An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the c...An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.展开更多
Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)...Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)control strategy based on a power outer loop and voltage-current inner loops,aiming to enhance the stability and current-limiting capability of GFM converters during grid fault conditions.During voltage sags,the GFM converter’s voltage source behavior is maintained by dynamically adjusting the reactive power reference to provide voltage support,thereby effectively suppressing the steady-state component of the fault current.To address the active power imbalance induced by voltage sags,a dynamic active power reference correction method based on apparent power is designed to mitigate power angle oscillations and limit transient current.Moreover,an adaptive virtual impedance loop is implemented to enhance dynamic transient current-limiting performance during the fault initiation phase.This approach improves the responsiveness of the inner loop and ensures safe system operation under various fault severities.Under asymmetric fault conditions,a negative-sequence reactive current compensation strategy is incorporated to further suppress negative-sequence voltage and improve voltage symmetry.The proposed control scheme enables coordinated operation of multiple control objectives,including voltage support,current suppression,and power angle stability,across different fault scenarios.Finally,MATLAB/Simulink simulation results validate the effectiveness of the proposed strategy,showcasing its superior performance in current limiting and power angle stability,thereby significantly enhancing the system’s fault ride-through capability.展开更多
针对当前视觉同时定位与建图(Simultaneous Localization and Mapping,SLAM)面对如纹理稀疏、光照变化强烈及图像模糊等挑战性场景时,普遍存在的前端特征跟踪鲁棒性不足的问题,提出了一个鲁棒的多相机定位系统,并对关键技术进行了深入...针对当前视觉同时定位与建图(Simultaneous Localization and Mapping,SLAM)面对如纹理稀疏、光照变化强烈及图像模糊等挑战性场景时,普遍存在的前端特征跟踪鲁棒性不足的问题,提出了一个鲁棒的多相机定位系统,并对关键技术进行了深入的研究与优化。该系统设计了一种优于主流方案的前端跟踪算法,通过融合惯性测量单元(Inertial Measurement Unit,IMU)测量数据实现特征点重投影预测,并对跟踪的灰度图进行动态校正,有效提升了复杂场景下特征跟踪的成功率和稳定性。此外,该系统利用多相机观测信息构建了具备3层自适应置信度加权算法的状态估计器,并将卷积神经网络运用于交叉回环检测,有效提高了回环检测的成功率与准确率。通过一系列公开数据集的实验,验证了该多相机定位算法在精度和稳定性方面已达到最先进技术水平,且在本地环境中的测试结果也证实了该系统在实际应用中的可行性与有效性。展开更多
调配缓冲槽作为核燃料含铀含硝酸废液回收处理的重要设备,其液位控制稳定性直接影响整个含铀含硝酸废液处理系统的安全稳定运行。若缓冲槽液位控制稳定性差,可能会导致含放射性与有毒物质的核燃料废液溢流、上游工艺系统非计划停车等安...调配缓冲槽作为核燃料含铀含硝酸废液回收处理的重要设备,其液位控制稳定性直接影响整个含铀含硝酸废液处理系统的安全稳定运行。若缓冲槽液位控制稳定性差,可能会导致含放射性与有毒物质的核燃料废液溢流、上游工艺系统非计划停车等安全生产事故,不仅造成控制系统无法连续稳定运行,还会影响下游蒸发浓缩系统、膜过滤系统的运行状态及处理效率。针对含铀含硝酸废液处理系统中缓冲槽液位控制稳定性差的问题,本文提出一种基于模型辨识的多输入单输出液位控制系统方法。首先,利用现场调试数据,采用模型辨识方法建立多输入单输出缓冲槽液位控制系统数学模型。其次,在已建模型基础上改进相关控制方式,提出三回路串级控制方式,经仿真验证得到了一种自适应规则整定比例-积分-微分(Proportional-Integral-Derivative,PID)参数。最后,在工程实际中通过集散控制系统(Distributed Control System,DCS)组态和控制器自适应整定规则的写入,对所提的方法进行了验证。结果表明,该方法具备较强自适应能力,可有效提升系统的稳定性,缩短调节时间,成功解决调配缓冲槽液位控制效果不佳的问题,保证整个工艺生产平稳运行。展开更多
随着新能源与储能系统并网工程的不断建设,部分新能源、储能、静止无功发生器(static var generator,SVG)与传统火电通过一个升压站并入电网,构成了复杂的多电源“打捆送出”系统,其相互作用引起的振荡问题也开始显现出来。首先,为评估...随着新能源与储能系统并网工程的不断建设,部分新能源、储能、静止无功发生器(static var generator,SVG)与传统火电通过一个升压站并入电网,构成了复杂的多电源“打捆送出”系统,其相互作用引起的振荡问题也开始显现出来。首先,为评估多电源并网系统宽频振荡的风险,采用单机阻抗建模-对比验证-整系统阻抗建模的思路,从等效阻抗的角度阐明了多电源并网系统宽频振荡的机理,分析了不同频段的幅频曲线特征与控制参数的影响,利用在线阻抗测量法对多电源系统的阻抗特性建模,具体分为基于硬件在环仿真的单机阻抗建模、基于电磁模型的单机阻抗建模、电磁暂态仿真与硬件在环对比验证、基于电磁模型的整站阻抗建模4个步骤。然后,通过系统短路比得到大电网的阻抗特性。最终,根据奈奎斯特定理来判定多源系统与大电网之间有无宽频振荡的风险,分析了单一工况幅频曲线的特征,明确了与大电网振荡风险的评估流程,为宽频域振荡评估与控制提供指导思路。展开更多
给出了一种简易的控制系统设计方法——标准特征多项式设计方法,多回路控制系统采用这种方法将使控制系统设计的工作量大为简化。在此基础上,采用NCD工具箱,用标准特征多项式方法得到的参数值作为NCD(nonlinear control design)模块的...给出了一种简易的控制系统设计方法——标准特征多项式设计方法,多回路控制系统采用这种方法将使控制系统设计的工作量大为简化。在此基础上,采用NCD工具箱,用标准特征多项式方法得到的参数值作为NCD(nonlinear control design)模块的初始化值对控制系统的参数进一步进行优化,并与任意选择的6组参数值作为NCD模块初始化值而得到的优化效果进行了比较。还对飞行控制的多回路控制系统的鲁棒性进行了研究。结果证明,用标准特征多项式和NCD优化方法,设计方便,并且系统有很好的鲁棒性。展开更多
基金Supported by the National Natural Science Foundation of China （60974061）.
文摘An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.
文摘Grid-Forming(GFM)converters are prone to fault-induced overcurrent and power angle instability during grid fault-induced voltage sags.To address this,this paper develops a multi-loop coordinated fault ridethrough(FRT)control strategy based on a power outer loop and voltage-current inner loops,aiming to enhance the stability and current-limiting capability of GFM converters during grid fault conditions.During voltage sags,the GFM converter’s voltage source behavior is maintained by dynamically adjusting the reactive power reference to provide voltage support,thereby effectively suppressing the steady-state component of the fault current.To address the active power imbalance induced by voltage sags,a dynamic active power reference correction method based on apparent power is designed to mitigate power angle oscillations and limit transient current.Moreover,an adaptive virtual impedance loop is implemented to enhance dynamic transient current-limiting performance during the fault initiation phase.This approach improves the responsiveness of the inner loop and ensures safe system operation under various fault severities.Under asymmetric fault conditions,a negative-sequence reactive current compensation strategy is incorporated to further suppress negative-sequence voltage and improve voltage symmetry.The proposed control scheme enables coordinated operation of multiple control objectives,including voltage support,current suppression,and power angle stability,across different fault scenarios.Finally,MATLAB/Simulink simulation results validate the effectiveness of the proposed strategy,showcasing its superior performance in current limiting and power angle stability,thereby significantly enhancing the system’s fault ride-through capability.
文摘调配缓冲槽作为核燃料含铀含硝酸废液回收处理的重要设备,其液位控制稳定性直接影响整个含铀含硝酸废液处理系统的安全稳定运行。若缓冲槽液位控制稳定性差,可能会导致含放射性与有毒物质的核燃料废液溢流、上游工艺系统非计划停车等安全生产事故,不仅造成控制系统无法连续稳定运行,还会影响下游蒸发浓缩系统、膜过滤系统的运行状态及处理效率。针对含铀含硝酸废液处理系统中缓冲槽液位控制稳定性差的问题,本文提出一种基于模型辨识的多输入单输出液位控制系统方法。首先,利用现场调试数据,采用模型辨识方法建立多输入单输出缓冲槽液位控制系统数学模型。其次,在已建模型基础上改进相关控制方式,提出三回路串级控制方式,经仿真验证得到了一种自适应规则整定比例-积分-微分(Proportional-Integral-Derivative,PID)参数。最后,在工程实际中通过集散控制系统(Distributed Control System,DCS)组态和控制器自适应整定规则的写入,对所提的方法进行了验证。结果表明,该方法具备较强自适应能力,可有效提升系统的稳定性,缩短调节时间,成功解决调配缓冲槽液位控制效果不佳的问题,保证整个工艺生产平稳运行。
文摘随着新能源与储能系统并网工程的不断建设,部分新能源、储能、静止无功发生器(static var generator,SVG)与传统火电通过一个升压站并入电网,构成了复杂的多电源“打捆送出”系统,其相互作用引起的振荡问题也开始显现出来。首先,为评估多电源并网系统宽频振荡的风险,采用单机阻抗建模-对比验证-整系统阻抗建模的思路,从等效阻抗的角度阐明了多电源并网系统宽频振荡的机理,分析了不同频段的幅频曲线特征与控制参数的影响,利用在线阻抗测量法对多电源系统的阻抗特性建模,具体分为基于硬件在环仿真的单机阻抗建模、基于电磁模型的单机阻抗建模、电磁暂态仿真与硬件在环对比验证、基于电磁模型的整站阻抗建模4个步骤。然后,通过系统短路比得到大电网的阻抗特性。最终,根据奈奎斯特定理来判定多源系统与大电网之间有无宽频振荡的风险,分析了单一工况幅频曲线的特征,明确了与大电网振荡风险的评估流程,为宽频域振荡评估与控制提供指导思路。
文摘给出了一种简易的控制系统设计方法——标准特征多项式设计方法,多回路控制系统采用这种方法将使控制系统设计的工作量大为简化。在此基础上,采用NCD工具箱,用标准特征多项式方法得到的参数值作为NCD(nonlinear control design)模块的初始化值对控制系统的参数进一步进行优化,并与任意选择的6组参数值作为NCD模块初始化值而得到的优化效果进行了比较。还对飞行控制的多回路控制系统的鲁棒性进行了研究。结果证明,用标准特征多项式和NCD优化方法,设计方便,并且系统有很好的鲁棒性。
