Performance Simulation Of Marine Steam Power System Based On Implicit GPC-PID Control Strategy

The steam power system is one of the most important equipments for marine ship,which affects the characteristic of voyage to a great degree.It is required to adapt the requirements of frequenct change,great amptitude in load,as well as response properties.In this paper,the main steam pressure Control strategy for simulation optimization.Analyze the characteristics of marine steam power system.Establish the math models of superchanged boiler,turbocharger unit,main turbine and condensation and feed-water system based on their concrete structure and working process through mechanism modeling method.As the main steam pressure control system for marine steam power system is nonlinear and has large hysteresis,a kind of control method which combines implicit generalized predictive control and PID control is raised to ensure that the main steam pressure can quickly reach a stable state.Research indicates: in the first case of the fifth case transition process the main steam pressure stabilization time is reduced from 7.8 min to 6.3min and overshoot is reduced from0.061 to 0.044 during lifting the load,and the main steam pressure stabilization time is reduced from 8 min to 7.2 min and overshoot is reduced from 0.061 to 0.053 during falling the load;in the first case of the third case transition process the main steam pressure stabilization time is reduced from 5.86 min to 4.87 min and overshoot is reduced from 0.024 to0.019 during lifting the load,and the main steam pressure stabilization time is reduced from7.61 min to 7.23 min and overshoot is reduced from 0.025 to 0.017 during falling the load.The results of the validation of the GPC-PID control method shows that:during the step-up load test the main steam pressure was stable within 15 min,the main steam pressure fluctuated within 1.014 and 0.982,the fluctuation range was within ± 1.8%;during the step-down load test,the main steam pressure is stable within 13 min,the main steam pressure fluctuates within 1.013 and 0.991,the fluctuation range is within ± 1.3%.Implicit GPC-PID control method has certain applicability to the steam power system.