Linear Electrical Generator for Hydraulic Free Piston Engine

In a free piston linear generator (FPLG), a free piston engine drives a linear electrical generator to produce electrical power. In this chapter, different parameters of an FPLG are analyzed. The parameters include stroke length, power, voltage frequency, and voltage. Firstly, the construction and working principle of an FPLG are explained. Among the parameters of FPLG, stroke length is discussed in the beginning. It is found that the minimum and maximum stroke lengths are 20 mm and 152.4 mm, respectively. Stroke lengths of a free piston engine and a linear electrical generator must match each other. Then output powers of different FPLGs are described and tabulated. The power range is found from 22.23 W to 95 kW. Voltage frequency of the FPLG ranges from 2 to 67 Hz which is listed in a separate table. The maximum output voltage is found to be 400 V whereas most of the FPLG produce less than 300 V. Performance of the FPLG depends on its design, different parameters, and construction material. Then simulation results of an FPLG are presented for using a conventional and the proposed XFlux materials. Voltage, current, power, flux linkage, and core loss of the FPLG are plotted with using different magnetic cores to observe their relative performance. It is found that because of applying XFlux to the FPLG, minimum core loss occurs. Recent progress of FPLGs and their specialty are summarized. The advancement and future scope of the FPLG has been proposed at the end of this chapter.