Abstract : In this work, a approach for controlling a hybrid system is presented thought the important application of a three cells multicellular converter. The hybrid nature of these systems lies in the presence of continuous variables and discrete variables, which represent the evolution of the load current and the voltage across the floating capacitors and the state of the switches respectively. In order to obtain a good operation of this converter, it is necessary to ensure the voltage balance in the cells. The objective is to control the floating voltages, and the load current around their reference values. For this reason the operating modes of the system are governed by the references of the floating voltages and the load current. The importance of the hybrid approach is demonstrated by intensive simulation results. It is shown that the presented controller for multicellular converter has fast tracking capability, and is robust to load disturbance.