High Speed Permanent Magnet Motor Research Articles

Research on Rotor Sleeve Winding Techniques for High-Speed Permanent Magnet Motors via NOL Ring Testing

Surface-mounted high-speed permanent magnet motors are known for their small size, high power factor, and reliable control and operation. However, these motors may have low mechanical strength and weak tensile strength in their rotor magnet, which necessitates the adoption of an external sleeve for protection. Currently, carbon fiber composite sleeves are garnering increasing attention for their durable and reliable protective capabilities. Despite the apparent benefits of carbon fiber composite protective sleeves, systematic research on the relevant parameters such as winding angle, fiber type, resin type, winding tension, and curing method is currently lacking in the literature for high-speed permanent magnet motors. In this context, this paper employs an innovative approach, utilizing the Taguchi method, the National Ordnance Laboratories (NOL) ring failure test, and a resin content test, to investigate the winding process parameters of carbon fiber composite protective sleeves for high-speed permanent magnet motors. The results indicate that the tensile strength of the composite sleeve with a winding angle of 45 and 30° is reduced by 20~25% compared with the sleeve with a pure hoop winding angle. The loss of strength caused by the manufacturing process accounts for 30%. When the wet winding tension is 130 N, the tensile and shear strength of the sleeve decreases by 13 and 12%, respectively, compared with that of 70 N. When the dry winding temperature rise rate is 3 min/°C, the strength of the sleeve decreases by 16% compared with that of 1 min/°C. For a small-thickness sleeve with a thickness of 1.5 mm, two-layer curing can increase the tensile strength of the sleeve, while three-layer curing or more can decrease the strength. By studying the process parameters of the sleeve, this article prepared a composite sleeve for a high-speed permanent magnet motor with a line speed of 200 m/s. This study provides a comprehensive analysis of the manufacturing process parameters of the rotor sleeve, which is helpful for the design and performance optimization of high-speed permanent magnet motors.

Design and analysis of a high loss density motor cooling system with water cold plates

Aiming at reducing the difficulty of cooling the interior of high-density motors, this study proposed the placement of a water cold plate cooling structure between the axial laminations of the motor stator. The effect of the cooling water flow, thickness of the plate, and motor loss density on the cooling effect of the water cold plate were studied. To compare the cooling performance of water cold plate and outer spiral water jacket cooling structures, a high-speed permanent magnet motor with a high loss density was used to establish two motor models with the two cooling structures. Consequently, the cooling effects of the two models were analyzed using the finite element method under the same loss density, coolant flow, and main dimensions. The results were as follows. (1) The maximum and average temperatures of the water cold plate structure were reduced by 25.5% and 30.5%, respectively, compared to that of the outer spiral water jacket motor; .(2) Compared with the outer spiral water jacket structure, the water cold plate structure can reduce the overall mass and volume of the motor. Considering a 100 kW high-speed permanent magnet motor as an example, a water cold plate cooling system was designed, and the temperature distribution is analyzed, with the result indicating that the cooling structure satisfied the cooling requirements of the high loss density motor.

Loss Analysis of High-Speed Permanent Magnet Motor for Cordless Vacuum Cleaner

Compared with traditional permanent magnet motors, high-speed permanent magnet motors (HSPMM) have the advantages of fast dynamic response, high efficiency, high reliability, small size, etc. Therefore, HSPMM has been widely used in household and industrial fields, and the research on high-speed permanent magnet motors has become a hot spot in the motor industry. In this paper, the high-speed permanent magnet motor is applied to the cordless vacuum cleaner, and the calculation and analysis of the iron loss and copper loss of the high-speed permanent magnet motor are emphatically studied for the HSPMM used in the cordless vacuum cleaner.

Loss analysis of high-speed permanent magnet motor based on energy saving and emission reduction

In recent years, with the increasing consumption of resources around the world, motors in various industries are also urgently added to the ranks of energy saving and emission reduction. High-speed permanent magnet air compressor is widely used in various new energy vehicles. The study on its loss can provide reference for motor manufacturing industry. In this paper, the 27 kW, 90000 r/min high-speed permanent magnet air compressor is studied and analyzed. Taking 0.1 mm thick silicon steel sheet as an example, two different kinds of silicon steel sheet materials were compared and analyzed through the study of stator core loss. At the beginning of the design of the motor, the material was tested, and the good performance, low carbon and environmentally friendly material was used in the design and manufacture of the motor, which played a good role in the stable operation of energy saving and emission reduction and the motor. The high-speed motor uses frequency converter for power supply, and its characteristics of large harmonic content and high frequency lead to the increase of rotor eddy current loss. Therefore, the analytical calculation method of rotor eddy current loss is derived. This method establishes the physical model in polar coordinate system, and considers the sub domains such as air gap, sheath and permanent magnet. A prototype and an experimental platform were made to study the influence of harmonics on the motor. In this paper, the actual output current harmonics with IGBT and SIC as controllers are studied by comparative method. The actual output current is collected and applied as excitation to the 2D finite element model of motor for analysis and calculation. Finally, the influence of motor loss is analyzed comprehensively, which has reference value for each motor manufacturing enterprise.

Friction Loss Calculation and Thermal Analysis of Submerged Low Temperature High Speed Permanent Magnet Motor

Friction Loss Calculation and Thermal Analysis of Submerged Low Temperature High Speed Permanent Magnet Motor

Rotor Design and Optimization of High-Speed Surface-Mounted Permanent Magnet Motor Based on the Multi-Physical Field Coupling Method

Rotor Design and Optimization of High-Speed Surface-Mounted Permanent Magnet Motor Based on the Multi-Physical Field Coupling Method

Rotor Stress Analysis of High-Speed Surface-Mounted Permanent Magnet Motors with Segmented Poles Considering Fillings

Rotor Stress Analysis of High-Speed Surface-Mounted Permanent Magnet Motors with Segmented Poles Considering Fillings

Investigation of Optimal Split Ratio of 6-Slot/2-pole High Speed Permanent Magnet Motor with Toroidal Winding

Split ratio, i.e. the ratio of stator inner diameter to outer diameter, has a closed relationship with electromagnetic performance of permanent magnet (PM) motors. In this paper, the toroidal windings with short end-winding axial length are employed in the 6-slot/2-pole (6s/2p) PM motor for high speed applications. The split ratio is optimized together with the ratio of inner slot to outer slot area, i.e. slot ratio, considering stator total loss (stator iron loss and copper loss). In addition, the influence of maximum stator iron flux density and tooth-tip on the optimal split ratio, slot ratio, and average torque is investigated. The analytical predictions show that when the slot ratio is 0.5, the maximum torque can be achieved, and the optimal split ratio increases with the decrease of slot ratio, as confirmed by the finite element (FE) analyses. Finally, some of predicted results are verified by the measured results of 6s/2p prototype motor with 0.5 slot ratio.

Optimal design of a rotor sleeve for a surface-mounted high-speed permanent-magnet motor with a multi-dimensional visualization strategy

Optimal design of a rotor sleeve for a surface-mounted high-speed permanent-magnet motor with a multi-dimensional visualization strategy

Convection Heat Transfer Coefficient Regression Models Construction for Fast High-Speed Motor Thermal Analysis

This article proposes a computationally efficient thermal study method that substitutes computational fluid dynamics (CFDs) with a finite-element analysis (FEA) involving minimal loss of accuracy and omission of the increased computational load. The suggested technique contributes toward the realization of multiphysics optimization of high-speed electrical machines that effectively includes critical thermal evacuation phenomena. The strategy is regression-based and succeeds in constructing convection coefficient regression models that typically involve many variables and small training datasets. The proposed scheme is verified in high-loss density and high-speed outer rotor surface-mounted permanent magnet (SMPM) motor geometries that an optimization algorithm typically encounters during execution. The reference target specifications correspond to 20 kW output power, 15k r/min rotating speed, and 2 kHz electrical frequency.

Research and Analysis on Design Characteristics of High-Speed Permanent Magnet Claw Pole Motor With Soft Magnetic Composite Cores for Wide Temperature Range

As the operating temperature of the motor increases, the material properties will be seriously affected, such as soft magnetic materials, hard magnetic materials, and winding insulation properties. For high-speed permanent magnet motors, the higher loss density and smaller heat dissipation area make the impact of temperature more serious. However, according to the test standard, the magnetic properties are usually measured at room temperature, ignoring the effect of temperature. To accurately design magnetic devices, it is necessary to understand the behavior of magnetic materials at different temperatures. In this article, a new high-speed permanent magnet claw-pole motor with soft magnetic composite for a wide temperature range is proposed. The design process mainly includes the calculation and analysis of material temperature characteristics, bearing support, topological structure, rotor stress calculation, and so on. Finally, a prototype is manufactured and tested to verify the design process.

Health diagnosis of permanent magnets under different cooling system effectiveness in high-speed permanent magnet motors for electric vehicles

Health diagnosis of permanent magnets under different cooling system effectiveness in high-speed permanent magnet motors for electric vehicles

Discussion on the Design Technology of High-speed Permanent Magnet Motor

Discussion on the Design Technology of High-speed Permanent Magnet Motor

Study on Calculation Model of High Speed Machine Silicon Steel Sheet Electromagnetic Characteristics Considering Magnetic, Stress and Temperature Condition

High-speed motor has the characteristics of high frequency, high temperature, and more stress, resulting in the field distribution inside the motor being complicated. To better study the electromagnetic characteristics of silicon steel sheet for high-speed motor. In this article, a study on the calculation model of silicon sheet electromagnetic characteristics considers the effects of electromagnetic, stress, and temperature factors. The study is divided into two parts, one is to propose the calculation model of silicon steel sheet's permeability; the other is to improve the calculation model of silicon steel sheet's loss. Then, the magnetic field, stress field, and temperature field of a surface mount high speed permanent magnet motor (SMHSPMSM) are analyzed by finite element method (FEM), and the results under the consideration of magnetic, stress, and temperature factors are brought into the calculation model for calculation. Finally, the accuracy of the calculation model for electromagnetic characteristics of silicon steel sheet is verified by comparing the calculated results with the finite element results.

Optimization Design of High-speed Interior Permanent Magnet Motor with High Torque Performance Based on Multiple Surrogate Models

In order to obtain better torque performance of high-speed interior permanent magnet motor(HSIPMM) and solve the problem that electromagnetic optimization design is seriously limited by its mechanical strength, a complete optimization design method is proposed in this paper. The object of optimization design is a 15kW, 20000r/min HSIPMM whose permanent magnets in rotor is segmented. Eight structural dimensions are selected as its optimization variables. After design of experiment(DOE), multiple surrogate models are fitted, a set of surrogate models with minimum error is selected by using error evaluation indexes to optimize, the NSGA-II algorithm is used to get the optimal solution. The optimal solution is verified by load test on a 15kW, 20000 r/min HSIPMM prototype. This paper can be used as a reference for the optimization design of HSIPMM.

Analysis of Load Loss Characteristics of FeCo Alloy High Speed Permanent Magnet Motor

In order to study the change law of loss and efficiency of high-speed permanent magnet motor (HSPMM) under load after using FeCo_B800 alloy material instead of silicon steel sheet DW310_35 material to make iron core, two FeCo_B800 stator materials with the same structure and size parameters were developed. HSPMM and HSPMM of silicon steel DW310_35 stator material. The loss and efficiency characteristics of the two motors under the same operating conditions were tested by the experimental method, and the losses of the two motors at different load rates were compared and analyzed by means of the finite element method. The research results show that at light load, the FeCo_B800 motor stator core loss is lower than the DW310_35 silicon steel sheet motor, and the efficiency advantage is very obvious; however, with the increase of the load rate, the FeCo_B800 motor stator core is seriously saturated, resulting in the distortion of the winding magnetomotive force waveform. The loss caused by the harmonics of the winding magnetomotive force is higher than that of the DW310_35 silicon steel sheet motor, and the efficiency advantage of the FeCo-B800 motor gradually decreases with the increase of the load rate.

Design and Analysis of the High-Speed Permanent Magnet Motors: A Review on the State of the Art

This paper provides an overview of the design and analysis of high-speed PM motors by focusing on prominent issues such as motor losses, temperature rise, rotor strength and vibration. The design challenges of high-speed PM motors are briefly described, and the application of various stator and rotor structures and materials is presented in electromagnetic design. Combined with the temperature distribution of the motor, various heat dissipation measures to suppress the temperature rise are summarized. Strength and dynamics analysis of the rotor are outlined with respect to the safety of rotor operation. The current status of coupled multi-physics domain design used to improve the comprehensive design capability of high-speed PM motors is reviewed. Future directions of technologies related to the design of high-speed PM motors are pointed out.

Rotor Investigation of High-Speed Permanent Magnet Motor with Roundness Error and CFD-Thermal Distribution Analysis

The rotor overtemperature caused by losses is one of the important issues for the high-speed electrical machine. This paper focuses on the rotor loss analysis and CFD-thermal coupling evaluation for 105 kW, 36,000 r/min HSPMSM. Three types of sleeve materials as carbon-fiber, Titanium alloy, and stainless steel are introduced in this paper, researching the effects of sleeve conductivity, thickness and rotational speed on rotor eddy current loss, balancing rotor mechanical strength. The sleeve made of titanium alloy material with a thickness of 3.5 mm is chosen to effectively suppress the rotor eddy current loss in high-speed motors in the paper. The air friction loss becomes significant based on the PM motor at high rotational speed. The roundness error of the rotor sleeve has the important impact on the air friction loss of the rotor and the rotor temperature of the motor, which leads to the over temperature of the rotor. Therefore, based on the CFD fluid model, the influence of roundness error, cooling parameters, rotational speed and temperature boundary on the air friction loss is studied in detail, and the expression is summarized to provide reference for estimating the air friction loss. According to the rotor structure in this paper, the optimal cooling air inlet velocity is 10 m/s. Finally, the loss separation method is used to obtain the air friction loss measurement results. The accuracy of the finite element calculation results of air friction loss is verified through the experimental data. The temperature rise of the HSPMSM was also measured with 5.5% error. In this paper, the conclusion and analysis method could provide some reference for the research of the rotor structure and the improvement of the efficiency of HSPMMs.

Comprehensive Design and Analysis of Rotor Stress for HSPMM Considering Cooling Method

In the design process of a high-speed motor, a reasonable rotor stress analysis is a necessary prerequisite to guarantee its safe and reliable operation. In this paper, the comprehensive design and analysis of the rotor stress of a 200 kW 20,000 r/min high-speed permanent magnet motor (HSPMM) with magnetic bearing are carried out. Firstly, the stress distribution characteristics of rotors with different permanent magnet structures and different thermal expansion coefficients of filling materials are analyzed and compared. Secondly, the rotor design is determined through a comprehensive comparative analysis of different sleeve thicknesses and shrink fit. Furthermore, considering the axial temperature gradient due to the axial ventilation cooling method adopted by the prototype, the rotor stress is checked through the coupling calculation of fluent and static stress. Finally, several long-period running tests are carried out, showing the good agreement between the calculated and measured results, and the safe and reliable operation of the prototype verifies the correctness of the above theoretical analysis.

Rotor Strength Analysis of FeCo-Based Permanent Magnet High Speed Motor

To solve the problem of tension stress caused by centrifugal force and caused by high-speed operation of permanent magnet (PM) rotor, a FeCo-based PM rotor structure model is proposed. Based on the thick-walled cylinder theory, the uniform analytical calculation formulas of strain field, displacement field, and stress field of high-speed permanent magnet rotor are derived, and the stresses of FeCo-based PM and sleeve are obtained. The correctness of analytical calculation method (ACM) is verified by finite element method (FEM). Based on the derived analytical formula, the influence of static interference, sleeve thickness, rotating shaft, and PM thermal expansion coefficient on the strength of high-speed permanent magnet rotor is analyzed, and the mechanical design law of high-speed permanent magnet rotor is summarized. Alloy sleeves are usually fitted outside the high-speed permanent magnet rotor to protect the PM from damage. In order to ensure safe operation of PM rotor under hot rotating conditions, strength calculation and check of sleeve and PM must be carried out. Based on the characteristics of slender structure of high-speed rotor, a high-speed permanent magnet motor (HSPMM) with a rated power of 100 kW and a rated speed of 18,000 r/min was produced, and a continuous operation test was carried out to verify the validity of the above theoretical analysis.