热工自动控制系统PID参数的优化整定及其应用研究

【作者】 张岳荣；

【导师】 吴军基； 黄悦照；

【作者基本信息】 南京理工大学 ， 动力工程， 2002， 硕士

【摘要】 近几年来，随着电力行业运行机制的改革，电力企业单元机组运行的安全性和经济性越来越重视。热工控制系统的性能对机组运行的安全性和经济性都有着直接的影响，尤其是对负荷变动较为频繁的机组。在控制系统结构一定的条件下，控制系统的性能在很大程度上取决于对控制系统控制器参数的整定。 目前，电厂热工自动控制系统普遍采用PID控制器。论文根据热工过程的特点，对PID控制器参数的优化整定问题进行了研究，其主要内容及进展为： 1．研究了有自平衡能力、无自平衡能力和稳态为零的三类典型的热工过程的传递函数模型的求取方法，并在此基础上开发了相应的应用软件。仿真研究结果表明，所开发的软件是有效的。为进一步基于传递函数模型进行PID参数优化整定提供了前提条件。 2．针对热工过程的特点，研究了单回路控制系统、串级控制系统、前馈-反馈控制系统和2×2多变量控制系统的PID参数整定方法，并在此基础上提出了以上述各系统的PID参数整定值作为初始参数值，采用单纯形算法对PID参数进行寻优的PID参数优化整定方案，并开发了相应的PID参数优化整定软件。对2×2多变量控制系统的PID参数优化整定进行了仿真研究，结果表明，所开发的PID参数优化整定软件是有效的。 3．对某电厂300MW直流机组锅炉过热汽温控制系统的参数优化整定进行了应用研究。首先通过现场试验获取过热汽温过程的阶跃响应曲线，再根据试验得到的过程阶跃响应数据求取相应过程的传递函数模型；然后，根据传递函数模型进行控制系统PID参数的优化整定；最后，对优化前后的控制系统性能进行了仿真研究。为优化整定结果在实际控制系统中的应用，提供了可靠的依据和保证。更多还原

【Abstract】 With the development of the power industry, the safety and economy of the boiler turbine generator units become more and more important. The performance of the control systems of units directly influences the safety and economy of units. For fixed structure control system, its performance depends on the adjustment of controller parameters.At present, the PID controller is widely used in thermal processes control in power plants. This dissertation studies on the problem of the PID parameters optimal adjustment according to the character of thermal processes. The main content include:1. The identification methods of transfer function are studied for three kinds of typical thermal processes. The related identification soft is developed. Simulations are carried out to show that the developed soft is valid.2. The PID parameters adjustment methods are studied for single loop- control sy stems ^ cascade control systems , feed forward back forward control systems and 2*2 multivariable control systems according to the character of thermal processes control. The optimal adjustment strategy of using simple shape algorithm to search the optimal PID parameters with the initial PID parameter values obtained by related adjustment methods is proposed. The optimal adjustment soft is developed also. Simulations for 2*2 multivariable control systems parameter adjustment are carried out. The results show that the proposed optimal adjustment strategy and the related soft are valid.3. The application study is carried out for the PID parameter optimal adjustment for the boiler steam temperature control system of a power plant. First, the step response of the steam temperature process is obtained by experimentation, and the transfer function of the controlled process is calculated out using the step response data of the process. Then, the PID parameters of the control system are optimized using the obtained process transfer function. Finally, simulations are carried out to show the performance of the optimization-before system and optimization-after system. The results provide reliable guarantee for the optimization results to be used in real control system.更多还原