In this work a design procedure of Power Electronic Converters (PECs) is proposed, which is based on system knowledge and systems theory. The proposed design procedure is composed of 4 stages and 10 steps and it allows to obtain all PEC parameters and its control structure such that established system operating requirements are satisfied. In this proposed design procedure, system controllability is tested based on set theory in control. The main achievement of this design procedure is to allow the PEC design to take into account its inherent dynamical nature, with verified controllability, but without fixing any control structure.