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Purpose – The aim of this paper is to analyse the influence of various methods of controlling a stepper linear reluctance motor on the dynamic parameters of this motor. Design/methodology/approach – Construction, principle of working, and mathematical model of a four-band stepper linear reluctance motor are shortly discussed. In order to elaborate an effective tool for motor performance analysis, a circuital approach was applied. To increase model accuracy, major parameters of the model (main self- and leakage inductances) were calculated on the basis of a 3D electromagnetic field distribution using Finite Element Method (FEM). The nonlinearity of the core was taken into account. Elaborated mathematical model was implemented in MatLab-Simulink environment. Selected results of investigations are presented. Findings – The elaborated mathematical model and the review of control methods are very useful for analysis of dynamic operation of stepper linear reluctance motors. Originality/value – The paper provides a review of control methods of stepper linear reluctance motors. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to propose a new electromagnetic spherical actuator with three-degree-of-freedom. Multi-degree-of-freedom actuators which can be operated in arbitrary axis come to attract attention because of the solution for efficiency, weight, size, and so on. Particularly, spherical actuators are studied as the application to the joints and eyeballs for robots because they can be freely rotated in every axis direction. Design/methodology/approach - The paper proposes a new electromagnetic spherical actuator with three-degree-of-freedom in rotation, and the torque characteristics of the actuator are computed by the 3D finite element method (FEM). The validity of the computation is confirmed through the measurement of a prototype. Findings - It is found that this actuator realized the high torque of more than 1.0?Nm in every axis circumference. Originality/value - A new spherical three-degree-of-freedom actuator is proposed. The torque characteristics of the improved model are calculated employing the 3D FEM. The validity of the analysis is verified through the comparison with the measured results of the prototype. Furthermore, the improved model is proposed to increase the torque, and the effectiveness of the model is confirmed. [ABSTRACT FROM AUTHOR]

Purpose - This paper aims to describe the simulation technique which can be used at the design stage in order to efficiently develop low-electromagnetic emission type lighting implements. Design/methodology/approach - The influence on the conducted noise by the change of the implements' shape is investigated employing the 3D finite element method. Because of the difficulty in modelizing the electronic ballast accurately as a noise source, the electronic ballast is replaced by a comparison spectrum transmitter. Line impedance stabilization network is used for the measurement of the noise. The validity of this numerical model is confirmed by comparing the measurement results. Findings - The validity of the computation was confirmed by comparison with the measured results of a simplified implement model. The difference between the measured and calculated results was less than 5?dB all over the frequency range. Research limitations/implications - The frequency range is from 10 to 30?MHz and the construction and wiring of the implement have a great influence on the electromagnetic field. Originality/value - In previous papers, circuit simulators are used to analyze conducted emission from an electronic circuit including inverter, where common mode current cannot be taken into consideration. Therefore, the displacement current was taken into consideration in the model. Not only the implement, but also the measurement method and environment are modelized in the analyzed model. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to elaborate the algorithm and computer code for the structure optimization of the outer rotor permanent magnet brushless DC motor and to execute optimization of selected motor structure using the non-deterministic procedure. Design/methodology/approach – The mathematical model of the device includes the electromagnetic field equations with the nonlinearity of the magnetic core taken into account. The numerical implementation is based on the finite element method and stepping procedure. The genetic algorithm has been applied for the optimization. The computer code has been elaborated. Findings – The elaborated computer software has been applied for the optimization and design of BLDC motors. The elaborated algorithm has been tested and a good convergence has been attained. Originality/value – The presented approach and computer software can be successfully applied to the design and optimization of different structure of BLDC motors. [ABSTRACT FROM AUTHOR]