火电厂过热汽温的优化控制算法研究

Research on Optimal Control Algorithm of Superheated Steam Temperature in Thermal Power Plant

摘要:

由于火电厂过热蒸汽温度控制具有大延迟、大惯性、非线性、强时变性的特性,传统PID控制算法难以实现良好的控制效果。为了优化火电厂过热汽温控制，提出了一种基于DMC的改进串级PID控制算法。该算法采用DMC改进主控制器输入参数，预测未来输出值，通过预测值与实际值的差值实现输入参数的校正。仿真结果分析表明，该算法与传统PID控制算法相比降低了过热蒸汽温度的超调量，缩短了汽温控制的过渡过程时间，提高了控制系统的抗扰动能力，使控制系统的动态性能和静态性能有了极大改善。

Abstract:

Due to the large delay, large inertia, nonlinearity and strong time-varying characteristics of superheated steam temperature control in thermal power plants, traditional PID control algorithms are difficult to achieve good control effects. In order to optimize the superheated steam temperature control of thermal power plants, an improved cascade PID control algorithm based on DMC is proposed. The algorithm uses DMC to improve the input parameters of the main controller, predicts the future output value, and corrects the input parameters by the difference between the predicted value and the actual value. The simulation results show that compared with the traditional PID control algorithm, the algorithm reduces the overshoot of superheated steam temperature, shortens the transition time of steam temperature control, improves the anti-disturbance capability of the control system, and makes the dynamic performance of the control system. Static performance has been greatly improved.