A Control Strategy for Combined Series-Parallel Pumps

[EN] 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.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2010). A Control Strategy for Combined Series-Parallel Pumps. Renewable Energy and Power Quality Journal. 1(8):1466-1469. http://hdl.handle.net/10251/92559S146614691

Capacitance Evaluation on Non-parallel Thick-Plate Capacitors by Means of Finite Element Analysis

[EN] In this work we show the influence of the edge-effect on the electric field distribution and, hence, on the inner and outer capacitance in an inclined-plate capacitor system 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 previously published works. Finally, using statistical tools, we obtain approximate expression for computing the relationship between capacitance and insulation material characteristics, insulation gap, plate dimensions and angle.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2011). Capacitance Evaluation on Non-parallel Thick-Plate Capacitors by Means of Finite Element Analysis. Journal of Energy and Power Engineering. 5(4):373-378. doi:10.17265/1934-8975/2011.04.012S3733785

FEM Edge Effect and Capacitance Evaluation on Cylindrical Capacitors

[EN] The purpose of this paper is to show the influence of the edge-effect on the electric field distribution, and hence on the inner capacitance and outer capacitance of a cylindrical capacitor surrounded by an insulating medium. To generalize the results, a two-dimensional axisymmetric finite element model of a cylindrical capacitor has been generated and the problem has been resolved taking into account the distance between the conductors for a complete set of dimensions. The available obtained results have been compared with previous published works. Finally, using statistical tools, the mathematical expression for computing the relationship between capacitance and insulation gap and cylindrical plates dimensions has been obtained.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S. (2012). FEM Edge Effect and Capacitance Evaluation on Cylindrical Capacitors. Journal of Energy and Power Engineering. 6(12):2063-2069. doi:10.17265/1934-8975/2012.12.022S2063206961

Capacitance evaluation on parallel-plate capacitors by means of finite element analysis

[EN] 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 thicknessCatalán Izquierdo, S.; Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Cavallé Sesé, F. (2009). Capacitance evaluation on parallel-plate capacitors by means of finite element analysis. Renewable Energy and Power Quality Journal. 1(7):613-616. http://hdl.handle.net/10251/92552S6136161

Capacitance evaluation on perpendicular plate capacitors by means of finite elemental analysis

[EN] 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.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S.; Cavallé Sesé, F. (2009). Capacitance evaluation on perpendicular plate capacitors by means of finite elemental analysis. Renewable Energy and Power Quality Journal. 1(7):617-621. http://hdl.handle.net/10251/92548S6176211

Modelization of earth electrode excited by atmospheric discharges based on FEM

[EN] 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.Bueno Barrachina, JM.; Cañas Peñuelas, CS.; Catalán Izquierdo, S.; Quijano Lopez, A. (2008). Modelization of earth electrode excited by atmospheric discharges based on FEM. Renewable Energy and Power Quality Journal. 1(6):727-732. http://hdl.handle.net/10251/92551S7277321

Grounding system impedance characterization using FEM

The exact knowledge of the grounding system impedance, including its expected variability, is a matter of paramount importance in the design of medium and high voltage infrastructures. The principles underlining the physical processes involved in grounding are well established and so are the engineering concepts regarding safe operation of the grounded systems. Quite a few theoretical expressions are widely used in the project stage of any installation. Unfortunately, these expressions are only valid for simple geometries and simplified material characteristics. Uncertainty arise from the intrinsic complexity of the grounding environment: buried grids and rods, reinforced concrete foundations surrounding them, weather dependent and non-uniform soil characteristics, etc To overcome these limitations, in this paper the finite element method is applied to obtain the grounding impedance and the potential distribution around a real grounding system excited with sinusoidal currents at several frequencies. Additionally, for validating purposes, a single vertical ground rod has been simulated and compared with the results obtained by other authors. FEM commercial software, in addition to some specific purpose user functions, has been used. The method presented in this paper can be applied to any real geometry, electrode configuration and type of soilBueno Barrachina, JM.; Catalán Izquierdo, S.; Cañas Peñuelas, CS. (2011). Grounding system impedance characterization using FEM. Renewable energy & power quality journal. 9(12). doi:10.24084/repqj09.353S91

Novel technique for estimating pollution-associated leakage current in high voltage insulators based on adaptive filtering in long-term recording

[EN] Moist polluting substances on high-voltage insulator surfaces can cause power-line failures by triggering electric arcs. There are at present no effective methods of measuring insulator pollution levels during normal operations. In this work, we attempt to estimate insulator pollution leakage current (PLC) as an indirect method of measuring deposits in a 30 month period of simultaneously recording leakage current and related environmental variables in substation insulators. We analyzed the relationship between raw leakage current and environmental variables. We canceled out the influence of relative humidity on leakage current by adaptive filtering and then obtained the PLC by filtering out the anomalous peaks in the recording. The proposed method considerably reduces the correlation between leakage current and relative humidity (0.826 vs 0.019). The resulting signal was only slightly correlated with other environmental variables (<0.03), suggesting that the relationships between leakage current and temperature, wind direction and speed are mainly attributable to their influence on relative humidity. The PLC presents a quasi-annual smooth fluctuation over time with a magnitude similar to those obtained in laboratory tests. This novel technique could be used to monitor insulator PLC in real time and thus improve power supply continuity and reduce maintenance costs.Bueno-Barrachina, J.; Cañas Peñuelas, CS.; Ye Lin, Y.; Fuster Roig, VL. (2021). Novel technique for estimating pollution-associated leakage current in high voltage insulators based on adaptive filtering in long-term recording. Measurement Science and Technology. 32(5):1-10. https://doi.org/10.1088/1361-6501/abea3dS11032

Evolución temporal de la corriente en un circuito serie RLC en RES

Se calcula la corriente en un circuito serie en régimen estacionario y senoidal (no se tiene en cuenta el transitorio). El circuito está cargado con una resistencia, una bobina y un condensador. La simulación permite al alumno comprobar la forma temporal de la tensión y la corriente, pudiendo establecer una relación entre el dominio temporal y el cálculo de circuitos utilizando el método simbólico.https://laboratoriosvirtuales.upv.es/eslabon/Ejercicio?do=circuitoRLCCañas Peñuelas, CS. (2010). Evolución temporal de la corriente en un circuito serie RLC en RES. http://hdl.handle.net/10251/770

Catenaria

La aplicación calcula la curva (catenaria) de un cable de transporte de energía eléctrica situado entre dos apoyos separados una distancia de 500m. Se dibujan dos curvas, la primera correponde a la posición de tracción máxima y la segunda a la que el alumno decida.https://laboratoriosvirtuales.upv.es/eslabon/Ejercicio?do=catenariaCañas Peñuelas, CS. (2010). Catenaria. http://hdl.handle.net/10251/770