An Approach to the Multivectorial Apparent Power in Terms of a Generalized Poynting Multivector

The purpose of this paper is to explain an exact derivation of apparent power in n-sinusoidal operation founded on electromagnetic theory, until now unexplained by simple mathematical models. The aim is to explore a new tool for a rigorous mathematical and physical analysis of the power equation from the Poynting Vector (PV) concept. A powerful mathematical structure is necessary and Geometric Algebra offers such a characteristic. In this sense, PV has been reformulated from a new Multivectorial Euclidean Vector Space structure (CGn-R3) to obtain a Generalized Poynting Multivector ( ~ S). Consequently, from ~ S, a suitable multivectorial form ( ~ P and ~D) of the Poynting Vector corresponds to each component of apparent power. In particular, this framework is essential for the clari¯cation of the connection between a Complementary Poynting Multivector (~D) and the power contribution due to cross-frequency products. A simple application example is presented as an illustration of the proposed power multivector analysis

Considerations on the non-active power using geometric algebra

Several approaches have been developed to define the non-active power concept under nonsinusoidal situations in electrical systems. Nevertheless, these contributions do not provide a complete and satisfactory solution to the non-active power reversibility between frequency domain and time domain. This paper presents a non-active power multivector concept, based on an original vector space frequency-domain approach that bridges the gap between both domains. The suggested correspondence can provide a convenient descriptive language to reconcile Fryze’s instantaneous non-active power with Budeanu´s deactive-power

Wavelet and Neural Structure: A New Tool for Diagnostic of Power System Disturbances

The Fourier transform can be used for analysis of nonstationary signals, but the Fourier spectrum does not provide any time-domain information about the signal. When the time localization of the spectral components is needed, a wavelet transform giving the time-frequency representation of the signal must be used. In this paper, using wavelet analysis and neural systems as a new tool for the analysis of power system disturbances, disturbances are automatically detected, compacted, and classified. An example showing the potential of these techniques for diagnosis of actual power system disturbances is presented

Continuous harmonic analysis and power quality measurements in three-phase systems

A virtual instrument, named Power Quality Meter, is presented for (a) measuring power consumption and harmonics in three-phase systems, under non-sinusoidal and imbalance conditions (b) detecting, classifying and organizes power disturbance events. Measurement of the power consumption follows the formulation proposed by the members of the IEEE Working Group on Nonsinusoidal Situations (1996). So, definitions are based on the analysis of functions in the frequency domain, separating the fundamental terms from the harmonic terms of the Fourier series. The virtual instrument has been developed too for monitoring and measuring power disturbances, which are automatically classified and organized in a database while they are being recorded. Software tools use the database structure to present summaries of power disturbances and locate an event by severity or time of occurrence. Records of actual measurements are included to demonstrate the versatility of the instrument

Wavelet-Fourier analysis of electric signal disturbances

The Fourier transform usually has been used in the past for analysis of stationary and periodic signals. Its interest is the knowledge of spectral components existing in a waveform; it doesn't matter the moment where they happen. However, when the time localization of the spectral components is needed, the Wavelet Transform (WT) can be used to obtain the optimal time frequency representation of the signal. In this paper, the joint wavelet-Fourier transform has been proposed for detecting, analyzing and compacting electrical disturbances. Finally, results of experiments have been included

Evaluación del papel de la dirección y los equipos docentes en la elaboración y desarrollo de los proyectos curriculares de centro

Investigación publicada. Convocatoria de Concurso Nacional de Proyectos de Investigación Educativa. Resumen basado en el de la publicación. D.L. tomado del catálogo de la Biblioteca NacionalSe realiza un estudio en 40 centros de Educación Primaria y Secundaria Obligatoria en Andalucía para conocer como intervienen las direcciones y equipos docentes en la elaboración y desarrollo de los proyectos curriculares del centro. Se estudian 40 proyectos curriculares de centro, y se reconstruye su proceso de elaboración. Para ello se realizan al menos tres entrevistas en cada centro, y se reúnen las principales normativas curriculares y los proyectos realizados por los principales editoriales. La información ha sido tratada con el programa informático NUDIST. Se han seleccionado diez centros, de los que se han realizado diez estudios de caso, mediante los cuales se ha realizado un informe multicasos.Ministerio Educación CIDEES