A study of short-circuit modes behind a power transformer in a 110/10 kV electrical network using the ENGEE simulation environment

In recent years, the domestic Engee modeling environment has been developed, which is an analog of MATLAB Simulink. The Engee modeling environment is widely used to study management processes, production mechanization, and other issues. At the same time, there is no work related to the modeling of electric power systems. In this paper, we have implemented a study of stable emergency modes in the 110/10 kV electrical network. The prototype of a computer model of a 110/10 kV electrical network is a single-circuit electric power system powered by a source with a short-circuit output of 500 MVA. An overhead 110 kV power transmission line with a length of 20 km is connected to the source, made with an uninsulated AC-185 wire and a TRDCN-80000/110 power transformer, on the low voltage side of which 10 kV damage was simulated. Oscillograms of current distributions on the sides of the high and low voltage of the 110/10 kV electrical network in stable emergency modes were obtained. It has been established that with a single-phase earth fault of phase «A» on the low voltage side of 10 kV and the use of a transformer with a circuit and a star-triangle winding connection group and an 11th connection group, currents in phases «A» and «B» on the high voltage side of 110 kV increase. With a two-phase short circuit of phases «B» and «C» on the low voltage side of 10 kV, the currents of all three phases on the high voltage side of 110 kV increase.