HARMONIC GENERATION AND SYSTEM RESPONSE CHARACTERISTIC IN ELECTRIFIED RAILWAY

초록

The harmonic current happened in the electric train is resonated at the specific frequency by the impedance characteristic of the power supply system. The resonance causes the amplification phenomenon of the harmonic current and various problems. The harmonic current make interference in the adjacent lines of communications and the railway signaling system. Furthermore, in case it flows on the side of power system, overheating and vibration at the power capacitors are caused. Also, abnormal operation at the protective devices can occur. Therefore, we need to evaluate harmonic problems accurately in planning step to construct new electric railway system In reference to this study, we showed how the system respond to the harmonics originated from electric train. That is, the system response to the harmonics was derived by computational algorithm with numerical formulas in theoretical aspects. However, the real catenary system has complex configuration of conductors. it is an important point that we can consider the circuit element of catenary conductors as uniformly a distributed RLC element. Moreover, harmonic characteristics of electric train depend on its operational modes [1]. From this point of view, measurements of harmonics are performed on the real railway power supply systems under the various operational modes. The spectrum and distortion analyses in measurement data are variously described in this study."