This work make up a preliminary analysis of the comparative study between three-phase converters of two and three branches, operating like grid-side converter (GSC) of a type-3 turbine, in a three-phase three-wire power system. In such a study, these converters aim to perform ancillary services of harmonic compensation and reactive power support. The topology used for analysis is a two level structure and the results are obtained via PSCAD/EMTDC software. The simulation results shows advantages of the 2L-2B compared to 2L-3B, such as oscillations on electrical torque and delivered powers by the stator circuit of the DFIG that were lower. The THDv was also lower in 2L-2B topology