Experimental measurement and simulation of harmonic frequency incurred from Czech railway network

Abstract

This paper deals with modeling and simulation of processes in the distribution network of electric energy. For the scope of this paper, the simulation means the simulation of quality of electric energy with the main focus on voltage and harmonic frequencies of current in distribution network. The point of connection of distribution network to the traction network was chosen as the point where measurements were taken and simulation was done. Introduction part deals with AC and DC traction network. Then the article discusses the problem of modeling of different parts of the distribution network and traction network, such as: overhead line, contact line, Filtration Compensation Equipment, twelve-pulse rectifier, three-phase three-wire transformer, traction transformer and load of railway tractive stock. The mathematical model of each part was drawn-up leading in a complex model of DC traction network connected to the 22 kV distribution network and the complex model of the one-phase AC traction network to the 110 kV distribution network. Software Pspice was employed to obtain simulations of particular components. Results of those simulations were compared with experimental measurements which were taken at the railway lap of traction current converter plant Hoštka – Mělník (for DC traction network) and at the railway lap of the traction sub-station Bohatice (for AC traction network). Based on comparision of measured and simulated data of AC and DC traction network it could be concluded that current harmonic frequencies take similar values, particular diferences are discussed in the paper. Another conclusion is that measeured and simulated data do not meet limits for harmonic frequencies of current given by standards PNE 33 3430 and ČSN IEC 61 000-3 -4. Limits for harmonic frequencies of voltage stated in the standard ČSN EN 50 160 ed.2 are not exceeded.