Search Results (207)

Magnetic integration couplers offer many advantages in wireless power transfer (WPT) system design, but additional coupling will lead to some drawbacks. This paper proposes a new magnetic integration scheme for an LCC–LCC compensation network in WPT systems. First, separate mutual inductance equivalent models are established for each type of additional coupling between the transmitting and receiving coils and the compensation coils. The effects of these additional couplings on the power-transfer characteristics are then analyzed. Second, finite element simulations are conducted to evaluate the decoupling performance of three magnetic integration schemes under aligned and misaligned conditions. The scheme employing DD-type transmitting and receiving coils arranged orthogonally with double-layer DD-type compensation coils demonstrates superior decoupling capability. Third, an integrated magnetic coupling mechanism is fabricated, and the coupling coefficients are measured under aligned and misaligned conditions. The proposed integration scheme effectively decouples multiple additional couplings, achieving about a 65% reduction in the compensation-coil additional coupling coefficient. Finally, an experimental prototype is implemented. The experimental results show a maximum transfer efficiency of 95.2%. Full article

Magnetic-field coupled wireless power transfer (MC-WPT) systems require reliable power delivery as well as real-time bidirectional data communication. To satisfy this requirement, a simultaneous wireless power and full-duplex data transfer (SWPFDT) system based on a three-coupled bilateral LCC topology is proposed in this paper. In the proposed structure, the power coil, backward-signal coil, and forward-signal coil are implemented as a solenoid-type monopole coil, a solenoid-type bipolar coil, and a DD (double-D) coil, respectively. By utilizing the orthogonal relationship among the magnetic-field distributions of different coils, the desired coupling within each channel and mutual decoupling among the three coil sets are achieved, thereby structurally reducing inter-channel crosstalk. Based on this configuration, an equivalent circuit model of the system is established, through which the constant-current output characteristics, forward and backward signal transmission gains, signal crosstalk, and power-to-signal interference are analytically derived. In addition, the resonant parameters and wave-trapping networks are designed accordingly. A laboratory prototype is developed for experimental verification. Experimental results show that the proposed system can achieve 150 W power transfer with an efficiency of 88.7%. With a 19.2 kbps communication rate, the system can stably realize full-duplex data transmission with limited interference between the forward and backward channels, while maintaining constant-current output and reliable communication under dynamic load switching. Full article

The main scope of this research was to complete and validate the analysis of stator winding topologies of six-phase AC machines using the winding quality factor by determining fault tolerance and validating it through experimental tests. This paper proposes a unified and practical methodology for evaluating the performance of stator windings in six-phase induction machines, with emphasis on magnetic field quality and fault-tolerant operation. The approach combines analytical modeling of the magnetomotive force (MMF) with its graphical representation using the MMF polygon, enabling an efficient assessment of harmonic content through a global indicator, referred to as the winding quality factor. Several representative winding topologies are analyzed within a common framework, including single-layer and double-layer configurations with full-pitch and short-pitch coils, suitable for generating homologous series of six-phase machines. The study considers both normal operating conditions and post-fault regimes, particularly operation with a single three-phase set. The results reveal the strong influence of winding topology on harmonic distortion and overall machine performance, highlighting the trade-offs between magnetic field quality and fault tolerance. It is shown that appropriate winding design can reduce spatial harmonics and improve robustness under degraded operating conditions. The theoretical findings are validated through experimental investigations, demonstrating good agreement between analytical predictions and measured data. A parallel analysis was performed between the theoretical findings and experimental data, and the results conform to the authors’ expectations. Full article

Introduction: Mild cognitive impairment (MCI) is a transitional stage between normal ageing and dementia, affecting ~35% of adults aged 70+ and carrying a 15–18% annual risk of progression. Cognitive training (CT) shows promise but outcomes are variable and transfer to daily function is unclear; intermittent theta burst stimulation (iTBS) may enhance prefrontal neuroplasticity. Few studies have evaluated whether combining CT and iTBS in MCI is practical, acceptable, and safe. Methods: This 18-week, randomised, double-blind, sham-controlled feasibility pilot trial will recruit 44 individuals with MCI, randomised 1:1 to CT + active iTBS or CT + sham iTBS. Participants complete 14 CT sessions over 10 weeks; accelerated iTBS is delivered in five sessions per day over five consecutive days at 75% resting motor threshold to the left DLPFC using neuronavigation, with reversed-coil sham. Primary outcomes are feasibility, acceptability, adherence, and safety; secondary (exploratory) outcomes are cognitive, functional, and psychological; tertiary (mechanistic) outcomes are EEG- and TMS-derived neurophysiological measures. The trial is not powered for efficacy: feasibility and neurophysiological outcomes will be analysed descriptively, while secondary outcomes will be analysed using linear mixed-effects models. Ethics and dissemination: Ethical approval has been granted by the Western Sydney University HREC (H16500); written informed consent will be obtained before enrolment. Trial registration number: ACTRN12625000952448. Full article

Wireless power transfer has become an increasingly widespread technology in electric vehicle and charging-system applications. Advances in power electronics have led to significant improvements in system efficiency, and in parallel, extensive research has been conducted on energy storage technologies and coil designs. In this study, a split-coil structure using a dual inverter system is analyzed, aiming to achieve a flatter magnetic-flux distribution for electric vehicle charging systems and battery energy storage circuits or an increase in total flux density for power applications. A flatter flux distribution will make a significant improvement in electric vehicle charging systems under misalignment conditions. The key point based on these concepts is the dually driven split coil, which is analyzed as both a single-layer and a double-layer coil. The main objective of the present study is to investigate the magnetic-flux distribution and the performance of the proposed fully symmetric two-layer coil structure under nominally aligned conditions. Owing to the fully symmetric geometry, the presented one-dimensional magnetic-flux scan is sufficient for comparing the flux-distribution characteristics of the proposed and conventional coil structures. Following the demonstration that the single-layer split coil design was ineffective, theoretical analyses and experimental data indicate that the double-layer split-coil design provides 10% higher efficiency. Full article

High-purity SiC powder is an important feedstock for SiC crystal growth, but thermal-field regulation becomes difficult during large-batch synthesis. This study examined an α-SiC powder-synthesis furnace with upper and lower induction-coil groups through numerical simulations and 70 kg synthesis experiments. A representative two-dimensional axisymmetric model was used to compare eight cases with different coil-turn or numerical power allocations. Redistributing the coil turns changed $E_1$, $E_2$, volumetric Joule heat density, $Q$, and the resulting temperature and calculated gas-phase velocity-magnitude fields. From C01 to C04, the maximum calculated temperature decreased from 2501.10 to 2359.13 K, while $\Delta T$ decreased from 242.57 to 76.20 K. Increasing the upper-coil numerical power raised the temperature level while reducing $\Delta T$ to 152.41 K. Increasing the lower-coil numerical power also raised the temperature level, but increased $\Delta T$ to 292.26 K. Equal-total-power comparisons showed that axial power allocation affected $T_{\mathrm{m}\mathrm{a}\mathrm{x}}$ and $\Delta T$. XRD identified 6H-SiC as the detected crystalline phase in both analyzed middle-region specimens, although X-ray-amorphous carbon could not be excluded. The specimens also differed in macroscopic appearance, measured impurity concentrations, and local nitrogen concentration profiles. Because the experimental conditions were maintained nominally unchanged except for the upper-coil current, these specimen-level differences may be associated with altered internal thermal conditions. Such changes may affect local equilibrium, supersaturation, and species transport, providing a possible link to the observed material differences. The numerical results identify coil-turn allocation and axial power allocation as variables for regulating the calculated furnace fields. Full article

Background/Objectives: Double-J stents (DJS) cause clinically significant lower urinary tract symptoms (LUTS) in 58–80% of patients following ureteroscopy (URS). The distal vesical coil is regarded as the primary anatomical source of trigonal irritation and detrusor instability. The single-J stent (SJS) eliminates this element while preserving the proximal renal pigtail for anti-migration anchorage. This study aimed to evaluate the safety and patient-reported symptom outcomes of a modified SJS compared with standard DJS following elective URS for ureteric stone disease. Methods: A prospective, single-arm, within-patient feasibility study was conducted in 28 adults undergoing elective URS at Austin Health, Melbourne, Australia (Human Research Ethics Committee (HREC)/25658/Austin-2025; NCT07535580). A modified SJS was fashioned from a commercially available 7Fr Bander™ ureteral diversion stent (Cook Medical, G14780) by trimming the shaft to 28 cm and affixing a 7 cm Prolene retrieval suture (Ethicon NW807) to the blunt distal end. The primary outcome was a cystoscopically confirmed SJS migration rate at removal (pre-specified feasibility threshold ≤5%). Secondary outcomes included change in Ureteral Stent Discomfort Test (USDT) total and domain scores (paired analysis, n = 24), adverse events, and patient preference. Results: The clinically significant migration rate was 0% (0/28); 27/28 stent tips were freely floating within the bladder, with one asymptomatic tip at the ureteric orifice at the scheduled removal visit. Mean total USDT score decreased from 39.92 ± 2.00 (DJS) to 30.42 ± 1.73 (SJS)—a mean absolute reduction of 9.50 points (23.8%; p < 0.001), a magnitude consistent with clinically relevant change, although a USDT-specific minimum clinically important difference has not been independently validated. All six USDT domains improved significantly (all p ≤ 0.014). No adverse events were recorded. All 28 patients (100%) reported they would choose the SJS again. Conclusions: The modified SJS demonstrated a favourable safety profile and was associated with lower patient-reported symptom scores than the preceding DJS across all USDT domains in this uncontrolled within-patient comparison. Because stent design, stone burden, and dwell time differed between the two assessment phases, these differences should be regarded as hypothesis-generating and provide a feasibility basis for a prospective randomised controlled trial evaluating the SJS following URS. Full article

A double-ended traveling-wave accurate fault location method based on variational mode decomposition (VMD), generalized S-transform (GST), and a symmetric difference energy operator (SDEO) is proposed for single-phase-to-ground faults in small-current grounding distribution networks. The method is designed for fault conditions in which the fault current amplitude is low, the transient duration is short, and the initial traveling-wave wavefront is easily affected by high-frequency oscillation, reflection, refraction, and noise. The three-phase voltage traveling waves measured at both ends of the fault section are first transformed using Clarke modal transformation, and the voltage line-mode component is selected as the input signal. VMD is then used to decompose the nonstationary traveling-wave signal into several finite-bandwidth intrinsic mode functions. The high-frequency mode containing the initial wavefront mutation is processed using the generalized S-transform to enhance local time–frequency features. Finally, the SDEO instantaneous energy spectrum is used to calibrate the initial wavefront arrival time. For distance calculation, an improved double-ended traveling-wave location formula based on the horizontal section length and the absolute propagation time ratio at both line ends is constructed. This formulation reduces the dependence on a fixed empirical wave velocity and weakens the influence of line length deviation caused by practical line geometry. The method is verified using a deterministic PSCAD/EMTDC v5.0.2 and MATLAB R2021b co-simulation model with a fixed distribution network topology and arc-suppression-coil grounding. The tested cases cover selected fault distances, transition resistances, and fault inception angles. The simulation results show that the absolute location error remains within 100 m under all tested deterministic cases. The representative location error is 15 m at the 2.5 km fault point, 45 m under a 500 Ω transition resistance at the 1.5 km fault point, and 11 m under a 90° fault inception angle at the 6.15 km fault point. Compared with EMD-TEO, VMD-TEO, and VMD-GST, the proposed VMD-GST-SDEO method provides more stable wavefront calibration and lower location error in the studied cases. The results indicate the feasibility of the proposed approach within the stated simulation scope; further validation under stochastic noise, synchronization error perturbation, different sampling frequencies, and measured field waveforms is still required for engineering deployment. The fundamental novelty of the study lies in the task-oriented integration of VMD, GST, and the SDEO as a complete wavefront calibration chain and in coupling this chain with a propagation-time-ratio-based double-ended location formula for small-current grounding distribution networks, rather than in treating VMD, GST, or the SDEO as new standalone signal-processing algorithms. Full article

Wireless power transfer (WPT) has emerged as a promising technology for electric vehicle (EV) charging owing to its capability to provide convenient, safe, and contactless energy transfer. This paper presents a comprehensive review of recent advances in wireless EV charging systems. Different charging architectures, including static, quasi-dynamic, dynamic, and bidirectional configurations, are discussed. Basic and hybrid compensation topologies are critically examined with emphasis on their operating characteristics and suitability for EV applications. Various magnetic coupler structures, ranging from conventional circular coils to double-D, quadrature, bipolar, and multi-coil configurations, are reviewed in terms of coupling performance and misalignment tolerance. In addition, conventional, advanced, and intelligent control strategies, including frequency, phase-shift, duty-cycle, model predictive, adaptive, sliding mode, fuzzy logic, artificial neural network, and reinforcement learning approaches, are comparatively analyzed. Finally, the major technical challenges, electromagnetic compatibility and safety issues, economic barriers, emerging technologies, and future research directions are highlighted. This review provides a comprehensive reference for researchers and engineers and offers insights into the development of highly efficient, intelligent, and sustainable wireless EV charging infrastructures. Full article

The research utilizes Ansys Maxwell 2024 R2, a 3D Finite Element Analysis (FEA) software, to compare the electromagnetic coil parameters, losses, and efficiency of planar spiral circular, square, and round-cornered square (RCS) coils for wireless power transfer (WPT) systems in electric vehicle (EV) applications. This study focuses on key coil parameters such as self-inductance, mutual inductance, and the coupling coefficient, which are crucial for determining power transfer and system efficiency. While analytical calculations for these parameters are straightforward for air-core transformers, they become complex and inaccurate when ferrite cores are incorporated to improve efficiency. Ansys Maxwell overcomes this challenge by employing a numerical method. Simulation results indicate that RCS coils offer uniform magnetic field distribution and reduced losses, similar to circular coils. They also exhibit better coupling and good misalignment tolerance, akin to square coils. These characteristics suggest that RCS coils are a superior choice for WPT applications. Electro-thermal management (ETM) co-simulation of the RCS coil is performed and analyzed using Ansys Icepak 2024 R2. Furthermore, an Ansys Twin Builder 2024 R2 co-simulation of a double-sided LCL-compensated WPT system, incorporating the reduced-order model of the RCS coil, is performed. Under standardized EV conditions, say 85 kHz, 35 mm, and 50 Ω load, the RCS coil achieves an efficiency of 94.81%. The research also includes loss analysis and misalignment tolerance studies, confirming the superiority of RCS coils. Full article

Compact wireless electronic devices require charging interfaces that can support different receiver positions and orientations within limited spaces. In this context, a double-sided mixed-coupling structure can provide independent magnetic- and electric-field power-transfer paths by combining coil-based and plate-based coupling mechanisms. This paper proposes a double-sided mixed-coupling wireless power transfer (DMPT) coupler for compact wireless electronic devices related to the Internet of Things (IoT) and the Internet of Drones (IoD). The proposed coupler integrates an upper coil-based magnetic-field coupling path and a lower stacked-plate-based electric-field coupling path within a single transmitter structure. Through this configuration, inductive wireless power transfer (IPT) and capacitive wireless power transfer (CPT) are implemented as independent double-sided power-transfer paths. To analyze the resonant behavior, a three-port equivalent circuit including mutual inductance and mutual capacitance is developed, and the resonance splitting under the uncompensated condition is investigated using even/odd mode decomposition. The predicted resonant frequencies agree with the ANSYS HFSS results with errors of 0.16% and 1.12%. After series-L compensation, the 60 × 60 × 7.31 mm³ coupler operates at the 6.78 MHz industrial, scientific, and medical band, showing S₁₁ ≈ 0.042, S₂₁ ≈ 0.68, and S₃₁ ≈ 0.64 under the double-sided aligned condition. Field and transient waveform analyses further verify that the upper H-coupling region and lower E-coupling region operate simultaneously while being spatially separated. The proposed DMPT coupler provides a coupler-level design framework for implementing IPT and CPT as independent double-sided coupling paths. Full article

This paper presents a five-coil array integrated wireless power transfer (WPT) system designed for implantable medical devices. The proposed structure features a collaborative design of driving and radiating coils, where each driving coil excites its corresponding radiating coil to emit power. All coil units are precisely tuned to operate at the 13.56 MHz ISM band. The unique array configuration generates a highly uniform magnetic field distribution within the target area, enabling excellent tolerance to lateral misalignment. System analysis based on scattering parameters (S-parameters) confirms the design’s outstanding power transfer efficiency at the operating frequency. By integrating the five-coil array onto a double-layer printed circuit board, the system achieves the miniaturization and high integration level required for implantable applications. The experimental results demonstrate that the system reaches a maximum transfer efficiency of 55% under ideal alignment conditions (with a transfer distance of 10–20 mm). Notably, even with a lateral displacement of 5–10 mm at a 10 mm transfer distance, the system maintains stable performance, with efficiency consistently exceeding 50%. These results validate the system’s capability for reliable and efficient wireless power delivery in clinical settings. Full article

In underwater inductive power transfer (IPT) systems, the variation of eddy-current losses with frequency can degrade the accuracy of parameter identification. To address this issue, this paper proposes a multi-parameter identification method for a double-sided LCC system. First, based on the circuit model and the frequency dependence of the equivalent eddy-current loss resistance, six sets of equations are established, transforming the parameter identification problem into an optimization problem. Then, to balance global search capability and convergence speed, a hybrid particle swarm optimization algorithm is employed to identify the unknown parameters. Simulation and experimental results show that, under different coil spacings, load conditions, and medium conductivities, the proposed method can accurately identify key parameters, with the overall relative error controlled within 5%. This method is applicable to parameter monitoring and performance regulation of underwater IPT systems. Full article

Aflatoxin B1 (AFB1) poses a serious threat to global food and feed safety. Laccase-based enzymatic degradation represents a promising green strategy for AFB1 removal; however, its industrial application is severely limited by the rapid thermal inactivation of wild-type enzymes under high-temperature processing conditions (>70 °C). Here, we engineered the thermal stability of a laccase from Bacillus amyloliquefaciens B10 through an integrated strategy combining computational structural biology with semi-rational design. By coupling molecular dynamics (MD) simulations with folding free-energy (ΔΔG) calculations, we identified key flexible regions associated with thermal instability and subsequently implemented iterative saturation mutagenesis. The best single mutant, R196C, retained more than 96% relative activity after heat treatment at 80 °C for 10 min. Further iterative mutational stacking progressively enhanced thermostability: the R90E/R196C double mutant showed 1.25-fold higher activity at 80 °C than R196C, and the R90E/R196C/H54F triple mutant showed a further 1.16-fold increase over the double mutant. The final quadruple mutant, R90E/R196C/H54F/R253I, achieved 86.9% AFB1 degradation at 80 °C after 24 h. High-temperature MD simulations (100 ns at 353.15 K) indicated that the enhanced thermostability was associated with reduced conformational flexibility, lower radius of gyration (Rg) and solvent-accessible surface area (SASA), and a coil-to-β-sheet transition that contributed to stabilization of the protein core. In addition, efficient secretory expression of the engineered enzyme was achieved in Pichia pastoris, reaching 3.0 U/mL, while the crude enzyme maintained more than 70% activity at 80 °C. Collectively, these results provide a practical basis for the rational engineering and scalable production of thermostable biocatalysts for AFB1 detoxification-related applications of AFB1 control, and offer broader insights into the targeted enhancement of thermal stability in industrial enzymes. Full article

This paper proposes a Hybrid-Field DD (HFDD) coupler designed for wireless power transfer (WPT) in mobile robots within smart manufacturing environments, utilizing a dual-coupling mechanism of magnetic and electric fields. The proposed coupler integrates Double-D coils for vertical magnetic field concentration with a split metal plate structure for enhanced electric field coupling in a compact, low-profile design. To evaluate the electromagnetic performance and the impact of inevitable eddy current interference, two distinct configurations—Front Plate Arrangement (FPA) and Back Plate Arrangement (BPA)—are analyzed through both theoretical modeling and 3D full-wave simulations (HFSSs). The comparative results demonstrate that the FPA model reduces the peak induced current intensity by 56.23 A/m compared to the BPA and achieves a peak leakage magnetic field intensity of 1.12 A/m, which is 28% lower than the 1.56 A/m observed in the BPA, offering a superior solution for suppressing leakage magnetic field and contributing to robust coupling stability. The high consistency between the proposed analytical methodology and numerical simulations underscores the theoretical robustness of the HFDD structure, establishing a clear design framework for efficient power transfer in robotic applications. Full article