Emergency Modes Modeling in Non-Traction Consumers Power Supply Systems

Abstract

The use of distributed generation (DG) plants, which includes renewable energy resources, allows to stabilize voltage levels, reduce losses in networks and to free couplings transfer capacities. Power quality can be enhanced based on DG in railroads power supply systems (RPSS), as well power supply efficiency and uninterruptedness of power consumers supply. However, when DG is used, a problem arises associated with the short circuit currents growth caused by additional power sources. To resolve this problem, development of methods emergency modes modeling in RPSS is required, when RPSS are equipped with DG plants. The article contains results of emergency modes study in power supply systems, with emergency modes caused by short circuits. A non-traction consumers' individual power supply region was modeled, which was connected to a traction substation through a DC link and which included the following DG plants: turbogenerator of minicogeneration plants; hydrogenerator of micro-hydropower plant; a wind power generation plant (WPGP) based on synchronous machine; WPGP based on DC machine and a solar power plant. The modeling results allow us to make the following conclusions: when DG plants are used, short circuits currents are growing which requires additional check of the switching equipment and changing relay protection setpoints to ensure selectivity; using DC link allows to significantly reduce short circuit currents, even when feed is available from DG plants; in case of two-phase short circuit a significant distortion of currents curves' harmonicity is observed, when currents are leaking from DG sources. Keywords—railroads power supply systems, distributed generation plants, emergency modes