Harmonic Currents Compensation for 1.5 kV DC Railway Substations
Résumé
This paper deals with harmonic current compensation for 1.5 kV DC railway substation. The main constraint is the filtering of the predominant harmonic components (11th and 13th) which are absorbed by the traction group. The possible structures for high power active filters with multi-cell converters are analysed and discussed. Two topologies, based on voltage source inverters connected to the medium voltage network through a step down transformer are proposed. For the control part, two methods of selective harmonics identification are proposed and compared. The first is based on extended pq algorithm and the second is original and based on the synthesis by observer. Extensive simulation results carried out with PSIM software coupled with Matlab Simulink are included to validate the concepts and the methods used for the design and control.