Radial-flux Motor Research Articles

A Study on Enhancing Axial Flux Motor Efficiency Using Cladding Core Technology

With the rise of eco-friendly policies, advanced motor technologies are being developed to replace fossil fuel-based engines in the mobility industry. Axial flux motors, known for their ability to reduce size and increase output torque compared to radial flux motors, require different materials and manufacturing techniques. Specifically, the production of complex stator cores and segmented magnets presents significant challenges, often leading to higher costs. To address this issue, soft magnetic composite (SMC) materials, which offer greater design flexibility, are being explored for use in stator cores. However, soft magnetic composite materials exhibit lower permeability and saturation flux density compared to laminated silicon steel, resulting in reduced output torque and efficiency. This paper investigates the effects of stator geometry on axial flux motor performance and explores cladding core technology, which combines soft magnetic composite materials with silicon steel. By conducting finite element method (FEM) analysis to evaluate the output torque and efficiency based on the shape of the silicon steel within the cladding core, this study proposes an optimized cladding core design to enhance the efficiency and output torque of axial flux motors.

Design of Radial Flux PM Synchronous Motor for EV Applications

Abstract: High-performance electric propulsion systems are becoming increasingly important as the automotive industry rapidly shifts to electric cars (EVs). The electric motor is an essential part of these systems as it determines the power, efficiency, and overall performance of the vehicle.This project uses Altair Flux, a full-featured finite element analysis (FEA) software suite, to build and optimize a radial flux motor (RFM) with permanent magnet synchronous motor (pmsm) . The main goal is to increase the power density and efficiency of the electric propulsion system for electric cars by utilizing Altair Flux's simulation and analytical capabilities.

Axial flux machine with non-slotted torus-ns rotor type. Design and investigate for electric traction

Introduction. The drive electric motor is one of the key components in the traction chain of an electric vehicle. Traditional radial flux motors used in electric vehicles, which use permanent magnets or induction motors in an electric field, are experiencing significant development aimed at optimizing their weight and cost. However, it can only go so far, so switching to a completely different type of machine, such as an axial flow, might be a good alternative. The novelty to this item is an axial flux permanent magnet motorization with non-slotted TORUS-NS rotor (single interior stator with two external rotors North-South) type housed in the wheel of the vehicle; this allows power to pass directly from the motor to the wheel, increasing the efficiency of the motor. System complexity is also less, as the transmission, differentials and driveshaft are eliminated. Purpose is to equip the electric car and choose the motor adapted to the application and the available space. The smaller size and weight allows for a lighter vehicle and more batteries, thus increasing range. The focus on customization is because vehicle performance is so dependent on the quality of the vehicle architecture , battery pack and axial flux motor design. The results obtained are in good agreement of accuracy, in particular the flux density at the air gap. The investigation is carried out by the finite element method. Machine model was run on Maxwell 16.0 business code.

Implementation of Different 2D Finite Element Modeling Approaches in Axial Flux Induction Motors

Axial flux induction motors (AFIM) are gaining popularity due to their higher torque density than radial flux motors. However, axial flux motors have a more complex structure than radial flux motors due to their diameters expanding from the inside out. Before manufacturing, designers have two contradictory goals in the simulation phase. These are high accuracy and short analyses time. The finite element method is a commonly utilized technique for verifying designs. However, in the early stages of AFIM design, a 2D radial flux modeling approach can yield faster results. This approach is well-suited for radial motors, where 2D analysis is widely employed to achieve accurate designs within reasonable analysis times. However, for AFIM with a non-axisymmetric flux path, the application of 2D analysis poses some difficulties. This study compares three modeling approaches, linear, inner rotor and outer rotor modeling approaches to a 3D model and examines their steady-state performance. The results show compatibility in performance data, with some deviations in the torque-speed curve for inner rotor modeling and outer rotor modeling approach methods, which can be reduced by resizing the slots. Overall, acceptable errors and consistent results were achieved between the models.

Magnetic equivalent circuit and finite element modelling of anisotropic rotor axial flux permanent magnet synchronous motors with fractional slot distributed winding

AbstractAxial flux motors have been in the focus of many research work due to their promising properties when compared to conventional radial flux machines. Axial flux permanent magnet synchronous motors (AFPMSM) studied in the literature were mostly limited to surface‐mounted permanent magnet machines (SPMSM), excluding only a few studies about axial flux internal permanent magnet (AFIPM) or permanent magnet‐assisted synchronous reluctance (AFPMaSynRM) machines. Since numerous rotor topologies have been proposed and investigated in case of radial flux motors, analogous design methodologies can be developed in case of axial flux motors with rotor saliency. The parametrisation and modelling of a magnetically anisotropic rotor axial flux motor are presented. This approach is described generally and the method is applied to an example motor geometry. The results were validated by FEA (Finite Element Analysis), using the 2D multi‐slice and 3D modelling approaches. The modelling error was calculated and the analytical and numerical methods were compared. It was found that the proposed model was suitable for calculating important parameters of the anisotropic rotor axial flux permanent magnet synchronous motor (AnR‐AFPMSM) during the design process.

Direct torque control of non-salient pole AFPMSMs with SVPWM inverter

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Efficiency Analysis of Axial Flux SynRM in Variable Speed Applications

Electrical machines find their place in every field, such as industrial, transportation, home, and commercial sectors. The suitability of the electrical machine for the area in which it will be used is important in terms of energy efficiency. The selection of the motor to be used for variable speed applications such as electric vehicles is also very important. Torque and power are the determining factors in the required speed/torque or speed/power combination for electric vehicles. For this reason, the efficiency map of the motor to be used in electric vehicles should be known in detail. In this study, due to its advantages such as its lighter structure, absence of magnet, and rotor winding loss, among others, the Axial Flux Synchronous Reluctance Motor (AF-SynRM) was preferred, and it was aimed at creating an efficiency map. The motor parameters for the determined speed/torque combinations were first obtained with FEM. Then, the FEM results were experimentally verified. In order to make the obtained results more meaningful, the experimental results were compared with radial flux motors with the same output power. In addition, using FEM, von Mises stress analysis and displacement analysis were performed on the motor shaft under overload conditions to observe the mechanical effects on the moving parts of the AF-SynRM. Furthermore, mechanical load analysis on the bearings was also performed. The results show that AF-SynRM can be preferred as an alternative to other motor types, especially for applications requiring variable speed, such as electric vehicles. The study has created the efficiency map of the AF-SynRM topology for the first time.

Harvesting Sea Wave Energy By Using Point Absorber and Blockchain Technology

In the current era of modern innovations, the applications of energy trading using secure software systems are increasing dramatically. The concept of energy generation using sea waves is slowly emerging. Moreover, to the best of our knowledge, the use of blockchain in this domain is in its infancy. In this research work, the Point absorber energy converter will be analyzed for power generation, which works with the power of the incoming and the outgoing waves. This system is more efficient and economical compared to old converters. The power in waves has potential force, which can be converted into kinetic force. This kinetic force is used to rotate the alternator, which produces useful power and this power can be stored in batteries or used directly by using various methods. The main benefit of this WEC is that it can be cone in very shallow waters and does not require deep waters to generate power. There is also another positive factor of this converter is that when the wave enters the converter’s incoming as well as the outgoing waves in the front and back direction and the height of the waves come onward, the shore the height of the water increases and decreases as the waves recede. This level changes in height and is used to move another alternator, which, is used on the same structure. The alternators used in the research are based on the axial flux alternator, which works on low rpm and has a power density much higher than the radial flux motor. For energy, trading, and control blockchain method has been employed considering power shortage and theft in our country and globally. The results of the paper reveal that the proposed system can be very effective if applied on a large scale.

Sensorless based SVPWM-DTC of AFPMSM for electric vehicles

AFPMSM is lighter, has a higher power-to-weight ratio, is shorter in length, is less expensive, and has a higher efficiency than the radial flux motor. Then AFPMSM is more suitable for driving the EV than radial flux motor. The proposed technique in this paper is the sensorless-based SVPWM-DTC of AFPMSM to drive electric vehicles. Sensorless research becomes more important in this circumstance since the axial motor can be placed inside the vehicle tire due to its condensed size and shape similar to the tires. DTC provides less fluctuation for the driver during driving for safety and comfort. SVPWM is preferred for its high performance. When measuring speed using a sensorless estimator, sensor inaccuracy is minimized, and the AFPMS motor can be mounted inside the tire. The control system is tested using two EVs driving cycles, and the results promise high performance. NEDC and HWFET driving cycles are used to test the proposed control scheme in 100 times less than the actual driving cycles’ time to test the coherence of the sensorless estimator. The results demonstrate that the proposed technique is valid for real-time applications with high-performance, minimum torque fluctuations, and minimum transient and steady-state errors.

Parameter Determination and Drive Control Analysis of Axial Flux Permanent Magnet Synchronous Motors

Axial flux electric motors have received a lot of attention in recent years due to successful implementations in industrial or traction applications. Particularly, axial flux permanent magnet synchronous motors (AFPMSM) can be an attractive choice in case of high torque-density requirements or when the drive environment (packaging) is geometrically limited to a disc-shaped motor. However, compared to radial flux motors, axial flux machine modeling possibilities are much less documented. In the present study, different electromagnetic modeling approaches have been compared through an example AFPMSM design. The motor parameters were determined by analytical and finite element methods. A 2D equivalent model (2D Linear Motor Modeling Approach – 2D-LMMA) and a 3D model results have been compared. The calculated values were used to carry out a drive control analysis of the axial flux motor.

Axial Flux PM In-Wheel Motor for Electric Vehicles: 3D Multiphysics Analysis

The Axial Flux Permanent Magnet (AFPM) motor represents a valid alternative to the traditional radial flux motor due to its compact structure; it is suitable for in-wheel applications so that the transmission gear can be suppressed. The modeling of the motor is a purely Three-Dimensional (3D) problem and the use of 3D finite element tools allows the attainment of accurate results taking also into account the effects of the end-windings. Moreover, a 3D multiphysics analysis is essential to evaluate not only the motor performance and its thermal behavior, but also the electromagnetic forces acting on the surfaces of the stator teeth and of the magnets that face the air gap. Moreover, as the vehicle’s motors often work in variable-speed conditions, the prediction of vibrations and noise for electric motors over a wide speed range is usually necessary. The paper presents a double-sided AFPM motor for a small pure electric vehicle; the basic drive architecture includes four axial flux motors installed directly inside the vehicle’s wheels. The aim is to propose advanced and integrated electromagnetic, vibroacoustic and thermal analyses that allow the investigation of the axial flux motor behavior in a detailed and exhaustive way.

Optimisation of Magnet Shape for Cogging Torque Reduction in Axial-Flux Permanent-Magnet Motors

This paper presents a new method for reduction of the cogging torque in axial flux permanent-magnet motors based on the shape of the edges of the magnets. First, starting from a previous work, developed for 2D radial flux motors, and extending it to the case of 3D axial flux motors, the new cogging torque cancellation conditions are set. From these conditions, the optimised profile of the magnets is derived, for which an original and precise method based on superposition has been developed. Furthermore, the proposed method does not need Finite Element Method (FEM) iterations to achieve the required precision, which makes it really very fast. The cancellation condition is fully compatible with the optimisation of other characteristics related to magnets, such as the waveform of the induced EMF and the torque ripple. Both the new cogging torque cancellation condition and the magnet profile design method to meet this condition constitute the main contributions of this work. The results obtained are in good agreement with those obtained by FEM simulation. Finally, the proposed method of minimising the cogging torque has been successfully validated experimentally by employing three different configurations of a single-stator single-rotor axial flux motor. The practical reduction of the obtained cogging torque is noticeable even when using non-skewed magnets and when the number of slots is an integer multiple of the number of magnets.

Performance Comparison Between PCB-Stator and Laminated-Core-Stator-Based Designs of Axial Flux Permanent Magnet Motors for High-Speed Low-Power Applications

Gearless and small motors operating at speeds above 10 000 rpm are finding many applications nowadays. Axial flux permanent magnet (AFPM) motors are compact and lightweight compared to radial flux motors and hence, are considered for various high-speed applications. Eliminating the stator core minimizes the associated high-frequency losses, and hence, coreless AFPM motor can be an option for high-speed applications. Furthermore, the coreless AFPM motor design minimizes the cogging torque and the axial attraction force between the stator core and the rotor magnets. However, the reduction of flux linkage in the stator windings is a challenge in coreless AFPM motor. In this article, the advantages and disadvantages of the printed circuit board (PCB)-based AFPM motor for high-speed, low-power applications are investigated. A detailed performance comparison of the PCB-based coreless AFPM motor and the AFPM motor with the laminated stator core is made. Finite-element analysis is carried out for the electromagnetic, mechanical, and thermal comparison of the two motors and the simulation results are presented. Finally, motor prototypes are fabricated and are tested to ascertain the simulation results.

Influence of pole and slot combinations on vibration and noise in external rotor axial flux in‐wheel motors

This study provides a detailed finding of the influence of pole and slot combinations on vibration and noise in external rotor axial flux in-wheel motors (AFWMs). Firstly, electromagnetic force exerted on the surface of permanent magnet is discussed and a two-dimensional fast Fourier transformation is implemented to analyse its spatial distribution and frequency characteristics. Then, a multiphysics model is developed to predict the vibration and noise and figure out the main origin from the perspective of electromagnetism. The influence of pole and slot combinations on vibration and noise is also analysed via the proposed model. Finally, the effect of load on vibration and noise in AFWMs is further investigated. It turns out that zeroth spatial order of axial electromagnetic force is the main origin of vibration and noise in axial flux motors, which is quite different from radial flux motors. Moreover, AFWMs with larger lowest common multiple (LCM) of pole number (2 p ) and slot number ( Q s ) show lower noise level and for the motors that satisfy LCM(2 p,Q s ) ≠ 6 p , vibration and noise are greatly influenced by load. This study provides guidance for the design of low noise AFWMs.

Magnetic modeling of radial-flux and axial-flux permanent-magnet motors for direct drive automotive. Specifications and comparison

Magnetic modeling of radial-flux and axial-flux permanent-magnet motors for direct drive automotive. Specifications and comparison

Torque Density of Radial, Axial and Transverse Flux Permanent Magnet Machine Topologies

Torque density of radial, axial and transverse flux machine topologies is investigated. A 10-kW, 200-rpm motor is chosen as a test case. Radial and axial flux motors that fulfill the key specifications of the selected test case are designed employing in-house analytical dimensioning tools and MATLAB genetic multi-objective optimization. Rather simple numerical approach is taken to study the transverse flux motor. A 20-pole-pair radial flux motor is found to outperform its axial and transverse flux counterparts in terms of torque density.

Blowers of Vacuum Cleaners Utilizing Coreless and Sensorless Axial-Flux Motors with Edge-Wire Coils

Axial-flux motors (AFM) generally have higher torque and power densities, smaller volume and weight, larger diameter to length ratio, and compact construction for the same power level than radial-flux motors (RFM). Hence, AFM are attractive alternative to conventional RFM for applying in low torque and speed servo control systems. Additionally, magnetic Hall-effect sensors and commutation circuits are unsuitable for environment with high temperature and restricted space, so sensorless driving control method of AFM by detecting zero-crossing of back-EMF signals has been achieved. Furthermore, coreless design can reduce motor total weight, normal attractive force and torque pulsation and can increase efficiency of machines as compared with conventional design with cores. Thus, this study focuses on sensorless AFM design applying for blowers in vacuum cleaners to follow the concepts of axial-flux, edge-wire with high space-utilization factors, and stators without ferromagnetic cores. The closed-loop velocity controller designs by adopting proportional-integral-derivative (PID) and fuzzy logic control (FLC) algorithms have been demonstrated effectively for the design sensorless AFM of blowers in vacuum cleaners. As a result, the settling time of velocity closed-loop control methods can be converged within 1.0 second; i.e. the vacuum cleaners can switch and operate in various speeds with different operational environment rapidly. Therefore, the system characteristics and lifetime of the designed sensorless AFM have been enhanced and satisfied the demands of blowers to employ in vacuum cleaners.

Simplified Thermal Model of a Radial Flux Motor for Electric Vehicle Application

Heat transfer is the science that seeks to predict the energy transfer that takes place between material bodies as a result of a temperature difference. When designing an electric motor, the study of heat transfer is as important as electromagnetic and mechanical design. However, due to its three dimensional nature, it is generally considered to be more difficult than the prediction of the electromagnetic behaviour. For this reason, and the fact that the majority of designers have an electrical rather than mechanical background, thermal analysis is usually not given as much emphasis as the electromagnetic design. This paper presents the thermal model simplified of Per manent Magnet Synchronous Motor (PMSM) with radial flux for electric vehicle (EV) application. The thermal design technique used is the analytical lumped circuit. The equivalent circuit of the motor is implemented and simulated with MATLAB simulator. Simulations by Motor-CAD software were made in order to shows the accuracy of the proposed thermal model.

Design and Performance Analysis of an Axial-Flux Disk-Type Switched Reluctance Motor for Hybrid Scooters

Switched reluctance motors (SRM) possess several superiorities such as simplicity in structure, ruggedness, and good reliability, which make it viable for the transportation applications. In this paper, an axial-flux disk-type switched reluctance motor (DSRM) for hybrid scooters is proposed. The DSRM can be used to drive the scooter and as an engine starter simultaneously. Moreover, the torque density of axial flux motors is more superior to that of radial flux motors in this application. Instead of utilizing FEM, the permeance model is employed to model the DSRM. With the analytical expressions, the output torque and current can be obtained dynamically and the geometries of the DSRM can be further optimized. Finally, the hardware-in-the-loop (HIL) simulation environment is constructed to perform full system simulation and the DSRM is shown to be capable of being an auxiliary power source for hybrid scooters.

Test and Simulation of Axial Flux-Motor Characteristics for Hybrid Electric Vehicles

High power density is the main advantage of the axial flux motors compared to the conventional radial flux motors. Therefore, they are suitable candidates for the power train of hybrid electric vehicles. In addition, operating speed range and efficiency of axial flux motors can be improved by changing the air gap of the machine. In this paper, for each operating point, the optimal air gap is estimated based on the measured efficiency at different air gaps. The motor model is developed using the estimated optimal air gap and efficiency. Vehicle performance with the axial flux motor is also simulated based on the developed motor/controller model. Furthermore, the actual motor performance in a typical vehicle environment is analyzed with a vehicle simulator by applying the concept of hardware in the loop without installing the motor in the vehicle. Actual motor performance is compared with the simulation results as well. Motor performance in different drive cycles is also tested. The test motor can be used for the drivetrain of a series hybrid electric vehicle.