Вплив відновлювальних джерел енергії на технічний стан обладнання розподільних мереж

Abstract

The transient processes has been researched in the article during the switching on and switching-off of electrical equipment (EE), for instance, of photovoltaic power plants (PPP), in the local electrical systems (LES). Were shown results of PPP impact studies with inverters PCS-9563 and RC filters, which are contained in each phase are capacitor with a capacity of 300 μF and an inductor of 0,1 mH, on the currents in the high voltage winding of measuring transformers of voltage, and it is proved that during switching overvoltage, caused by the switching ON or OFF of several PPP inverters, the currents in high voltage windings of these transformers may grow, while in the cable couplings can increase the current due to insulation resistance. The analysis of the results of using the fast transform of Fourier during the study of the curve of change of current in a high-voltage winding indicates that in the current of this winding, among the most of influential on the graph, there are not only harmonics of an industrial frequency of 50 Hz, but also other harmonics, for example, harmonics, with frequencies 150, 300 and 450 Hz. Such overvoltages can cause operations of arresters and reduce their switching resources. It is shown that the use of methods of mathematical modelling, methods of the theory of electric circuits and software package of Wolfram Mathematica allows to obtain mathematical models of processes of change of currents and voltages in the equipment of local electrical systems with renewable sources of energy (RSE). Attention is drawn to the fact that the complexity of mathematical expressions of currents and voltages in the equipment of local electrical systems with RSE, which have been obtained using the software package of Wolfram Mathematica worsens their perception and understanding and their analysis, therefore, more expedient using the research computer models created in the software providing by PS CAD, Matlab Simulink, etc