Zhang Dongming, Hu Yong, Gao Yaokui
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Changping District, 102206 Beijing, China; Key Laboratory of Measurement and Control New Technology and System for Industrial Process, North China Electric Power University, Changping District, 102206 Beijing, China.
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Changping District, 102206 Beijing, China; Key Laboratory of Measurement and Control New Technology and System for Industrial Process, North China Electric Power University, Changping District, 102206 Beijing, China.
ISA Trans. 2022 Sep;128(Pt A):435-449. doi: 10.1016/j.isatra.2021.10.027. Epub 2021 Oct 29.
This paper firstly established a nonlinear dynamic model of a 330 MW drum boiler unit, which has a clear physical meaning and is conducive to the design of coordinated control system (CCS). On this basis, the boiler energy storage coefficient is calculated, and its relationship with that in direct energy balance (DEB) strategy is analyzed. Secondly, this paper proposes a CCS based on dynamic matrix control (DMC) algorithm and DEB strategy, in which: (1) energy demand and status signals of DEB are taken as the setting point and process value of DMC controller, so as to overcome the internal disturbance of the boiler; (2) a compensation signal is constructed as the feedforward input of DMC controller, so as to overcome the external disturbance of the turbine and realize the timely utilization and supplement of boiler energy. Simulation shows: (1) there is a certain deviation in main steam pressure when the energy demand and status signals are taken as the setting point and process value, but this is an illusion of insufficient energy, and in fact the energy status can already meet the demand; (2) compared with the main steam valve, the constructed compensation signal takes into account more operating parameters of the unit, which greatly improves the accuracy of the compensation. Practical application shows: the grid dispatch order can be well tracked by the unit, the maximum deviation of main steam pressure is ±0.6 MPa in constant pressure mode, and that is ±1.2 MPa in sliding pressure mode, thereby improving the control performance of the unit under high, medium, low, and overall load conditions.
本文首先建立了330MW汽包锅炉机组的非线性动态模型，该模型具有明确的物理意义，有利于协调控制系统（CCS）的设计。在此基础上，计算了锅炉蓄热系数，并分析了其与直接能量平衡（DEB）策略中蓄热系数的关系。其次，本文提出了一种基于动态矩阵控制（DMC）算法和DEB策略的CCS，其中：（1）将DEB的能量需求和状态信号作为DMC控制器的设定值和过程值，以克服锅炉的内部干扰；（2）构建补偿信号作为DMC控制器的前馈输入，以克服汽轮机的外部干扰，实现锅炉能量的及时利用和补充。仿真结果表明：（1）将能量需求和状态信号作为设定值和过程值时，主蒸汽压力存在一定偏差，但这是能量不足的假象，实际上能量状态已能满足需求；（2）与主蒸汽阀相比，构建的补偿信号考虑了机组更多的运行参数，大大提高了补偿精度。实际应用表明：机组能够很好地跟踪电网调度指令，定压模式下主蒸汽压力最大偏差为±0.6MPa，滑压模式下为±1.2MPa，从而提高了机组在高、中、低负荷及全负荷工况下的控制性能。
