Influence of the Catenary Distributed Parameters on the Resonance Frequencies of Electric Railways Based on Quantitative Calculation and Field Tests

High-order harmonic resonance is a key issue in the traction power supply systems (TPSS) of electric railways for safe operation. The effective evaluation frequency critical taking measures to suppress resonance. In this paper, influence distributed parameters networks on frequencies based accurate calculation proposed. quantitative assessments impedance and admittance are investigated. Furthermore, theoretical directly verified using field tests at high voltage level equal 25 kV. results show that TPSS mainly affected by parameters, including self-admittance self-impedance contact wires, positive feeders. addition, connected parallel has greater effect than series-connected impedance. method also adapted renewable energy.