Abstract: An equilibrium-manifold based LPV (Linear Parameter Varying) modeling method was put forward. Firstly, according to the equilibrium manifold theory, the equilibrium manifold of a turbofan engine was parameterized by a scheduling variable. Then, a conventional LPV model of a turbofan engine was constructed based on the turbofan engine nonlinear model. Next, the conventional LPV model was modified by using the parameterized equilibrium manifold, in which the equilibrium point was estimated in real-time and was used to update the reference equilibrium point in the conventional LPV model. Lastly, a speedup process from idle speed to max speed was simulated with the turbofan engine nonlinear model, the conventional LPV model, and the modified LPV model, separately. The simulation results show that the modified LPV model achieves much higher steady precision and fidelity than the conventional LPV model, which could afford a reliable model to design and analysis the turbofan engine control system.

Key words: Aeroengine; Equilibrium manifold; Linear-parameter-varying (LPV) model; Scheduling variable

摘要： 针对航空发动机线性变参数模型,基于平衡流形原理,研究了一种改进LPV建模方法。首先,根据平衡流形原理,构造涡扇发动机平衡流形参数化形式。其次,根据某型涡扇发动机非线性模型,建立基于局部线性模型的涡扇发动机准LPV模型。然后,建立基于平衡流形的航空发动机改进准LPV模型,即:利用平衡流形参数化形式,根据调度变量实时估算发动机平衡态,以更新发动机准LPV模型的参考平衡态。最后,通过对发动机从慢车状态到最大状态的阶梯加速过程进行仿真,表明改进LVP模型的稳态和动态响应特性与发动机非线性模型保持很好地一致。

关键词: 航空发动机; 平衡流形; 线性变参数模型; 调度变量