Synthesis of line impedance expressions for railway traction systems

An important element for the analysis of the electromagnetic conducted emissions in railway traction systems is the line impedance Z at the pantograph terminals. Simplified expressions of Z are derived under various assumptions, and their validity is checked against an analytically derived reference expression. A sensitivity analysis of Z is performed with respect to some electrical parameters of the traction line. The influence of the substation impedance as a terminal condition for the traction line is considered for dc substations; several substation configurations (rated power and filter characteristics) in use in different countries are considered.