The ornamental design for a controlpanel for a hydrogen generation system, as shown and described.
FIG. 1 is a front view of a control panel for a hydrogen generation system of the new design; and,
FIG. 2 is a front, right side, and top perspective view of a control panel for a hydrogen generation system of the new design in the environment of an enclosure for a hydrogen generation system.
The broken lines showing of the environment structure and the indicia are for illustrative purposes only and form no part of the claimed design.