Measuring and Analyzing Power Quality in Electric Traction Systems

Abstract

Power Quality phenomena in a broad sense, stationary and transient, are considered focusing on railway applications: dc and ac traction lines are considered, identifying the main sources (fixed, like substations, and moving, like vehicles), their characteristic emissions, how they propagate and combine along the traction lines and back to the three-phase ac supply lines. The analysis covers the railway standards applicable to the traction line and the industrial standards applicable to the ac feeding lines. The peculiarity of railway applications, that is the presence of moving distorting loads interconnected by a non-ideal transmission line and characterized by variable operating conditions and by the superposition of multiple sources with different dynamics, requires specific processing, analysis and visualization methods, that are addressed by means of examples based on real data.