Theoretical aspects and problems of calculating short-circuit currents power supply systems or the traction electric drive of an active semi-trailer

The article describes and analyzes theoretical aspects and problems arising from the calculation of short-circuit currents of the power supply system of the traction electric drive of alternating current. The power system includes a semiconductor rectifier and a traction inverter. The electric drive is located on the chassis of a semi-trailer, an active semi-trailer, which is part of the “Arctic road train”. The above issues have been worked out, but, nevertheless, the conclusions require clarification through additional experimental verification. The active semi-trailer is designed to transport a multifunctional module for medical and household purposes at ambient temperatures from minus 50 to plus 40 ° C on paved roads, on dirt roads of various conditions, on terrain with soils with weak bearing capacity and virgin snow. The traction electric drive as part of an active semi-trailer is designed to create additional traction forces in difficult vehicle driving conditions in order to overcome obstacles, off-road and hills. This semi-trailer is being created as part of a project to develop a unified family of vehicles “Arctic Bus” and “Arctic Road Train with a Transportable Functional Module” to organize the safe transportation of passengers and mobile social points in the Far North at low temperatures (up to minus 50 °C) and to ensure the connectivity of the territories of the Arctic zone of the Russian Federation. In this regard, traditional methods for calculating short-circuit currents, as well as typical principles for choosing protection devices, checking their settings, fuse settings, resistance of cable lines and buses to short-circuit currents cannot be applied to the power supply system of the traction electric drive of an active semi-trailer, which determines the relevance and necessity of further research in this area. This article proposes calculations which can be used in the development of a methodology for calculating short-circuit currents of the power supply system of a traction electric drive using reversible and irreversible semiconductor converters with a direct current link.