Displacement Profile Optimization of Free Piston Engine Generator

The free piston engine generator is a new type of power device. Compared with the traditional reciprocating internal combustion generator, it abandons the mechanical structure of the crank connecting rod. This difference in the mechanical structure between the two improves the freedom of piston movement. In actual applications, depending on load demand and operating conditions, the generator's output power may be adjusted to balance energy utilization and system stability. In view of this characteristic of the free-piston internal combustion generator, a piston displacement profile optimization method is proposed in this paper to maximize the average power. First, clarify the research objectives and constraints, and determine the variables and constraints that need to be optimized. Secondly, a mathematical model was established to describe the displacement and geometric relationship of the piston movement. Finally, a genetic algorithm was selected to find the optimal displacement profile, and compared with the average power of six typical displacement curves to verify the superiority of this method.