Design Of Single-phase Linear Generator With Permanent Magnet Mover For Free Piston Engine

Free piston power generation system(FPEG)is a new type of energy conversion device,which has the advantages of high efficiency,high power density,low manufacturing cost and low emission.It has been widely concerned and studied in recent years.Aiming at the application requirements of the fourth-generation FPEG system developed by the research group,this paper completed the design of linear generator,including the following aspects:(1)Based on the performance requirements of FPEG for linear generator,two structural schemes of tubular moving magnet linear generator(TMMLG)and plate moving magnet linear generator(PMMLG)were designed.(2)The structural scheme of TMMLG was designed,the material selection and structural design were completed.The electromagnetic finite element model of was established and its thrust,EMF,generating power and generating efficiency were analyzed.The development of prototype was completed,and the accuracy of electromagnetic finite element model was verified through prototype test.(3)The structure scheme of PMMLG was designed,the main dimension parameters of PMMLG were determined.The finite element model was established,and its thrust,EMF,loss,generating power and generating efficiency were analyzed.The temperature field model of PMMLG was established,and the temperature rise characteristics of the mover were analyzed based on the loss of the electromagnetic field model.(4)The development of PMMLG prototype was completed,and the prototype test paltform was built.The prototype test was carried out,and TMMLG and PMMLG were compared with the existing moving coil linear generator in the research group.The results show that the moving magnet linear generator has higher power density and is more suitable for the application of this paper.The power density and generating efficiency of TMMLG and PMMLG were 162 W/kg,91% and 183 W/kg,95% respectively.PMMLG can be used as the main research direction of FPEG in the future due to its lower mover mass,lower cogging force and faster response.