In this paper the analytical expression of the contribution of the fundamental image component to the discrete spectrum of a sine-wave weighted by a cosine class window is derived. It is then analysed for some commonly used windows in the case when the considered Discrete Fourier Transform (DFT) samples fall either inside or outside the band defined by the window spectrum main lobe centred at the sine-wave fundamental frequency. From the achieved results some conclusions about the behaviour of the image component contribution to the discrete spectrum of a sine-wave are drawn. The accuracies of the derived expressions are verified through computer simulations.

The paper presents basic description and some simulation results of a correlation method which together with the fractional delay sampling technique can be applied to measurements of the complex amplitude ratio of sinusoidal voltages with superimposed Gaussian noise. The method allows reduction of the influence of the white noise on the result of measurement.

New fast plant system controllers are being designed and developed for ITER (International Thermonuclear Experimental Reactor). They require to manage and to process massive data that is being acquired at high sampling rates. This data has to be archived for being posteriorly analysed in order to rebuild several aspects of the experiment. Our group is currently involved in different works related with ITER, and more concretely related with their fast control technologies. ITER fast plant system controllers will require data archiving, and based on ITER requirements our group developed a data archiving solution based on NetCDF-4 technology. At this time, ITER is supporting HDF-5 scientific file format, as data archiving solution for its control systems. In this sense, we have created a set of tests scenarios in order to analyse and compare both scientific data archiving solutions from ITER fast plant system controller requirements point of view.

The adoption of a Hybrid MPPT (HMPPT) technique is mandatory in PV applications operating under mismatching conditions. It is called Hybrid because it is neither only Distributed (on the PV modules) nor only Centralized (on the inverter). In this paper it is shown how to properly optimize an HMPPT technique based on the periodic scan of the Power vs. Voltage characteristic at the input of the inverter in order to locate the optimal operating value, from the energetic efficiency point of view, of the bulk inverter voltage. Therefore, numerical simulations and experimental measurements on a reduced scale laboratory prototype are carried out to confirm the validity of the theoretical predictions.

In this study, a real-time monitoring system has been prepared by using Field Programmable Gate Arrays (FPGA) in order to monitor three phase voltage harmonics instantly. In this monitoring system, a signal input card has been designed for the purpose of transferring three phase voltage signals of the network to the FPGA card. Harmonic values of the voltage signals belonging to each phase have been instantly calculated with the 128 floating point FFT algorithm embedded in the FPGA card. The obtained harmonic values are transferred onto computer with the RS232 communication protocol created in the FPGA device. A software featuring a graphical interface has been prepared on the computer for the purpose of visually displaying the voltage signals and the harmonic data belonging to the voltage signals. All the parameters regarding the monitoring system can be monitored easily on this software. The monitoring system that was designed for the present study was set up and tested in the laboratory at the Department of Electrics and Electronics Engineering, Tunceli University. The results show that the monitoring system can successfully obtain the voltage signals and the harmonic values of these signals.