Electronic Control System Of GDI Free Piston Linear Generator

As a result of environmental pollution and energy security,more and more attention has been paid on free piston linear generator(FPLG).FPLG could be divided into two parts.One is free piston engine,which converts the chemical energy of fuel into mechanical energy of piston.The other one is linear generator,which converts the mechanical energy of piston into electric energy.Compared with reciprocating engine,FPLG has no crankshaft connecting rod and flywheel.Piston is directly connected with the forcer of linear generator.Because of the simple structure of FPLG,its cost is lower compared with traditional engine.There is no lateral force between piston and cylinder,so the friction loss is small.In addition,the stroke of free piston engine is not a constant,which makes high compression ratio and thermal efficiency.High pressure fuel injection of GDI could make a more homogeneous air-fuel mixture and higher thermal efficiency.The study object is a FPLG prototype designed and constructed by other researchers.By the analysis of control system's function demand,the selection and constitute of hardware was proposed.Then based on the parameters of prototype,a one dimensional model of FPLG was established in simulink.The control method of running assisted by electromagnetic force was verified in the Simulink model.Furthermore,control program was designed by LabVIEW.Finally tests of displacement verification,running with different electromagnetic force,running with different injection pressure and running with fixed injection pulse were done on the prototype.The results show that 100 N is the best electromagnetic force when starting the FPLG.Higher injection pressure makes for a better combustion and less circulatory disturbance.And due to the disturbance of Air intake quantity,running with fixed injection quantity is not good for theimprovement of combustion and circulatory disturbance.