Influence of dispersed generation on reliability of electrical networks

Abstract

Greater part of renewable sources of energy is represented by solar power plants (SPP). Their operation mode depends on natural conditions of the region, where they are located. That is why the problem of SPP stability estimation is important in the problem of covering the daily schedule of energy consumption. The system operator, in his study, emphasizes that photovoltaic and wind power plants are unreliable in terms of electrical power stability. Deviations from scheduled charts over the course of the day amount to more than 450 MW at a set power of 1217 MW. One more specific feature of the installation of renewable energy sources is their uneven distribution throughout Ukraine. Thus, the presence of one powerful source of up to 3 MW, or several less powerful ones up to 0.5 MW, connected to one substation of the distribution network (REM), makes it possible to consider REM as a local electrical system (LES). And for the local electric system, there are not yet clear legislative acts according to which renewable energy sources will function. Particularly acute for distributive electrical networks is the question of reliability and uninterrupted power supply. The article analyzes the pace of increase in the generation of photovoltaic stations in the context of the combined electricity system of Ukraine and the energy supply company of "Vinnytsyaoblenergo". The analysis of existing normative documents regulating the work of photovoltaic stations is carried out. Within the framework of the considered documents, the criteria for assessing the reliability of the operation of electric networks, namely SAIDI, are the length of long interruptions in the electricity supply of electricity consumers. The interconnection of changes in the reliability indices of electrical networks with the increase in the number and installed capacity of renewable energy sources, in particular photovoltaic stations, is shown. To increase the technical and economic efficiency of joint operation of distributed power sources and distribution electric networks, it is necessary to solve a number of tasks, which will allow to increase electricity generation of RES, reduce electricity losses in distribution electric networks, improve the quality and reliability of electricity supply to consumers.In order to efficiently exploit distributed energy sources and their integrated use in power grids, especially in the sense of improving the reliability of power supply, it is necessary to develop a method for restoring electricity supply to forest users, with a loss of centralized power supply