Modeling waveform distortion produced by DC locomotive conversion system. Part 2: Italian railway system

The paper presents a new high computational efficiency model for the calculation of the waveform distortion, caused in the supply electrical system, at AC/DC substations by the new locomotive E404P in the Italian DC railway system. The adjustable speed drive converters of this locomotive are described and modeled. The proposed model based on the twelve-pulse converter switching function and on the iterative harmonic and interharmonic analysis is validated by comparing its results with those of time domain simulations. The waveform distortion evaluated in different operating conditions shows the good accuracy of the results obtainable by means of the new model, also in presence of resonance phenomena in the supply system impedance.