民用涡扇发动机起动过程改进的分段组合控制计划研究与试验

Research and experiment on improved sectional combination control scheme for civil turbofan engine's startup process

针对某型民用涡扇发动机,将n-dot闭环控制算法应用于涡扇发动机起动过程,设计了涡扇发动机起动过程开环与闭环分段组合的控制计划,仿真表明:涡扇发动机起动过程采用n-dot闭环控制算法在初始阶段会出现参数摆动的情况.为此,基于油气比作控制变量进行消喘的原理,对n-dot闭环控制算法进行了改进,以消除起动初始阶段的参数摆动.试验结果表明:改进后的分段组合的控制计划能够有效抑制参数摆动现象;并且,对于不同大气条件的起动测试,起动过渡态过程高压转子转速的数值差距不大于1.0%,延时不超过0.9s;而对于不同飞行状态的起动测试,起动过渡态过程高压转子转速的数值差距不大于1.0%,延时不超过1.2s,具有良好的稳定性和重复性.

An-dot closed loop control algorithm was applied to the startup process for a civil turbofan engine.Therefore,an openned/closed loop sectional combination control scheme for turbofan engine＇s starup process was designed.The simulation result shows that the n-dot closed loop control algorithm could cause oscillation at the beginning of startup process of turbofan engine.To eliminate the parameters＇oscillation at the beginning of startup process,the n-dot closed loop control algorithm was improved according to the rationale of surge recovery by using fuel air ratio unit as the control variable.The experiment results illustrate that the improved sectional combination control scheme could effectively restraine the parameters＇oscillation,and furthermore the startup transition process had satisfying sta-bility and repetitive.The numerical difference of high pressure rotor speed under different atmosphere conditions does not exceed 1.0%and the time delay does not exceed 0.9s;meanwhile the numerical difference of high pressure rotor speed under different flight conditions does not exceed 1.0% and the time delay does not exceed 1.2s.