Sensitivity analysis and control methodology for linear engine alternator
Linear engine generator design optimization traditionally has been difficult because each independent variable alters the motion with respect to time, and therefore alters the engine and alternator response to other governing variables. An analogy is drawn to an engine with a very light flywheel, where the rotational speed effectively is not constant. However, when springs are used in conjunction with a linear engine alternator (LEA), the motion becomes more consistent and more sinusoidal with increasing spring stiffness. This reduces some attractive features, such as variable compression ratio HCCI operation, but aids in reducing cycle to cycle variation for conventional combustion modes. To understand the cycle-to-cycle variations, we have developed a comprehensive model of an LEA with a 1kW target power in MATLAB®/Simulink, and an LEA corresponding to that model has been operated in the laboratory.