Comparative analysis of experimental and calculation methods for determination of the traction current harmonics distribution in rails

Abstract

The purpose of this work is to perform the comparative analysis of experimental and calculation methods for determination of the distribution of traction current harmonics in rails. To investigate the distribution of traction current in the rails, the special marks (flags) were set up at a certain distance (100, 300 and 500 m) from the point of measurement along the track. The moments of passing the train past the flags were recorded in a computer due to a sound signal from the train, as well as visual observation. The train was moving in the measuring section in a quasi-stationary mode with an average speed of about 48 km/h. Traction current was measured in circuit of the inter-throttle jumper with using an inductive contactless sensor and registered using computer.The distribution of the return traction current harmonics in rails for AC feeding systems were modeled by using the multi-conductor transmission line (MTL) model.Some discrepancies in the results of experimental and calculation methods were observed. One of main reason of measurement errors were an inaccuracy in determining distances from the train to the measurement point. Calculation errors were related mainly with using inaccurate electrical parameters of track in model, in particular, the track ballast resistance and the ground resistances.However, in general, the considered model can be used for investigation of the traction current harmonic propagation in rails from train, and their influence on the track circuits receivers for different cases including the variation of the track circuits electrical parameters, as well as the number of rolling stock units in the feeder zone. Such analysis of harmonic in rails is important for revealing the causes of failures in railway signalling system operation under simultaneous affecting on it several factors adverse to safe operation.