Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have bee...Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have been widely applied.Moreover,as the worldwide interest and development in smart grid have increased significantly,the digital information availability and communication capability of modern substation have been improved.Different with traditional substation protection configuration based on local information,Integrated Protection(IP)is used to denote the integration of several protective devices for multiple power equipment within the substation into one protective relay,obtaining all the real time information of the substation by communication network.The analysis of sharing information and cooperation among different protection functions helps to realize more reliable and sensitive fault detection.This paper describes several different integrated protection schemes and their respective advantages and disadvantages.The principles and functions applied in integrated protection systems are addressed to provide an overview of the current state of the technology.A new coordinated protection system based on inter-substation information is proposed and simulation study is discussed to verify the improved reliability and sensitivity.展开更多
研究连续Morlet小波变换矩阵行矢量的线性相关性,这种相关性使得连续Morlet小波变换的结果存在很大的冗余,利用奇异值分解(Singular value decomposition,SVD)来压缩这种冗余性。理论分析表明,SVD技术可以将连续Morlet小波变换矩阵的信...研究连续Morlet小波变换矩阵行矢量的线性相关性,这种相关性使得连续Morlet小波变换的结果存在很大的冗余,利用奇异值分解(Singular value decomposition,SVD)来压缩这种冗余性。理论分析表明,SVD技术可以将连续Morlet小波变换矩阵的信息完全压缩到少数的非零奇异值及其对应的正交奇异矢量中,分析压缩前后数据量的比例,证实矩阵维数越大,压缩效果越好。研究确定性信号和噪声的连续Morlet小波变换结果的奇异值的分布特点,发现确定性信号的有效奇异值数量由信号中的频率数量决定,有效奇异值之后的奇异值会很快地下降到零,而噪声的奇异值序列的变化比较均匀,下降速度比较缓慢。利用确定性信号和噪声奇异值的这种差异,可以实现对含噪信号的连续Morlet小波变换结果的提纯,只要选择前面合适的奇异值进行SVD重构,大部分噪声奇异值的信息会被抛弃,因而可在很大程度上消除噪声对连续Morlet小波变换结果的影响。展开更多
基金supported by the National Natural Science Foundation of China under Grant 51277009,and the Application Technology Research and Engineering Demonstration Program of National Energy Administration under Grant NY20150302.
文摘Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have been widely applied.Moreover,as the worldwide interest and development in smart grid have increased significantly,the digital information availability and communication capability of modern substation have been improved.Different with traditional substation protection configuration based on local information,Integrated Protection(IP)is used to denote the integration of several protective devices for multiple power equipment within the substation into one protective relay,obtaining all the real time information of the substation by communication network.The analysis of sharing information and cooperation among different protection functions helps to realize more reliable and sensitive fault detection.This paper describes several different integrated protection schemes and their respective advantages and disadvantages.The principles and functions applied in integrated protection systems are addressed to provide an overview of the current state of the technology.A new coordinated protection system based on inter-substation information is proposed and simulation study is discussed to verify the improved reliability and sensitivity.
文摘研究连续Morlet小波变换矩阵行矢量的线性相关性,这种相关性使得连续Morlet小波变换的结果存在很大的冗余,利用奇异值分解(Singular value decomposition,SVD)来压缩这种冗余性。理论分析表明,SVD技术可以将连续Morlet小波变换矩阵的信息完全压缩到少数的非零奇异值及其对应的正交奇异矢量中,分析压缩前后数据量的比例,证实矩阵维数越大,压缩效果越好。研究确定性信号和噪声的连续Morlet小波变换结果的奇异值的分布特点,发现确定性信号的有效奇异值数量由信号中的频率数量决定,有效奇异值之后的奇异值会很快地下降到零,而噪声的奇异值序列的变化比较均匀,下降速度比较缓慢。利用确定性信号和噪声奇异值的这种差异,可以实现对含噪信号的连续Morlet小波变换结果的提纯,只要选择前面合适的奇异值进行SVD重构,大部分噪声奇异值的信息会被抛弃,因而可在很大程度上消除噪声对连续Morlet小波变换结果的影响。
