Ricerc@Sapienza

The paper reports a methodology to analyze the voltage unbalance induced by a railway line electrified at 2×25 kV 50 Hz on the main high voltage network.Starting from the knowledge of maximum power consumption by trains, carrying out a train performance, a Simulink model of a real railway line electrified at 2×25 k-50 Hz has been carried out in order to calculate the voltage unbalance.Taken into account CEI EN 50160 and IEEE Std. 1159-1995, some technical solution have been proposed in order to mitigate the voltage unbalance under threshold limit imposed by standard.

The paper describes and analyzes the electrical system of a long tunnel placed along the 'Naples-Bari' High-Speed railway line. In particular, a critical situation, due to a blackout event has been investigated. A generator set must guarantee the service continuity to supply safety and signaling system, emergency lighting and auxiliary equipment of electrical substations. A shunt reactor has been installed to compensate the reactive power produced by the long feeding cable and to respect the capability curve of the generator.

The paper proposes a novel approach to modelling time-varying non-linear loads in power systems, based on demand conditions. The model allows a pre-evaluation of harmonic disturbances under variable conditions using normal and uniform distribution to randomize the electrical values of the non-linear loads and the related harmonic spectra. A measurement campaign conducted on an industrial area, a deposit/maintenance and repair site utilized for trains in operation on the metro line B of Rome, has been taken into account to verify the model performance.