Mode Transition Modeling and Coordinated Control of a Parallel TBCC

This paper investigates the modeling and coordinated control of a certain parallel turbine based combined cycle (TBCC) during mode transition. In view of the strong time-varying nonlinearity of the TBCC mode transition and the large range of changes in the state variables and splitter plate opening, a TBCC mode transition coordinated control method based on the polynomial nonlinear parameter-varying (PPV) model is proposed. Based on the component-level models of Turbine and Ramjet engine, PPV models are established using system identification method, which can simultaneously reflect the time-varying and nonlinear characteristics of the engine. State feedback controllers are designed based on gain scheduling and PPV stabilization control theory, and verified on the PPV model. The simulation results show that the proposed method can achieve good control effect, and the actual thrust can quickly track the target thrust, thereby realizing coordinated control of mode transition and smooth transition of total thrust. Moreover, compared to the gain scheduling controller, the proposed method can achieve thrust tracking more quickly and smoothly.