Load following controller for single free-piston generator

The controller that used to follow the change of load for the single free-piston engine generator is presented here. It aims to achieve the stable operation with the piston oscillation. Based the energy balance equation in consecutive cycles, the kinetic energy of the free piston was described by discrete state functions. According to its error varying with minimums, the following controller was established to set the fuel injection. It was applied into the performance simulation. The results indicate that the controller is available. Due to the discrete characteristic of the energy transfer, the restoration progress has to require two or three cycles at least. And the stroke is increased with the load stepped up. The top dead center position has smaller changes than the bottom dead center. The displacement versus velocity limit loop is bigger than before. It will be used in the prototype design in the experimental research.