Greg Hammond, Ilya Budovsky
TRACEABLE CALIBRATION OF POWER HARMONICS AND FLICKER ANALYSERS

The paper describes a precision measurement system developed at NML for the calibration of three-phase instruments measuring harmonics of current up to 16 A, voltage fluctuation and flicker. Particular attention is given to establishing a traceable link to the Australian primary standards of electrical quantities. Current and voltage harmonics up to the 99^th and fluctuating voltages can be generated and measured with relative uncertainties close to 1·10^-5.

Patrick Boets, Leo van Biesen
CROSSTALK BETWEEN TWISTED PAIRS WITH A MISMATCH OF THE PAIR EXTREMITIES

A new crosstalk model between two twisted pairs when a mismatch of the wire pairs extremities exist, is proposed. The crosstalk model allows to predict the PSD at the near-end and far-end of the victim line if the PSD of the disturber is known. The model takes any mismatch into account which exists when a line is not terminated with its characteristic impedance. Using the same unbalance assumptions as other authors used with success in the past, analytical expressions are given to calculate the crosstalk.

Giovanni Betta, Domenico Capriglione, Claudio De Capua, Carmine Landi
A COMPARATIVE ANALYSIS IN TERMS OF CONDUCTED SUSCEPTIBILITY OF PC-BASED DATA ACQUISITION SYSTEMS

In this paper, a performance comparison between PC-based data acquisition systems is carried out with reference to their immunity to electromagnetic conducted disturbances. The aim is to identify suitable measurement procedures at present not available both in the literature and in EMC standards. The data acquisition system (personal computer and data acquisition board) is approached as a whole system and subjected to the more relevant conducted interference considered by EN standards, electrical fast transient and noise by conducted radio frequency field. Experimental tests, carried out in a shielded environment, highlight the relevance of a specific EMI characterisation of this apparatus.

L. Asnin, V. Backmutsky, M. Sedlachek
USING DSP METHODS FOR ACCURATE DYNAMIC MEASUREMENTS IN POWER SYSTEMS

This paper presents the results of comparison of a new method of magnitude spectrum estimation of periodical signals in Power Systems, which uses Discrete Fourier Transform (DFT) and special FIR filters, with other methods of spectrum analysis, based on a preliminary estimation of the dynamically changed signal frequency. The main purpose of the suggested method is to reduce the leakage errors under conditions of desynchronization between the signal and the sample frequencies. Digital modeling of this method shows that accuracy of the estimation of magnitudes of the signal harmonics increases essentially by reference to other methods based on the interpolation of samples. This method can be used especially in Power System dynamics investigation (relay protection, UPS tuning, etc).

Cipriano Bartoletti
MODELLING AND MEASUREMENTS ON A DEVICE FOR CURRENT FOCUSING IN AN ELECTROLYTIC PROCESS

An electrical model of ionic current distribution in electrolytic solutions, in asymmetrical geometry of electrodes, is proposed. The results are compared with the known ones carried out by a software specialised in symmetrical current flow computing. By means a systematic campaign of computing, the electrical and geometrical parameters of a ionic current focusing device are found. A computer controlled experimental apparatus, based on such parameters, is also presented. Early measurements on this device seem to confirm the model validity.