Study on the electromagnetic ring network in bilateral power supply mode of electrified railway

The electromagnetic loop network problem of power system is a kind of power network problem that evolves with the development of power grid. In order to avoid the further spread of the problems caused by the electromagnetic ring network, the open-loop operation mode is widely used in the power grid below 500kV to reduce the impact on the power system. In electrified railways, the same phase connection of adjacent traction substations can be achieved through bilateral power supply technology, which increases the terminal voltage level of the traction network. However, an electromagnetic loop network is formed at the 27.5kV traction feeder. The purpose of this paper is to study the generation mechanism of electromagnetic ring network and its influence to power system under bilateral power supply technology. Theoretical support and technical guidance are provided for engineering practice and trial operation.