燃气轮机导叶执行机构模糊切换控制策略研究

Research on Fuzzy Switch Control Strategy of Guide Vane Actuator in Gas Turbine

为缓解重型燃气轮机双余度导叶执行机构的切换过程给系统造成的冲击,提出了一种基于模糊规则的余度切换控制策略。首先基于双余度导叶执行机构的工作原理,建立了电液位置伺服系统各部件的数学模型,然后以导叶作动筒位移误差和速度作为输入参数,主备伺服回路切换系数作为输出参数,设计了一种二维模糊切换控制器,并针对伺服阀单向卡滞、伺服阀喷嘴堵塞2种典型故障工况进行了联合仿真分析。结果表明,采用传统阈值切换的方式,各物理量在切换点位置波动明显,而采用模糊切换的控制策略能够有效削弱切换过程对导叶作动筒位移、速度和两腔压力造成的冲击及振荡,从而实现双余度导叶执行机构之间的平稳切换。

A switch control strategy based on fuzzy rules was proposed to mitigate the impact of switch process of dual-redundancy guide vane actuator on the system in heavy-duty gas turbine.Firstly,the mathematical model of each component in electro-hydraulic position servo system was established based on the working principle of dual-redundancy guide vane actuator.Secondly,a two-dimensional fuzzy switch controller was designed with displacement error and velocity of guide vane actuator as input and switch coefficient of main and standby servo loops as output.Furthermore,a co-simulation analysis was carried out for two typical fault conditions of the servo valve,which were unidirectional stuck and nozzle block.The results showed that each physical quantity fluctuated obviously at the switch point while using traditional threshold switch method,while the fuzzy switch control strategy could effectively reduce the impact and oscillation on the displacement,velocity and two-chamber pressure of the guide vane actuator during the switching process,thus a smooth switch between the dual-redundancy guide vane actuator could be achieved.