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In this article, a new electro-thermal optimization algorithm is proposed to determine the parallel power cables arrangement to obtain the maximum ampacity. The optimization procedure is based on the imperialist competitive algorithm (ICA). Electrical calculations are performed using the sub-conductors method and consideration of the skin and proximity effects. FEM thermal model and electrical calculations are coupled with optimization procedure to determine the ampacity in the optimization algorithm. Optimized arrangements are determined under sinusoidal and harmonic load currents conditions. Furthermore, the effects of different boundary conditions of the ground surface such as isothermal and convective heat flux are evaluated. The underground single conductor cables with solid bonded metallic sheaths and existing of circulating currents are considered. Cables are considered to be installed adjacent to each other in different rows above each other in flat formations. Also, the artificial bee colony (ABC) optimization algorithm is performed to validate the ICA procedure. Experimental measurement of a case study is carried out for simulation confirmation and the results show good agreement. [ABSTRACT FROM AUTHOR]

Eccentric air-gaps occur very likely in wind generators as the turbines are subject to continued mechanical stresses. This article analyzes the effects of rotor eccentricity on axial flux permanent magnet machines’ performances, such as air-gap flux density, cogging torque, and unbalanced force. In modeling axial flux machines, three–dimensional finite-element method models are required for accurate calculations. However, three-dimensional finite-element analysis is usually time consuming. In order to have a quick evaluation of the axial flux machine performance suitable for online identification, an analytical approach that utilizes quasi three-dimensional computation is developed. The proposed method allows taking into account variation of tooth skewing and different magnet shapes. The results have been validated using two-dimensional and three-dimensional finite element computations. It is shown that by using the proposed analytical approach, it is possible to assess the performance of the axial flux permanent magnet generators under eccentricity with reasonable accuracy. [ABSTRACT FROM AUTHOR]