Effects on harmonic distortion in high power systems supplying AC electric railways

Abstract

This thesis presents effects and investigations of harmonic distortion in power supplying AC electric railways. The details of the system studied were provided by the supply network in the area of Czech Republic and Vietnam railways junction. The mainly studies focus specifically on the order high harmonic components and total harmonic distortion (THD) of the voltages in electric railway supply systems with the influence of one phase system electrified traction. Sources and effects of harmonic distortion with relations are also studied. The details harmonic distortions of the voltages in high power supply on perform 110 kV and 27 kV levels are measured with the LabVIEW program support. The total harmonic distortions at difference positions in real power system network are calculated in percentage. The results of measurements are analyzed, compared and investigated in conformity with the harmonic standards. Based on the real electrified railway system, modeling of electric high power supplying AC electric railways are created by simulation in the real power supply in the area Czech Republic railways junction. The research results are analyzed and investigated for practical application on traction power supply in Vietnam energy. The simulation is discuses on performed of the ATP version of the electromagnetic transient program (EMTP). In addition, the thesis also discusses aspects of the design considerations filtering compensation in AC electric railway system. The static var compensator (SVC) installation represents difference variants of the filtering compensation solution to reduce harmonic distortion. The simulation results acquired with the program are given in comparison at substations in high power supply with the data obtained from measuring in the traction transformer substations with the recommended limits set by the harmonic standards.