Catalin Damian, Cristian Zet, Cristian Fosalau
REAL, REACTIVE AND APPARENT POWER COMPUTING USING FPGA AND PWM INTERMEDIARY CONVERSION

In the paper, an instrument for simultaneous measurement of active, reactive and apparent power is presented. Its functionality is based on a PWM intermediary conversion multichannel analog to digital converter (ADC). The instrument is implemented on an Altera’s Flex10k70 Field Programmable Gate Array (FPGA) device for single phase. It fits roughly 60% of logic cells without any resource sharing algorithm. All the operations are executed in a parallel mode, providing a very short execution time.

M. Annoni, L. Cristaldi, M. Faifer
ELECTRIC POWER SIGNATURE ANALYSIS FOR HIGH PRESSURE WATER JET PUMP FAULT CLASSIFICATION

Water jet and Abrasive Water Jet (WJ/AWJ) are manufacturing technologies suitable for particular operations (cutting, milling, turning, surface treatment, etc.) on different types of materials. The use of water (or water mixed to abrasive in AWJ technology) allows working both soft and hard materials without damaging the interested area of the workpiece. In previous studies the authors have just shown how it is possible to detect wrong operating conditions or to foresee them for an AWJ system analyzing the instantaneous electric power signal measured at the supply section of the system. Starting from this assumption, it is possible to define a monitoring procedure operating on the supply section of the plant, that performs a non intrusive continuous diagnostic activity during all the plant components’ life. In particular in this work, a procedure based on the analysis and classification of the instantaneous power signal features is presented. The followed approach is based on the electric power signal signature analysis.

P.Arpaia, G. Spiezia
PERFORMANCE ANALYSIS OF THE PXI-BASED BUS COMMUNICATION OF A FAST DIGITAL INTEGRATOR FOR MAGNETIC MEASUREMENTS

A procedure for bottlenecks analysis of the PXI bus communications of an automatic measurement station is proposed. The experimental case study of the Fast Digital Integrator (FDI), a general purpose data acquisition and processing card developed at the European Organization for Nuclear Research (CERN), is illustrated.

Cristian Zet, Olga Plopa,Cătălin Damian, Cristian Foşalău
VIRTUAL IMPEDANCE SPECTROSCOPY FOR ELECTROLYTICAL CELLS

Impedance spectroscopy play an important role in fundamental and applied electrochemistry and materials science. In a number of respects it is the method of choice for characterizing the electrical behavior of systems in which the overall system behavior is determined by a number of strongly coupled processes, each proceeding at a different frequency. The paper presents a virtual instrument and the associated hardware that allows to perform the impedance spectroscopy on an electrolytical cell. It is aimed for studying phenomena (charge transfer, difusion or electrode polarisation) that occur while growing nanowires in polycarbonate templates. The hardware consists of a NI PCI6111 data acquisition board and external analog front end (programmable current to voltage converter and programmable mixed AC – DC voltage generator). The software is developed in Labview and allows to perform the impedance spectroscopy and to save the data on a file. With a different software, the system can be used also for electrochemical deposition or for etching of the polymer membranes with ion tracks. Detailed schematic description is presented, together with experimental results.

Germano Bianchi, Federico Perini, Claudio Bortolotti, Jader Monari, Stelio Montebugnoli, Mauro Roma
ADC BIT NUMBER AND INPUT POWER NEEDED, IN NEW RADIO-ASTRONOMICAL APPLICATIONS

For the most part, so far radio astronomy observations have been performed in protected frequency bands, reserved by ITU for scientific purposes. This means that, ideally, only the amplified equivalent system noise is present at the end of the receiver chain (i.e. the ADC input). So, typically, only a few bits are necessary to describe the signal (VLBI signals are digitised with only 2 bits), but today astronomers, in order to get more sensitivity and to boldly observe where no one has observed before, would like to study the radio sky even outside the protected bands. In these cases, a lot of man-made signals, coming both from terrestrial and space radio communication systems, are added to the very weak sky noise. For the first time, radio telescope designers must take in account the problem of the A/D converter dynamic range, since the increase of the total received power could lead the A/D to saturation. Here, a procedure to estimate the required number of bit (resolution and dynamic) and the input power level of an A/D converter, is described and applied to a new radio astronomical system which is under development at the Medicina radio observatory (Italy).