the permanent magnets without distinguishing any direction, which is equivalent to combining the scenarios of the four sub-permanent magnets together.

[0054] Table 3. Combinations of mixed demagnetization faults in a faulty permanent magnet array composed of five sub-permanent magnets.

[0055] There are many combinations of fault permanent magnet arrays composed of six sub-permanent magnets. The combination method is the same as the arrangement of four or five sub-permanent magnets, so it will not be described again.

[0056] Fourthly, in this application, the limiting blocks, besides separating adjacent back irons, are also used to set the pole pitch. Therefore, by uniformly changing the size or number of the limiting blocks, the pole pitch can be adjusted (although the pole pitch of the secondary structure changes after adjustment, all pole pitches remain consistent). Combined with different demagnetization conditions of the sub-permanent magnets, demagnetization fault simulation of permanent magnet synchronous linear motors under different pole pitches can be achieved. Note that during the adjustment process, the size and contact surface of the limiting blocks ensure the continuity of the magnetic circuit, thereby avoiding magnetic circuit losses caused by adjustment.

[0057] The fifth method involves individually adjusting the size or number of limiting blocks to simulate demagnetization in cases of unequal pole spacing, thereby studying the fault effects of uneven magnetic field distribution or weakened magnetic force.

[0058] In addition, linear motors may experience demagnetization similar to eccentricity and skewed pole demagnetization, but their manifestations and principles differ from those of rotary motors. During operation, linear motors may experience a shift in the relative position between the mover and stator due to installation errors, mechanical wear, etc., similar to eccentricity in rotary motors. This shift causes uneven distribution of the air gap magnetic field, leading to changes in the magnetic field acting on the permanent magnet locally, potentially triggering localized demagnetization, i.e., a situation similar to eccentricity demagnetization. Regarding skewed pole demagnetization, linear motors sometimes employ skewed poles or slots to suppress thrust fluctuations. If the tilt angle of the permanent magnet does not meet design requirements during manufacturing, or if the permanent magnet tilts due to external forces during operation, it will lead to abnormal magnetic field distribution, resulting in a problem similar to skewed pole demagnetization, affecting the performance of the linear motor.

[0059] This application achieves a non-equidistant arrangement of permanent magnets by changing the volume and number of limiting blocks 5 and setting different tilt angles for the limiting blocks 5. The change in the spacing between permanent magnets—effectively altering the magnetic circuit—creates an effect similar to air gap changes, thus simulating electromagnetic eccentricity. Therefore, through the design of the tilt angles of the limiting blocks 5 and the back iron 9, each permanent magnet can maintain the same tilt angle or have different angles, thereby realizing the skewed pole demagnetization fault. In one embodiment, this application can adjust the overall offset angle of the fault-adjustable permanent magnet array or the offset of individual sub-permanent magnets. Combined with the above-mentioned demagnetization fault combinations, the entire permanent magnet array can be arranged in a skewed or eccentric manner, thereby efficiently simulating complex fault modes such as skewed pole demagnetization and eccentric demagnetization. Compared with the normal installation of the sub-permanent magnets, the offset angle of the offset sub-permanent magnets is 0°-30°. This range covers the entire experimental spectrum from no skew to strong skew. Adjustments within this range allow for a systematic study of the relationship between skew angle and thrust fluctuations. Furthermore, in actual engineering projects, skew caused by installation errors or mechanical deformation can be simulated. In cases where the skew angle is small or moderate, a skew angle of 0°-30° can simulate typical scenarios of minor and severe faults caused by the skew angle. For example... Figure 10 As shown, a single back iron 9 is normally installed parallel to the length direction of the base 1. When simulating a demagnetization fault, the back iron 9 carrying the sub-permanent magnet is rotated at a certain angle along the horizontal plane, while keeping both ends of the sub-permanent magnet outside the horizontal line A and horizontal line B. Figure 10 The horizontal lines A and B are schematically drawn with dashed lines. The area between horizontal lines A and B is the part of the adjustable permanent magnet array 4 connected to the magnetic circuit. In this embodiment, since the installation position of the back iron 9 changes, the end hole of the back iron 9 is required to be an elongated hole or a U-shaped hole to ensure that when the back iron 9 is tilted at a certain angle, it can always be connected to the slide block 2 in the slot 12 by tightening and loosening bolts 3. This allows for adjustment of demagnetization faults at different tilt angles without completely removing the back iron 9. In this case, when changing between normal installation and tilt installation of the sub-permanent magnet, it is not necessary to replace the back iron 9, and the tilt angle can be adjusted arbitrarily within a certain angle.

[0060] In another embodiment, such as Figures 12 to 14 As shown, the back iron 9 and the limiting block 5 are designed with irregular shapes. Taking the limiting block 5 as an example, the two ends of the horizontal bar of the limiting block 5 (referred to as the first end and the second end respectively) are misaligned and connected by a middle bar between the two ends. The sub-permanent magnet is fixed on the middle bar. If the limiting block 5 has a protrusion, the protrusion is located on the bottom surface of the first end and the second end. The shape of the back iron 9 is similar and will not be described in detail.

[0061] Furthermore, the back iron 9 and the limiting block 5 are designed with at least one V-shaped positioning protrusion on one side and a V-shaped positioning recess 11 that mates with the V-shaped positioning protrusion on the other side, thereby facilitating the alignment of all back irons 9 and limiting blocks 5 during installation. The shapes of the V-shaped positioning protrusion and the V-shaped positioning recess 11 are adjusted according to the actual situation when the back iron 9 is installed normally and when it is installed at an angle. Figure 11 As shown, when the permanent magnet is installed normally (the length direction of the back iron 9 is perpendicular to the length direction of the two slots 12) or a straight strip shape is used, Figure 10 The back iron 9 shown has a V-shaped positioning protrusion that protrudes from one side of the first long side, and a corresponding V-shaped positioning recess 11 that is recessed from one side of the second long side. Figure 12-14 As shown, when the sub-permanent magnet is installed at an angle (simulating a skewed pole fault), and the back iron 9 and the limiting block 5 are irregularly shaped, not only can the skewed pole demagnetization fault simulation (electromagnetic eccentricity simulation) be realized, but also V-shaped positioning protrusions and V-shaped positioning recesses 11 that cooperate with the V-shaped positioning protrusions can be formed on both sides of the back iron 9 and the limiting block 5, thereby ensuring that all the back irons 9 and the limiting blocks 5 can be aligned during installation.

[0062] This application achieves rapid assembly and disassembly of permanent magnets through modular design, eliminating the need for customized overall secondary components or forceful disassembly, as well as the need for repeated construction of experimental prototypes. It can quickly and cost-effectively reconstruct various demagnetization fault scenarios, providing high flexibility in fault simulation, significantly reducing experimental costs and greatly improving experimental efficiency. In addition to simulating traditional uniform and local demagnetization, it innovatively achieves accurate simulation of complex mechanical demagnetization faults such as skewed poles, eccentricity, and unequal spacing through adjustable limit block 5. This greatly expands the simulable fault modes and improves the realism and effectiveness of demagnetization fault simulation of permanent magnet synchronous linear motors under different conditions. It provides an effective device platform and valuable resources for fault diagnosis algorithm research, motor performance analysis, and demagnetization fault simulation of such motors.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A device for simulating demagnetization faults of a permanent magnet linear motor, characterized in that: The system includes a base (1) and a detachable combined secondary structure disposed on the base (1); the combined secondary structure includes an adjustable permanent magnet array (4) and several limiting blocks (5); the adjustable permanent magnet array (4) includes several sub-permanent magnets arranged at intervals, the sub-permanent magnets being attached to a back iron (9); at least one limiting block (5) is disposed between the back irons (9) of two adjacent sub-permanent magnets, the back iron (9) being adjacent to the limiting block (5); the sub-permanent magnets are normal permanent magnets (8) or faulty permanent magnets (10).

2. The permanent magnet linear motor demagnetization fault simulation device according to claim 1, characterized in that: The demagnetization of the faulty permanent magnet (10) can be one or more of the following: demagnetization along the length magnetization direction, demagnetization along the height magnetization direction, demagnetization along the width magnetization direction, demagnetization along a random magnetization direction, and complete demagnetization of the permanent magnet.

3. The permanent magnet linear motor demagnetization fault simulation device according to claim 1, characterized in that: The adjustable permanent magnet array (4) includes at least one fault permanent magnet array (7), and one of the fault permanent magnet arrays (7) includes four to six sub-permanent magnets, and the sub-permanent magnets in the fault permanent magnet array (7) are arranged in a combination to set the permanent magnet fault.

4. The permanent magnet linear motor demagnetization fault simulation device according to claim 3, characterized in that: The widths of the limit blocks (5) in different faulty permanent magnet arrays (7) may be the same or different; the widths of the limit blocks (5) in the same faulty permanent magnet array (7) may be the same or different.

5. The permanent magnet linear motor demagnetization fault simulation device according to claim 3, characterized in that: When the fault permanent magnet array (7) composed of four sub-permanent magnets is used to simulate whole demagnetization faults or local demagnetization faults, the sub-permanent magnets of the fault permanent magnet array (7) can be arranged and combined into 15 fault types; when the fault permanent magnet array (7) composed of five sub-permanent magnets is used to simulate mixed demagnetization faults, the sub-permanent magnets of the fault permanent magnet array (7) can be arranged and combined into 30 fault types.

6. The permanent magnet linear motor demagnetization fault simulation device according to claim 1, characterized in that: The base (1) has at least two parallel slots (12) on its surface. Several slides (2) are provided in the slots (12). The back iron (9) is fixed on the slides (2) by fasteners.

7. The permanent magnet linear motor demagnetization fault simulation device according to claim 6, characterized in that: The slot (12) extends through the base (1) along the arrangement direction of the sub-permanent magnets.

8. The permanent magnet linear motor demagnetization fault simulation device according to claim 6, characterized in that: The length of the limiting block (5) is not less than the center distance between the two slots (12). The lower surface of the limiting block (5) is provided with a protrusion that can extend into the slot (12), and the protrusion abuts against the slide.

9. The permanent magnet linear motor demagnetization fault simulation device according to claim 1, characterized in that: The length direction of the back iron is inclined to the length direction of the base.

10. The permanent magnet linear motor demagnetization fault simulation device according to claim 1, characterized in that: A V-shaped positioning protrusion is provided on one side of the back iron (9) and the limiting block (5), and a V-shaped positioning recess (11) is provided on the other side of the back iron (9) to cooperate with the V-shaped positioning protrusion.

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