A regenerator for a fluid power system is arranged to control flow rates while converting pressure drops accompanying resulting changes in flow rates into useful work. A gang of displacers are incorporated into a fluid flow network that also includes an array of selectable flow paths through the displacers. A control system, responsive to changes in demand for the flow of fluid, selects among the flow paths to operate the displacers in various combinations as motors, pumps, and recirculators for dividing the flow of fluid into two variably sized portions. One portion of the flow is sized to match the demand for fluid flow, and the other portion of the flow is converted into useful work.