Aspects Concerning the Simulation of Active Filters Used in Urban Transportation Substations Using SPICE

The paper presents some of the active filters topologies used for the improving of power quality. One presents some recordings and numerical simulations made over the electric signals from a substation used for the supplying of a d.c. line of 600 V. Based on the obtained results one proposes solutions for active compensations with the consideration of a number of filtering components. In order to verify the compensation efficiency, through SPICE simulation one estimates the effects of compensation. One can also notice a power factor correction effect through the displacement of the filtered current waveform in advance relative to the initial current.