Long-term monitoring of power quality parameters in regional distribution networks in the Czech Republic

In the power company CEZ in the North Moravia Region (the Czech Republic) the monitoring of a number of selected parameters of the quality of electrical energy (harmonics, flicker and unbalance) is being carried out in cooperation with research laboratories of the Faculty of Electrical Engineering and Computer Science, VSB - Technical University of Ostrava. The monitoring is being carried out in a complex manner in 59 feeding points 400 V, always within one week intervals, and at the same time on all voltage levels (HV, MV and LV). The whole cycle lasted for 3 years, and currently the fourth cycle of monitoring is performed. 3 full cycles enable comparing of the status after twice three years. In the paper, the results of the first, second, third and part of fourth cycle of the complex monitoring will be summarized together with the comparison of the changes of parameters after three years. In the second cycle of monitoring, there were measured currents in the neutral conductor. The results of monitoring of harmonic components of current in the neutral conductor will be presented in the paper.