1,720,985 research outputs found
Identification of synchronous reluctance motor parameters
No full textThe detection of the neutral point voltage of three-phase synchronous reluctance motors is useful for obtaining information on the operating conditions of the motor and also on the Fourier coefficients of the air gap permeance. It is known that these parameters are crucial for the accurate evaluation of the motor’s main quantities. Modelling the motor so as to take into account of the harmonics of both magneto-motive force and air gap permeance, the homopolar component of the induced voltages is obtained. It is shown that amplitude and phase of each harmonic of the homopolar voltage can be expressed as a function of two Fourier coefficients of air gap permeance, which suggests using a procedure for on-line calculating these coefficients. The parameters of a small prototype of reluctance motor have identified using a seven bit digitizing oscilloscope connected to a digital computer in which a DFT algorithm has been implemented for evaluating amplitude and phase of the harmonics of neutral point voltage
Comparative analysis between active and passive current transducers in sinusoidal and distorted conditions
No full textA numerical approach to the evaluation of uncertainty in nonconventional measurements on power systems
No full textThe application of the rules endorsed by the ISO Guide to the expression of uncertainty in measurement (GUM) can turn into a difficult task when quantities that characterize the operation of modern power systems are measured by means of DSP-based instruments.
A numerical approach to easily tackle this task is proposed in this paper, as an alternative to the uncertainty evaluation based on the analytical solution of the uncertainty propagation law, as prescribed by the GUM.
The validity of the numerical approach, which is based on a Monte-Carlo procedure, is first proved in the case of the spectral analysis of a periodic signal, which is the first step for many non-conventional measurements. Then the evaluation of the accuracy of a method for the measurement of the harmonic losses in a power transformer supplying nonsinusoidal load currents is dealt with as an application exampl
INDAGINE SUGLI INDICI DI POWER QUALITY PER LA DISTORSIONE ARMONICA IN PRESENZA DI CONDENSATORI
No full textOn the measurement of power-quality indexes for harmonic distortion in the presence of capacitors
No full textDifferent techniques have been recently proposed in the literature for the identification of the sources of harmonic distortion in electric-distribution systems. Each of them has its own advantages and limitations as far as reliability, accuracy, and practical usability are concerned. In this paper, these techniques are grouped into three main fundamental criteria in order to investigate their performance in the presence of capacitors. A case study is analyzed by means of both experimental tests and computer simulations. The results put in evidence some major problems that may concern the information provided by the considered methodologies, in virtue of the interaction of the capacitors with the other network components
UNA PROCEDURA PER DEFINIRE IL NUMERO E LA POSIZIONE DEI SENSORI DI IRRAGGIAMENTO IN GRANDI IMPIANTI FOTOVOLTAICI
No full text
- …
