A new methodology to optimize the efficiency of a multi-sources and multi-converters system under harmonic constraints. Application to light rail system

A new HVDC power supply network for light rail systems is presented and compared to classical distribution networks based on AC/DC controlled converters. This original supply network use an intermediate high voltage DC feeder which supplies the vehicle through simple synchronous buck converters. Nevertheless, as the number of substations can be increased to improve the line voltage control, harmonic interactions between substations may increase both. Therefore, an adapted tool of power converter filter design has to be developed for such a dynamic complex system with power electronics converters, AC and DC networks, moving vehicles and harmonic interactions. After a brief presentation of the supply network, two levels of modelling are then presented. A dynamic model is first described by using a generalized state-space averaging model of converters, which takes into account global losses in converters for switching and conduction phases. Then, ta second model is proposed to optimize the parameters of input and output filters of converters according to maximal current and voltage ripples. Finally, this methodology of sizing is applied on a simplified supply network of light rail.