This paper presents the design and implementation of a modular single phase multilevel inverter using the asymmetric cascade multilevel converter type. The converter output allows 7, 15 and 31 levels and use the step modulation strategy. The selective harmonic elimination (SHE) technique was used for the computation of the firing angles. All the results were simulated in MATLAB professional software and validated by the implementation of the converter, evaluating the performance using the total harmonic distortion factor (THD).