Study of Resonances in 1 × 25 kV AC Traction Systems

Abstract

AC traction systems are 1 × 25 or 2 × 25 kV 50-Hz single-phase, non-linear, time-varying loads that can cause power quality problems. One of the main concerns about these systems is voltage distortion, because adjustable-speed drives for trains may inject harmonic currents of frequencies below 2 kHz. Since the presence of parallel resonances in the contact feeder section of the traction circuit worsens the scenario, traction system resonance phenomena should be analyzed to prevent problems. Several works addressed these phenomena, but they only drew weak numerical conclusions based on the frequency scan method. This article studies 1 × 25 kV traction system resonances at pantograph terminals and provides more effective analytical expressions to locate them and determine the impact of traction system parameters on them. These expressions are validated from several traction systems in the literature.

Keywords:

• harmonic analysis
• resonance
• traction systems
• power quality
• railway systems

Additional information

Notes on contributors

Lluís Monjo

Lluís Monjo was born in Tremp, Spain, in 1983. He received his B.S. in electrical engineering, his M.Eng. in energy, and his Ph.D. in industrial engineering from the Universitat Politècnica de Catalunya (UPC), Barcelona, Spain, in 2007, 2009, and 2013, respectively. He is with the Electrical Engineering Department, UPC, where he has been since 2007. His areas of interest include electric machines, renewable generation, and power system quality.

Luis Sainz

Luis Sainz was born in Barcelona, Spain, in 1965. He received his B.S. and his Ph.D., both in industrial engineering, from UPC, Barcelona, Spain, in 1990 and 1995, respectively. Since 1991, he has been a professor in the Department of Electrical Engineering, UPC. He is the Head of the Electrical Supply Quality Group (QSE), UPC, recognized by the Government of Catalonia. His research interests are in the areas of power quality.