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Transverse linear switched reluctance motors (TLSRMs) are generally challenged by high-force ripples that contribute to a lower average propulsion force. This undermines the overall efficiency of the TLSRM in various industries. This paper presents structural modifications to improve the force performance of a TLSRM for transit applications. In this new design, a split-teeth stator design was proposed to virtually increase the number of stator teeth without increasing the number of translator teeth. The proposed TLSRM contains a movable translator with 16 poles for direct transmission with no gear mechanism. A hybrid TLSRM design method is presented, modifying the conventional design method to accommodate these structural modifications. A specific power output equation for the proposed motor was derived by correlating the force, power, and physical dimensions. The proposed motor was designed and analyzed using the FEM software to ensure the accuracy of the design.

In this paper, topology optimization of the rotor flux-barrier of an interior permanent magnet synchronous motor using a normalized Gaussian network is proposed to improve traction in a hybrid electric vehicle. The flux-barrier that impacts on the electromagnetic performance such as average torque, torque ripple and power is important in the design of electromagnetic motors. The normalized Gaussian network was used to obtain the shape of the optimal flux-barrier, and the weighting coefficients used in this method were optimized using a genetic algorithm. To prevent indiscriminate creation of the flux-barrier, the design region was divided into detailed subregions. The weighting coefficients were generated using different methods in each subregion. In addition, to increase the mechanical stability of the shape by eliminating unstable shapes, the post-processing is performed. The superiority of the performance due to optimizing the topology was confirmed, with the average torque increased by 8.43% and the torque ripple decreased by 20.07%p. The mechanical stability of the optimal shape is verified by conducting stress analysis.

This paper proposes the optimization algorithm, an adjusted evolution strategy (AES) and verifies performance of the AES applying the optimal design of the outer-rotor surface mounted permanent magnet synchronous motor (SPMSM) for unmanned aerial vehicle. The proposed algorithm improved disadvantage of the conventional evolution strategy, which requires long computation time when solving the optimization problem, utilizing an exponential function of the annealing factor. In addition, the AES further enhances the convergence characteristic by combining with the compass segment method which is deterministic algorithm. This paper shows that the superiority of AES over NGA and ES in three test functions, with 30% to 70% reduction in the number of function calls, and an improvement of 5%p to 30%p in the convergence accuracy. Finally, the AES is applied to the optimization design of the outer-rotor SPMSM, and this paper derived the optimal model of the SPMSM to increase average torque and reduce torque ripple that causes vibration in unmanned aerial vehicle. As a result, proposed algorithm successfully derived the optimal model and verified the robustness. Therefore, the results of this study are expected to be widely applied to the multimodal optimization problem of various electrical machines utilizing FEM.

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study proposes an optimization methodology for automotive permanent-magnet synchronous motors (PMSMs) to achieve maximum efficiency, maximum average torque, and minimum torque ripple. Many geometrical parameters can be used to define the PMSM of an automobile. To identify the most significant parameters for optimization, the fractional factorial design of the design of experiment (DOE) was employed for screening, considering the interaction effects. The central composite design was used to construct the proxy model between the optimization target and optimization variable, and the effectiveness of the model was judged. Aiming at the multi-objective optimization problem of a motor, a new mechanism for grey wolf optimizer (NMGWO) algorithm combining an elite reverse learning strategy, a local search strategy, and a nonlinear control parameter strategy is innovatively proposed. This algorithm was applied to solve the multi-objective optimization model. The numerical calculation results show that this is an effective optimization design method that can improve the performance of automotive PMSMs. The effectiveness of the NMGWO algorithm on the optimization results of permanent-magnet synchronous motors is verified by the experimental results. [ABSTRACT FROM AUTHOR]

To realize the omni-directional steering function of urban micro electric vehicle and avoid the defects of traditional multi-degree-of-freedom (multi-DOF) drive, a multi-DOF spherical induction motor (SIM) as hub motor is presented, which is used to replace the conventional wheel and steering system to drive vehicles directly. SIM is mainly composed of three arc-shaped stators and one spherical rotor. And torque is directly output from the surface of the spherical rotor. The structure parameters of SIM are determined based on the design methodology of linear induction motor (LIM), and a finite element model (FEM) is established. Meanwhile, the field-oriented control (FOC) system of SIM is designed, and a multiple physics field co-simulation platform is constituted. By electromagnetic transient simulation and co-simulation, the effectiveness of structure parameters and FOC system are verified systematically. To realize the multi-dimension drive of SIM, the torque model is analyzed, and a multi-DOF drive control strategy is proposed, which is realized by mathematical modeling. The results indicate that SIM can achieve two rotational DOF drive without the angle limitation, and the control system has appropriate dynamic and tracking performances. The design scheme and control strategy proposed are reasonable. [ABSTRACT FROM AUTHOR]

This paper proposes a method that combines random forest technology (RF) and a genetic algorithm (GA) for optimal design of traction motors for electric vehicles (EVs). The target motor is a permanent magnet assisted synchronous reluctance motor (PMa-SynRM), for which the design goal is to increase the average torque and efficiency while reducing the total harmonic distortion (THD) of the line-to-line back electromotive force (LtoL BEMF) and torque ripple. The superiority of the RF technology was verified by comparison with other machine learning methods through two mathematical test functions. Prediction accuracy was improved through hyperparameter tuning using the GridSearchCV technique. The design variables, selected for the optimal design of the target application, were proved to be an influential variable through sensitivity analysis techniques. Finally, stress analysis, thermal analysis, and irreversible demagnetization analysis were conducted to prove the validity of the selected optimal design. The applicability of the proposed method was verified by increasing the average torque by 12.92% and reducing torque ripple, cogging torque, and LtoL BEMF THD by 36.01%, 50.0%, and 4.58% respectively.

The need for alternate transportation is driven by the increased fossil fuel cost and the adverse effects of climatic change. Electric vehicles (EVs) are the best option as they have less carbon footprint and reduced dependency on fossil fuels. Prodigious efforts to enhance the efficiency of EVs resulted in the development of highly efficient three-phase induction motors. Difficulties in designing highly efficient induction motors (IM) with high torque and power factors hindered the success of EV applications. Hence, our aim is to diagnosis fault in the designed IM under variable load conditions. The proposed EV motor is designed for 415V, 50Hz, and 5HP output power rating using ANSYS RMxprt simulation software. A fault detection strategy is also implemented with various machine learning (ML) techniques like Support Vector Machine (SVM), K-nearest neighbors (k-NN), ML perceptron (MLP), Random Forest (RF), Decision Tree (DT), Gradient boosting (GB), Extreme Gradient Boosting (XGBoost), and Deep Learning (DL) for both healthy and faulty conditions. Short Circuit (SC), High Resistance connection (HRC), and Open-Phase circuit (OPC) are considered as faulty states for this study. Motor performance with variable load for all the states healthy and faulty are evaluated through machine learning.

This work presents finite element analysis, design, and construction of an improved linear switched reluctance motor for elevator application. In the proposed motor, both stator and translator have separate poles; thus, the motor is lighter and more appropriate for vertical motion applications. In addition, the proposed structure has low core losses due to the separate and short magnetic paths. The only set of windings is placed on stator poles while the translator has no winding or permanent magnet. In order to broaden the positive force region, non-uniform air-gap is designed and optimized via non-dominated sorting genetic algorithm. Finite element analysis and experimental tests of the motor are performed and characteristics of the proposed structure are compared with a previous structure in the elevator application. Finite element analysis have been done in ANSYS software.The results confirm that the proposed linear motor has higher average force with an acceptable ripple in force.

This study has designed a set of motor operating devices for a 126 kV vacuum circuit breaker (VCB) to improve its reliability and controllability. A finite‐angle permanent magnet brushless motor (FAPMBM) with a multi‐slot stator structure and a dovetail rotor structure has been designed based on the torque and speed requirements of the motor. These requirements were determined by a dynamic analysis of the operating device and its short‐time, finite‐angle working characteristics. The work performance of the prototype motor has been evaluated in an online experiment with a 126 kV VCB, and based on this, a segmented control method has been designed. The motion process of the operating device has been divided into four stages in combination with the output torque demand of the driving motor. At each stage, the output torque of the motor has been changed dynamically to prevent contact collision, shorten the pre‐breakdown time, and make the circuit breaker work more reliably. The results show that the FAPMBM can meet the operating time and speed requirements of the interrupter for the operating device. In addition, the segmented control method improves the work reliability and optimizes the movement of the operating device, which helps the circuit breaker work intelligently. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electromagnetic torque and eddy current loss are two important indexes of permanent magnet synchronous motor. Under the limited conditions of volume, effectively improving electromagnetic torque and reducing rotor eddy current loss are the key for motor design. In view of this problem, the analytical method is used to calculate the electromagnetic torque and eddy current loss respectively, and the PSO algorithm is used to optimize the size parameters of the motor. The analytical model includes armature reactive magnetic field and no-load magnetic field model. When calculating eddy current loss, eddy current reaction and circumferential segmentation of permanent magnet are considered. The objective function of the optimization algorithm uses weight values to convert multi-objective into single objective. The comparison between the analytical solution and the time-stepping finite element numerical solution shows that the error of the analytical solution is about 2%. The response surface of parameter influence analysis reveals that the correlation between electromagnetic torque and eddy current loss is consistent when the stator winding pitch is 25°. The optimization iteration results show that the optimized design reduces the average eddy current loss by 76%, the average electromagnetic torque by 22%, and the electromagnetic torque ripple by 68%. [ABSTRACT FROM AUTHOR]

Refuse-collecting vehicles are significant polluters due to their expected drive cycles involving frequent stops and long idle periods. Electric refuse-collecting vehicles, still in their infancy, promise to address this through the replacement of internal combustion engines with batteries and electric traction motors. Today, typical motors for these vehicles involve heavy use of rare earth permanent magnets, which are subject to high price volatility, environmentally damaging mining practices, and occupational health hazards associated with refinement. The switched reluctance motor, which makes use of no permanent magnets, is a suitable substitute. This type of motor technology offers several advantages such as simple and robust construction, the ability to operate at high speeds and high temperature conditions, fault tolerance capability, and lower production costs in comparison with other technologies. This paper focuses on the design process of a switched reluctance motor for a battery electric refuse-collecting vehicle. The designed motor has a 36/24 outer rotor configuration, and its electrical and mechanical characteristics are based on the commercial traction motor TM4 SUMO HD HV3500-9P. The performance of the motor is evaluated using simulation tools such as JMAG and MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

To improve the quality of starting torque and suspension force, a composite cage rotor bearingless induction motor (CCR-BIM) is designed, which adopts a composite cage rotor structure that combines an inner rotor and an outer rotor. First, the overall structure of the CCR-BIM is designed, the composite cage rotor of the CCR-BIM is specially designed and analyzed for the induction principle, and the mathematical model of suspension force and torque is deduced. Second, the initial structural parameters are determined, and motor qualities, such as starting torque quality and suspension force quality, are compared and analyzed between the proposed motor and BIM using a finite element model (FEM). Third, based on the response surface model (RSM), a multi-objective improved NSGA-II is constructed, and the three optimization objectives of starting torque, suspension force, and suspension force pulsation are optimized. Finally, the results of the experimental setup prove that the starting torque increases by 6.98%, the suspension force increases by 5.45%, and the suspension force pulsation decreases by 18.54%. The effectiveness of the proposed motor and the correctness of the multi-objective optimization strategy are verified. [ABSTRACT FROM AUTHOR]

Aiming at the defects of long axial dimension and low torque density in the radial flux permanent magnet motor used in the electric drive joint of the existing quadruped robot, based on the performance index requirements of the electric drive joint for the motor, an electromagnetic design scheme of an axial flux permanent magnet synchronous motor with a double stator and single rotor structure was proposed. The three-dimensional finite element model of the motor was established using Maxwell software, and the electromagnetic simulation analysis was carried out. The simulation results show that the rated power of the axial flux permanent magnet motor is 260 W and the rated output The torque is 2.53 N·m, the motor efficiency is 85.36%; the peak power is 630 W, and the peak torque is 7.52 N·m. The simulation results meet the requirements of motor performance indicators. The torque analysis of the axial flux permanent magnet motor and the radial flux permanent magnet motor under the same working conditions, the output torque of the axial flux permanent magnet motor is higher than that of the radial flux permanent magnet motor. The electromagnetic solution of the axial flux permanent magnet motor provides a new idea for the design of the high torque density and high power density of the quadruped robot electric drive joint motor. [ABSTRACT FROM AUTHOR]

In recent years, the mobility sector is undergoing a revolution, which is resulting also into a worldwide spread of light electric vehicles, such as electric scooters and bicycles. The increasing public concern about environmental problems further feeds this revolution. Electric-bicycles (or e-bikes) are a new trend which fits different riders' needs. In fact, they offer extended range and ease of use, allowing riders to travel in urban centres, but also to take longer trips. E–bikes are reliable, easy to ride, affordable, and they help people live and travel a little greener, with a great benefit for their health. Many Companies (such as Brose, Bafang, Bosch and Shimano) developed performing e-bike motor drives. However, there is not a detailed general procedure to help the choice and design of electric bikes, in particular concerning the electric machine. This review focuses on the analysis of different motors for e-bike application. First, the e-bike system state of art is presented. The pedal-assist and power-on-demand e-bike system typologies are presented, together with the most popular parallel configuration and the less common series configuration. Further on, the environmental resistances are analysed for a traditional bicycle system and then the force balance is extended to the electric vehicle example. The most common Lithium-ion battery and the battery management system state of art is discussed, presenting design schemes and typical performances. Concerning the electrical machine, some electromagnetic design approaches are described, together with some data on commercial motors. Finite element analysis of a common motor model is carried out and some experimental tests are presented to highlight their capabilities. Different control strategies are compared, including innovative solutions and new trends. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Digest is the property of Automotive Digest Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Linear switched reluctance motor (LSRM) and its applications in different industries have been an interesting research topic for the past few years. LSRMs have proved to be a suitable alternative in a variety of applications requiring linear motion. However, its use is not that popular which instigated an active interest in the evolution of newer LSRM configurations. Enhancement in its propulsion force along with the reduction in force ripples, weight, acoustic noise, and vibration have been the main objectives in recently proposed LSRM designs. In this paper, recently proposed LSRM designs are reviewed and analyzed. The paper presents a one-stop introduction and a complete update to the designs, both in terms of qualitative and quantitative parameters. In addition, it takes into account the challenges in the implementation of these designs. Based on a detailed comparison of these designs as presented in this paper, an appropriate design can be chosen for a given application.

This work deals with minimizing fluctuations of propulsion force and improving the motion quality in a linear switched reluctance motor. In order to minimize the jerks in the moving part of the motor, a new profile is used to generate an appropriate reference speed profile. Then, a simple fuzzy logic system which is able to overcome the uncertainties problem in nonlinear systems is designed and applied to the motor. The fuzzy control system can regulate the motor performance so that it tracks the reference speed with minimum error and fluctuation. The system is designed and its efficiency is shown through simulation and experimental tests in different performance situations. The obtained results confirm that the proposed strategy outperforms other conventional methods. [ABSTRACT FROM AUTHOR]

The hybrid-excitation permanent magnet (HEPM) motor is a synchronous motor characterized by a rotor that includes both permanent magnets and excitation windings. Thus, an active change in the magnetic flux by means of the excitation current is possible. In particular, the hybrid-excited rotor studied in this paper can be used to change the number of poles of the rotor itself. At the same time, the stator winding is also designed to perform a polarity change. The change in polarity allows users to obtain different torque versus speed characteristics with the same motor. In particular, a configuration with a lower pole number exhibits low torque at high speeds, while a configuration with a higher pole number produces high torque at low speeds. In this way, a single HEPM motor behaves like two different machines, extending the usual operating speed range of synchronous motors. In this paper, an HEPM rotor configuration is designed, and its performance is analyzed through finite element electromagnetic and thermal simulations. [ABSTRACT FROM AUTHOR]

The transportation sector is the second largest energy consumer and is growing every year. Electric Vehicles (EVs) driven by electric motor reduces the usage of fossil fuels. Induction Motors (IMs) are particularly gaining attention in the EV world for their advantages over traditional motors, such as flexibility in control, low material cost, and superior ventilation and cooling. However, machine designers face difficulties in designing EV IM with higher efficiency, power factor, and high torque with good performance and operational features. The Squirrel Cage Induction Motor (SCIM) can provide a compact design through the choice of proper materials. This paper proposes choice of material and design of IM for EV application. The design and analysis process uses the ANSYS RMxprt and Maxwell simulation software. The proposed model for EV is designed with 415 V, 50 Hz, and 5 HP output power. The design process focuses on comparative analysis of the core and winding materials using Finite Element Analysis (FEA) in ANSYS Maxwell. The performance of designed motor is analysed under both healthy and faulty conditions. The results obtained using ANSYS Maxwell indicate that the design is effective and accurate.

Single-phase induction motors (SPIMs) are commonly used in domestic and industrial applications because of their robustness, low power rating, and simple input power requirement. Due to their widespread application, the dynamic performance and efficiency at the operating point have become vital to ensure energy conservation. This paper is aimed to optimise both the dynamic performance and efficiency of SPIM for water pump application at rated speed. Multi-objective optimisation is performed by employing the genetic algorithm using a Maxwell-2D transient solver. The analysis presents the comparison between the optimised and basic motor designs while considering various manufacturing constraints. The study proposes a framework for performance enhancement of SPIM while verifying the optimal solution through sensitivity analysis. The obtained results show the high performance of optimised SPIM design with a 17% increase in efficiency compared to the basic motor. [ABSTRACT FROM AUTHOR]

In this article, we propose an interactive visualization method for motor design. We have proposed a visualization system for education using augmented reality (AR) and virtual reality (VR). As a further development of this, we are working on motor design as an industrial application. There are two issues in achieving high-speed interactivity. One is a fast mesh modification method in finite element analysis, and the other is a fast solving method. We propose a high-speed mesh modification method that utilizes regularly arranged grid points and coordinate transformation. In the proposed design system, the user can immediately observe the analysis result of the design change. Furthermore, if the proposed system is executed in cooperation with the projector, designers can change the design of the motor with their fingers and discuss it on the board. Furthermore, since this system can be executed on a Web browser, it can also be executed on a smartphone or tablet PC. [ABSTRACT FROM AUTHOR]

In this paper, the AC copper losses in classical random windings are investigated and mitigated using several techniques across a range of permanent magnet synchronous motor designs. At high operating frequencies, AC copper losses can represent a substantial share of the total loss in electrical machines, thus, reducing the machine's overall performance, and increasing the thermal loading. Recently, different approaches for modelling AC copper losses have been proposed. This paper utilises simulation software to quantify the expected AC losses in six different propulsion motor designs. The motor designs are then modified to reduce the AC winding losses through the implementation of five different methods. Using two-dimensional finite element analysis, the magnetisation direction, magnet to airgap ratio, copper stranding, magnetic wedges and the motor slot openings are modified to reduce AC losses. The paper considers distributed, fractional, slot and concentrated windings, and the results show promising reductions across these different winding configurations. [ABSTRACT FROM AUTHOR]

Recently, electric vehicle marketing strategies focus on the high efficiency and cost effectiveness provided by the permanent magnet synchronous machines required for electric vehicle traction. Therefore, the main objective of this study is to produce an efficiently and economical technology for the electric vehicle market offering high power density permanent magnet synchronous machines. The methodology consists of considering an electric vehicle traction chain based on the permanent magnet synchronous machine thanks to its several advantages like efficiency, wide operating range, and high torque density. The machine design improvement is treated as the main component of the considered traction chain in order to assure the power density raise. The approach of the machine design by optimization is based on the elaboration of analytical models to find its feasible structure considering the multi-disciplinary analysis. The relevance of these models is validated by the finite element method. The models are integrated to elaborate the optimization problem based on a particle swarm optimization in order to improve the power density of the proposed machine by minimizing the mass of its active constructive materials. As a result, an optimal permanent magnet synchronous machine is offered for the electric vehicle drive train market, providing a 44.17% power density raise. [ABSTRACT FROM AUTHOR]

This article proposes an analytical method for the selection of machine parameters and inverter power ratings of a synchronous motor operated in an open-end winding (OEW) configuration with one of the two voltage-source inverters (VSIs) connected to a floating capacitor (FC) in order to meet a specific torque–speed profile. With the derived normalized expressions and curves, all the suitable synchronous motors operated with an OEW-FC and a standard two-level VSI drive can be easily compared according to the power rating and desired speed–torque characteristic. [ABSTRACT FROM AUTHOR]

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conventionally, the small mean and variance of peak-to-peak cogging torque of permanent magnet (PM) machines considering manufacturing uncertainties can be achieved by a robust design or by reducing the uncertainties range. However, the consequent compromise of other design objectives or the increase in the manufacturing costs are frequently inevitable. In this paper, the combination sequence of the uncertainties is highlighted and implemented to achieve a stable performance even for a non-robust design without increasing the cost too much. A PM assembling approach is proposed to mitigate the influences of PM uncertainties on cogging torque by means of combining the uncertainties in a particular sequence, where the effects of uncertainties would counteract each other. Both the singular type of PM uncertainties and the combined ones are considered in the assembling approach. Furthermore, the proposed approach is verified by comparing the cogging torque performance with PM randomly assembled models, where several hundreds of models featuring different uncertainties are calculated through the finite element method. The proposed approach is discussed, particularly for the application of mass production and a small amount of prototypes. Two prototypes with different PM assembling sequences are fabricated and further verify the effectiveness of the proposed PM assembling approach. [ABSTRACT FROM AUTHOR]

This paper proposes an automatic design method of typical parameters such as number of phases, number of poles, stack thickness, stator outer diameter, rotor outer diameter, and number of turns of a switched reluctance motor from the requirement of the N‐T characteristic. In particular, a specific parameter related to the magnetic saturation is defined in order to arbitrarily determine how much to use the magnetic properties of the iron core material. In the proposed method, the typical motor parameters in order to realize a miniaturized volume which satisfies an input N‐T characteristic are obtained by setting the parameter related to magnetic saturation, maximum electrical frequency, maximum current density, maximum copper loss, conductor slot fill factor, magnetic properties of material, and input voltage. The designed motor is analyzed using the Finite Element Method (FEM) in order to validate the proposed method. [ABSTRACT FROM AUTHOR]

The aim of this study is to present the possibilities of reducing the size of large induction motors with new electrical materials taken into account of thermal constraints. This study highlights the possibilities of reducing losses, increasing the efficiency, and decreasing the weight, by taking different grades of materials. A nonlinear multiobjective optimization is used to determine the best solution, by varying the internal and external geometric parameters.

Given the problem that the drive system of the traditional mine transportation winch outputs a large traction force through the cooperation of an induction motor and reducer to meet the needs of a large traffic volume and heavy-load starting, this paper studies a low-speed and high-torque dual-stator permanent magnet direct drive motor with a separated magnetic circuit. The tinner motor is a torque motor, and the outer motor is a direct drive motor, which is characterized by no magnetic circuit coupling and independent control. The proposed motor has an excellent heavy load starting ability and operation efficiency, and it improves the output torque without increasing the motor volume, which belongs to a special application. According to the working characteristics of the inner and outer motors and the constraints between the overall dimensions, the size equation is derived, and the design principles of the electromagnetic parameters, pole-slot combination and winding structure are described. The torque characteristics and temperature rise characteristics of the motor are simulated using the finite element method and compared with the torque performance and electromagnetic materials cost of the single stator low-speed and high-torque permanent magnet motor with different rotor structures. The results show that the proposed motor has a high torque density and starting torque, and it greatly reduces the motor volume on the basis of a small cost difference.

Refuse-collecting vehicles are significant polluters due to their expected drive cycles involving frequent stops and long idle periods. Electric refuse-collecting vehicles, still in their infancy, promise to address this through the replacement of internal combustion engines with batteries and electric traction motors. Today, typical motors for these vehicles involve heavy use of rare earth permanent magnets, which are subject to high price volatility, environmentally damaging mining practices, and occupational health hazards associated with refinement. The switched reluctance motor, which makes use of no permanent magnets, is a suitable substitute. This type of motor technology offers several advantages such as simple and robust construction, the ability to operate at high speeds and high temperature conditions, fault tolerance capability, and lower production costs in comparison with other technologies. This paper focuses on the design process of a switched reluctance motor for a battery electric refuse-collecting vehicle. The designed motor has a 36/24 outer rotor configuration, and its electrical and mechanical characteristics are based on the commercial traction motor TM4 SUMO HD HV3500-9P. The performance of the motor is evaluated using simulation tools such as JMAG and MATLAB/Simulink.

In recent years, the mobility sector is undergoing a revolution, which is resulting also into a worldwide spread of light electric vehicles, such as electric scooters and bicycles. The increasing public concern about environmental problems further feeds this revolution. Electric-bicycles (or e-bikes) are a new trend which fits different riders’ needs. In fact, they offer extended range and ease of use, allowing riders to travel in urban centres, but also to take longer trips. E–bikes are reliable, easy to ride, affordable, and they help people live and travel a little greener, with a great benefit for their health. Many Companies (such as Brose, Bafang, Bosch and Shimano) developed performing e-bike motor drives. However, there is not a detailed general procedure to help the choice and design of electric bikes, in particular concerning the electric machine. This review focuses on the analysis of different motors for e-bike application. First, the e-bike system state of art is presented. The pedal-assist and power-on-demand e-bike system typologies are presented, together with the most popular parallel configuration and the less common series configuration. Further on, the environmental resistances are analysed for a traditional bicycle system and then the force balance is extended to the electric vehicle example. The most common Lithium-ion battery and the battery management system state of art is discussed, presenting design schemes and typical performances. Concerning the electrical machine, some electromagnetic design approaches are described, together with some data on commercial motors. Finite element analysis of a common motor model is carried out and some experimental tests are presented to highlight their capabilities. Different control strategies are compared, including innovative solutions and new trends.

The hybrid-excitation permanent magnet (HEPM) motor is a synchronous motor characterized by a rotor that includes both permanent magnets and excitation windings. Thus, an active change in the magnetic flux by means of the excitation current is possible. In particular, the hybrid-excited rotor studied in this paper can be used to change the number of poles of the rotor itself. At the same time, the stator winding is also designed to perform a polarity change. The change in polarity allows users to obtain different torque versus speed characteristics with the same motor. In particular, a configuration with a lower pole number exhibits low torque at high speeds, while a configuration with a higher pole number produces high torque at low speeds. In this way, a single HEPM motor behaves like two different machines, extending the usual operating speed range of synchronous motors. In this paper, an HEPM rotor configuration is designed, and its performance is analyzed through finite element electromagnetic and thermal simulations.

In this paper, the AC copper losses in classical random windings are investigated and mitigated using several techniques across a range of permanent magnet synchronous motor designs. At high operating frequencies, AC copper losses can represent a substantial share of the total loss in electrical machines, thus, reducing the machine’s overall performance, and increasing the thermal loading. Recently, different approaches for modelling AC copper losses have been proposed. This paper utilises simulation software to quantify the expected AC losses in six different propulsion motor designs. The motor designs are then modified to reduce the AC winding losses through the implementation of five different methods. Using two-dimensional finite element analysis, the magnetisation direction, magnet to airgap ratio, copper stranding, magnetic wedges and the motor slot openings are modified to reduce AC losses. The paper considers distributed, fractional, slot and concentrated windings, and the results show promising reductions across these different winding configurations.

In this paper, a novel linear switched reluctance motor (LSRM) is introduced in which the total electromagnetic losses and dimensions are significantly reduced compared to the conventional LSRMs. The LSRM's stator has a segmental structure, while its rotor possesses a seven pole configuration with three rotor poles equipped with the winding sets to generate the magnetic flux. The other remaining four rotor poles, i.e., auxiliary poles, are responsible for closing the magnetic flux path loop. In the proposed LSRM-auxiliary mover poles (LSRM-AMP), the flux path length is effectively reduced using the optimized provided auxiliary poles. Therefore, the required magnetomotive force (MMF) is reduced compared to the conventional LSRMs. In addition, as only half of the generated flux passes the stator segments, the dimensions of the stator segments and their corresponding weights are significantly reduced without any saturation issue. In order to verify the finite element (FE)-based performance prediction of the proposed structure, the electromagnetic operating principles and the design rules of the LSRM-AMP are separately investigated. A sensitivity analysis and comparative study for the proposed LSRM-AMP and conventional LSRM topologies are presented to show the performance and characteristics superiority of the optimized LSRM-AMP structure. [ABSTRACT FROM AUTHOR]

Conventionally, the small mean and variance of peak-to-peak cogging torque of permanent magnet (PM) machines considering manufacturing uncertainties can be achieved by a robust design or by reducing the uncertainties range. However, the consequent compromise of other design objectives or the increase in the manufacturing costs are frequently inevitable. In this paper, the combination sequence of the uncertainties is highlighted and implemented to achieve a stable performance even for a non-robust design without increasing the cost too much. A PM assembling approach is proposed to mitigate the influences of PM uncertainties on cogging torque by means of combining the uncertainties in a particular sequence, where the effects of uncertainties would counteract each other. Both the singular type of PM uncertainties and the combined ones are considered in the assembling approach. Furthermore, the proposed approach is verified by comparing the cogging torque performance with PM randomly assembled models, where several hundreds of models featuring different uncertainties are calculated through the finite element method. The proposed approach is discussed, particularly for the application of mass production and a small amount of prototypes. Two prototypes with different PM assembling sequences are fabricated and further verify the effectiveness of the proposed PM assembling approach.