Search Results (45)

Electric Water Pumps (EWPs) are being adopted more widely to improve thermal management in internal combustion engines and electrified powertrain systems. In this context, the drive motor must deliver high efficiency and reliability despite a strict volume constraint. This paper addresses a key drawback of coreless printed circuit board (PCB) stator axial-flux permanent-magnet machines for EWP use: the PCB traces are directly exposed to the magnet flux, which increases AC loss, while the required phase resistance also leads to non-negligible DC copper loss. To mitigate both loss components within the same conductor design space, a pyramid trace concept is introduced. A magnetic equivalent circuit (MEC) based model is first used to estimate the baseline performance as the number of PCB stator modules changes, and the resulting scalability is examined in terms of module commonality. The final design then applies the pyramid trace layout with a layer-dependent trace width that is narrower on the layers closer to the magnets and wider on the layers farther away—the trade-off between AC loss and DC loss is optimized using 3D finite element analysis. Torque predictions from the simplified MEC model are cross-checked against 3D finite element analysis (FEA), and finally, a prototype is built to validate the analysis with experimental measurements; for the final selected model, the torque prediction error is 2.37% compared with the validation result. Full article

This paper proposes a multiphysics-based optimal design process for a 750 W axial-flux ferrite consequent-pole (AFCP) pump motor aimed at reducing permanent magnet usage. To mitigate the high computational cost associated with repetitive numerical analyses, a metamodel (surrogate model)-based optimization framework is adopted. A consequent-pole (CP) structure is applied to an initial ferrite axial-flux permanent magnet (AFPM) motor, and ten key design variables are selected for optimization. The electromagnetic performance corresponding to variations in these variables is evaluated using three-dimensional finite element analysis (3D FEA), and the resulting dataset is used to construct metamodels. In AFPM motors incorporating ferrite permanent magnets and a CP structure, electromagnetic performance, thermal saturation, and structural stability collectively limit reliable operation. Therefore, a multiphysics-based evaluation is essential. The optimal design is assessed through electromagnetic, thermal, and structural finite element analyses. According to the 3D FEA results, the optimal model achieves a 46.85% reduction in permanent magnet volume while improving efficiency by 0.75%, reaching 95.53%, compared to the initial model. The torque ripple and peak-to-peak cogging torque are reduced by 28.81% and 31.37%, reaching 0.08 Nm and 0.06 Nm, respectively. In addition, the total harmonic distortion (THD) of the back-electromotive force waveform decreases from 12.4% to 2.53%. Stable operating characteristics are confirmed through demagnetization, thermal, and structural analyses, demonstrating that the proposed optimal design process successfully achieves both permanent magnet reduction and overall performance improvement in ferrite-based AFCP motors. Full article

Reducing iron loss in axial flux permanent magnet (AFPM) motors is critical for improving efficiency. This study proposes a design-optimization procedure that combines 3D finite-element analysis (FEA) data with an artificial neural network (ANN) surrogate. For four design variables—airgap length, rotor back-yoke thickness, stator slot width, and stator slot depth—the search bounds were defined to avoid tooth and back-yoke saturation, and the corresponding space was sampled to construct a dataset. Using this dataset, the ANN was trained and then used to explore low-iron loss solutions. On an independent validation set, ANN predictions showed high agreement with 3D-FEA reference values, enabling rapid evaluation of many design candidates. As a result of the optimization, total iron loss decreased relative to the baseline, and torque increased by 3 Nm. These results demonstrate that the ANN-based surrogate model can reliably perform geometry-dependent iron loss optimization in AFPM motors, providing a fast and accurate alternative to repetitive 3D-FEA evaluations. Full article

This paper presents the design, optimization, and validation of a dual three-phase yokeless and segmented armature (YASA) axial flux permanent magnet (AFPM) machine for aerospace actuators. The proposed 12-slot, 10-pole topology employs segmented soft magnetic composite (SMC) stator teeth integrated into an additively manufactured aluminium holder, combining modularity, weight reduction, and improved thermal conduction. A multi-objective optimization process based on 3D finite element analysis (FEA) was applied to balance torque capability and losses. The manufacturable design achieved a peak torque of 28.3 Nm at 1400 rpm and a peak output power of 3.5 kW with an efficiency of 81.6%, while limiting short-circuit currents to 14 Arms. Transient structural simulations revealed that three-phase short circuits induce unbalanced axial forces, exciting rotor wobbling—a phenomenon not previously reported for YASA machines. A prototype was fabricated and tested, with static torque measurements deviating by 8.6% from FEA predictions. By contrast, line-to-line back-EMF and generator-mode power output exhibited larger discrepancies (up to 20%), attributed to the frequency-dependent permeability and localized eddy currents of the SMC stator material introduced during EDM machining. These results demonstrate both the feasibility and the limitations of YASA AFPM machines for aerospace applications. Full article

Traditional pedestrian evacuation models struggle to balance global exit guidance with local, individual decision making under hazards. We address this by decomposing long-term objectives into Particle Swarm Optimization (PSO)-based micro-goals and proposing a hybrid Cellular Automaton (CA) and PSO model. The hybrid design reduces the decoupling between spatial discretization and individual choices and more tightly couples hazard and density fields with movement decisions. Two contributions are central. First, we develop an autonomous following pathfinding mechanism (AFPM) that linearly blends the direction toward a PSO micro-goal with a herd following direction and adds a small reward for directional consistency. This mitigates path chaos from purely autonomous moves and congestion aggregation from purely herding moves. Second, we build a multi-dimensional interpretability and robustness framework that combines the empirical Cumulative Distribution Function (CDF) and a kernel-smoothed Probability Density Function (PDF) of key evacuation times (T_clear, T_95%_alive) together with vulnerability curves, to analyze the data and assess robustness. It combines Shapley Sobol analysis to quantify parameter effects on clearance time T_clear and the 95% survival evacuation time T_95%_alive, with CDF/PDF summaries and vulnerability curves to assess anti-interference performance. Experiments use a simulated underground shopping mall. In a 60 pedestrian case, a geometry-only baseline yields T_clear $\approx 33 \mathrm{s}$; hazard- and density-aware strategies produce slightly longer T_clear but reduce peak bottleneck congestion by 20–30%. When one exit is closed, the exceedance probability at $\tau =70 \mathrm{s}$ drops from 0.44 to 0.36, reducing long tail risk. Compared with geometry-based Dijkstra, the proposed model slightly increases clearance time while lowering peak congestion by 20–30%, achieving a balance between efficiency and safety. The model and evaluation protocol provide technical support for evacuation policy, facility layout, and emergency system design in large complex buildings. Full article

This study investigates the comparative applicability of Somaloy 700HR 5P and Fe-5.0 wt.%Si powders for axial flux permanent magnet (AFPM) motor cores in low-speed electric vehicles. Optimal forming conditions were derived through Taguchi-based simulations, considering corner radius, forming temperature, and forming speed, followed by prototype fabrication and validation. Simulation and SEM-EDS analyses confirmed consistent density distribution trends, and XRD verified phase stability during forming. While Fe-5.0 wt.%Si exhibited ~10% ± 2 superior electromagnetic performance in the powder state, its motor dynamo performance decreased by 19–25% (n = 1) compared to Somaloy 700HR 5P. This discrepancy was attributed to its ~4% lower target density (7.19 ± 0.02 g/cm³ vs. 7.51 ± 0.01 g/cm³, n = 3), assembly-induced mechanical losses, and non-uniform insulation layer caused by residual H₃PO₄ and Mo segregation. Somaloy 700HR 5P, despite a higher relative density variation (0.084 ± 0.002 g/cm³ vs. 0.063 ± 0.003 g/cm³ for Fe-5.0 wt.%Si), achieved an average density close to 7.5 g/cm³ and delivered more stable motor performance. Overall, Somaloy 700HR 5P was identified as a more suitable candidate for AFPM motor cores in low-speed EV applications, balancing formability and electromagnetic performance. Full article

This study proposes an optimal design approach incorporating rotor skew to reduce torque ripple in a 5 kW in-wheel axial flux permanent magnet (AFPM) motor. Nine design variables, including the skew angle, were selected for optimization. The variation ranges of these variables were defined, and sample points were generated using the optimal Latin hypercube design (OLHD). Response data corresponding to the sample points were obtained through three-dimensional finite element method (3D FEM) analysis. Metamodels were then constructed using five different methods and evaluated based on the root mean square error (RMSE). The optimization results showed that the average torque of the optimized model increased by 2.3% compared with the initial design, reaching 48.85 Nm. Torque ripple was reduced by 42.01% to 2.83 Nm, while peak-to-peak cogging torque decreased by 42.76% to 2.61 Nm. In addition, efficiency improved by 0.07% to 95.53%, and the total harmonic distortion (THD) of the back-EMF waveform was reduced by 50.72% to 2.4%. These findings demonstrate that the proposed method provides an effective and systematic design strategy for enhancing the performance of AFPM motors. Full article

Axial flux permanent magnet (AFPM) machines offer some advantages over conventional radial flux machines for the case of a limited space in the axial direction, such as high torque density, compact structure, and modular design ability. They, therefore, are increasingly used in wind power and electrical vehicles. This paper focuses on developing an effective analytical model and equivalent auto-finite element method (FEM), including rotor linear motion for the design of axial flux permanent magnet generators in vertical axis wind turbines. The initial design of a 1.35 kW-AFPM generator with an outer double rotor and double layer concentrated windings is based on analytical equations, and then it is refined using equivalent time-stepping transient FEM, including rotor linear motion to calculate voltage, electromagnetic force, and torque. The automatic generation of an equivalent transient 2D-FEM model to replace a time-consuming 3D-FEM model is investigated. As a consequence, the influence of slotting the effect on a 1.35 kW-AFPM machine’s performances, such as air gap flux density, internal voltage, and cogging torque, is announced. Full article

Duct fan motors must provide high torque within limited space to maintain airflow while requiring low vibration characteristics to minimize fluid resistance caused by fan oscillation. Axial Flux Permanent Magnet Motor (AFPM) offers higher torque performance than Radial Flux Permanent Magnet Motor (RFPM) due to their large radial and short axial dimensions. In particular, the coreless AFPM structure enables superior low-vibration performance. Conventional AFPM typically employs a core-type stator, which presents manufacturing difficulties. In core-type AFPM, applying a multi-stator configuration linearly increases winding takt time in proportion to the number of stators. Conversely, a Printed Circuit Board (PCB) stator AFPM significantly reduces stator production time, making it favorable for implementing multi-stator topologies. The use of multi-stator structures enables various topological configurations depending on (1) stator placement, (2) magnetization pattern of permanent magnets, and (3) rotor arrangement—each offering specific advantages. This study evaluates and analyzes the performance of different topologies based on efficient arrangements of magnets and stators, aiming to identify the optimal structure for duct fan applications. The validity of the proposed approach and design was verified through three-dimensional finite element analysis (FEA). Full article

This study proposes a multi-via structure as a loss-reduction design technique to mitigate current crowding in a slotless axial flux permanent magnet motor (AFPM) equipped with printed circuit board (PCB) stators. The PCB stator enables high current density operation through parallel copper-foil stacking and supports an ultra-compact structural configuration. However, current concentration in the via regions can increase copper loss and phase resistance. In this work, the via position and diameter were defined as design variables to perform a sensitivity analysis of current distribution and phase resistance variation. The effects of current density dispersion and the potential for copper loss reduction were evaluated using three-dimensional finite-element analysis (FEA). The results confirm that adopting a multi-via structure improves current path uniformity and reduces electrical losses, thereby enhancing overall efficiency. Furthermore, the analysis shows that excessive via enlargement or overuse does not necessarily yield optimal results and, in certain cases, may lead to localized current peaks. These findings demonstrate that the multi-via structure is an effective and appropriate design strategy for PCB stators and highlight the importance of optimized via placement tailored to each stator configuration. Full article

With growing demand for high-performance and high-efficiency motors, Axial Flux Permanent Magnet Motors (AFPMs) have received significant attention. These motors typically use rare-earth magnets due to their high magnetic and energy density. However, rare-earth magnets face challenges such as limited availability and price volatility, prompting research into reducing magnet usage. This study aims to reduce magnet consumption by applying a Consequent Pole (CP) structure to AFPMs. While CP structures improve magnet efficiency, they also introduce significant back-EMF ripple. To address this, an Intersect Consequent Pole (ICP) structure is proposed, which reduces ripple through alternating magnet placement within the rotor. Since ICP implementation is difficult in single-rotor AFPMs, a double-rotor, single-stator configuration was used. Simulation results show that the proposed design effectively reduces magnet usage and back-EMF ripple, demonstrating its potential for maintaining high performance with reduced rare-earth dependency. Full article

A PCB stator axial flux permanent magnet (AFPM) motor is presented that overcomes the manufacturing challenges associated with the complex geometry of conventional stators by employing a PCB substrate. Traditionally, AFPM motors are produced by winding coils around the stator teeth, a process that requires specialized winding machinery and is both labor intensive and time consuming, ultimately incurring considerable manufacturing costs and delays. In contrast, PCB substrates offer significant advantages in manufacturability and mass production, effectively resolving these issues. Furthermore, the primary material used in PCB substrates, FR-4, exhibits a permeability similar to that of air, resulting in negligible electromagnetic cogging torque. Cogging torque arises from the attraction between permanent magnets and stator teeth, creating forces that interfere with motor rotation and generate unwanted vibration, noise, and potential mechanical collisions between the rotor and stator. In the PCB stator design, the conventional PCB circuit pattern is replaced by the motor’s coil configuration, and the absence of stator teeth eliminates these interference issues. Consequently, a slotless motor configuration with minimal vibration and noise is achieved. The PCB AFPM motor has been applied to a vehicle-mounted electric water pump (EWP), where mass production and space efficiency are critical. In an EWP, which integrates the impeller with the motor, it is essential that vibrations are minimized since excessive vibration could compromise impeller operation and, due to fluid resistance, require high power input. Moreover, the AFPM configuration facilitates higher torque generation compared to a conventional radial flux permanent magnet synchronous motor (RFPM). In a slotless AFPM motor, the absence of stator teeth prevents core flux saturation, thereby further enhancing torque performance. AC losses occur in the conductors as a result of the magnetic flux produced by the permanent magnets, and similar losses arise within the PCB circuits. Therefore, an optimized PCB circuit design is essential to reduce these losses. The Constant Trace Conductor (CTC) PCB circuit design process is proposed as a viable solution to mitigate AC losses. A 3D finite element analysis (3D FEA) model was developed, analyzed, fabricated, and validated to verify the proposed solution. Full article

The rapid advancement of technology has increased our reliance on axial flux permanent magnet machines (AFPMMs), making Printed Circuit Boards (PCBs) essential for modern, lightweight designs. This study reviews PCB roles in AFPMMs for low- and high-power applications by examining research from 2019 to 2024. Using the PRISMA methodology, 38 articles from IEEE Xplore and Web of Science were analyzed. This review focuses on advancements in PCB manufacturing, defect mitigation, winding topologies, software tools, and optimization methods. A structured Boolean search strategy (“Printed Circuit Board” OR “PCB” AND “axial flux permanent magnet machine” OR “AFPM”) guided the literature retrieval process. Articles were meticulously screened using the Rayyan software for titles, abstracts, and content, with duplicate removal performed via the Mendeley software V2.120.0. Findings show significant progress in lightweight AFPMMs with PCBs, improving power quality and performance. Research activity over the 6 years showed inconsistent growth, with concentrated trapezoidal winding emerging as the dominant configuration, followed by distributed winding designs. These configurations were particularly applied in single stator double rotor (SSDR) coreless AFPM machines, characterized by minimal defects, minimal losses, and optimized single-layer winding designs utilizing tools such as ANSYS and COMSOL. Growing interest in double stator single rotor (DSSR) and multi-disk configurations highlights opportunities for innovative designs and advanced optimization techniques. Full article

Circular Design methodology is essential for sustainable industrial practices. This study provides a methodology with a Python-based computational tool that optimizes industrial products’ disassembly sequences, focusing on Design for End of Life (DfEoL) and Design for Disassembly (DfD) to promote Circular Design. The tool creates disassembly precedence graphs and shows the best disassembly path for target components, facilitating material recovery and environmental sustainability. The tool was applied to a case study on an Axial Flux Permanent Magnet (AFPM) electric motor. The approach provides a flexible and open access solution for optimizing product design within a Circular Design framework. Full article

The study demonstrates an application of actual technologies and tools for the development of an axial-flux electricity generator. The specifics of its application—a run-of-river sited power station—predefine some of the design parameters that are close to a wind turbine generator. An extensive study of available solutions is used as a starting point for further concept development. The study aims to provide a viable solution for a large-scale electrical machine. A step-based methodology is defined for concept parameters’ assessment and a feasibility study. It demonstrates the advantages of virtual prototyping when assessing various design parameters such as air gaps, coil thickness, and the number of rotor disks. Several simulations over different virtual prototypes provide sufficient information to elaborate an improved design concept. The major result is a ready-for-detailed design concept, with defined major parameters and studied work behavior for a specific, large structure of an electrical machine. Another important result is the presentation of the application of virtual prototyping in the assessment of large structures, for which physical prototyping is an expensive and time-consuming approach. The application of virtual prototyping at a very early product development stage is an effective way to undertake efficient solutions involving the concept of the product. Full article