Quad-cylinder Structure for Electrical Loss-reduction in Free-piston Engine Linear Generator with Four-stroke Engine

A new energy conversion device is the free-piston engine linear generator (FPEG) without a crank mechanism. Among these, the four-stroke FPEG engine is regarded as a highly efficient engine generator that complies with emission laws. However, because the linear machine is used as a motor, the energy conversion efficiency of the proposed FPEG using a four-stroke engine is poor. As a result, a quad-cylinder FPEG is proposed in this study. Four free-piston engines and a linear machine make up the quad-cylinder FPEG. When compared to a dual-cylinder FPEG, the suggested construction allows continuous operation with just generation and reduces electrical loss by 71%. As a result, the suggested and traditional structures' energy conversion efficiency was 42% and 38%, respectively.