The control of gas fractionation unit(GFU) in petroleum industry is very difficult due to multivariable characteristics and a large time delay.PID controllers are still applied in most industry processes.However,the t...The control of gas fractionation unit(GFU) in petroleum industry is very difficult due to multivariable characteristics and a large time delay.PID controllers are still applied in most industry processes.However,the traditional PID control has been proven not sufficient and capable for this particular petro-chemical process.In this work,an incremental multivariable predictive functional control(IMPFC) algorithm was proposed with less online computation,great precision and fast response.An incremental transfer function matrix model was set up through the step-response data,and predictive outputs were deduced with the theory of single-value optimization.The results show that the method can optimize the incremental control variable and reject the constraint of the incremental control variable with the positional predictive functional control algorithm,and thereby making the control variable smoother.The predictive output error and future set-point were approximated by a polynomial,which can overcome the problem under the model mismatch and make the predictive outputs track the reference trajectory.Then,the design of incremental multivariable predictive functional control was studied.Simulation and application results show that the proposed control strategy is effective and feasible to improve control performance and robustness of process.展开更多
风电参与系统调频是提升新能源高占比电力系统频率安全稳定水平的关键措施之一。然而风电机组的现有调频控制策略难以适应系统多样化的功率扰动,未能充分发挥风电机组的快速频率支撑能力。建立了直驱型风电机组调频控制的通用电磁暂态模...风电参与系统调频是提升新能源高占比电力系统频率安全稳定水平的关键措施之一。然而风电机组的现有调频控制策略难以适应系统多样化的功率扰动,未能充分发挥风电机组的快速频率支撑能力。建立了直驱型风电机组调频控制的通用电磁暂态模型,并对现有调频控制策略下风电机组的动态特性进行了分析,明确了限制其调频能力的原因。在此基础上,通过建立计及风电调频的改进系统频率响应模型,实现了系统功率扰动程度的评估,并进一步提出了基于该评估结果的风电机组的主动频率支撑控制策略。该策略基于扰动发生后的最大频率变化率(rate of change of frequency, RoCoF)判断系统功率扰动程度,结合风电机组的运行模式,选择不同的调频控制组合,能够在充分发挥风电机组的主动频率支撑能力的同时,显著降低系统频率的二次跌落风险。仿真结果表明,相比于定参数调频策略和传统自适应调频策略,所提方法在不同扰动程度下的调频性能优势明显,证明了方法的有效性。展开更多
从遥感影像上自动解译铁路设计控制要素是实现“一键成图”的关键,但深度学习遥感影像智能解译需要大量标注样本。依据铁路线路设计原则,提出一种多源遥感数据的设计控制要素智能解译样本库构建方法。首先,基于数字正射影像图(Digital O...从遥感影像上自动解译铁路设计控制要素是实现“一键成图”的关键,但深度学习遥感影像智能解译需要大量标注样本。依据铁路线路设计原则,提出一种多源遥感数据的设计控制要素智能解译样本库构建方法。首先,基于数字正射影像图(Digital Orthophoto Map,DOM)、数字线划地图(Digital Line Graphic,DLG)和激光雷达(Light Detection and Ranging,Lidar)点云多源数据自动生成初始样本;其次,基于增量主动学习迭代方法对初始样本进行优化,达到高质量、全面覆盖铁路沿线的目的;然后,以长赣铁路为例,构建以铁路沿线周边房屋、道路、水体和植被四类铁路线路设计控制要素为重点的高分辨率智能解译样本数据库——铁路线路设计控制要素智能解译样本库(Wuhan University Sample Database of Control Elements of Railway Route Design,WHU-RRDSD),其地面分辨率为0.1 m,样本总数超过20万张;最后,为验证样本库的可用性,分别从定性评价、定量评价以及其他场景应用案例三方面进行详细验证,结果表明,基于房屋、道路、水体和植被四类样本库的IoU评价指标分别为84.43%、82.38%、90.19%、90.28%,表现出优异的解译效果;基于WHU-RRDSD训练得到的智能模型迁移至宜涪高铁场景中房屋、道路、水体和植被要素的解译,验证样本库在其他场景的可用性;简要介绍基于WHU-RRDSD样本库进行的高分辨率遥感图像弱监督建筑提取和高分辨率遥感图像地物分类两个应用案例,进一步验证本文方法所构建样本库可用性。展开更多
基金Project(61203021)supported by the National Natural Science Foundation of ChinaProject(2011216011)supported by the Scientific and Technological Program of Liaoning Province,China+2 种基金Project(2013020024)supported by the Natural Science Foundation of Liaoning Province,ChinaProject(2012BAF05B00)supported by the National Science and Technology Support Program,ChinaProject(LJQ2015061)supported by the Program for Liaoning Excellent Talents in Universities,China
文摘The control of gas fractionation unit(GFU) in petroleum industry is very difficult due to multivariable characteristics and a large time delay.PID controllers are still applied in most industry processes.However,the traditional PID control has been proven not sufficient and capable for this particular petro-chemical process.In this work,an incremental multivariable predictive functional control(IMPFC) algorithm was proposed with less online computation,great precision and fast response.An incremental transfer function matrix model was set up through the step-response data,and predictive outputs were deduced with the theory of single-value optimization.The results show that the method can optimize the incremental control variable and reject the constraint of the incremental control variable with the positional predictive functional control algorithm,and thereby making the control variable smoother.The predictive output error and future set-point were approximated by a polynomial,which can overcome the problem under the model mismatch and make the predictive outputs track the reference trajectory.Then,the design of incremental multivariable predictive functional control was studied.Simulation and application results show that the proposed control strategy is effective and feasible to improve control performance and robustness of process.
文摘风电参与系统调频是提升新能源高占比电力系统频率安全稳定水平的关键措施之一。然而风电机组的现有调频控制策略难以适应系统多样化的功率扰动,未能充分发挥风电机组的快速频率支撑能力。建立了直驱型风电机组调频控制的通用电磁暂态模型,并对现有调频控制策略下风电机组的动态特性进行了分析,明确了限制其调频能力的原因。在此基础上,通过建立计及风电调频的改进系统频率响应模型,实现了系统功率扰动程度的评估,并进一步提出了基于该评估结果的风电机组的主动频率支撑控制策略。该策略基于扰动发生后的最大频率变化率(rate of change of frequency, RoCoF)判断系统功率扰动程度,结合风电机组的运行模式,选择不同的调频控制组合,能够在充分发挥风电机组的主动频率支撑能力的同时,显著降低系统频率的二次跌落风险。仿真结果表明,相比于定参数调频策略和传统自适应调频策略,所提方法在不同扰动程度下的调频性能优势明显,证明了方法的有效性。
文摘从遥感影像上自动解译铁路设计控制要素是实现“一键成图”的关键,但深度学习遥感影像智能解译需要大量标注样本。依据铁路线路设计原则,提出一种多源遥感数据的设计控制要素智能解译样本库构建方法。首先,基于数字正射影像图(Digital Orthophoto Map,DOM)、数字线划地图(Digital Line Graphic,DLG)和激光雷达(Light Detection and Ranging,Lidar)点云多源数据自动生成初始样本;其次,基于增量主动学习迭代方法对初始样本进行优化,达到高质量、全面覆盖铁路沿线的目的;然后,以长赣铁路为例,构建以铁路沿线周边房屋、道路、水体和植被四类铁路线路设计控制要素为重点的高分辨率智能解译样本数据库——铁路线路设计控制要素智能解译样本库(Wuhan University Sample Database of Control Elements of Railway Route Design,WHU-RRDSD),其地面分辨率为0.1 m,样本总数超过20万张;最后,为验证样本库的可用性,分别从定性评价、定量评价以及其他场景应用案例三方面进行详细验证,结果表明,基于房屋、道路、水体和植被四类样本库的IoU评价指标分别为84.43%、82.38%、90.19%、90.28%,表现出优异的解译效果;基于WHU-RRDSD训练得到的智能模型迁移至宜涪高铁场景中房屋、道路、水体和植被要素的解译,验证样本库在其他场景的可用性;简要介绍基于WHU-RRDSD样本库进行的高分辨率遥感图像弱监督建筑提取和高分辨率遥感图像地物分类两个应用案例,进一步验证本文方法所构建样本库可用性。
