Análisis, control y mejora de la estabilidad de convertidores de electrónica de potencia conectados a catenarias ferroviarias

Abstract

This industrial phd is the result of the collaboration between the University of Alcalá and Ingenieria Viesca S.L. It’s focused on the resolution of an existing problem in the railway sector through the design of controllers for its application in the control of the auxiliary converter present in the trains. Three main objectives are pursued: the shaping of the input admittance of the voltage-controlled auxiliary converter, the tracking of references to achieve the desired voltage at the output of the equipment following the current railway regulations and the design of low-order controllers so that they can be implemented industrially. One of the most common problems that occur in the railway system is the presence or triggering of oscillations-unsteadiness in the connection of power electronic converters to catenary both DC and AC, although this thesis focuses on the study of problems in DC networks of 750 VCC , typical tramway power supply voltage. These problems are due to the interaction between the different converters and the LC filter between the catenary and the different equipments because they behave as constant power loads in a certain frequency range. To solve this problem we propose the shaping of the input admittance of the auxiliary converter, type of converter in which the company Ingeniería Viesca is specialized, by means of the classical control technique QFT and the modern control technique H∞ structured. By approaching the problem from two different points of view, it can be concluded which are the advantages and disadvantages of both methods. The results obtained with the structured H∞ technique have been satisfactory both in simulation and experimentally. In addition, the controller obtained is of very low order, since it is a PI controller, which shows that the problem can be solved from an industrial point of view.