Firstly, the research progress of grey model GM （1,1） is summarized, which is divided into three development stages： assimilation, alienation and melting stages. Then, the matrix analysis theory is used to study th...Firstly, the research progress of grey model GM （1,1） is summarized, which is divided into three development stages： assimilation, alienation and melting stages. Then, the matrix analysis theory is used to study the modeling mechanism of GM （1,1）, which decomposes the modeling data matrix into raw data transformation matrix, accumulated generating operation matrix and background value selection matrix. The changes of these three matrices are the essential reasons affecting the modeling and the accuracy of GM （1,1）. Finally, the paper proposes a generalization grey model GGM （1,1）, which is a extended form of GM （1,1） and also a unified form of model GM （1,1）, model GM （1,1,α）, stage grey model, hopping grey model, generalized accumulated model, strengthening operator model, weakening operator model and unequal interval model. And the theory and practical significance of the extended model is analyzed.展开更多
A novel maglev transportation system was proposed for large travel range ultra precision motion.The system consists of a levitation subsystem and a propulsion subsystem.During the propulsion subsystem driving the movi...A novel maglev transportation system was proposed for large travel range ultra precision motion.The system consists of a levitation subsystem and a propulsion subsystem.During the propulsion subsystem driving the moving platform along the guideway,the levitation subsystem uses six pairs of electromagnets to steadily suspend the moving platform over the guideway.The model of the levitation system,which is a typical nonlinear multi-input multi-output coupling system and has many inner nonlinear coupling characteristics,was deduced.For testifying the model,the levitation mechanism was firstly controlled by proportional-integral-differential(PID) control,and then a lot of input-output data were collected for model parameter identification.The least-square parameter identification method was used.The identification results prove that the model is feasible and suitable for the real system.展开更多
经典低阶频率响应模型可快速计算各项频率指标,但由于高比例新能源系统扰动类型多样,运行方式复杂多变,难以准确获取系统参数和扰动功率大小,同时模型本身线性化会引起较大误差,导致频率预测值和实际值存在较大差异。为使频率响应模型...经典低阶频率响应模型可快速计算各项频率指标,但由于高比例新能源系统扰动类型多样,运行方式复杂多变,难以准确获取系统参数和扰动功率大小,同时模型本身线性化会引起较大误差,导致频率预测值和实际值存在较大差异。为使频率响应模型适应实际应用场景中高精度的要求,该文提出了模型-数据融合驱动的频率稳定智能增强判别方法(model-data driven intelligent enhanced method for frequency stability discrimination,MD-IEFSD),利用扰动初期频率响应数据对模型关键参数进行辨识,建立结合卷积神经网络和注意力机制的CNN-Attention频率参数预测模型,构建了融合参数预测误差和频率响应曲线预测误差的损失函数,引入了参数的敏感性和学习速率的分析,实现了频率稳定性的准确判别。最后以中国电科院万节点测试系统为算例,验证所提方法的可行性和有效性。展开更多
基金supported by the National Natural Science Foundation of China(70971103)the Specialized Research Fund for the Doctora Program of Higher Education(20120143110001)
文摘Firstly, the research progress of grey model GM （1,1） is summarized, which is divided into three development stages： assimilation, alienation and melting stages. Then, the matrix analysis theory is used to study the modeling mechanism of GM （1,1）, which decomposes the modeling data matrix into raw data transformation matrix, accumulated generating operation matrix and background value selection matrix. The changes of these three matrices are the essential reasons affecting the modeling and the accuracy of GM （1,1）. Finally, the paper proposes a generalization grey model GGM （1,1）, which is a extended form of GM （1,1） and also a unified form of model GM （1,1）, model GM （1,1,α）, stage grey model, hopping grey model, generalized accumulated model, strengthening operator model, weakening operator model and unequal interval model. And the theory and practical significance of the extended model is analyzed.
基金Projects(50735007,51005253) supported by the National Natural Science Foundation of ChinaProject(2007AA04Z344) supported by the National High-Tech Research and Development Program of China
文摘A novel maglev transportation system was proposed for large travel range ultra precision motion.The system consists of a levitation subsystem and a propulsion subsystem.During the propulsion subsystem driving the moving platform along the guideway,the levitation subsystem uses six pairs of electromagnets to steadily suspend the moving platform over the guideway.The model of the levitation system,which is a typical nonlinear multi-input multi-output coupling system and has many inner nonlinear coupling characteristics,was deduced.For testifying the model,the levitation mechanism was firstly controlled by proportional-integral-differential(PID) control,and then a lot of input-output data were collected for model parameter identification.The least-square parameter identification method was used.The identification results prove that the model is feasible and suitable for the real system.
文摘经典低阶频率响应模型可快速计算各项频率指标,但由于高比例新能源系统扰动类型多样,运行方式复杂多变,难以准确获取系统参数和扰动功率大小,同时模型本身线性化会引起较大误差,导致频率预测值和实际值存在较大差异。为使频率响应模型适应实际应用场景中高精度的要求,该文提出了模型-数据融合驱动的频率稳定智能增强判别方法(model-data driven intelligent enhanced method for frequency stability discrimination,MD-IEFSD),利用扰动初期频率响应数据对模型关键参数进行辨识,建立结合卷积神经网络和注意力机制的CNN-Attention频率参数预测模型,构建了融合参数预测误差和频率响应曲线预测误差的损失函数,引入了参数的敏感性和学习速率的分析,实现了频率稳定性的准确判别。最后以中国电科院万节点测试系统为算例,验证所提方法的可行性和有效性。
