A synergistically optimized permanent magnet synchronous motor rotor structure and multi-parameter design method

Abstract

This invention relates to the field of permanent magnet synchronous motor rotor structure technology, specifically to a collaboratively optimized permanent magnet synchronous motor rotor structure and a multi-parameter design method. The collaboratively optimized permanent magnet synchronous motor rotor structure includes a rotor shaft, a rotor core, and permanent magnets. The rotor core is sleeved on the outer periphery of the rotor shaft, and the rotor core has magnetic barriers and permanent magnet slots. Multiple auxiliary slots are provided on the outer side of the rotor core. The permanent magnets are embedded in the permanent magnet slots, and a gap is left between the permanent magnet slots and the permanent magnets, which is filled with epoxy resin potting compound. The collaboratively optimized permanent magnet synchronous motor rotor structure of this invention solves the problems of poor matching between permanent magnets and magnetic barrier structures, high operating losses, and difficulty in balancing efficiency and torque output in existing large hollow rotor permanent magnet synchronous motors. Through the collaborative optimization of the core structure and the precise design of key parameters, a comprehensive improvement in motor performance is achieved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor rotor structure technology, and in particular to a collaboratively optimized permanent magnet synchronous motor rotor structure and a multi-parameter design method. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) have been widely used in the electric vehicle field due to their high efficiency, high power density, and high output torque. Currently, the urgent demand for extended driving range in the new energy vehicle market is driving the rapid iterative upgrades of PMSMs towards higher efficiency and higher power density. High efficiency directly improves the energy utilization rate of the electric drive system, thereby extending the overall vehicle range, while high power density reduces the motor installation space, allowing for more redundancy in the battery pack layout, ultimately increasing the driving range. However, it should be noted that high power density design inevitably increases the motor's heat dissipation pressure. Improving motor operating efficiency can reduce heat generation, alleviating heat dissipation pressure at its source and ensuring motor reliability. Therefore, the efficient operation of PMSMs has become a key research focus in the industry. To overcome the technical bottlenecks in the efficient operation of PMSMs, developing high-efficiency PMSM design methods has become an urgent technical challenge. Given that the core of improving motor efficiency lies in loss suppression, in-depth research into the generation mechanism of PMSM losses and its suppression strategies has significant engineering application value.

[0003] Rotor core structure optimization is a mature method for suppressing iron losses and eddy current losses in permanent magnets in motors, and it is now widely used in the field of industrial motor design. It optimizes the magnetic field distribution by adjusting the core structure, reducing the harmonic content of the air gap magnetic flux density and the magnetic saturation of the core, ultimately achieving the goals of reducing losses and improving efficiency. However, existing large hollow permanent magnet synchronous motors suffer from technical drawbacks such as poor matching between permanent magnets and magnetic barrier structures, high operating losses, and difficulty in simultaneously achieving high efficiency and torque output. Summary of the Invention

[0004] The purpose of this invention is to provide a collaboratively optimized rotor structure and multi-parameter design method for permanent magnet synchronous motors, aiming to solve the problems of poor matching between permanent magnets and magnetic barrier structures, high operating losses, and difficulty in balancing efficiency and torque output in existing large-hollow rotor permanent magnet synchronous motors.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a synergistically optimized permanent magnet synchronous motor rotor structure, comprising a rotor shaft, a rotor core, and permanent magnets;

[0006] The rotor core is sleeved on the outer periphery of the rotor shaft. The rotor core is provided with magnetic barriers and permanent magnet slots. Multiple auxiliary slots on the rotor surface are provided on the outer side of the rotor core. The permanent magnet is embedded in the permanent magnet slot. A gap is left between the permanent magnet slot and the permanent magnet, and the gap is filled with epoxy resin potting compound.

[0007] The number of permanent magnet slots and permanent magnets are both multiple, and the number of magnetic barriers is also multiple. Every two permanent magnets and one magnetic barrier located inside the rotor core form a U-shaped arrangement, and every two permanent magnets located outside the rotor core form a V-shaped arrangement.

[0008] Secondly, the present invention also provides a multi-parameter design method for the rotor structure of a co-optimized permanent magnet synchronous motor, comprising:

[0009] The rotor of the large hollow high-efficiency permanent magnet synchronous motor adopts a large hollow structure, and the core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor are determined by finite element simulation.

[0010] The permanent magnet and the magnetic barrier of the rotor yoke form a synergistic optimization structure, which corresponds to thirteen key structural parameters.

[0011] Thirteen key structural parameters were divided into three groups of structural optimization parameters according to their significance level through partial factorial experimental design and analysis of variance. Then, a phased optimization strategy and a genetic algorithm were used to jointly optimize and determine the optimal combination of structural parameters, ultimately forming the globally optimal combination of structural parameters.

[0012] The core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor include stator and rotor size parameters, permanent magnet installation arrangement, and suitable pole slot matching structure.

[0013] The stator and rotor size parameters include stator size parameters and rotor size parameters. The stator size parameters include the stator outer diameter, stator inner diameter, and key stator slot parameters. The rotor size parameters include the rotor outer diameter and rotor inner diameter. The permanent magnet installation arrangement is a U-shaped and V-shaped embedded arrangement structure. The pole slot matching structure is a combination of 72 stator slots and 8 rotor poles, which is an integer slot configuration.

[0014] The thirteen key structural parameters corresponding to the collaborative optimization structure include the magnetic barrier position, magnetic barrier width, magnetic barrier thickness, radial position of the first layer of permanent magnets, circumferential position of the first layer of permanent magnets, V-angle of the magnetic poles of the first layer of permanent magnets, width of the first layer of permanent magnets, thickness of the first layer of permanent magnets, radial position of the second layer of permanent magnets, V-angle of the magnetic poles of the second layer of permanent magnets, width of the second layer of permanent magnets, thickness of the second layer of permanent magnets, and width of the magnetic bridge of the second layer of permanent magnets.

[0015] The stator and rotor cores of the large hollow high-efficiency permanent magnet synchronous motor are both made of B27AHV1400, the rotor permanent magnet is made of N42UH, the stator winding is made of flat copper wire, the winding structure is an 8-layer distributed winding, and the winding pitch is set to 9.

[0016] The three sets of structural optimization parameters include first-stage optimization parameters, second-stage optimization parameters, and third-stage optimization parameters. The first-stage optimization parameters are the radial position of the second permanent magnet layer, the thickness of the second permanent magnet layer, the width of the first permanent magnet layer, the V-angle of the magnetic poles of the second permanent magnet layer, and the width of the second permanent magnet layer. The second-stage optimization parameters are the thickness of the first permanent magnet layer, the radial position of the first permanent magnet layer, the position of the magnetic barrier, and the thickness of the magnetic barrier. The third-stage optimization parameters are the width of the magnetic barrier, the circumferential position of the first permanent magnet layer, the V-angle of the magnetic poles of the first permanent magnet layer, and the width of the magnetic bridge of the second permanent magnet layer.

[0017] Among these steps, thirteen key structural parameters were divided into three groups of structural optimization parameters according to significance level through partial factorial experimental design and analysis of variance. Then, a phased optimization strategy and a genetic algorithm were used to collaboratively find the optimal combination of structural parameters, ultimately forming the globally optimal combination.

[0018] The three sets of structural optimization parameters were determined sequentially through phased optimization, with the optimization objectives being to maximize torque, maximize efficiency, minimize total loss, minimize copper loss, and minimize iron loss.

[0019] This invention discloses a synergistically optimized rotor structure for a permanent magnet synchronous motor and a multi-parameter design method. The rotor permanent magnets are embedded in permanent magnet slots with a large internal area, leaving gaps between the slots and the permanent magnets, which are filled with epoxy resin potting compound. Auxiliary slots on the rotor surface improve the motor's electromagnetic performance. When the motor is idling, the rotor core provides a path for the permanent magnet flux, reducing rotor magnetic reluctance. When the motor is under load, the rotor core simultaneously provides a flow path for both the permanent magnet magnetic field and the armature reaction field, enabling electromagnetic energy exchange. The permanent magnets adopt a U+V type embedded arrangement structure, which effectively optimizes the magnetic circuit distribution and improves magnetic energy utilization. This invention's synergistically optimized rotor structure for a permanent magnet synchronous motor solves the problems of poor matching between the permanent magnets and the magnetic barrier structure, high operating losses, and difficulty in balancing efficiency and torque output in existing large-hollow rotor permanent magnet synchronous motors. Through synergistic optimization of the core structure and precise design of key parameters, a comprehensive improvement in motor performance is achieved. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0021] Figure 1This is a schematic diagram of the overall structure of a co-optimized permanent magnet synchronous motor rotor structure according to the present invention.

[0022] Figure 2 This is a partial structural diagram of a cooperatively optimized permanent magnet synchronous motor rotor structure according to the present invention.

[0023] Figure 3 A schematic diagram showing the locations of the thirteen key structural parameters corresponding to the collaborative optimization structure.

[0024] Figure 4 This is a magnified view of the location of the thirteen key structural parameters corresponding to the synergistic optimization structure.

[0025] Figure 5 This is another enlarged view of the location of the thirteen key structural parameters corresponding to the collaborative optimization structure.

[0026] Figure 6 A comparison chart of the efficiency of the large hollow permanent magnet synchronous motor with front and rear rotors was created to optimize the efficiency.

[0027] Figure 7 A comparison chart of output torque and output power of a large hollow permanent magnet synchronous motor with front and rear rotors to optimize performance.

[0028] Figure 8 A comparison diagram of the no-load cogging torque of the large hollow permanent magnet synchronous motor with front and rear rotors is provided to optimize the design.

[0029] Figure 9 A comparison of simulation and actual measurements of the external characteristic curves of a large hollow permanent magnet synchronous motor with a front rotor is shown to optimize the design.

[0030] Figure 10 This is a flowchart of a multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization, according to the present invention.

[0031] 1-Rotor shaft, 2-Rotor core, 3-Permanent magnet, 4-Magnetic barrier, 5-Permanent magnet slot, 6-Rotor surface auxiliary slot, 7-Permanent magnet one, 8-Permanent magnet two, 9-Permanent magnet three, 10-Permanent magnet four. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0033] Firstly, please refer to Figures 1-2The present invention provides a synergistically optimized rotor structure for a permanent magnet synchronous motor, comprising a rotor shaft 1, a rotor core 2, and a permanent magnet 3. The aforementioned solution solves the problems of poor structural matching between the permanent magnet 3 and the magnetic barrier 4, high operating losses, and difficulty in balancing efficiency and torque output in existing large-hollow permanent magnet synchronous motors.

[0034] In this specific embodiment, the rotor core 2 is sleeved on the outer periphery of the rotor shaft 1. The rotor core 2 is provided with magnetic barriers 4 and permanent magnet slots 5, and multiple rotor surface auxiliary slots 6 are provided on the outer side of the rotor core 2. The permanent magnet 3 is embedded in the permanent magnet slot 5, and a gap is left between the permanent magnet slot 5 and the permanent magnet 3, which is filled with epoxy resin potting compound. The rotor core 2 is coaxially sleeved on the outer periphery of the rotor shaft 1, with one end axially limited and fixed by an end cap, and the other end assembled and fixed by a flange and bolts.

[0035] The number of permanent magnet slots 5 and permanent magnets 3 are both multiple, and the number of magnetic barriers 4 is also multiple. Every two permanent magnets 3 and one magnetic barrier 4 located inside the rotor core 2 form a U-shaped arrangement, and every two permanent magnets 3 located outside the rotor core 2 form a V-shaped arrangement.

[0036] This invention discloses a synergistically optimized permanent magnet synchronous motor rotor structure. The rotor shaft 1 is a hollow structure containing angular contact ball bearings. The rotor permanent magnet 3 is embedded in the permanent magnet slot 5. The permanent magnet slot 5 has a large internal area, with a gap between it and the permanent magnet 3, which is filled with epoxy resin potting compound. An auxiliary slot 6 on the rotor surface improves the motor's electromagnetic performance by altering the air gap reluctance distribution to suppress harmonic components of the air gap magnetic flux density, thereby reducing iron losses and torque ripple. The rotor core 2 provides a path for the permanent magnet flux during idling, reducing rotor reluctance. When the motor is under load, the rotor core 2 simultaneously provides a flow path for both the permanent magnet magnetic field and the armature reaction field, enabling electromagnetic energy exchange. For this embodiment, please refer to [reference needed]. Figure 1Multiple permanent magnets 3 and multiple magnetic barriers 4 constitute multiple combined arrangement structures. Each combined arrangement structure includes four permanent magnets 3 and one magnetic barrier 4. The four permanent magnets 3 include permanent magnet 7 and permanent magnet 8 in the first layer, and permanent magnet 9 and permanent magnet 10 in the second layer. Permanent magnet 7, permanent magnet 8, and the rotor yoke magnetic barrier 4 form a U-shaped arrangement structure, while permanent magnet 9 and permanent magnet 10 form a V-shaped arrangement structure on their own. The permanent magnets 3 adopt a U+V type embedded arrangement structure. This composite structure can effectively optimize the magnetic circuit distribution and improve the magnetic energy utilization rate. The synergistically optimized permanent magnet synchronous motor rotor structure of this invention solves the problems of poor structural matching between permanent magnets 3 and magnetic barriers 4, high operating losses, and difficulty in balancing efficiency and torque output in existing large hollow rotor permanent magnet synchronous motors. Through the synergistic optimization of the core structure and the precise design of key parameters, the overall performance of the motor is comprehensively improved.

[0037] Secondly, please refer to Figure 3-10 The present invention also provides a multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with coordinated optimization, comprising:

[0038] The rotor of the S1 large hollow high-efficiency permanent magnet synchronous motor adopts a large hollow structure, and the core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor are determined by finite element simulation.

[0039] The core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor include stator and rotor dimensions, the installation arrangement of permanent magnets 3, and the appropriate pole-slot configuration. The stator and rotor dimensions include stator outer diameter, stator inner diameter, and key stator slot parameters; the rotor dimensions include rotor outer diameter and rotor inner diameter. The permanent magnets 3 are installed in a U-shaped and V-shaped embedded arrangement. The pole-slot configuration is a combination of 72 stator slots and 8 rotor poles, an integer slot configuration. The stator and rotor cores of the large hollow high-efficiency permanent magnet synchronous motor are both made of B27AHV1400 steel, the rotor permanent magnets 3 are made of N42UH steel, and the stator windings are made of flat copper wire with an 8-layer distributed winding structure and a winding pitch of 9. The large hollow high-efficiency permanent magnet synchronous motor is used in the permanent magnet drive mode of new energy commercial vehicles. The permanent magnet 3 adopts a U+V type embedded arrangement structure, which can effectively optimize the magnetic circuit distribution and improve the magnetic energy utilization rate. The stator and rotor core materials of the rotor-hollow permanent magnet synchronous motor are both B27AHV1400 silicon steel sheets, which have high magnetic permeability and low iron loss characteristics; the rotor permanent magnet 3 is N42UH neodymium iron boron rare earth permanent magnet material, which can provide a stable rotor magnetic field and has high heat resistance; the stator winding is wound with flat copper wire, and the winding structure is an 8-layer distributed winding with a winding pitch of 9, which can reduce winding loss and improve motor efficiency.

[0040] S2 permanent magnet 3 and rotor yoke magnetic barrier 4 form a collaborative optimization structure, which corresponds to thirteen key structural parameters.

[0041] The thirteen key structural parameters corresponding to the collaborative optimization structure include the position, width, and thickness of the magnetic barrier 4; the radial position, circumferential position, and V-angle of the first permanent magnet 3; the width and thickness of the first permanent magnet 3; the radial position, V-angle, and width of the second permanent magnet 3; the width, thickness, and bridge width of the second permanent magnet 3; and so on. These thirteen key structural parameters were divided into three groups based on their significance level in influencing motor performance through partial factorial design and variance analysis. A phased optimization strategy and a genetic algorithm were then used to collaboratively optimize the parameters, ultimately forming the globally optimal combination of structural parameters, effectively avoiding structural interference problems caused by multi-parameter coupling.

[0042] The thirteen key structural parameters of S3 were divided into three groups of structural optimization parameters according to their significance level through partial factorial experimental design and analysis of variance. Then, the optimal combination of global structural parameters was determined by using a phased optimization strategy and a genetic algorithm.

[0043] The three sets of structural optimization parameters include first-stage optimization parameters, second-stage optimization parameters, and third-stage optimization parameters. The first-stage optimization parameters are the radial position of the second-layer permanent magnet 3, the thickness of the second-layer permanent magnet 3, the width of the first-layer permanent magnet 3, the V-angle of the magnetic poles of the second-layer permanent magnet 3, and the width of the second-layer permanent magnet 3. The second-stage optimization parameters are the thickness of the first-layer permanent magnet 3, the radial position of the first-layer permanent magnet 3, the position of the magnetic barrier 4, and the thickness of the magnetic barrier 4. The third-stage optimization parameters are the width of the magnetic barrier 4, the circumferential position of the first-layer permanent magnet 3, the V-angle of the magnetic poles of the first-layer permanent magnet 3, and the width of the magnetic bridge of the second-layer permanent magnet 3. In this step, the three sets of structural optimization parameters are determined sequentially through staged optimization. The optimization objectives are to maximize torque, maximize efficiency, minimize total loss, minimize copper loss, and minimize iron loss, ensuring the comprehensiveness of structural optimization.

[0044] Furthermore, a finite element model of the motor is constructed based on the globally optimal combination of structural parameters. Simulation verification shows that the simulation results are consistent with the prediction results of the quadratic regression model, meeting the engineering accuracy requirements and ensuring the reliability of the optimal structural parameters.

[0045] To better understand this invention, a specific embodiment is used below to illustrate the multi-parameter design method of the synergistically optimized permanent magnet synchronous motor rotor structure of this invention. In this embodiment, the synergistically optimized permanent magnet synchronous motor rotor structure adopts a large hollow structure. The permanent magnet synchronous motor is used in the permanent magnet drive condition of new energy commercial vehicles. The dimensional parameters include a stator core outer diameter of 230mm, a stator core inner diameter of 156.2mm, a rotor core outer diameter of 154.6mm, a rotor core inner diameter of 95.46mm, a stator slot depth of 16.9mm, and a stator slot width of 3.5mm. The single-sided air gap of the motor is 0.8mm. The stator winding is made of insulated flat copper wire, and the winding is designed as an 8-layer distributed winding with a pitch of 9 and an integer slot configuration of 72 slots and 8 poles.

[0046] In this embodiment, the stator and rotor cores of the motor are made of stacked B27AHV1400 silicon steel sheets, the rotor permanent magnet 3 is made of sintered N42UH neodymium iron boron rare earth permanent magnet material, and the stator windings are wound with flat copper wire. The density of the B27AHV1400 silicon steel sheet is 7650 kg / m3, the density of the N42UH permanent magnet 3 is 7500 kg / m3, the density of the copper wire is 8900 kg / m3, and the remanence of the N42UH permanent magnet 3 is 1.30 T.

[0047] refer to Figure 3 The co-optimized structure formed by permanent magnet 3 and rotor yoke magnetic barriers 4 corresponds to 13 key structural parameters, namely, the position a, width b, thickness c, radial position d, circumferential position e, pole V angle f, width g, thickness h, radial position j, pole V angle k, width l, thickness m, and bridge width n of the second permanent magnet 3. These 13 key structural parameters were divided into three groups based on their significance level in influencing motor performance through partial factorial design and variance analysis. A phased optimization strategy and a genetic algorithm were then used to collaboratively optimize the structure, ultimately forming the globally optimal combination of structural parameters, effectively avoiding structural interference problems caused by multi-parameter coupling.

[0048] a is the radial distance between the lower surface of the yoke magnetic barrier and the inner circle of the rotor core; b is the center width of the yoke magnetic barrier on one side along the rotor pole symmetry axis; c is the radial thickness of the yoke magnetic barrier along the central axis; d is the radial distance between the bottom of the first layer permanent magnet slot and the inner circle of the rotor core; e is the circumferential distance between the bottom of the first layer permanent magnet slot and the edge of the single-pole rotor; f is the angle between the first layer permanent magnet slot and the rotor pole symmetry axis; g is the width of the first layer permanent magnet perpendicular to the magnetization direction; h is the thickness of the first layer permanent magnet parallel to the magnetization direction; j is the radial distance between the bottom of the second layer permanent magnet slot and the inner circle of the rotor core; k is the angle between the second layer permanent magnet slot and the rotor pole symmetry axis; l is the width of the second layer permanent magnet perpendicular to the magnetization direction; m is the thickness of the second layer permanent magnet parallel to the magnetization direction; n is the circumferential distance between the second layer permanent magnet and the rotor pole symmetry axis.

[0049] The three sets of structural optimization parameters are as follows: The first-stage optimization parameters are the radial position j of the second-layer permanent magnet 3, the thickness m of the second-layer permanent magnet 3, the width g of the first-layer permanent magnet 3, the V-angle k of the second-layer permanent magnet 3, and the width l of the second-layer permanent magnet 3; the second-stage optimization parameters are the thickness h of the first-layer permanent magnet 3, the radial position d of the first-layer permanent magnet 3, the position a of the magnetic barrier 4, and the thickness c of the magnetic barrier 4; the third-stage optimization parameters are the width b of the magnetic barrier 4, the circumferential position e of the first-layer permanent magnet 3, the V-angle f of the first-layer permanent magnet 3, and the width n of the magnetic bridge of the second-layer permanent magnet 3. The optimization process aims to maximize torque, maximize efficiency, minimize total loss, minimize copper loss, and minimize iron loss, ensuring the comprehensiveness of the structural optimization.

[0050] The optimal combination of global structural parameters was verified by finite element simulation. The simulation results and the prediction results of the quadratic regression model were consistent with the engineering accuracy requirements, further ensuring the reliability and practicality of the structural parameter design.

[0051] The optimal parameter combination is as follows: the position a of the magnetic barrier 4 is 4.803 mm, the width b of the magnetic barrier 4 is 4.286 mm, the thickness c of the magnetic barrier 4 is 4.007 mm, the radial position d of the first layer permanent magnet 3 is 3.825 mm, the circumferential position e of the first layer permanent magnet 3 is 11.203 mm, the V angle f of the first layer permanent magnet 3 is 37.219°, the width g of the first layer permanent magnet 3 is 14.294 mm, the thickness h of the first layer permanent magnet 3 is 3.089 mm, the radial position j of the second layer permanent magnet 3 is 63.503 mm, the V angle k of the second layer permanent magnet 3 is 60.000°, the width l of the second layer permanent magnet 3 is 11.640 mm, the thickness m of the second layer permanent magnet 3 is 4.195 mm, and the width n of the second layer permanent magnet 3 magnetic bridge is 4.007 mm.

[0052] refer to Figures 1-2The rotor shaft 1 adopts a hollow design, with two angular contact ball bearings installed inside to support the stepped shaft, thereby achieving stable transmission of output torque between the two ends of the motor and effectively improving space utilization. The armature winding of this motor adopts an 8-layer distributed winding structure with a winding pitch of 9. The magnets adopt a U+V type embedded structure, with the pole V angles of the first layer permanent magnet 3 and the second layer permanent magnet 3 being 74.438° and 120° respectively. The permanent magnets 3 are made of N42UH neodymium iron boron material. Both the stator core and the rotor core 2 are made of B27AHV1400 silicon steel sheets.

[0053] refer to Figures 3-5 The individual rotor poles of this motor have a left-right symmetrical structure along the axis of symmetry. Therefore, the structure optimization of the entire rotor pole can be achieved by adjusting the rotor parameters on only one side of the axis of symmetry. The permanent magnet 3 is embedded inside the permanent magnet slot 5. By adjusting the width g and l of the permanent magnet slot 5, the width dimension of the permanent magnet 3 can be indirectly controlled.

[0054] refer to Figure 6 , Figure 6 To optimize the efficiency MAP comparison chart of the large hollow permanent magnet synchronous motor before and after optimization, it can be seen from the figure that the area of ​​the motor with efficiency above 96% is significantly expanded after optimization, while the area of ​​the other efficiency ranges remains basically unchanged.

[0055] refer to Figure 7 , Figure 7 A comparison of the output torque and output power of the large hollow permanent magnet synchronous motor before and after optimization is shown in the figure. As can be seen from the figure, within the constant torque range, the output torque of the optimized motor is slightly reduced; when the motor speed exceeds 4000 rpm, the output torque remains essentially the same before and after optimization. Regarding output power, when the motor speed is below 8000 rpm, the output power of the optimized motor is slightly higher than that of the unoptimized motor; when the motor speed exceeds 8000 rpm, the output power of the optimized motor is slightly lower than that of the unoptimized motor.

[0056] refer to Figure 8 , Figure 8 The figure shows a comparison of the no-load cogging torque of the large hollow permanent magnet synchronous motor before and after optimization. As can be seen from the figure, the no-load cogging torque of the optimized motor is lower than that of the un-optimized motor in the entire speed range.

[0057] refer to Figure 9 , Figure 9 To optimize the simulation and measured comparison of the external characteristic curves of the front rotor large hollow permanent magnet synchronous motor, it can be seen from the figure that the simulated values ​​and measured values ​​of the external characteristic curves of the front rotor large hollow permanent magnet synchronous motor are well fitted.

[0058] This invention discloses a collaboratively optimized rotor structure for a permanent magnet synchronous motor (PMSM). The PMSM rotor employs a hollow structure and is designed for electromagnetic drive applications in new energy commercial vehicles. Utilizing partial factorial design, analysis of variance, a phased optimization strategy, and a genetic algorithm, the invention achieves collaborative structural design of the permanent magnet (3) and magnetic barrier (4), precise optimization and selection of 13 key parameters, and constructs a high-efficiency, low-loss, and balanced rotor-type PMSM structure. Experimental testing was conducted to obtain the external characteristic curves of the rotor-type PMSM before optimization, verifying the agreement between simulation results and measured data. This invention provides theoretical reference and technical support for loss suppression and efficiency improvement in rotor-type PMSMs.

[0059] This invention discloses a multi-parameter design method for the rotor structure of a co-optimized permanent magnet synchronous motor. The high-efficiency, hollow rotor structure of the permanent magnet synchronous motor is based on a large hollow rotor design. The core innovation lies in constructing a co-optimized structure between the permanent magnet (3) and the magnetic barrier (4) of the rotor yoke. Through scientific parameter design and optimization strategies, optimal matching of structural performance is achieved. After structural optimization of the high-efficiency, hollow rotor permanent magnet synchronous motor using this method, the maximum efficiency of the motor is increased to 96.45%; the maximum iron loss is reduced to 1727.81W, a decrease of 3.9%; the maximum output torque is 326.44Nm and the maximum output power is 123.73kW, corresponding to reductions of 2.7% and 0.32% respectively. The torque and power reductions are both controlled within 5%, which is within the acceptable range for engineering applications. Simultaneously, the no-load cogging torque of the motor is reduced by 1.62%. The motor structure is based on a large hollow rotor design. Its core innovation lies in the construction of a synergistic optimization structure of permanent magnet 3 and rotor yoke magnetic barrier 4. Through scientific parameter design and optimization strategy, the optimal matching of structural performance is achieved.

[0060] The synergistically optimized permanent magnet synchronous motor rotor structure designed in this invention has the following beneficial effects:

[0061] 1. After structural optimization, the efficiency and loss performance of the motor are greatly improved: the maximum efficiency is increased to 96.45%, and the operating efficiency is improved; the maximum iron loss is reduced to 1727.81W, a reduction of 3.9%, which effectively alleviates the heat dissipation pressure of high power density motors.

[0062] 2. Structural design balances efficiency improvement and torque output stability: While optimizing losses, the maximum output torque of the motor is 326.44 Nm and the maximum output power is 123.73 kW, with corresponding reductions of 2.7% and 0.32% respectively, both controlled within 5%, which is within the acceptable range for engineering applications; at the same time, the no-load cogging torque is reduced by 1.62%, further improving the smoothness of motor operation.

[0063] 3. Strong structural practicality and adaptability to industrial applications: The large hollow rotor and U+V type embedded permanent magnet structure design are compatible with existing processing technology and have the advantage of simple processing; the optimization logic and optimization strategy of the core structural parameters can be transferred to the design of similar motors, and the application scenarios are wide; and the application of the phased optimization strategy significantly shortens the structural optimization cycle, reduces the occurrence rate of structural interference, and improves the overall design efficiency.

[0064] In summary, this invention, through the collaborative structural design of permanent magnet 3 and magnetic barrier 4, precise optimization of 13 key parameters, and scientific optimization strategies, constructs a high-efficiency, low-loss, and performance-balanced rotor large hollow permanent magnet synchronous motor structure. This not only solves the problems of poor structural matching and difficulty in balancing performance in existing technologies, but also has the advantages of convenient processing and strong portability, providing an efficient and reliable structural solution for rotor large hollow permanent magnet synchronous motors for new energy commercial vehicles.

[0065] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A collaboratively optimized rotor structure for a permanent magnet synchronous motor, characterized in that, Includes rotor shaft, rotor core and permanent magnet; The rotor core is sleeved on the outer periphery of the rotor shaft. The rotor core is provided with magnetic barriers and permanent magnet slots. Multiple auxiliary slots on the rotor surface are provided on the outer side of the rotor core. The permanent magnet is embedded in the permanent magnet slot. A gap is left between the permanent magnet slot and the permanent magnet, and the gap is filled with epoxy resin potting compound.

2. The collaboratively optimized permanent magnet synchronous motor rotor structure as described in claim 1, characterized in that, The number of permanent magnet slots and permanent magnets are both multiple, and the number of magnetic barriers is also multiple. Every two permanent magnets and one magnetic barrier located inside the rotor core form a U-shaped arrangement, and every two permanent magnets located outside the rotor core form a V-shaped arrangement.

3. A multi-parameter design method for a co-optimized permanent magnet synchronous motor rotor structure, applied to the co-optimized permanent magnet synchronous motor rotor structure as described in any one of claims 1-2, characterized in that, include: The rotor of the large hollow high-efficiency permanent magnet synchronous motor adopts a large hollow structure, and the core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor are determined by finite element simulation. The permanent magnet and the magnetic barrier of the rotor yoke form a synergistic optimization structure, which corresponds to thirteen key structural parameters. Thirteen key structural parameters were divided into three groups of structural optimization parameters according to their significance level through partial factorial experimental design and analysis of variance. Then, a phased optimization strategy and a genetic algorithm were used to jointly optimize and determine the optimal combination of structural parameters, ultimately forming the globally optimal combination of structural parameters.

4. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 3, characterized in that, The core structural parameters of the large hollow high-efficiency permanent magnet synchronous motor include stator and rotor size parameters, permanent magnet installation arrangement, and suitable pole slot matching structure.

5. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 4, characterized in that, The stator and rotor size parameters include stator size parameters and rotor size parameters. The stator size parameters include the stator outer diameter, stator inner diameter, and key stator slot parameters. The rotor size parameters include the rotor outer diameter and rotor inner diameter. The permanent magnet installation arrangement is a U-shaped and V-shaped embedded arrangement structure. The pole slot matching structure is a combination of 72 stator slots and 8 rotor poles, which is an integer slot configuration.

6. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 5, characterized in that, The thirteen key structural parameters corresponding to the collaborative optimization structure include the magnetic barrier position, magnetic barrier width, magnetic barrier thickness, radial position of the first layer of permanent magnets, circumferential position of the first layer of permanent magnets, V-angle of the magnetic poles of the first layer of permanent magnets, width of the first layer of permanent magnets, thickness of the first layer of permanent magnets, radial position of the second layer of permanent magnets, V-angle of the magnetic poles of the second layer of permanent magnets, width of the second layer of permanent magnets, thickness of the second layer of permanent magnets, and width of the magnetic bridge of the second layer of permanent magnets.

7. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 6, characterized in that, The stator and rotor cores of the large hollow high-efficiency permanent magnet synchronous motor are both made of B27AHV1400, the rotor permanent magnets are made of N42UH, the stator windings are made of flat copper wire, the winding structure is an 8-layer distributed winding, and the winding pitch is set to 9.

8. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 7, characterized in that, The three sets of structural optimization parameters include first-stage optimization parameters, second-stage optimization parameters, and third-stage optimization parameters. The first-stage optimization parameters are the radial position of the second-layer permanent magnet, the thickness of the second-layer permanent magnet, the width of the first-layer permanent magnet, the V-angle of the magnetic poles of the second-layer permanent magnet, and the width of the second-layer permanent magnet. The second-stage optimization parameters are the thickness of the first-layer permanent magnet, the radial position of the first-layer permanent magnet, the position of the magnetic barrier, and the thickness of the magnetic barrier. The third-stage optimization parameters are the width of the magnetic barrier, the circumferential position of the first-layer permanent magnet, the V-angle of the magnetic poles of the first-layer permanent magnet, and the width of the magnetic bridge of the second-layer permanent magnet.

9. The multi-parameter design method for the rotor structure of a permanent magnet synchronous motor with collaborative optimization as described in claim 8, characterized in that, Thirteen key structural parameters were divided into three groups based on significance level through partial factorial experimental design and analysis of variance. Then, a phased optimization strategy and a genetic algorithm were used to collaboratively determine the optimal combination of structural parameters, ultimately forming the globally optimal combination. The three sets of structural optimization parameters were determined sequentially through phased optimization, with the optimization objectives being to maximize torque, maximize efficiency, minimize total loss, minimize copper loss, and minimize iron loss.

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