This paper discusses the effect of inductive coil shape on the sensing performance of a linear displacement sensor. The linear displacement sensor consists of a thin type inductive coil with a thin pattern guide, thus being suitable for tiny space applications. The position can be detected by measuring the inductance of the inductive coil. At each position due to the change in inductive coil area facing the pattern guide the value of inductance is different. Therefore, the objective of this research is to study various inductive coil pattern shapes and to propose the pattern that can achieve good sensing performance. Various shapes of meander, triangular type meander, square and circle shape with different turn number of inductive coils are examined in this study. The inductance is measured with the sensor sensitivity and linearity as a performance evaluation parameter of the sensor. In conclusion, each inductive coil shape has its own advantages and disadvantages. For instance, the circle shape inductive coil produces high sensitivity with a low linearity response. Meanwhile, the square shape inductive coil has a medium sensitivity with higher linearity.

Recently, a three-phase Field Excitation Flux Switching Motor (FEFSM) with salient rotor structure has been introduced with their advantages of easy rotor temperature removal and controllable FEC magnetic flux particularly suitable for high torque, high power as well as high speed diverse performances. Nevertheless, the salient rotor structure is found to lead a longer magnetic flux path between stator and rotor producing weak flux linkage along with low torque performances. Besides, the overlap armature coil and FEC windings yield high coil end length, producing much high copper loss and large motor size. In this paper, a new FEFSM using segmental rotor with non-overlap armature coil and FEC windings is proposed. The shorter magnetic flux path of the proposed segmental rotor is noticeably to be more focused to produce much higher torque while the non-overlap armature and FEC will reduce the copper loss and motor weight. Both FEFSMs with salient and segmental rotors are designed using 2D-FEA JMAG Designer version 14.1 for comparison. As a result, magnetic flux of the segmental rotor design is 11 times higher than the salient rotor structure mainly due to shorter magnetic flux linkage between two stator teeth and single rotor segment. The torque and power of 0.91 Nm and 293 W, respectively are obtained from the new FEFSM which are much higher than salient rotor design. In addition, the simulation and experimental results show a good agreement in back-emf amplitude and waveform at various speed, as well as similar increment of torque versus FEC current characteristics. As conclusion, the proposed FEFSM with non-overlap and segmental rotor structure has produced much higher flux, with significant improvement of torque and power performances compared with existing FEFSM with salient rotor.

This paper is aimed to analyze the thrust characteristics for two types of linear oscillatory actuator using 3D-finite element method (FEM). The coil currents are analyzed according to the variation displacement of moving yoke of the first one of the LOA. The thrust, normal force and cogging force are analyzed according to the variation of the air-gap length, thickness taper and high taper of second LOA. The size of both model of LOA is same but comparison refers to the characteristic of voltage, coil current, number of winding and force. The result of this project can be see from the graph of characteristic both model. Finally, the best characteristics of LOA can be constructed from the result.

The switched reluctance synchronous motors (SRSM) have been utilised as replacements for induction motors (IM) and permanent magnet synchronous motors (PMSM). The SRSM is a feasible solution for electric motors because of its robust and straightforward structure, resulting in low maintenance, manufacturing, and operating costs. However, the SRSM has several flaws, including low mean torque, low torque density and excessive torque ripples. The SRSM performance can be improved by considering the structure topology and driving system. This paper reviewed the performance characteristic of SRSM based on the structural topology. Several literature studies on the segmented structure topologies of SRSM were compared with the conventional structures. The performance of the SRSM can be estimated by using either numerical or analytical methods. The FEA and BEM are numerical techniques extensively used to optimise electrical motor performance. Although the numerical method can accurately estimate motor performance, the significant drawback is quite complicated, time-consuming, and difficult to implement the control algorithm with FEA software. However, the analytical method, especially the MEC method, is faster in evaluating motor performance and significantly reduces computational complexity, either with or without solving high-dimensional system matrices.

This study discusses the modelling of torque and speed characterisation of the double stator slotted rotor brushless DC motor (DSSR‐BLDC). Most double stators have a surface mount rotor structure. The problem with this structure is that it has a large air gap, expensive permanent magnet, and cannot operate at high speed. In addition to flux leakage when this type of rotor structure is used. To overcome this problem, the DSSR‐BLDC has been introduced. The usage of the DSSR‐BLDC is to minimise the flux leakage, thus increasing the flux linkage. This will increase the torque production for the DSSR‐BLDC. The aim of this research is to model the torque and speed characterisation of the DSSR‐BLDC. This model uses the permeance analysis method and finite element method. The maximum torque and speed can be determined using both methods. The analyses of the electromagnetic torque, output power, and efficiency for various voltages are also presented. The simulation and measurement result show a good agreement with each other. The highest measurement value of the electromagnetic torque is 11 N m at 100 rpm. In conclusion, this study reveals that the modelling of the torque and speed characterisation of the DSSR‐BLDC is suitable for portable applications.