Abstract.The electric field distribution produced by any disposition of insulating and conducting materials is a key aspect in electrical design, but exact values can only be obtained in simple geometries. In this work, using commercially available F.E.M. software we show the influence of the edge-effect on the electric field distribution of a two parallel-plane conducting plates system surrounded by an insulating medium taking into account the thickness of the conducting plates. We compare our results with previous published works. Finally, we obtain the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and plate thickness.

In this work we show the influence of the edge-effect on the electric field distribution, and hence on inner capacitance and outer capacitance of the inclined angle, of a inclined-plate capacitor system in a plane, surrounded by an insulating medium taking into account the thickness of the conducting plates for a complete set of dimensions and insulating characteristics. Where available we compare our results with previous published works. Finally, using statistical tools, we obtain the expression for computing the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and inclined angle.

When a solution is adopted for a pumping irrigation system, to variable or constant wealth, the engineer has to evaluate the different alternatives to decide the most suitable system of pumping. The majority of the companies of the sector, they choose for systems of pump gradation in parallel at constant speed, with what the variable that they control is the wealth. In this paper there is proposed a system of pumping that connects pumps in parallel and pumps in series, working at variable speed, controlled by an algorithm that allows that every bomb should work inside the area of maximum efficiency.

Abstract.The aim of this paper is to obtain the distribution of tensions in the land excited by currents type ray using different types of electrodes: the goad electrodes and the deep goad electrodes, and as an exceptional case an electrode type drags was used. In this work, the program ANSYS ® that is based on the finite elements method (FEM) was used. After the simulation of the distribution of tensions, different parameters were obtained, such as the tensions of step (Vp) and of contact (Vc) which determine the security of the installation of put in the earth (PE) protection.

Abstract.The study in electric field distribution in the space by different charged geometries, allows to improve the designs of the devices used in electrical engineering. In this work the capacities of a charged unit cube by two different methods have been calculated by means of technical of finite element analysis. Firstly infinite elements in the air that surrounds the charged unit cube were considered, and secondly the conditions of contour of the Trefftz method were used. The proposed models has been achieved to calculate the capacitance of a unit cube based on the size of the element.