High Speed Permanent Magnet Motor Research Articles

Electromagnetic Optimization of a High-Speed Interior Permanent Magnet Motor Considering Rotor Stress

High-speed interior permanent magnet (IPM) motors require highly reliable rotors. Some measures must be adopted to improve rotor safety, but its electromagnetic performance is seriously affected. It is a challenge to achieve excellent electromagnetic characteristics while satisfying mechanical strength. This paper presents an electromagnetic optimization design of high-speed IPM motors considering rotor stress. Firstly, the permanent magnet (PM) is segmented by adding stiffeners to improve stress distribution. The effects of the bridge and stiffener thickness on the rotor stress and electromagnetic performance are analyzed. Secondly, an electromagnetic optimization model is built based on a three-segment PM rotor structure, aiming for maximum efficiency and minimum rotor core losses. Then, the initial design and optimized scheme are compared, the results show that the efficiency, safety and temperature performance of the motor are improved. Finally, a 140 kW, 18,000 rpm prototype is manufactured and tested. The above analysis provides a valuable reference for the design and widespread application of high-speed IPM motors.

Electromagnetic Optimization of a High-Speed Interior Permanent Magnet Motor Considering Rotor Stress

Electromagnetic Optimization of a High-Speed Interior Permanent Magnet Motor Considering Rotor Stress

Multi-Physical Field Analysis and Optimization Design of the High-Speed Motor of an Air Compressor for Hydrogen Oxygen Fuel Cells

The hydrogen oxygen fuel cell is a power source with significant potential for development. The air compressor provides ample oxygen for the fuel cell, and as a key component of the air compressor, the performance of the motor greatly impacts the efficiency of the fuel cell. In order to enhance the system performance of high-speed permanent magnet motors, optimization was conducted on the motor’s geometric dimensions to minimize rotor loss and maximize power density, taking into account the comprehensive constraints of electromagnetic and mechanical properties. The finite-element method was employed to analyze the motor’s performance, conducting a multi-physical field analysis that included electromagnetic field, rotor loss, and mechanical strength analysis, as well as temperature field analysis. Aiming at the problem of high temperature rise in high-speed motor winding, the influence of the cooling water flow rate on the winding temperature rise was analyzed and simulated. Based on the analysis results, the minimum cooling water flow rate was obtained. According to the optimized design results, a prototype of an 18 kW, 100,000 rpm motor was manufactured, and the efficiency and temperature rise were tested. The experimental results verify the correctness and effectiveness of the optimal design.

Comparative study of a high‐speed permanent magnet motor when powered by different methods

AbstractThe authors present the multi‐physical field performances comparative research for a 30 kW, 30,000 r/min high‐speed permanent magnet motor (HSPMM) when the motor is powered by the sinusoidal pulse width modulation (SPWM) voltage inverter and sinusoidal voltage source, respectively. Firstly, electromagnetic performances including torque, voltage and current of the HSPMM with different driving methods are compared and analysed by the finite element method (FEM). Considering the effects of high operation frequency, power losses of the HSPMM with different driving methods under full‐load conditions are calculated and compared with the skin effect and the proximity effect considered for HSPMM winding copper loss estimation. Based on the above analysis, a prototype driven by the SPWM voltage inverter is manufactured, with its electromagnetic and thermal performances tested and verified. In addition, several influencing factors of the HSPMM rotor eddy current loss are studied, with their effects on the HSPMM under different driving methods further analysed and compared as well. A novel equivalent power supply method is proposed to effectively save the calculation time with a negligible error. Finally, in order to further improve the heat dissipation capacity of the HSPMM, a novel cooling method is intensively studied with its influencing factors further analysed. The cooling effect of the novel cooling method and the temperature of the motor components are verified and calculated by the computational fluid dynamics (CFD) method.

Analytical Multi-Element Rotor Thermal Modelling of High-Speed Permanent Magnet Motors Accounting for Retaining Sleeve

Analytical Multi-Element Rotor Thermal Modelling of High-Speed Permanent Magnet Motors Accounting for Retaining Sleeve

Comparison of Toroidal and Tooth-Coil Winding 2-Pole Slotted High-Speed Permanent Magnet Motors

Comparison of Toroidal and Tooth-Coil Winding 2-Pole Slotted High-Speed Permanent Magnet Motors

Enhancement of local anti-demagnetization ability of permanent magnet by selected area grain boundary diffusion toward high-speed motors

The working environment of permanent magnets in high-speed motors is harsh, because they are seriously affected by multi-physical fields such as temperature, stress, weak magnetic control field, etc., and irreversible demagnetization is easy to occur under the extreme working conditions. In this work, a model of high-speed Interior Permanent magnet Motor is established, the easy demagnetization area of the permanent magnet is simulated by electromagnetic and thermal simulations to determine, and its local anti-demagnetization optimization is performed. Dy/Tb co-infiltration is carried out in the easy demagnetization region of the permanent magnets, and the process of selective zone diffusion is analyzed based on the principle of selective zone grain boundary diffusion. Through microscopic observation and macroscopic magnetic performance test, the effect of local anti-demagnetization performance enhancement of the optimized permanent magnets is verified. The results show that the magnetic properties of the optimized permanent magnets are obviously improved after the optimization of the selected zones. The present approach is important for the follow-up less heavy-rare-earth research of permanent magnet and its application in high-speed motors.

Research on intelligent control system of permanent magnet motor for high-speed flywheel energy storage system based on deep learning

With the continuous development of society, more and more people pay attention to energy issues, and the realization of energy storage has become a hot research direction today. Despite advancements, the control system of the high-speed flywheel energy storage system’s permanent magnet motor still encounters issues in effectively regulating the magnetic suspension bearing and motor speed. In addressing this issue, a technical solution involves the implementation of an intelligent control system for the high-speed flywheel energy storage system’s permanent magnet motor, utilizing deep learning principles. This innovative approach employs deep neural networks to model, optimize, and regulate the flywheel energy storage system. The essence of flywheel energy storage lies in the conversion of electrical energy into mechanical energy, followed by its reconversion into electrical energy during output. It has the advantages of high energy density, high power density, long cycle life, fast charging and discharging, maintenance-free and environmental protection. A permanent magnet motor is a motor that uses permanent magnets to generate a magnetic field. It has the characteristics of high efficiency, high power density, and low rotor loss. It remains the most widely utilized motor in flywheel energy storage systems. An intelligent control system is characterized by its use of artificial intelligence technology to adapt, self-learn, and self-organize complex systems. This system is distinguished by its robust nonlinear processing capabilities and resilience to faults. The high-speed flywheel energy storage system permanent magnet motor intelligent control system based on deep learning can improve the performance, efficiency and reliability of the flywheel energy storage system, reduce costs and risks, and is suitable for electric vehicles, rail transit, power grid frequency regulation and other fields. In this paper, the convolutional neural network and PSO algorithm are used to obtain the PSNN neural network structure to predict the speed of the motor, so as to achieve its control. And the reliability of the structure is verified by experiments.

A Discrete-Time Current Control Method for the High-Speed Permanent Magnet Motor Drive Using the Modular Multilevel Converter

High-speed permanent magnet motors (HSPMMs) have received attention in direct drive systems from the industry. Modular multilevel converters (MMCs) have become the most practical solution for HSPMMs in industrial applications due to the advantages of their highly modular structure, high-quality output and high reliability. In this article, the symmetrical discrete-time model of the MMC for the HSPMM drive is presented. Based on this symmetrical discrete-time model, the discrete-time current regulator has been designed. Moreover, the submodel (SM) capacitor energy balance models for MMC have been described, and the energy balance control scheme is introduced. Finally, the simulation and experimental results show that the presented discrete-time current regulator has a strong dynamic response at high speed (15 kr/min), and the SM capacitor voltage balance control is also achieved. Compared with the conventional PI current controller, the proposed discrete-time current regulator improves the current loop dynamic performance at high-speed, and the energy balance control scheme can ensure the SM capacitor voltage balance of the MMC.

Analysis and suppression of circulating current loss of high-speed permanent magnet motor

Analysis and suppression of circulating current loss of high-speed permanent magnet motor

Design and Optimization of High-Speed Permanent Magnet Motor Based on Artificial Neural Network

Design and Optimization of High-Speed Permanent Magnet Motor Based on Artificial Neural Network

Design and optimisation of high-speed permanent magnet motor based on artificial neural network

Design and optimisation of high-speed permanent magnet motor based on artificial neural network

Research Status of High-speed Permanent Magnet Motor Control System

In this paper, for the topology optimization design problem of low rotating iron consumption and high rotor strength high-speed permanent magnet motor and the high dynamic, high force-to-energy ratio and strong robust control problem of high-speed permanent magnet motor, we briefly introduce the research status of scholars at home and abroad on the two problems in order to realize the high-speed permanent magnet motor with low rotating iron consumption, high rotor strength, and fast dynamic response and to provide the basic conditions for further research.

Investigation on the Influence of Eccentricity on the AC Copper Loss of High-Speed Slotless Permanent Magnet Motor

The armature winding of slotless motor is directly exposed to the air gap magnetic field. During high speed operation, the effective part of the armature winding cuts the flux lines directly, which would inevitably cause large AC copper loss. Moreover, when the rotor is eccentric, appreciable distortions would be appeared in the air gap flux density. The additional flux density would aggravate the AC copper loss. In this paper, the mechanism of AC copper loss of high speed slotless motors is explained firstly. Then the influence of eccentricity on AC copper loss is evaluated. Finally, the difference in the effect of dynamic and static eccentricity on AC copper loss is compared.

Influence of Interference Fit and Temperature on High-Speed Permanent Magnet Motor

A high-speed permanent magnet motor is the core driving component of a centrifugal air compressor. The power of the centrifugal air compressor is output by the motor. Its safety and reliability are embodied in the stability of the rotor structure, which greatly affects the stability and working efficiency of the centrifugal air compressor. Much research has focused on the material strength, structural characteristics, and fit clearance of a high-speed rotor, whereas few research articles have focused on the influence of interference fit of high-speed and ultra-high-speed permanent magnet motors, and there is also little research on the thermal failure caused by temperature in high-speed motors. In this paper, the influence of the interference fit and temperature of the high-speed permanent magnet motor is studied. Using finite element analysis conducted by Ansys to obtain simulation data, the influencing factors of the strength of the interference are analyzed comprehensively in the centrifugal compressor rotor system. The interference value and rotational speed range are determined via numerical calculation. Under the condition of minimum interference, when the calculated speed reaches 137,628.82 rpm, the structure of the rotor is loose and fails, which is a mechanical failure caused by the relative sliding of the magnet and the sheath. The calculated speed value differs from the simulation result by about 1.2%. The simulation results show that the maximum stress of the structure can be reduced from 1186.1 MPa to 308.42 MPa by adding chamfer to the end covers in interference fit structure. The effects of interference value, rotational speed, temperature, and sheath thickness on the structure are also analyzed. From the perspective of temperature on structural reliability, the failure temperature of the structure decreases when the interference value increases. The lowest failure temperature is 182.3 °C when the interference value is 70 μm. After that, the interference value increases and the failure temperature increases. The reason for this is the interaction between radial stress and contact stress. These results are caused by the interaction between interference fit and temperature, which should be paid attention to when the structure of a high-speed permanent magnet motor is designed.

Study on fluid friction loss on rotor surface of FeCo based high speed permanent magnet motor

The linear speed of the rotor surface of high speed permanent magnet motor (HSPMM) is as high as 100 m/s, and the air friction loss on the rotor surface is much higher than that of ordinary motors, accounting for a large proportion of the total loss, and the actual air friction loss on the rotor surface is much higher than that of ordinary motors. It is extremely difficult to directly measure and verify the size of the rotor surface. At the same time, the air friction loss on the rotor surface is related to various factors such as motor speed, air gap structure and rotor surface roughness. It is difficult to accurately calculate through theoretical analysis and analytical methods. Based on the 3D fluid field physical model, this paper analyzes the relationship between the rotor air friction loss of FeCo based HSPMM and the rotor speed, rotor geometry, surface roughness and axial wind speed. Based on HSPMM, the calculation and test method of rotor surface air friction loss are studied. Through the FeCo based HSPMM no-load test, according to the relationship between the rotor air friction loss and other losses and the motor speed, the rotor surface air friction loss can be separated from the total loss. The experimental results are consistent with the calculated values, indicating that the HSPMM rotor air friction loss calculation method based on 3D fluid field analysis is effective.

Multi physical comprehensive design of a new type of FeCo based high speed permanent magnet motor

In order to solve the problem that the design of high-speed permanent magnet motor (HSPMM) is constrained by multi-physical fields, this paper starts with the comprehensive study of multi physical fields, introduces the finite element calculation model of rotor strength-rotor dynamics-electromagnetic field-fluid field and temperature field, carries out the comprehensive design of a 100 kW, 18 000 r/min FeCo based HSPMM, and gives the detailed and complete research process of the main parameters of HSPMM under multi-physical field constraints. First, the initial dimensions of the motor are obtained by electromagnetic and mechanical design theory. Secondly, the influence of design parameters on rotor stress is analyzed in detail, including the influence of bearing rigidity, impeller mass, rotor diameter, rotor core length and gyroscopic effect on critical speed. Subsequently, the electromagnetic characteristics of the motor are comprehensively studied, the cooling system is designed in the Flow-Heat coupling calculation model and the temperature field is studied. Finally, the prototype test verifies the correctness and validity of the comprehensive research method of multi physical field.

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.