A Study on RC-Bank Parameters for Improving the Resonance Characteristics of AC Electric Railway Power Supply Systems

Harmonic currents generated by vehicles can combine with the impedance characteristics of the power supply infrastructure, amplifying specific harmonic components or inducing new resonance phenomena. In fact, cases have occurred where specific harmonics generated by vehicles overlapped with the resonant frequency of the AC electric railway system, exacerbating voltage waveform distortion and damaging equipment. This paper analyzes the harmonic amplification and equivalent impedance of the electric railway system to improve resonance characteristics. Furthermore, we derive parameters for a passive filter (RC bank) and demonstrate the resulting improvement in harmonic amplification.