针对智能电网中火力发电的主要设备——锅炉中蒸汽温度控制系统的时变特性和系统大滞后特性,电网要求发电机组既能快速响应负荷变化,又能保证自身的安全、稳定、经济运行.为了提高电力系统的安全运行水平,以及常规电源的利用效率,结合了锅炉对负荷需求响应快,以及汽轮机随主蒸汽压力变化平稳的优点,提出了一种负荷跟踪型的机炉协调控制方式,并加入了基于模糊PID(proportional-integral-derivative,比例-积分-微分)算法控制的智能时间常数补偿环节.该环节能在负荷变化较大、需要利用锅炉蓄热时发挥作用.仿真实验结果表明,与常规PID控制的协调系统相比,模糊PID控制能够得到更佳的动态性能参数和控制效果.
According to the time-varying and lag characteristics of the control steam for steam temperature in a boiler, a power grid requires that the generator can quickly respond to load changes, and ensure safety, stability and economic operation. To improve safety and efficiency in the conventional power supply, this paper proposes a coordination and control method with a load-tracking model. It combines advantages of the boiler's quick responding to the load, and the turbine's stably following changes in the main steam pressure. In addition, an intelligent time-constant compensation part using the fuzzy PID (proportional-integral-derivative) control algorithm is added. Thus, the intelligent part can work properly when large load changes occur and where the boiler thermal storage is needed. The simulation results show that, compared with the traditional PID control, the fuzzy PID control can derive better dynamic performance parameters and a better control effect.