基于LMI的过渡态主控回路闭环控制律优化设计

Optimal design of transient main closed-loop control law based on LMI

针对涡扇发动机过渡态多变量控制设计难的问题,提出了一种基于抽功法在过渡态加减速线上的准稳态工作点处提取线性模型的方法,并在此基础上提出了一种过渡态主控回路闭环控制律的优化设计方法。通过功率输入和功率提取解决过渡态动态特征提取难题,基于增益调度可作为非线性动态控制策略的基本原理,将稳态多变量控制规律的线性矩阵不等式(LMI)设计方法推广到涡扇发动机过渡态主控回路闭环控制的设计中,并通过最小化矩阵迹优化闭环极点配置。针对2种不同过渡态主控回路闭环控制策略,分别设计了最小化矩阵迹寻优的过渡态主控回路的多变量闭环控制律,并进行从慢车到中间状态的基于涡扇发动机非线性动态模型的双通道过渡态性能仿真验证,结果表明:方案1过渡态控制双通道N_(1)、N_(2)的调节时间不大于5.0 s,超调量不大于0.8%;方案2过渡态控制双通道π_(T)、N_(2)的调节时间不大于5.6 s,超调量不大于0.8%。

In order to solve the problem that it is difficult to design transient multivariable control law for turbofan engines,a method of extracting linear model at quasi steady working point of transient acceleration and deceleration line based on power import and extraction is proposed.Based on this,a transient main closed-loop control optimal design method is proposed.It is extended from the steady multivariable control law’s linear matrix inequality(LMI)design method to the design of transient main closed-loop control for turbofan engines because the gain-schedule can be used as nonlinear dynamic control method.Minimum matrix trace optimization closed-loop pole is configured to ensure the feasibility of the method.As demanded by two different transient main closed-loop control schedules,two different minimum matrix trace optimization transient multivariable main closed-loop control laws were designed respectively.Dual channels transient performance ground simulations based on a nonlinear turbofan engine model and containing the dynamic state between idle state and maximum power setting state were done.The results show that settling time of transient control dual channels N_(1) and N_(2) is no more than 5.0 s and the maximum overshoot is 0.8%in case one.In case two,settling time of transient control dual channelsπ_(T) and N_(2) is no more than 5.6 s and the maximum overshoot is 0.8%.