In this study, a Simulink simulation is realized for a converter system that is located between fixed-speed wind turbine and grid. The 3-phase output voltage has been modelled as a squirrel cage induction generator output as being the most widely used generator type in wind turbines. The output line voltages of wind turbine has been converted to DC using a 12-pulse uncontrolled rectifier, and applied to the inverter that is controlled using sinusoidal pulse width modulation. The DC-AC conversion using three-level SPWM controlled inverter has been realized in this study, which is performed using Matlab/Simulink. The output harmonics of the designed converter system, which is based on a 10 kW wind turbine, have been minimized adjusting the values such as modulation index (mi) and switching frequency (fsw). The THD ratio of line currents has been decreased to 0.03% at the inverter output, while it was 8.38% at the turbine output. The minimum THD ratios of harmonic analysis are 0.03% for line-to-line currents and 1.11% for line-to-line voltages. The measured THD ratios are proper to IEEE-519 standards. Using a controlled rectifier will minimize the harmonic contents for the designed and analyzed system. Copyright (C) 2010 John Wiley & Sons, Ltd.