The serial multicellular structure of static converters is widely used for high power applications. However, some controls of these converters are unreliable and are sensitive to fluctuations in some of its parameters. In this article is proposed a control by Petri nets that has overcome these deficiencies by making the converter robust vis-à-vis fluctuations that can affect the load or the input voltage. This has been successfully tested by digital simulation in the case of a two-cell converter connected to a non-strictly dissipative non-linear load.