This paper presents a rapid-convergent sliding mode proportional-integral (PI) technology with fuzzy gain scheduling for hydrogen energy applications. The rapid-convergent sliding mode control can provide insensitivity to system uncertainties and finite system-state convergence time to origin, however undesirable chattering behavior exists. The proposed technology utilizes the expansion of the plant model for designing the formation of a rapid-convergent sliding mode PI control and then the chatter is remarkably lessened. Moreover, a fuzzy gain scheduling assists in tuning the PI control parameters against uncertain disturbances. Simulations show that the presented hydrogen energy system leads to low distorted output-voltage under nonlinear load and fast transience under step load change. Lab experiments obtained with a developed hydrogen energy system using a digital signal processing algorithm have been offered to demonstrate the performance improvement, especially in the presence of seriously nonlinear circumstance. In contrast with the proposed hydrogen energy system, the classic sliding mode-controlled hydrogen energy system has also been evaluated via both simulation and experiment. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.