Assessment of the reliability of the mathematical model of the 0.4 kV rural electric network in Matlab Simulink on the example of a study of the steady-state mode of a single-phase short circuit

Abstract

PURPOSE. Currently, modeling is one of the most reliable ways to study normal and emergency modes of operation of electrical networks. In this regard, a mathematical model of the 0.4 kV rural electric network was developed in the MATLAB Simulink program.PURPOSE. Evaluation of the accuracy of the parameters of the operating modes of the 0.4 kV rural electric network obtained by modeling in MATLAB Simulink by estimating the values of the steady-state single-phase short circuit current at different distances from the transformer substation.METHODS. The currents obtained using the 0.4 kV electrical network model developed in MATLAB Simulink were compared with the currents obtained using other calculation methods (according to GOST 28249-93, the simplified phase-zero loop method and the mathematical model «Project RZA»).RESULTS. It was revealed that the discrepancy in the results at individual points was 9-11%. When simulating a steady-state single-phase short circuit in MATLAB Simulink, it was found that the voltage of the damaged phase A decreases to 0 V, while the voltages on the two remaining intact phases increase by 1.4-1.5 times, i.e.E. by a factor of 2 to the values of 335-354 V when short-circuiting at the transformer terminals and to the values of 329-338 V when short-circuiting behind a section of a 0.4 kV power line.CONCLUSIONS. The resulting mathematical model of a 0.4 kV rural electric network in the MATLAB Simulink program can be used to study normal and emergency operating modes, study the modes of joint operation of renewable energy sources with a centralized network, and the processes of switching on backup generation sources.