The paper discusses an information system for control and supervision of power transmission network in the Republic of Croatia. For upgrading the existing system, various types of information models have been analyzed and compared to find a model that would satisfy the needs of an efficient management and control of an electric power system and electricity market. The models analyzed include a device model, an object-oriented approach model, and the models based on IEC standards. Examples are given for application of modelling to a group of process information facilitating supervision and control of electric power systems. The models were compared with respect to the characteristics included in the information system modelling by application of an object-oriented approach. The result of the analysis was a model that can satisfy the demands set for supervision, control and implementation of electricity market functions.Index Terms--IEC Standards, object oriented methods, power transmission, SCADA systems J. Simunic is with the Croatian Electric Power Company,

No abstract

No abstract

Recently, the share of renewable sources in the energy mix of production units has been steadily increasing. The unpredictability of renewable sources leads to difficulties in planning, managing and controlling the electric energy system (EES). One of the ways to reduce the negative impact of unpredictable renewable sources is to predict the availability of these energy sources. Short-term forecasting of photovoltaic power plant production is one of the tools that enable greater integration of renewable energy sources into the EES. One way to gather information for the short-term forecast production model is to continuously photograph the hemisphere above the photovoltaic power plant. By processing the data contained within the images, parameters related to the current output power of the observed power plant are obtained. This paper presents a model that utilises a convolutional neural network to analyse images of the hemispherical sky above a power plant to predict the current output power of the power plant. Estimating current production is a crucial step in developing models for short-term solar forecasts. The model was specifically developed for photovoltaic power plants and is capable of achieving high accuracy in power prediction. The estimation of power production from photovoltaic power plants enables the use of next-frame prediction for short-term forecasting.