A Study on the Characteristic Analysis for Resonance Harmonic Order in AC Railway Systems to Harmonic Resonance

As the integration of active equipment based on power electronics technology is expected to form an eco-friendly railway system, it is necessary to review the durability of the AC railway system against harmonic currents injected from converters. Recently, a dissipation of lightning arrester had been occurred due to overvoltage caused by harmonic resonance during the operation of railway vehicles, therefore the need for system analysis to avoid resonance has increased. This paper defined the length of the catenary system and the capacity of the Scott transformer as factors affecting the resonance harmonic order and magnitude of impedance in AC railway systems, and analyzed their effects. In addition, the change in the resonance harmonic order and the magnitude of impedance whether RC bank is applied or not was analyzed.