Abstract-This paper revisits classical Lucas-Kanade (LK) and Horn-Schunck (HS) optical flow techniques. The aim is to provide a baseline for other researchers on these two timeless techniques. The formulations presented incorporate modern practices, namely multichannel, multi-resolution with refinement procedure (warping), non-quadratic penalisers and non-linear formulation of the brightness assumption. The experiments conducted demonstrate the performance enhancement that can be assigned to each modern practice. Thereby, the performance of the LK and HS is renewed in order to enable a fair comparison to other state-of-art techniques.

Consumer electronics, domestic appliances and a large range of industrial applications, namely power electronics based, can cause high disturbances in the supplied electricity. In this paper, the power quality characteristics is addressed in terms of the related standards and in the possible measures to increase it. Going from single to three phase networks and discussing passive and active filtering solutions, the paper presents simulation and experimental results obtained with a three phase active filter prototype.

Generation of electrical energy in large conventional power plants (thermal, hydro and nuclear) in last ten years worldwide is being supplemented by small generation utilities that are fuelled by renewable sources, waste etc. In Republic of Croatia few years ago first small power plants projects were started. One such project was constructing small thermal power plant as a part of sanitary landfill treatment process in Zagreb, capital of Republic of Croatia. It is first power plant in Republic of Croatia of that kind which is fuelled by landfill gas that is result of decomposition process. After the commissioning of small thermal power plant (STPP) Jakusevec a detailed analysis of voltages and currents at the point of connection to the local distribution network was conducted. Results of that analysis are given in this paper.

Voltage and current harmonics on an electric power system are consequence from the non-linear operating characteristics of system loads and network components. Power electronic devices, arc furnaces and transformer saturation usually produce the harmonic currents. In order to minimise voltage distortion and improve the power quality of the system, harmonic filters are used and they can be designed and tuned in accordance with the pollution sources, the load demand and the network topology.In this paper it is studied and analysed the influence of the system reconfiguration in the harmonic distortion, using the software package Harmonique applied to a test power system. Different load levels and changes in power factor compensation were analysed. For each of these scenarios it was studied the influence of the network reconfiguration after the occurrence of a contingency.Finally, some conclusions that provide a valuable contribution to the better understanding of the current and voltage distortion in order to tune harmonic filters in an electric power system are pointed out.

This paper discusses some of the most important Photovoltaic (PV) systems characteristics related to its global efficiency like MPP tracking efficiency, static efficiency, conversion efficiency as well as the Euro efficiency. The losses models of the power semiconductors constituting the Power Electronics (PE) subsystems as well as the models of transformers and DC and AC cables are reviewed. Three topologies are selected, representing the PV market and simulation results are discussed. Given the importance of the global efficiency of an installation for the owner, recorded field results with the same systems are presented. The main conclusion is that the global efficiency of a PV installation depends not only on the PE subsystem, with or without isolation transformer in the low or high-frequency stages, but also on the DC and AC conduction losses, and on the distance of the installation to the coupling point to the electric grid.