Research On Control Strategy Of High-pressure Common Rail Fuel System For Marine Engine

This thesis built up the control strategy of high-pressure common rail fuel system for marine engine and tested it with simulation.Based on the engineering drawings and operational principle, the high-pressure common rail fuel system model was built up with Simulink. According to the simulation and analysis on this model, the control strategy of high-pressure common rail fuel system was established. The strategy included two parts: the variable-parameter compound control of rail pressure and the injection control based on the self-learning algorithm.Then this thesis did the model-in-the-loop simulation from both the steady-state and dynamic processes with Silver. The results show that:1. For the steady-state process, the variable-parameter compound control strategy can achieve optimal control under any operating conditions. Farther off the rated operating condition, the more it can reflect its superiority.2. As to the process of changing injection quantity, it reduces the probability of undesirable control result by 75% compared with the regular compound control strategy. As to the process of changing speed, the transition period is shortened by about 2.5s.3. As to the steady-state process, the actual injection quantity was controlled to be the same as the target injection quantity by the fuel injection control strategy. The maximum deviation is less than 3%. And the difference between the actual and target injection advance angle is only 0.16 °. The deviation is only about 1.25%.4. As to the dynamic process, it overcomes the difficulties of injection control caused by changing injection speed. The change of working injector quantity may lead to a big difference between the actual and target injection quantity. Except for this, the deviation does not exceed 5%.