随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase co...随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase compensation based active disturbance rejection control,PC-ADRC)方法。首先,阐述过热汽温系统的工作原理和控制难点。然后,采用低频近似法详细推导相位补偿(phase compensation,PC)网络模型,提出采用PC网络对模型动态特性进行补偿,得到等效降阶模型的简化思路。为便于工程应用,给出PC-ADRC系统的简单实现方法和等效模型分析。最后,对PC-ADRC系统的稳定性和鲁棒性进行研究。理论分析和仿真结果表明,所提出的PC-ADRC系统能有效提升高阶过程控制系统的鲁棒性和快速响应能力。展开更多
The present article aims at elucidating the effect of thermo-mechanical controlled processing(TMCP), especially the finish cooling temperature, on microstructure and mechanical properties of high strength low alloy st...The present article aims at elucidating the effect of thermo-mechanical controlled processing(TMCP), especially the finish cooling temperature, on microstructure and mechanical properties of high strength low alloy steels for developing superior low temperature toughness construction steel. The microstructural features were characterized by scanning electron microscope equipped with electron backscatter diffraction, and the mechanical behaviors in terms of tensile properties and impact toughness were analyzed in correlation with microstructural evolution. The results showed that the lower finish cooling temperature could lead to a considerable increase in impact toughness for this steel. A mixed microstructure was obtained by TMCP at lower finish cooling temperature, which contained much fine lath-like bainite with dot-shaped M/A constituent and less granular bainite and bainite ferrite. In this case, this steel possesses yield and ultimate tensile strengths of ~ 885 MPa and 1089 MPa, respectively, and a total elongation of ~ 15.3%, while it has a lower yield ratio of ~ 0.81. The superior impact toughness of ~ 89 J at-20 °C was obtained, and this was resulted from the multi-phase microstructure including grain refinement, preferred grain boundaries misorientation, fine lath-like bainite with dot-shaped M/A constituent.展开更多
文摘随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase compensation based active disturbance rejection control,PC-ADRC)方法。首先,阐述过热汽温系统的工作原理和控制难点。然后,采用低频近似法详细推导相位补偿(phase compensation,PC)网络模型,提出采用PC网络对模型动态特性进行补偿,得到等效降阶模型的简化思路。为便于工程应用,给出PC-ADRC系统的简单实现方法和等效模型分析。最后,对PC-ADRC系统的稳定性和鲁棒性进行研究。理论分析和仿真结果表明,所提出的PC-ADRC系统能有效提升高阶过程控制系统的鲁棒性和快速响应能力。
基金financially supported by the National Natural Science Foundation of China(Grant No.51904071)the Independent Project of State Key Laboratory of Rolling and Automation,Northeastern University(Grant No.ZZ202001)+1 种基金the Key Research and Development Program of Hebei Province of China(Grant No.18211019D)the Start-up Project of Doctor Scientific Research of Liaoning Province(Grant No.2020-BS-271)。
文摘The present article aims at elucidating the effect of thermo-mechanical controlled processing(TMCP), especially the finish cooling temperature, on microstructure and mechanical properties of high strength low alloy steels for developing superior low temperature toughness construction steel. The microstructural features were characterized by scanning electron microscope equipped with electron backscatter diffraction, and the mechanical behaviors in terms of tensile properties and impact toughness were analyzed in correlation with microstructural evolution. The results showed that the lower finish cooling temperature could lead to a considerable increase in impact toughness for this steel. A mixed microstructure was obtained by TMCP at lower finish cooling temperature, which contained much fine lath-like bainite with dot-shaped M/A constituent and less granular bainite and bainite ferrite. In this case, this steel possesses yield and ultimate tensile strengths of ~ 885 MPa and 1089 MPa, respectively, and a total elongation of ~ 15.3%, while it has a lower yield ratio of ~ 0.81. The superior impact toughness of ~ 89 J at-20 °C was obtained, and this was resulted from the multi-phase microstructure including grain refinement, preferred grain boundaries misorientation, fine lath-like bainite with dot-shaped M/A constituent.
