Research On Modeling And Adaptive Control Of A Gas Turbine

Modeling,research on control algorithm,simulation and test are essential elements in the development process of a gas turbine,and they are also technical difficulties.This paper focuses on these three points.Firstly,volume inertia method is used to establish a three-shaft gas turbine nonlinear dynamic model instead of Newton-Raphson method,which taking variable specific heat,air bleeding,cooling and so on into consideration.The simulation accuracy of the model is verified by comparing with test data.Using volume inertia method can improve the real-time performance of the model,and the dynamic process of the model is also closer to the real operating state of the gas turbine.The parameter oscillation phenomenon in the low-speed simulation is analyzed,and it can be eliminated by add characteristic data of low speed.A method is proposed to obtain the low-speed characteristics of the compressor which is based on exponential balance and spline fitting.The extrapolation calculation and analysis of the low compressor characteristic data shows that this method has good accuracy.Secondly,according to the characteristics of heavy-duty gas turbine,such as strong nonlinearity,large inertia and variable load,an adaptive controller based on deep belief network is proposed.This controller combines the deep belief network and the traditional PID controller,in which the deep belief network can adjust the PID parameters online,and the traditional PID controller is to calculate and output the control result.The digital simulation proves that the controller meets the requirements of gas turbine speed control,and it also has good adaptability.Under different working conditions of gas turbine,the speed can be controlled accurately and quickly,with no overshoot.Finally,in view of the need of a gas turbine hardware-in-loop simulation platform,an interface simulator is designed,which can collect and simulate voltage,current and frequency signals in various ranges.The hardware-in-the-loop control platform of gas turbine is built.The interface simulator and controller are calibrated,and the real-time performance of the platform is also verified before the test.The multi-task embedded control system based on RTX operating system is developed on the existing controller.It is proved that the controller designed by this paper has good control effect and strong adaptive ability through hardware-in-the-loop test.