自旋动力恢复过程涡轴发动机快速响应控制律对比研究

A Comparison Study of Turbo-Shaft Engine Fast Response Control Schemes in Power Recovery Process During Helicopter Autorotation

关键词:  自旋动力恢复  涡轴发动机  快速响应  多变量控制

Key words:  Autorotation power recovery  Turbo-shaft engine  Fast response  Multi-variable control

摘要:

针对直升机自旋过程中对动力快速安全恢复的问题，充分利用涡轴发动机气路中的导叶、涡轮放气控制，提出了两种涡轴发动机多回路多变量鲁棒控制规律，以实现自旋训练过程中发动机扭矩的快速响应，同时降低旋翼转子瞬态下垂量。采用保性能H2/H∞鲁棒控制算法，分别设计了基于燃油流量&压气机导叶调节，以及燃油流量&涡轮放气调节的具有快速响应能力的发动机转子转速控制规律，使得涡轴发动机在直升机自旋动力恢复过程中，在保证气动稳定安全的前提下，输出扭矩能够快速响应，且旋翼转子下垂量由常规燃油控制的5%下降至3%以内，并能够显著改善燃油动态特性。最后，通过数字仿真对两种控制方法进行了对比分析，得出了在工程应用中两者可能存在的优缺点。

Abstract:

For getting a safer and faster power recovery in helicopter autorotation，two new control schemes for turbo-shaft engines are proposed herein to realize engine output torque fast response and therefor lower rotor speed droop，fully taking advantage of compressor guided vanes or turbine bleeding. On the basis of H2/H∞ performance guaranteed design algorithm，two novel fast response control schemes for turbo-shaft engines are devised，which are fuel flow cooperating with compressor guided vanes control，and fuel flow combined with turbine bleeding control，respectively. These two methods can make the output torque response faster under a safe stall margin and limit the free turbine speed droop less than 3% during power recovery process in helicopter autorotation，otherwise the droop value about 5% when employing the traditional fuel flow control. Moreover，the fuel flow transient using the new methods is smoother than that when using the traditional one. At last，simulation results give comparisons between these two control methods，and the merits as well as its defections are also discussed.