Permanent Magnet (PM) machines are favorable as an alternative to other machine topologies due to simpler construction and high torque density. However, it may result hight torque ripple due to an influence of cogging torque and electronic commutation. In this paper, comparisons of phase back-emf, static torque and cogging torque due to influence of tooth-tip asymmetry in 12-slot/10-pole double-layer and 12-slot/10-pole single layer winding machines are carried out using 2D Finite-Element Analysis. At rated condition, the stator asymmetry has great influence on the torque performance as there is significant reduction of torque ripple in 12-slot/10-pole mahine equipped with single layer winding than one equipped with double layer winding machine. It si confirmed that an optimum torque performance is desirable via stator iron modification in PM machines.

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.

This paper discusses the modeling and analysis of three phase double stator slotted rotor permanent magnet generator (DSSR-PMG). The use of double stator topology through the double magnetic circuit helps to maximize the usage of flux linkage in the yoke structure of the single stator topology. The analytical computation is done using Permeance Analysis Method (PAM). Finite Element Analysis (FEA) is used for numerical verifications and to verify the design structure a prototype laboratory is performed. The analysis is done with various loading conditions to derive the electromagnetic torque, output power and efficiency for the proposed structure. The analytical, numerical and experimental results from the analysis are found to be in good agreement. The maximum power developed by this generator at rated speed of 2000 rpm is of 1 kW with the operational efficiency of 75%. A rectifier bridge circuit is used to make the generated voltage a storage capable constant voltage to make it suitable for mobile applications (such as Direct Current DC generator). The proposed generator structure is highly recommended for applications such as micro-hydro and small renewable plants.

<span lang="EN-US">Brushless DC (BLDC) motor is widely used for various applications such as transportation. BLDC motor has many advantages compared to brush motor such as more compact, high robustness and simplest construction. The maintenance of this motor also low compared to brush motor due to absent of the brush inside the motor. For electric bicycle application, the conventional motor has low electromagnetic torque because not properly designed. It faces low torque density as the motor in full load condition especially during climb uphill. In this research, an optimum magnetic energy is being determine by proper selection of permanent magnet size. In addition, this research also increases the input current in dynamic condition into the designed BLDC motor. Finite element method (FEM) is used to analyze other performance characteristic of improved motor such as back electromotive force (EMF), electromagnetic torque, flux linkage, and stator flux density. Parameter for improve the current motor are selected and varied based on the required specification. In conclusion, the research proposed the new motor specification that has highest electromagnetic torque of brushless DC motor. Finally, this research provides guidelines, suggestions and proposes a better improved structure in optimize the magnetic energy in BLDC motor.</span>

This paper discusses about design of hollow-rotor Brushless DC (BLDC) motor. A conventional BLDC motor has more leakage flux circling at the end of the permanent magnet that will limit torque. To overcome this problem, a new BLDC model known as hollow-rotor is proposed. The objective of this research is to design a hollow-rotor motor that will have higher torque density compared to conventional BLDC motor using Finite Element Method (FEM). In addition, performance analysis of the proposed hollow-rotor has also been carried out. For validation, the result of FEM is compared with the measurement result. It shows that, the simulation result has good agreement with the measurement result. For comparison, hollow-rotor shows higher torque density compared to conventional BLDC motor. As a conclusion, this paper provides guidelines and analysis in designing high torque hollow-rotor motor.

The inclusion of a high energy density permanent magnet into magnetic gear improves the machine's torque density. However, it also contributes to eddy current loss, especially in a high-speed application such in electric vehicle. In this paper, the losses from eddy current and iron loss are investigated on concentric magnetic gear (CMG). Torque multiplier CMG is designed with 8/3 gear ratio for this study. Iron loss and eddy current loss are compared and discussed. Based on this study, eddy current loss contributes to almost 96% of the total loss. This finding is hoped to direct the researcher to focus more on reducing loss associated with eddy current loss.

This paper analyzes the performance of a brushless direct current (BLDC) motor for agro electric vehicle (agro-EV) applications. Agro-EV technology is being developed in response to increasing environmental pollution. Various types of electric motors are in agro-EV, one of which is the BLDC. With its good capabilities, it has been chosen for further exploration in this research. On the other hand, some issues limit the usage of the conventional BLDC motor in heavy applications, such as low torque performance caused by weak magnetic energy. Therefore, this research aims to analyze the effect of magnetic energy based on slot-pole combinations to evaluate the BLDC motor's performance. Three BLDC models with different slot-pole numbers are designed and simulated using a fixed structure size, permanent magnet volume, and magnetomotive force (MMF). Finite element method (FEM) software known as Altair Flux 2D is used to compute the cogging torque, back-electromotive force (BEMF), magnetic flux density, and the torque produced. As a result, an 18/20 slot-pole was chosen for its high torque (105 Nm) and BEMF (35.9 V). In conclusion, this research simulation presents guidelines and an overview regarding the effect of slot-pole numbers on the performance of the BLDC motor for agro-EV applications.

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