Voltage regulation of AC/DC converters for railway applications: a comparison among control strategies

Several railway networks and all metro-rail systems are fed by electrical substations (ESSs) equipped with diode AC/DC converters which frequently do not lead to satisfactory performance due to line voltage drop and load sharing among substations. Starting from the formulation of a general model of electric traction systems, the authors deal with the benefits of substation voltage regulation. Some regulation strategies, based on minimization of objective functions, have been tested through computer simulation whose results show that effective regulating actions can be achieved by assuming a cost function that takes into account both the line voltage and power delivered by electrical substations.