Assessment of the application of relay protection and automation of traction substations of a subway on the basis of monitoring system SMTN-3

The article provides an analysis of the replacement of obsolete analogue-electromechanical relay protection and automation using an advanced microprocessor relay protection. A very significant economic effect can be obtained thanks to such a feature of digital relays as measuring and storing the values of short-circuit currents. Digital relays allow you to remotely determine the place of damage to the cable line with a sufficiently high accuracy, which makes it possible not only to save money for bypassing the damaged line, but mainly to reduce the time of interruption of power supply and damage to consumers. Assessing the economic effect of the use of microprocessor relay protection in monetary terms, we must not forget about other positive factors that appear due to digital relay protection, including improving the safety of personnel serving electrical installations, introducing electrical specialists to modern hardware and software for automated control systems of electrical installations, including relay protection and automation equipment, improving the operating culture and improving the working conditions of workers in energy enterprises.