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The permanent magnet wind turbine is the fundamental element inside small wind turbines with power ratings of less than 3MW. The operation of the internal components of wind turbines is little known by electrical engineers. This work aims to show the dynamic behavior of Permanent Magnet Synchronous Generators types with 3-stage converters. The equations that describe the dynamic behavior of each of the stages that make up the wind turbine are presented, starting with the 3-blade wind turbine, which is one of the most efficient at present, and ending with the passive filter necessary for its synchronization with the power system. Using the obtained dynamic equations, simulations of each stage are made separately and the operation of each of the parts and of the whole are demonstrated. [ABSTRACT FROM AUTHOR]

Eccentricity in salient poles synchronous generators (SPSG) is a failure mode that requires particular attention due to its possible catastrophic consequence. To diagnose it, specialists have focused on the frequency spectrum of the stator current, obtained from the Fast Fourier Transform (FFT). Other techniques, such as transient current analysis, flux and vibration have proven to be valuable sources of information. The paper aims to illustrate the state of the art on the diagnosis of eccentricity in SPSG and proposes a new state variable for the diagnosis of this failure mode with the asset in service. As a result of the work on the technology and the theoretical research carried out, it is concluded that it is possible to diagnose the eccentricity of the electric generator from the behavior of the neutral current of the machine in operation. [ABSTRACT FROM AUTHOR]

This research presents a review of existing trends in the development of electrical generators for small wind turbines. At present, wind power systems operate at variable orfixed speed, using the principale of direct current generators, induction generators using a gear box system, and synchronous generators, which operate at low wind speeds without a gear box. ,being these the most used in small comercial wind turbines. Both the strengths and weaknesses of existing configurations are discussed, emerging technologies in low-speed electric generators are investigated, and a comparative analysis of the misperformed. The objective of selecting the most suitable generatoror generators for its construction in workshops with minimal technological conditionsto be used in efficient small wind energy systems is fulfilled, and a simple of commercially available wind turbines is presented. [ABSTRACT FROM AUTHOR]

Copyright of Revista CIENCIA UNEMI is the property of Universidad Estatal de Milagro (UNEMI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tests that are carried out to electric machines need of: taking of data, their prosecution and determination of their parameters or performances. All that you can automate, being more important if it is about repetitive processes. In this work the open circuit, short circuit and zero power factor tests of a synchronous machine were automated in what concerns to obtaining data for determines the generator performance relative to its voltage regulation utilizing Potier method. It utilizes a very simple hardware based on an acquisition card in orde to introduce them to a computer and by means of a software implemented in Matlab, to determine the regulation of voltage. In order to simplify the calculations, an analytic method is used instead of the known graphical method. The proposed method can be introduced in the Electric Machines Laboratories without changing the existent equipment. [ABSTRACT FROM AUTHOR]

This article studies the effects of operating a generator with an inadequate grounded conductor. Interpretation of the selection method, and calculations necessary to specify the recommended neutral grounding types, followed the IEEE Std C62.92.2™-2017 [1], IEEE Std C37.101™-2006 standards [2] and GTC-206 [3]. The conception that a software should have to facilitate the process of selection and specification of the grounding of the neutral wire of a synchronous generator is presented, which later was developed by means of a free programming environment, that allowed for the specification of all types of implementation of the recommended grounding in the aforementioned standards. As an application exercise, through the use of the developed software, compliance with these regulations could be determined in the current neutral grounding of the four generation units of the Calima Hydroelectric Power Plant. [ABSTRACT FROM AUTHOR]

The stator core of an electric machine for teaching applications, with 12 teeth and open slots, is used and a rotor, of sintered magnetic material, is constructed to configure a flux switching three-phase heteropolar inductor alternator. The optimization of the rotor design consists of obtaining the best number of teeth that provides a waveform of the output voltage closest to a sinusoidal function and with a higher effective value (rms). An analytical model is presented, allowing to establish a comparison of the values of the permeances, depending on the number of teeth of the rotor. Results are compared with simulation values, using a finite element program. The conclusion reached is that seven is the ideal number of teeth and slots of the rotor. [ABSTRACT FROM AUTHOR]

In this paper, the design and implementation of a wind turbine emulator bank is proposed. The bank takes into account the dynamics of the extraction of effective wind energy. This dynamic is modelled mathematically. The DC motor emulates the rotary movement due to wind energy, generating the angular velocity profiles according to the torque measured by a torque meter on the coupling shaft between the DC motor and the permanent magnet synchronous generator. Additionally, the paper presents a test experiment that consists of a controlled boost converter to which a maximum power extraction algorithm is applied in order to validate the operation of the DC motor-permanent magnet synchronous generator bank. [ABSTRACT FROM AUTHOR]

Considering that there are electromagnetic, mechanical and thermal constraints that determine the design of high-speed electrical machines, the criteria that lead to adequate selection of the machine are established in this work. Moreover, taking into account the current state of technology, the critical values in the ratio (output power)/(rotation speed), are presented. The paper focuses on the high-speed synchronous generators, especially in permanent magnet generators, inductor alternators and flux switching alternators, emphasizing their constructive fundamentals and their advantages and disadvantages. The analysis is completed with a critical assessment that classifies them according to previously defined requirements. Although the decision of the final choice is largely determined by the application of interest, it can be said that, in general, synchronous generators with permanent magnets in the rotor are the best option. [ABSTRACT FROM AUTHOR]

Copyright of Revista Técnica Energía is the property of Centro Nacional de Control de Energia CENACE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article a methodology to diagnose faults in rotating electrical machines is presented. The method uses spectral frequency analysis of the phase currents sidebands. Online systems to verify the magnitude of these frequencies, caused not only by mechanical faults but also electrical faults, are presented. The results of a faulty set formed by a direct current motor plus a synchronous generator of 5 kVA and two squirrel-cage induction motors of 5 HP, one with slacked bearings faults and other with broken rotor bars, are presented. Also, the results of the spectra using a conventional current sensor are compared with those of a Rogowski coil, showing that the results of both sensors are suitable to detect machine faults. [ABSTRACT FROM AUTHOR]

In this work, a black-box model for the estimation of the rotor angle of a synchronous generator is developed by using voltage and current measurements at the terminals. The model is based on neural networks of the multilayer perceptron (MLP) type. From time-domain simulations for a basic power system, which consists of a generator connected to an infinite bus bar, voltage and current records are collected, which are used as a database to train and validate the neural network that is proposed for the estimation of the rotor angle. It is found that the neural-network based model adapts itself very well to the classic model of the generator, exhibiting a mean square error of 1x10-10. The results show the validity of the estimation method and foster its potential use for stability studies of the synchronous generator. [ABSTRACT FROM AUTHOR]

Synchronous Machine tests, such as no load, short circuit and zero power factor, are achieved to trace Zero Power-factor, Regulation and External Load characteristics, in addition to Voltage Regulation for any given state. To carry out this results we are familiarized with graphical methods, which are cumbersome and imprecise. This is a new cuasi analytic approach to this problem by means of a MATLAB software. Algorithm is similar to that followed by someone who is carrying out solutions by traditional way. It was implemented Magneto Motriz Force method. Saturation was approached to an inverse tangent curve in a least means square sense. To compute the interception point between curves it was used numerical methods which achieved a precision higher than experiments offer. This software is intended to be used either in Indutry or in universities with academic purpose. [ABSTRACT FROM AUTHOR]

In this paper, we make an evaluation of the complete ground-fault protection of the stator of synchronous generators by use of the subharmonic injection method. Firstly, we describe two approaches for the complete protection of the stator: the third harmonic method and the method of subharmonic injection. Secondly, we analyze the error in the determination of the ground-fault resistance for an 11.4 kV synchronous generator from the consideration of various operating conditions. This error is related to the type of voltage transformers being used, the occurrence of signal noise, the digitalization process, and variations in the numerical values of the required parameters. Lastly, we show that the subharmonic injection method is very useful for the determination of the ground-fault resistance and performs well for the complete protection of the stator. [ABSTRACT FROM AUTHOR]