汽轮机功频控制机理的分析

Analysis of Power-frequency Governing Mechanism of Steam Turbine

根据自动控制理论和汽轮机热力系统的工艺流程,分析了汽轮机功频控制系统的控制机理,纠正了现有教材或资料中对汽轮机功频控制系统理解的不正确说法。指出汽轮机功频控制系统中的发电机有功功率信号是前馈信号,不是反馈信号;汽轮机调节级压力反馈控制实际上就是汽轮机功率反馈控制;汽轮机功频控制系统实际上就是前馈-反馈串级控制系统;一次调频回路实际上就是汽轮机功频控制系统的主回路。

According to automatic control principle and thermal system of steam turbine, the power-frequency governing mechanism of steam turbine is analysed and the wrong wordings in teaching materials or documents about power-frequency governing system of steam turbine are corrected. It is shown that the generated power inside power-frequency governing system is feedforward variable and is not feedback variable. The first stage pressure feedback control loop is in reality the steam turbine power feedback control loop. The power-frequency governing system of steam turbine is in reality the feedforward-feedback cascade control system. The primary frequency governing loop is in reality the primary control loop of the power-frequency governing system of steam turbine.