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This paper proposes the design and analysis of a flux modulated (FM) permanent magnet (PM) linear actuator for the long track gantry robot system used to detect fire hazards in an electric energy storage system (ESS). A detailed design framework for the FM-linear actuator inspired by the magnetic gearing effect is proposed which includes the selection of slot-pole pair numbers and assigning optimal geometric parameters based on working harmonic characteristics. Using the optimal model, the electromagnetic performances both under no-load and full load conditions are performed to check the feasibility of the actuator for the gantry system. A prototype is built to validate the results obtained using the 2D and 3D finite element analysis (FEA). [ABSTRACT FROM AUTHOR]

The transverse flux machine (TFM) is a promising driving machine, especially for the low-speed applications, because it has greater power density, torque, and efficiency than the conventional electrical motors. However, the TFM has a complicated structure, a large torque ripple, and, occasionally, an unbalanced magnetic force. This paper investigates the effects of teeth geometry on torque ripple and unbalanced magnetic force in a rotatory two-phase TFM using the 3-D finite element method, and proposes a rotatory two-phase TFM with herringbone teeth to reduce the torque ripple and eliminate the unbalanced magnetic force. Index Terms--Herringbone teeth, torque ripple, transverse flux machine (TFM), unbalanced magnetic force.

The traditional engine valve train in a combustion engine is the mechanically driven camshaft system that provides one-fixed valve timing. The variable valve timing (VVT), however, is highly required to achieve the significant improvement in fuel economy and lower emission. To provide the VVT, the double solenoid type of actuators with steel-made armature have been developed in past years, but it requires electric power in the most engine operating period, the starting is difficult and the efficiency is low. In this paper, a new linear actuator using permanent magnets is proposed and the dynamic performances are analyzed by finite-element analysis. The results show that the designed colenoid system has a fast transition time between valve events suitable for the practical use in combustion engine valve system Index Terms--Colenoid, finite-element analysis, linear actuator, solenoid, variable valve timing (VVT).

In this paper, a transverse flux reluctance motor circuit-field model, based on a variable equivalent air gap permeance concept, is introduced. The core nonlinearity is fully considered through a saturation factor, calculated with the support of the finite-element method (FEM) analysis. A simplified model variant is developed and the calculated values are compared with the ones obtained by the FEM analysis. The model provides simple analytical expressions useful for dynamic analysis as well as for online control. Index Terms--Circuit-field model, saturation coefficient, transverse flux reluctance linear motor (TFRLM).

This paper presents the development of a transverse flux linear motor (TFLM) with permanent-magnet excitation for Stocker system, which is used for transferring glasses in the liquid crystal display industry. Magnetic field is analyzed by three-dimensional equivalent magnetic circuit network method and two-dimensional finite-element analysis is used to determine the influence of the end effect of a mover on the performance of TFLM. The experimental results of a prototyped motor are in good agreement with the analysis ones. Index Terms--Direct drive, equivalent magnetic circuit network, high force density, transverse flux linear motor.

This work presents a coursework design process to study the fugitive dust generation and detection method in South Korean Cities. The work is broadly classified into two parts, namely, designing of a software-based virtual platform to study the fugitive dust generation sites i.e the construction sites in a 3D computational fluid dynamics (CFD) environment and developing a low-cost dust concentration detection sensor to perform the different laboratory-based test within undergraduate coursework. The work also evaluates the effectiveness of the dustproof nets usually used by the construction industry in preventing fugitive dust. A detailed background check in terms of theoretical and legal rules has been studied. Then detailed simulations are performed and finally, the sensor system is developed to perform field tests. [ABSTRACT FROM AUTHOR]

This article proposes a 65 kW rim-driven direct-drive flux concentrated permanent magnet synchronous generator (FCPMSG) used in urban water pipeline energy harvester (UWEH) system. The proposed UWEH system plans to use hydraulic bearing; thus, a balanced radial force topology should be selected with high electromagnetic performance. Considering the hydraulic bearing mechanism and the installation of the proposed PM synchronous generator (PMSG), the effect of the loading and slot harmonics on the radial magnetic forces is analyzed. Furthermore, by studying the effect of the passive and active electric loads on the PMSGs, radial force characteristics are analyzed to select the operation region. [ABSTRACT FROM AUTHOR]

This article proposes the design and driving mechanism of a single drive motor integrated electromechanical actuator system for the application in computer numerical control (CNC) lathe machines. The electromechanical actuator is designed in such a way that it can replace the conventionally used hydraulically powered headstocks of the lathe machine. To achieve a drawbar thrust of 50 kN and a spindle speed of 4000 r/m, a detailed design with an explanation of different internal parts of the electromechanical actuator is presented. The production ready model was simulated to select the safety factor of the whole system and to enquire the amount of deformation when 50 kN thurst is generated. A prototype is manufactured based on the analysis model and is tested for different modes of operation. The experimental results validate the capability of the electromechanical actuator to produce the require drawbar thrust of 50 kN and spindle speed of 4000 r/m. [ABSTRACT FROM AUTHOR]

In this article, the design and characteristic research of the coaxial magnetic gear for the contra-rotating propeller in the premium yacht are presented. The scale-down model of 1/25 is reviewed as the research of the applicability of the coaxial magnetic gear. The space harmonic characteristics of the magnetic field in the coaxial magnetic gear with the low gear ratio from 1 to 2 are investigated, and the optimized models with the surface-mounted permanent magnet and quasi-Halbach array are obtained using the response surface method. In the several operating points of the diesel engine, the magnetic loss and the resultant thermal characteristics are analyzed and compared in each model. Finally, the desired coaxial magnetic for the contra-rotating propeller in the premium yacht is achieved. [ABSTRACT FROM AUTHOR]

Featured Applications: electric vehicle, personal mobility, propulsion systems, renewable energy systems, aerospace, and defense industry. The doubly fed magnetic geared motor, which has dual AC windings, can be operated with different frequencies in the inner and outer windings. However, the inner and outer windings have different numbers of pole pairs to meet the pole combination derived by the magnetic gearing effect, and hence undesirable space harmonic components of the magnetic flux are produced at the air gaps. These space harmonics affect the iron losses at each core, and the resultant iron loss and efficiency are varied by the frequencies of the inner and outer windings. Thus, in this paper, first, the effect of the space harmonic components of the air gap magnetic flux density in the inner stator, outer stator, and the modulating pieces is separately investigated. In addition, the iron loss characteristics of each ferromagnetic material are presented according to the frequency combinations in the inner and outer windings. Secondly, the iron loss maps and the efficiency maps according to the frequency conditions of the inner and outer windings are drawn, and the causes of the characteristic differences in each map are analyzed. Thirdly, the frequency control sequence and the roles of the inner and outer windings as the armature and field parts are changed, and the analysis of the iron loss map and efficiency map is repeated. Finally, the results in the inner-armature case and the outer-armature case are compared with each other, and the possibility of improving the overall operating efficiency over the multiple operating points by using the individual frequency control and frequency combination selection is proved. [ABSTRACT FROM AUTHOR]

This paper proposes two novel airgap profile designs and distributed airgap arrangement scheme for reduction of winding and thermal losses in high frequency current transformer (HFCT) sensors. The novel airgap profiles namely, zigzag and stepped airgap profiles are proposed to reduce fringing flux around the winding conductors. Moreover, to decrease winding and thermal losses, distributed airgap arrangement scheme is proposed. In distributed airgap arrangement, a single airgap is distributed to multiple equidistant smaller airgaps around the magnetic core. The analysis is performed using 3D finite element analysis (FEA) method. The 3D-finite element analysis results confirm that the HFCT sensors with the proposed airgap profiles and arrangement scheme can reduce winding and thermal losses ensuring high performance for HFCT sensors. [ABSTRACT FROM AUTHOR]

Recently, the permanent magnet vernier machine (PMVM) is studied extensively because of its merits such as the high torque density. Similar to the magnetic gears, the PMVM operates on the principle of flux modulation. However, there is a distinct difference in between the two as unlike the magnetic gear, in case of PMVM, the winding MMF harmonics rotates with different speed as that of the fundamental. As a result, these harmonics are capable of making a working magnetic field by interacting with different permeance harmonics. Therefore, this paper aims to provide an analytical explanation of this whole process, which is helpful to understand the effect of the flux modulation on the output torque. Furthermore, using the analytical formulation, this work finds the optimal geometric parameters which maximize the working magnetic field and hence the torque. A detailed analysis of the PMVM with the doubly salient structure is studied and the performance is analyzed using the finite element method (FEM) and the experimental setup. The FEM and experimental results verify the maximum torque production by using the optimal geometric parameters in the PMVM modeling, obtained using the analytical formulation. [ABSTRACT FROM AUTHOR]

This paper proposes the design of a linear magnetic position sensor (LMPS) to detect the mover position of the permanent magnet linear synchronous machines (PMLSMs). The working principle of the LMPS is based on the well-known Hall-Effect. The Hall-Effect-based design of LMPS is considered because it provides a low cost and relatively harsh environment susceptible alternative for the position detection for long track PMLSM system. The initial design was performed using 3D-finite element analysis and genetic algorithm-based deterministic optimization. Based on the initial model, four LMPS were manufactured and tested under the output constraint of peak flux density > 0.1T and total harmonic distortion < 3%. From the test results, it is concluded that the manufactured LMPS suffered significant deviation in output compared to the simulation model. These anomalies arise because of the manufacturing tolerances. To further improve the design and manufacturing process of the LMPS considering the effect of tolerance, a reliability-based robust design optimization (RBRDO) of the LMPS is proposed. The results of RBRDO confirms its usefulness for the design process of the LMPS in terms of undesired design non-compliance cost and great robustness without sacrificing the accuracy of the output signal. [ABSTRACT FROM AUTHOR]

Axial‐flux permanent magnet synchronous machines (AF‐PMSM) using printed circuit board (PCB) windings are attracting interest because of an increased demand for machines with thinner geometries. A critical element in designing these machines is the choice of its PCB winding which should ensure high‐performance characteristics with an efficient use of the PCB surface. However, there is a gap in the knowledge regarding the performance of different PCB topologies. The research reported here is motivated by the need to compare common wave‐type PCB windings stator topologies. Accordingly, overlapping parallel wave, non‐overlapping radial wave and overlapping radial wave PCB winding topologies are assessed, using finite‐element analysis, and compared based on their key performance characteristics such as the generated back‐electromotive forces, inductances and electromagnetic torque. The PCB winding that provides the best torque production is then chosen and manufactured. Experimental tests on the prototyped PCB AF‐PMSM provide validation. [ABSTRACT FROM AUTHOR]

Unlike the coaxial magnetic gear (CMG), the magnetic geared machine (MGM) has the ac armature winding on the inner part or the outer part. Besides, the PM excitation field of the CMG and the ac armature field of the MGM have different space harmonic components of magnetic field from one other. Hence, the flux modulation characteristics in the CMG and the MGM are different, and the resultant magnetic radial forces at the modulating pieces are also occurred differently from one another. Thus, in this paper, first, the flux modulation characteristics of the PM excitation field in the CMG and the ac armature field in the MGM are presented. Second, the characteristics of the magnetic radial forces at the modulating pieces are analyzed, and the causes of the radial force according to the space harmonic components of the magnetic field are compared in the CMG and the MGM. [ABSTRACT FROM AUTHOR]

The problem of the computationally efficient analysis of the electromagnetic system with nonlinearity is considered in the proposed work. Unlike the previously proposed proper orthogonal decomposition (POD)-based model order reduction (MOR), the proposed method based on the dynamic mode decomposition works well even under the highly nonlinear system. Using the proposed method, a highly saturated interior permanent-magnet (IPM) motor model is analyzed. Comparisons in terms of the radial air-gap flux density and torque are made with that of the full and POD-based models. The results show that the proposed method is capable of giving a good approximation of the full model of the IPM motor. Also, a reduction in the computational time can be achieved compared with that of the traditional POD-based MOR. [ABSTRACT FROM AUTHOR]

This paper presents a novel parametric design analysis of the magnetic sensor module used to find mover positions in linear motors. The proposed framework utilizes a computationally inexpensive proper orthogonal decomposition-dynamic mode decomposition-based model order reduction (MOR), coupled with a multiparameter moment matching method. The model is then utilized by a moment-based probabilistic design optimization method that considers the manufacturing uncertainties to find the optimal sensor design. A magnetic sensor module is designed for employing the proposed framework, and the results show that: 1) the proposed MOR technique is accurate; 2) the reliability analysis performed during the probabilistic design optimization can help to reduce the excessive non-compliance costs for the manufacturers; and 3) the combined framework is able to significantly expedite the optimal design search. [ABSTRACT FROM AUTHOR]

This paper investigates the vibration and noise characteristics of the coaxial magnetic gear (CMG) by the electromagnetic forces. In the CMG, the vibration and noise can be generated by the exciting forces acting on three parts, namely, low-speed rotor, high-speed rotor, and modulating pieces, respectively. The electromagnetic forces acting on three parts of the CMG and their force frequencies are calculated by using the Maxwell stress tensor method. Also, the mode shapes of the CMG full model and their resonance frequencies are obtained by the modal analysis. Through the electromagnetic forces and the result of the modal analysis, the vibration calculation is performed by using the 3-D-finite element method. Then, the effect of displacement on noise is confirmed by comparing the vibration calculation data and experiment data. The result shows the most affected part among the three parts of the CMG due to the noise is the low-speed rotor. [ABSTRACT FROM AUTHOR]

This paper investigates the characteristics of the radial force density according to the shapes of the flux modulation poles (FMP) in a surface-mounted vernier machine (SPMVM). The air-gap flux density harmonics obtained from the finite-element analysis method are analyzed using the analytical equations derived from the magnetomotive force and the air-gap permeance distributions. Then, in order to find the radial force density harmonics that generate the exciting force on the stator, the spatial orders and the angular frequencies of the radial force density harmonics are calculated by using the Maxwell stress tensor method. The analysis results show that the permeance harmonics generate the radial force density harmonics, but the resulting harmonics of the radial force density are time-invariant in the spatial domain. Consequently, the variation of the FMP shape can improve the torque characteristics of the SPMVM without the increase of the exciting force on the stator core. [ABSTRACT FROM AUTHOR]

This paper presents an accurate initial pole position (IPP) estimation method for a surface mounted permanent magnet synchronous motor (PMSM) without the use of pole sensors. To estimate the IPP, the proposed method uses the concept of reference frame. In this method, three torque commands, separated by 45° electrically from each other, are applied to the PMSM. Using the reference torque commands, moving distances are measured and transformation matrix is applied to eliminate the load torque term. Finally, the IPP is determined using the secant method. The IPPs under no load and at specific loaded condition are measured. The result of the load condition is compared with the previously proposed two reference frame method. The proposed method gives better result under load condition, compared with the two reference frame method, which fails to give satisfactory result under load condition. [ABSTRACT FROM AUTHOR]

This paper proposes a design method for the flux modulation poles (FMPs) formed on the stator of surface-mounted permanent magnet vernier machines (SPMVM) considering the winding configurations. In three types of the SPMVM with the different winding configurations, the FMP shapes to maximize the output torque are optimized by employing the analytical equations for the magneto-motive force (MMF) due to the windings, permeance, and flux density in the air-gap. Then, the validity of the optimal shapes for the FMPs is verified by the finite element analysis. It is found that the optimal FMP shapes are designed differently in the three types of the SPMVM and increase the output torque by different ratios according to the winding configurations. In addition, the experimental results for the prototype show that the proposed method can optimally design the FMP shape by analyzing mathematically the effects of the winding configuration and the FMP shape on the output torque of the SPMVM. [ABSTRACT FROM AUTHOR]

The magnetic geared motor, which has improved torque density because of the magnetic gearing effect, has been researched. However, its narrow operating region due to the operating mechanism by the magnetic gearing effect and field flux by the PM is a challenge that needs to be overcome. Whereas, the doubly fed magnetic geared motor (DFMGM) can extend the operating region because of the double stator and double winding structure with the individual frequency control of the current fed to the inner and outer windings. However, two rotating magnetic fields, which are produced by the inner and outer winding flux, exist at the air-gap, and the large numbers of space harmonic components of the modulated flux density are produced at the air-gaps. These space harmonic components, which are produced by the winding MMF, influence not only the back-EMF of the winding but also the performances of the operating torque. Besides, the inner and outer windings affect each other in the back-EMF, and its characteristics appears differently in the inner and outer windings. Thus, in this paper, the structure, operating strategy, and basic characteristics according to the frequency condition in the inner and outer windings are presented. [ABSTRACT FROM AUTHOR]

This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric variables of the sensor module are considered while developing the parametric study. The operation of the sensor module is based on the principle of the airgap flux density distribution detection by the Hall Effect IC. Therefore, the design objective is to achieve a peak flux density (PFD) greater than 0.1 T and total harmonic distortion (THD) less than 3%. To fulfill the constraint conditions, the specifications for the sensor module is achieved by using POD-DMD based reduced model. The POD-DMD based reduced model provides a platform to analyze the high number of design models very fast, with less computational burden. Finally, with the final specifications, the experimental prototype is designed and tested. Two different modes, 90° and 120° modes respectively are used to obtain the position information of the linear motor mover. The position information thus obtained are compared with that of the linear scale data, used as a reference signal. The position information obtained using the 120° mode has a standard deviation of 0.10 mm from the reference linear scale signal, whereas the 90° mode position signal shows a deviation of 0.23 mm from the reference. The deviation in the output arises due to the mechanical tolerances introduced into the specification during the manufacturing process. This provides a scope for coupling the reliability based design optimization in the design process as a future extension., Competing Interests: The authors declare no conflict of interest.

A new method to detect the mover position of a linear motor is proposed in this paper. This method employs a simple cheap Hall Effect sensor-based magnetic sensor unit to detect the mover position of the linear motor. With the movement of the linear motor, Hall Effect sensor modules electrically separated 120° along with the idea of three phase balanced condition ( va + vb + vc = 0 ) are used to produce three phase signals. The amplitude of the sensor output voltage signals are adjusted to unit amplitude to minimize the amplitude errors. With the unit amplitude signals three to two phase transformation is done to reduce the three multiples of harmonic components. The final output thus obtained is converted to position data by the use of arctangent function. The measurement accuracy of the new method is analyzed by experiments and compared with the conventional two phase method. Using the same number of sensor modules as the conventional two phase method, the proposed method gives more accurate position information compared to the conventional system where sensors are separated by 90° electrical angles.