In this paper, a Fuzzy Logic Controlled parallel connected synchronous buck DC-DC converter for water electrolysis system is presented. General design of a fuzzy logic controller, based on Matlab/Simulink is performed. This design can be compared with Proportional Integrated Proportional Derivative controller. The complete control system has been developed, analyzed and validated by simulation study. Performances have then been evaluated in detail for different study conditions. The stability of converter has been analyzed different nonlinear electrolyses loads.