Research on Distribution Characteristics of Stray Current in Metro Network

In order to analyze the stray current in metro network, a lumped parameter modeling method is proposed in this paper. In this method, the ground grid of transfer station is the connection node of different metro lines. And in the proposed model, rail, stray current collection mat, through-grounding conductor are established. Comparing the proposed model with the distributed parameter model, the results of rail potentials and stray currents are the same. Using the proposed metro network model, the influence of over-voltage protection device (OVPD) operation condition on the distribution characteristics of stray current is analyzed. The results show that, in metro network, the operation of OVPD affects the stray currents levels in other metro lines.