Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and conseq...Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control （SSC） technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.展开更多
An improved automatic voltage coordination control strategy （AVCCS） based on ;automatic voltage control （AVC） and battery energy storage control （BESC） is proposed for photovoltaic grid-connected system （PVGS）...An improved automatic voltage coordination control strategy （AVCCS） based on ;automatic voltage control （AVC） and battery energy storage control （BESC） is proposed for photovoltaic grid-connected system （PVGS） to mitigate the voltage fluctuations caused by environmental disturbances. Only AVC is used when small environ- mental disturbances happen, while BESC is incorporated with AVC to restrain the voltage fluctuations when large disturbances happen. An adjustable parameter determining the allowed amplitudes of voltage fluctuations is introduced to realize the above switching process. A benchmark low voltage distribution system including ]？VGS is established by using the commercial software Dig SILENT. Simulation results show that the voltage under AVCCS satisfies the IEEE Standard 1547, and the installed battery capacity is also reduced. Meanwhile, the battery＇s service life is ex- tended by avoiding frequent charges/discharges in the control process.展开更多
基金Item Sponsored by National Science and Technology Support Programfor 11th Five-Year Plan of China (2006BAE03A13)International Cooperation Research Project of Shanxi Province (2009081013)
文摘Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control （SSC） technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.
基金Supported by National Basic Research Program of China ("973" Program,No. 2009CB219701 and No. 2010CB234608)Tianjin Municipal Science and Technology Development Program (No. 09JCZDJC25000)Specialized Research Fund for Doctor Discipline of Ministry of Education of China (No. 20090032110064)
文摘An improved automatic voltage coordination control strategy （AVCCS） based on ;automatic voltage control （AVC） and battery energy storage control （BESC） is proposed for photovoltaic grid-connected system （PVGS） to mitigate the voltage fluctuations caused by environmental disturbances. Only AVC is used when small environ- mental disturbances happen, while BESC is incorporated with AVC to restrain the voltage fluctuations when large disturbances happen. An adjustable parameter determining the allowed amplitudes of voltage fluctuations is introduced to realize the above switching process. A benchmark low voltage distribution system including ]？VGS is established by using the commercial software Dig SILENT. Simulation results show that the voltage under AVCCS satisfies the IEEE Standard 1547, and the installed battery capacity is also reduced. Meanwhile, the battery＇s service life is ex- tended by avoiding frequent charges/discharges in the control process.
