Axial Flux Switched Reluctance Motor Research Articles

Reduction of Torque Ripple and Axial Force in a Fully Pitched Axial Flux Switched Reluctance Motor Using a Double Stator Structure

Reduction of Torque Ripple and Axial Force in a Fully Pitched Axial Flux Switched Reluctance Motor Using a Double Stator Structure

Performance Analysis of a Novel Axial Radial Flux Segmental Rotor Switched Reluctance Motor

Based on the characteristics of axial flux switched reluctance motor (SRM) and radial flux SRM, this paper proposes a new type of axial radial flux segmental rotor switched reluctance motor (ARFSRSRM). The motor has the left and right dual axial stator structures, which forms a kind of axial flux path with the segmental rotor in the middle, and a radial stator structure, which shares a kind of radial flux path with the segmental rotor on the outside of the motor. Compared with the conventional SRM, this motor combines the advantages of high output torque and torque density due to the inclusion of two kinds of flux paths, making it suitable for high-efficiency and high-torque fields such as electric vehicles. In this paper, the topology and operating principle of the new motor are first introduced. Then the initial structural parameters are derived, and the multi-objective optimization of the proposed motor is carried out using Taguchi’s algorithm. The static and dynamic performance of the motor is comprehensively analyzed using the 3-D finite element method. Finally, the experimental results obtained through the trial production of a prototype machine verify the good performance of the new motor.

Performance Improvement for Double-Stator Axial Flux SRM Using a New Winding Reconfigurable Power Converter

This paper presents a new power converter topology that enables reconfigurable winding operation in a double stator axial flux switched reluctance motor (DSAFSRM). The proposed power converter allows the winding working in series and parallel connection methods and requires fewer components. By applying the reconfigurable winding converter and implementing the mode selection scheme, both the wide speed range of the parallel mode and the high efficiency of the series mode are obtained, thus achieving high-efficiency operation over a wide speed range. At first, the topology and operating modes are introduced. The six available working states are also detailed. Then the drive system simulation model with the reconfigurable winding power converter is established in the MATLAB/Simulink environment. The steady-state performance of the two modes and the dynamic switching performance are simulated and analyzed. Finally, the DSAFSRM drive based on the reconfigurable winding converter is built and experimentally tested. The performance results verify the validity and correctness of the presented power converter.

Quasi-3-D Nonlinear Analytical Modeling of Magnetic Field in Axial-Flux Switched Reluctance Motors

Analytical modeling (AM) of the magnetic field for axial-flux switched reluctance motors (AFSRMs), considering three-dimensional (3-D) features and nonlinear saturation effects, remains to be a knotty problem. This paper proposes a quasi-3-D nonlinear AM method to predict magnetic field distributions and electromagnetic performances of an AFSRM. Firstly, the harmonic modeling technique is applied to obtain the spatiotemporal distribution characteristics of the axial and tangential magnetic flux density at the mean radius. Secondly, the nonlinearity of the soft magnetic material in teeth is considered by an adaptive convergence rate algorithm. Finally, a radial dependence function is formulated to extend the solution of the annular section to any point in the 3-D space of the AFSRM. To confirm the accuracy of the proposed method, the analytical solutions of magnetic flux density and electromagnetic torque have been compared with FEM simulation results. Meanwhile, an additional validation has been done for the stability of this nonlinear AM method under severe saturation conditions. At last, the reasonable selection of the harmonic truncation order number has been discussed to reach a good balance between the accuracy and time cost. The quasi-3-D nonlinear AM method can consider the curvature and edge effect as well as the saturation effect effectively, which is suitable for performance predictions and parametric studies of AFSRMs.

Design Improvements in Double-stator Axial Flux Switched Reluctance Motor for Smoother Torque Profile

Design Improvements in Double-stator Axial Flux Switched Reluctance Motor for Smoother Torque Profile

Investigation and Comparative Study of 12/16 C-core and Conventional Radial Flux Switched Reluctance Motor under Coil Fault Conditions . (Dept. E)

Owing to the large quantity of conventional passenger vehicles with internal combustion engines, energy shortages and environmental pollution are now Seen as important problems. Electric vehicles (EVs) have the best energy savings and zero emission vehicles option. Radial Flux Switched Reluctance Motor (RFSRM), and Axial Flux Switched Reluctance Motor (AFSRM) have shown promise in wheel motor design of electric vehicles. While C-core is modelled, giving advantages of both radial and axial flux SRM. Based on a three-phase 12/16 pole structure, C-core RFSRM and conventional RFSRM are investigated and compared under different types of coils failures, while their impact on the average torque for both motors is presented. Comparisons of average torques at different coils` fault conditions between C-Core RFSRM, and conventional RFSRM have been done by finite element analysis (FEM). The segmental structure of C-Core RFSRM and its independent separate magnetic path for its coils, give it the superiority more than conventional RFSRM for in-wheel electric vehicle application.

تحلیل و شبیهسازی موتور سوئیچ رلوکتانس شارمحور با استاتور تغییر ساختاریافته در حالت استاتیکی و دینامیکی

تحلیل و شبیهسازی موتور سوئیچ رلوکتانس شارمحور با استاتور تغییر ساختاریافته در حالت استاتیکی و دینامیکی

Principle and design of a novel axial flux-switched reluctance motor with short flux path

Principle and design of a novel axial flux-switched reluctance motor with short flux path

Lumped Parameter Thermal Model for Axial Flux Switched Reluctance Motors

The accurate prediction of temperature rise in various parts of a machine plays a significant role in ensuring that the machine delivers the required performance avoiding failures that arise due to high temperatures. In this paper, a lumped parameter thermal model is presented for exterior-rotor axial flux switched reluctance motors. Depending on its geometry, each part of the motor is modeled as a thermal equivalent circuit based on general cylindrical or cuboidal components. A total thermal network is obtained by proper connection of these sub-circuits. The model was calibrated by a stationary test; then, running conditions were applied to the model. The sensitivity of the model to the heat transfer coefficients was investigated by considering the effect of the coefficient variation on the estimated steady-state temperatures. Results show that the winding temperature, as the hottest part of the motor, is the most sensitive to the frame-to-ambient heat transfer coefficients.

Optimal Design of an Axial-Flux Switched Reluctance Motor With Grain-Oriented Electrical Steel

This paper employs grain-oriented electrical steel (GOES) in an axial-flux switched reluctance motor (AFSRM) to improve its torque characteristic, taking advantages of the material's excellent magnetic properties in the rolling direction. Based on the study on the parameter and switching characteristics of an AFSRM, GOES can be divided into pieces and arranged in the rotor and stator teeth so that the magnetic flux mainly travels along the rolling direction of the material. AFSRMs with different lamination shapes and deviation angles between the magnetic flux and rolling direction of the GOES have been studied to further improve the output performance; the maximum electromagnetic torque of the proposed design shows a 20.5% increase in comparison with that of the conventional nonoriented electrical steel motors under identical conditions. The rotor retaining ring is composed of epoxy resin lamination to constrain the rotor teeth modules. Thermal and stress analyses under fault conditions are analyzed to verify the reliability of the retaining ring. Furthermore, an AFSRM prototype is built and experiments are conducted to validate the calculated data.

Electromagnetic evaluation of an in-wheel double rotor axial-flux switched reluctance motor for electric traction

In this paper, a novel in-wheel double rotor axialflux switched reluctance motor for electric traction is presented. The proposed double rotor axial-flux switched reluctance motor has a particular disposition of the stator and rotor poles that provides short flux path without flux reversal. The ferromagnetic pieces of the stator and the rotor are built using soft magnetic composites. Electromagnetic analysis is performed using three dimensional finite element analyses, 3D FEA. Matlab-Simulink simulation coupled with the results of finite element analysis proves that the proposed motor drive is suitable for the propulsion of a given E-scooter.

A High Torque Density Axial Flux SRM with Modular Stator

A novel structure of Switched Reluctance Motors (SRMs) is proposed. The proposed structure uses the benefits of the axial flux path, short flux path, segmental rotor, and flux reversal free stator motors all together to improve the torque density of the SRMs. The main geometrical, electrical and physical specifications are presented. In addition, some features of the proposed structure are compared with those of a state-of-the-art radial flux SRM, considered as a reference motor. Then, the proposed structure is modified by employing a higher number of rotor segments than the stator modules and at the same time, reshaped stator modules tips. Achieved results reveal that, compared with the reference motor, the proposed and the modified proposed motors deliver about the same torque with 36.5% and 46.7% lower active material mass, respectively. The efficiency and torque production capability for the extended current densities are also retained. These make the proposed structures a potentially proper candidate for the Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) as an in-wheel motor.

Mutual Inductances Effect on the Torque of an Axial Magnetic Flux Switched Reluctance Motor

This paper evaluates the performance of a 6/4 axial flux switched reluctance motor (AFSRM), with only one stator, considering the contribution of the mutual inductances on the torque. To estimate the self and mutual inductances, one computational approach based on the three-dimensional finite element method, was implemented. Different from the most conventional models of the radial flux SRM, this study shows that the contribution of mutual inductances is important in the performance of the axial flux SRM when its control strategy considers two phases simultaneously energized, as verified by dynamic simulation results.

A Novel Approach to the Design of Axial-Flux Switched-Reluctance Motors

This paper presents the design of a new axial-flux switched-reluctance motor (AFSRM) topology for in-wheel drive vehicle applications. The features of the topology include a short flux path and an outer-rotor configuration. The proposed topology also uses a sintered-lamellar soft magnetic composite core material, and permits displacement of the rotor along the suspension axis, which reduces damage to the stator caused by impacts and vibrations. The combination of these features makes this new topology competitive with other in-wheel motors in regard to torque density, durability, and cost. To describe the behaviour of the topology, a model of the topology is developed using a new integral inductance function. That model is used to select the design parameters of an 8/6 AFSRM, for which a fuzzy controller is also developed to control the phase current. Several simulations of the 8/6 AFSRM are performed to calculate its energy conversion efficiency, thermal performance, and torque density, and results indicate that the new AFSRM has a higher energy conversion efficiency, and can produce more torque/kg than other switched-reluctance motors used for in-wheel drive vehicle applications.

Modification in Geometric Structure of Double-Sided Axial Flux Switched Reluctance Motor for Mitigating Torque Ripple

Due to very high torque/weight ratio, the axial flux switched reluctance motor (AFSRM) can be appropriately used in many applications, especially electric vehicles and aerospace systems. Since the torque ripple is generally the drawback of SRMs, a new structure is suggested for the double-sided AFSRM in which the torque ripple is significantly reduced. In order to show the effectiveness of the technique proposed for reducing the torque ripple, the 3-D finite-element (FE) transient analysis of a typical 8/6 double-sided AFSRM is carried out using MAXWELL FE package and the simulation results are presented.

Development of Novel Controllers for an Axial-Flux Switched-Reluctance Motor

To increase the utility of switched-reluctance motors (SRMs) in electric vehicles it is required to increase torque per unit volume (torque density) while maintaining low cost and low torque ripple. This paper presents the design of three new control methods for in-wheel axial-flux SRMs that increase torque density using switching angles and optimal current profiles. All three control methods are compared to two reference control methods from the literature. The second method is shown to be superior in terms of the precision of its switching angle calculations to the first, and speed to the third, though the first method produces lower torque ripple, and the third uses a better model of switching dynamics. In addition, both first and second methods reveal improved performance compared to the control methods adopted from the literature. Thus, all three proposed control methods can be used to improve the performance of in-wheel SRMs, but the second method produces the highest torque density. The second method can be used for in-wheel motor applications which need online switching angle calculations that balance the requirements of high torque density and low torque ripple.

Designing and Prototyping a Novel Five-Phase Pancake-Shaped Axial-Flux SRM for Electric Vehicle Application Through Dynamic FEA Incorporating Flux-Tube Modeling

Switched reluctance motors (SRMs) show crucial attributes to applications where light weight, high-temperature adaptability, fault-tolerance capability, ruggedness, and simplicity are strongly required. The axial-flux configuration of SRM has additional features over the radial-flux configuration. This paper presents the design and analysis of a novel axial-flux SRM. Detailed procedures of deriving the output power equation as a function of the motor dimensions and parameters are provided. A modified phase winding design approach is thoroughly explained, a flowchart describing the design algorithm is presented, and the inductance determination by different methods is verified experimentally. The 3-D finite-element analysis (FEA) unveils the excessive end core and radial-flux fringing effects in the axial-flux configuration. An exclusive pole-shape design is also proposed. The operation of the motion model using 3-D dynamic FEA is analyzed, and its prototype development process and static testing are demonstrated.