Aspects regarding the power and energy losses evaluation from public electricity repartition systems

The electricity repartition public systems from our country are made up of 110 kV overhead and cable lines that usually operate in normal steady state in complex loop configuration, as well as 110 kV/MT step-down stations. Under these conditions, the active power and energy losses computation or assessment in operation must be done simultaneously on all components due to the fact that their operating states are inter-conditioned. The level of these losses is generally influenced both by the system configuration and the consumers operating state, as well as the loads of different power sources that discharge in the system, such as, for example, alternators from the power stations, reactive power sources, etc. For the above-mentioned reasons, best results regarding the active power and energy losses estimation are obtained through repeated steady state computation for a necessary and sufficient number of levels for the characterization as complete as possible of the system operation, taking both into account the consumption variation and power sources that inject energy in system. For these purposes, within the paper, for an existent and extended repartition public system in complex loop configuration, the evaluation possibilities are analyzed with best precision regarding active energy losses, through repeated steady state computation, the load curves being split into 24 hourly levels.