Выявление факторов разрыва транзита электроэнергии в системе внешнего электроснабжения и ее подпитки через контактную сеть

Abstract

One of the most difficult emergency modes is feeding the place of a short circuit in the external power supply system through the contact network in case of disconnection of a transit power line, which causes appearance of equalizing currents. In this case, it is proposed to use a combination of directional current protection that reacts not only to the amount of current in the protected line, but also to the direction of the short-circuit current, i.e., to the phase of the current in the line relative to the bus voltage and protection against excess voltage in any of the phases. In order to determine the signs of the specified mode, mathematical modeling of a section of the electrified 2×25 kV railway was performed in the Fazonord software package. During the simulation, the values of equalizing currents, power over-flows, voltages in the circuit nodes, and voltage asymmetry coefficients of the reverse sequence were obtained for the case of feeding the external power supply system through the contact network. In order to determine the factors that make it possible to identify the phenomenon of recharge of the external power supply system from the contact side when the transit of the power line breaks, it is proposed to use InTer-27.5-FVV terminals in combination with rupture monitoring based on the information and measuring complex «Black Box-2000», by which, based on the calculation of the voltage asymmetry coefficient of the reverse sequence, in cases of exceeding the set point value, a signal is transmitted to the control room.