调节阀特性非线性补偿方式对动态特性的影响

调节阀的升程流量特性基本上是非线性的,为了实现机组静态特性的线性化,必须对阀门的非线性特性进行补偿。本文通过计算机仿真,对不同补偿方式时系统的动态特性进行了研究。结果表明,采用输入信号补偿时,若油动机滑阀没有限幅,补偿环节对动态特性则没有影响;若油动机滑阀具有限幅,补偿特性环节放大倍数或扰动增加时系统不稳定。采用反馈补偿时,无论油动机滑阀是否限幅,补偿环节放大倍数有一个保证系统稳定的范围,超出此范围时系统不稳定。所做工作为调节系统补偿环节的设计提供了理论依据。

Effect of Non-Linear Compensating type of Governing Valve Property on System Dynamic Response Characteristics

The steam turbine governing valves usually have a nonlinear position-flow characteristic.In order to obtain a linearization static governing property for the unit,the nonlinear characteristic should be compensated.In this paper,the dynamic properties of the governing system with different compensation methods are analyzed by simulation and some results are obtained.By adopting input signal compensating method,there has no effect on the dynamic characteristic of the system even when the motion of the pilot valve of the actuator is(unlimited.) But with the increase of magnification of the compensation link or the disturbance,the system could be unstable when the motion of the pilot valve of the actuator is limited.As the feedback signal(compensating) method is taken,there has a significant effect on the dynamic property of the system.No matter what the motion of the pilot valve is limited or not,in order to keep the stability of system,the magnification of the compensation should be limited in a range.When the magnification of the compensation link is smaller than a lower limit and/or bigger than an upper-limit,the system should be unstable.A theoretical element is provided for the design of the governing system compensating link.