The Internal Impedance of Traction Rails for DC Railways in the 1–100 kHz Frequency Range

The electrical behavior of the sample steel traction rails is analyzed, considering the resistance and internal inductance. Measurements are performed on a sample rail with a circulation of audiofrequency current (with frequency regulated on a wide frequency interval range of 1–100 kHz) superimposed on a dc supply current. The results complete the other measurement results obtained with a 50-Hz bias current; the resistance values are 30%–50% smaller, whereas the internal inductance is almost similar.