A control framework for turboshaft engine based on thermo-gas-dynamic model

The main control methods for helicopter turboshaft engines are cascade feedforward control and model predictive control. The former is difficult to solve the delay of power turbine response caused by the large inertia of the rotor system, while the latter often requires a great amount of computation due to the iteration of the optimal algorithm. To improve the real-time rapidity of power turbine control for turboshaft engines, a control system framework based on thermo-gas-dynamic performance model is proposed in this paper. The calculation of this model is lightweight based on component characteristics, and a double closed-loop feedback control system of the two rotational speeds of gas generator (GG) and power turbine (PT) based on small-step fuel flow (Wf) is further designed. The simulation results show that the power turbine speed is stable, the engine power response is fast, and the control process can be fast and reliable when this control framework is utilized for the acceleration and deceleration processes of the engine.