除氧器异出力控制算法

Control algorithm for deaerator different strength multiply actuators

除氧器主、副调节阀异出力控制系统设计通常存在主、副调节阀顺序开启时在自动、手动控制方式下无扰切换如何实现等问题。在除氧器主、副调节阀控制系统中设计一带跟踪功能的偏置块,通过偏置块输出值及PID块的跟踪功能全面实现主、副调节阀在手动、自动控制方式的无扰切换。针对控制系统中的跟踪要求,通过数学分析与线性变换推导,得出PID块在主、副调节阀均在手动方式运行时的跟踪值,以及偏置块在主、副调节阀在手动或自动方式运行时的输出值。该控制算法可有效实现系统各种运行方式的无扰切换,保证了系统的稳定性。将该控制策略应用于某1 000MW机组除氧器水位与凝结水母管压力控制系统中,解决了系统运行方式切换过程指令大幅波动现象,满足了主、副调节阀手、自动控制方式的无扰切换,主、副调节阀可以在手动、自动控制方式下运行,并且无需限制保证主、副调节阀的开启顺序,2阀在任何开度下均可投入自动,系统未发生指令突变的现象,大大简化了系统的操作步序。

Troubles usually exist in different strength multiple actuators combined regulator of deaerator＇s main and assisted valves,such as no disturbance switching of different control modes.A kind of improved control strategy was proposed in order to dispose of troubles occurred in this type control systems.The newly tacking loop was designed by BIAS and PID block with tacking function to satisfy no disturbance switching of the control system.Furthermore,the tacking value of PID block and the output value of bias block of the control algorithm.Thus the no disturbance switching and system stability could be achieved by this control algorithm proposed in this paper.Finally,the proven control algorithm was utilized in the de-aerator level control system and condensation water head pressure control system of a 1 000 MW unit.The problems that main and vice valves fluctuating by a wide margin in the course of switching operation pat-tern was resolved thoroughly.The operation results indicate that the no disturbance switching and well control effect are achieved after improved control system was implemented.