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Recently, linear generators have been widely employed to convert oceanic wave energy into electricity. Among various linear generators, linear permanent magnet generators (LPMGs) have gained attention due to their special characteristics such as high power density and simple control structure. In this paper, flat double‐sided LPMG is investigated and designed. Considering all effective design variables, a particle swarm optimization algorithm‐based optimization method is employed to maximize efficiency and minimize weight. The optimization results show an increase in efficiency and a reduction in the weight of the generator. Finally, the design results are evaluated and validated using magnetic equivalent circuit and finite element analysis methods. [ABSTRACT FROM AUTHOR]

This paper develops a new model with adjustable accuracy to evaluate performance of permanent magnet Vernier machine (PMVM) based on flexible magnetic equivalent circuit (MEC) method. The desired machine parameters such as number of flux modulation poles (FMPs), winding pole‐pairs, and geometrical dimensions can be chosen in the presented model. By utilizing nonlinear core magnetization curve, saturation effect is taken into account. There are two main contributions in this study. First, the flexible MEC model is developed to predict the machine performance accurately. The second contribution is that the developed model can be used to evaluate the performance of the machine under no‐load and loading conditions at the same time. The results of MEC model under no‐load and loading conditions are compared with 2D‐finite element method (FEM) and 3D‐FEM in terms of accuracy and simulation time. The results indicate acceptable accuracy and suitable processing time of the proposed MEC model. [ABSTRACT FROM AUTHOR]

This paper presents an improved magnetic equivalent circuit (MEC) method for modeling linear permanent-magnet synchronous motors (LPMSMs) with adjustable accuracy. The performance of machine with different dimensions, poles and slot numbers can be studied by the proposed flexible MEC, where the core nonlinearity is fitted on the material B–H curve. End effect is modeled by considering two virtual zones with desired accuracy at both entrance and exit ends of the primary. A new structure based on magnets segmentation is also proposed to investigate its effect on the motor performance. Finally, the results of the proposed method are compared with 3D-FEM to show the effectiveness of the presented model. The results show improvement in processing time with good accuracy compared to previous classic methods. In general, introducing a new model based on an improved MEC approach for modeling LPMSMs considering slot effect, iron core saturation and segmented PMs with flexible accuracy by adjusting the number of flux tubes is the paper novelty which is studied in this work. [ABSTRACT FROM AUTHOR]

The paper presents a novel technique for modeling ladder-secondary single-sided linear induction machines. Saturation effect is considered by core non-linearity characteristic for both primary and secondary. The proposed modeling method is based on magnetic equivalent circuit with adjustable accuracy. The machine parameters such as its dimensions, pole numbers, bar numbers, and also model accuracy can be chosen arbitrary in the proposed model. The end effect is considered by virtual teeth at the entry and exit ends of the machine primary. The results of the proposed method are compared with finite element method (FEM) in terms of accuracy and processing time. The results show the effectiveness of the proposed method. In addition, due to having long processing time of the FEM, the proposed method is a very suitable manner for modeling of this particular machine. Also, the accuracy of the proposed method has been confirmed by experimental results, in starting. [ABSTRACT FROM AUTHOR]

This paper presents a new method to model healthy and faulty wound-rotor induction machines (WRIMs) with and without inter-turn short circuit fault by a single set of equations. The model is presented for a machine with arbitrary pole, and rotor and stator slot numbers. A single set of equations, including both electric and magnetic parts, is solved to obtain full dynamic behavior of the machine. Therefore, the modified magnetic equivalent circuit with non-linear elements is used for modeling and a numerical technique is employed to solve the non-linear equations. The proposed modified method has a simple calculation procedure in comparison with the conventional magnetic equivalent circuit method. Solving the electric and magnetic equations by a single set of equations is the main advantage of the presented method, which is proposed for a WRIM machine, for the first time. In addition, to increase the accuracy, the saturation phenomenon is also considered in the model. Due to the saturation effect, there are some non-linear algebraic magnetic equations, which should be simultaneously solved with differential equations. A trapezoidal technique is used to convert differential equations to algebraic ones. To solve the non-linear equations, non-linear equations, Newton Newton–Raphson method is employed. Current signature analysis is used for rotor and stator inter-turn short circuit fault detection. Finally, the finite-element method is used to verify the effectiveness of the proposed modeling method. It is worth noting that the proposed method can model a healthy and faulty machine with different faults by a single model. [ABSTRACT FROM AUTHOR]