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Permanent magnet Vernier (PMV) machines have attracted more and more attention for their merits of high torque density and simple structure. And principle of electromechanical energy conversion is the most common way to investigate the PMV machine by calculating back EMF and electromagnetic torque. In this paper, a new perspective on the mechanism of PMV machines based on the Maxwell stress tensor...
Flux reversal permanent magnet (FRPM) machine, with magnets mounted on or inserted into the stator, is favorable for the direct drive applications. In this paper, a novel FRPM machine with Ralbach array magnets in stator slot opening is proposed. While the magnets are moved to the slot opening, effective airgap length is reduced and slot area is enlarged. The analysis results indicates that the torque...
This paper presents thermal analysis of a water-cooled dual-stator axial-flux permanent magnet (AFPM) machine with focus on the sandwiched rotor. The rotor of the machine is featured by combined rectangle-shaped magnets. Firstly, the eddy current losses in the PM are calculated and analyzed. Secondly, lumped-parameter and FE thermal models are established to calculate the temperature distribution...
This paper reports on a content addressable memory (CAM) employing a multi-Vdd scheme for low power pattern recognition applications. The complete design, simulation and testing of the chip is presented along with an exploration of the multi-Vdd design space. The proposed design, operating at an optimal operating point in a triple-Vdd configuration, increases the delay range by 2.4 times and consumes...
In this paper, a novel stator structure with axially tapered stator tooth tip is proposed to mitigate cogging torque and reduce the machine back EMF harmonics. Furthermore, the stator tooth tips are specifically designed to provide balanced axial electromagnetic force. In order to realize continuous variation of stator tooth tip widths, the soft magnetic composite (SMC) material is used for the stator...
Surface permanent magnet vernier (SPMV) motors are gaining more and more attentions over recent years due to their high torque density. Generally, most researches focuses on their applications in low speed, high torque area, and the study on their high speed operation is rarely seen. In this paper, a SPMV motor with 12 slot, 20 rotor pole is evaluated for traction application. The optimal designed...
On stochastic transport network, travelers tend to reserve travel time budget (TTB) for every alternative route, to assure their on-time arrive with a predefined confidence level. This paper incorporates the concept of TTB into a deterministic nonlinear dynamic system, to model the day-to-day evolution process of travelers' risk-taking route choices on stochastic degradable road network. This paper...
This paper investigates the effect of AC losses on the steady-state temperature rise distribution in concentrated windings of permanent magnet machines with parallel strands by combined electromagnetic and thermal finite-element analyses. The copper losses are decomposed into DC loss, strand-level AC loss and bundle-level AC loss. It shows that the AC losses can significantly increase the winding...
In recent years, the magnetic field modulation motors (MFMM) are attracting more and more attentions due to their compact structure and contactless torque transmission function, etc. However, multi-design parameters and output ports make the optimization for the MFMM necessary and difficult. In this paper, an automatic multi-objective optimization of the MFMM based on the advanced differential evolution...
For autonomous air refueling (AAR) of unmanned aircraft, the measurement of relative position between receiver aircraft and tanker aircraft is critical in the docking phase. This paper proposes a monocular vision-based relative position estimation method, which calculates the location coordinate by recognizing the beacons on the drogue with image processing. To increase the robustness for rejecting...
To simulate the EM telemetry system in deviated and horizontal drilling, the underground formation is assumed to be horizontally layered media, and the long, metal drill string acts as an antenna that may be treated as a thin wire excited by a gap voltage source located near the drill bit. The numerical model employs the electric field integral equation (EFIE) and the method of moments (MoM) to obtain...
The on-line estimation of the DMSO (Dimethyl Sulphoxide) concentration of PAN-based carbon fibers is of significance to monitoring the quality of carbon fibers during production. In wet-spinning process, large amount of solvent (DMSO) diffuses from the interior of the coagulating fiber into the bath, and large amount of water diffuses in the reverse direction. This process can be modeled by a diffusion...
Recent extensions in the computation of Green's functions for multi-layered media and half-space problems are reported. For anisotropic problems, a two-level asymptotic singularity extraction is combined with extended Sommerfeld-related identities and the weighted average approach to provide additional acceleration and smoothing of Sommerfeld integrals for efficient simplex interpolation. For lossy...
In this paper, an exact analytical method is developed to computer the air-gap magnetic field of surface-mounted permanent-magnet (SMPM) motors for valuating slotting effects accurately. In order to improve the flux density and reduce cogging torque, the genetic algorithm toolbox of Matlab is used to optimize the motor, in which the actual depth of slot, slot opening, the length of gap and pole-arc...
An interior permanent magnet (IPM) machine applied in rail transportation is designed and optimized in this paper. A quasi-octagonal stator iron yoke is adopted in the machine in order to meet the requirement of the installation while the parallel slot structure is also employed due to the arrangement of the performed windings. The method of equivalent stator slot is proposed in this paper to analyze...
This paper mainly focuses on the analysis of the eddy current loss in permanent magnet (PM) of the surface-mounted PM vernier machine (SPMVM). The eddy current losses under open-circuit, armature reaction and load conditions are detailed investigated by the analytical method and finite-element analysis (FEA). The influence of the pole ratio, which is defined as the ratio of the rotor PM pole-pairs...
Fractional-slot concentrated-winding (FSCW) interior permanent magnet synchronous motors (IPMSMs) have been attracting considerable attention due to their high power density, high efficiency, short end-winding, high slot fill factor, low cogging torque, excellent flux-weakening and fault tolerance capability. However, compared to integer-slot distributed-winding (ISDW) IPMSMs, the key challenge of...
This paper first chooses Epanechnikov Kernel Density Estimation for moving foreground detection. Targets are extracted by labeling connected regions in the detected binary image. Kalman filter is then employed to proffer initial searching window for CAMShift algorithm to track targets and predict the future position of the targets. Meanwhile, the histogram of target is updated by the color information...
Facial aging is a complicated process which usually affects the facial appearance (e.g., wrinkles). Variations of facial appearance pose a big challenge to the automatic face recognition problem. How to eliminate the influence of aging factors to the verification performance is a very challenging problem. Multi-task learning has provided a principled framework for jointly learning multiple related...
This paper proposes an advanced spoke type permanent magnet (PM) servo motor with high torque density. The optimizations of split ratio and trapezoidal magnet dimensions are performed, and unequal airgap is employed to reduce the cogging torque. The designed trapezoidal magnets are used in one 3 Nm prototype to remove the rotor iron bridge, which introduces heavy leakage flux especially for the brushless...
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