在高风电渗透率的刚性源端系统中,风电参与调度运行的模式需从负负荷向部分可控电源转变,而集群风电以虚拟机组(wind farm cluster virtual power generation unit,WCVPG)形式参与调度运行是提高风电可调度性的可行方案。该文作为系列...在高风电渗透率的刚性源端系统中,风电参与调度运行的模式需从负负荷向部分可控电源转变,而集群风电以虚拟机组(wind farm cluster virtual power generation unit,WCVPG)形式参与调度运行是提高风电可调度性的可行方案。该文作为系列文章的第2部分,基于文章第1部分建立的WCVPG时变概率模型,提出一种WCVPG调度特性与风险指标量化方法,为其以电源形式参与调度模型做出定量化的性能评价。首先,从可发功率、可发功率极限、出力调节范围和爬坡率四个方面提出WCVPG调度特性指标概率量化方法;然后,基于条件风险价值理论,提出WCVPG的安全性和经济性风险指标量化方法;进而,基于多状态概率分布基本运算,提出调度特性与风险指标计算方法;最后,基于实测数据比较了单个风电场与同一风电场公共连接点(point of common coupling,PCC)的风电场组合WCVPG调度特性指标和风险指标差异;分析了风电不确定性和波动性概率分布时变特性对WCVPG调度特性和风险指标的影响。展开更多
Through the construction of the comprehensive evaluation index system and the coordination degree model of the rural in- frastructure and the rural economic development level, the author carries out an empirical analy...Through the construction of the comprehensive evaluation index system and the coordination degree model of the rural in- frastructure and the rural economic development level, the author carries out an empirical analysis on the rural infrastructure and economic coordinated development in the country＇s 31 regions. Research shows that the gap between the levels of the development of the rural in-frastructure in China is large, presenting the gradually reducing gradient distribution from the east to the west. The rural infrastructure de- velopment level has significant positive correlation with the level of economic development. For those provinces of the high development level of the rural economy, the infrastructure construction level is also relatively high. From the view of the coordination degree, it presents the obvious ＂dumbbell＂ shape, and there are more provinces which belong to the high quality coordination and the serious imbalance, with the coordinated degree in the eastern regions obviously higher than that in the central and western regions.展开更多
A three-dimensional autonomous chaotic system is discussed in this paper. Some basic dynamical properties of the system, including phase portrait, Poincar′e map, power spectrum, Kaplan–Yorke dimension, Lyapunov expo...A three-dimensional autonomous chaotic system is discussed in this paper. Some basic dynamical properties of the system, including phase portrait, Poincar′e map, power spectrum, Kaplan–Yorke dimension, Lyapunov exponent spectra, signal amplitude and topological horseshoe are studied theoretically and numerically. The main finding by analysis is that the signal amplitude can be modulated via controlling the coefficients of the linear term, cross-product term and squared term simultaneously or respectively, and the phase of x3 can be modulated by the product of the coefficients of the linear term and cross-product term. Furthermore, scaling chaotic attractors of this system are achieved by modified projective synchronization with an optimization-based linear coupling method, which is safer for secure communications than the existed synchronization scheme since the scaling factors can be regarded as the security encoding key.展开更多
文摘在高风电渗透率的刚性源端系统中,风电参与调度运行的模式需从负负荷向部分可控电源转变,而集群风电以虚拟机组(wind farm cluster virtual power generation unit,WCVPG)形式参与调度运行是提高风电可调度性的可行方案。该文作为系列文章的第2部分,基于文章第1部分建立的WCVPG时变概率模型,提出一种WCVPG调度特性与风险指标量化方法,为其以电源形式参与调度模型做出定量化的性能评价。首先,从可发功率、可发功率极限、出力调节范围和爬坡率四个方面提出WCVPG调度特性指标概率量化方法;然后,基于条件风险价值理论,提出WCVPG的安全性和经济性风险指标量化方法;进而,基于多状态概率分布基本运算,提出调度特性与风险指标计算方法;最后,基于实测数据比较了单个风电场与同一风电场公共连接点(point of common coupling,PCC)的风电场组合WCVPG调度特性指标和风险指标差异;分析了风电不确定性和波动性概率分布时变特性对WCVPG调度特性和风险指标的影响。
文摘Through the construction of the comprehensive evaluation index system and the coordination degree model of the rural in- frastructure and the rural economic development level, the author carries out an empirical analysis on the rural infrastructure and economic coordinated development in the country＇s 31 regions. Research shows that the gap between the levels of the development of the rural in-frastructure in China is large, presenting the gradually reducing gradient distribution from the east to the west. The rural infrastructure de- velopment level has significant positive correlation with the level of economic development. For those provinces of the high development level of the rural economy, the infrastructure construction level is also relatively high. From the view of the coordination degree, it presents the obvious ＂dumbbell＂ shape, and there are more provinces which belong to the high quality coordination and the serious imbalance, with the coordinated degree in the eastern regions obviously higher than that in the central and western regions.
基金Supported by Hunan Provincial Natural Science Foundation of China under Grant No.2016JJ4036University Natural Science Foundation of Jiangsu Province under Grant No.14KJB120007the National Natural Science Foundation of China under Grant Nos.11504176and 11602084
文摘A three-dimensional autonomous chaotic system is discussed in this paper. Some basic dynamical properties of the system, including phase portrait, Poincar′e map, power spectrum, Kaplan–Yorke dimension, Lyapunov exponent spectra, signal amplitude and topological horseshoe are studied theoretically and numerically. The main finding by analysis is that the signal amplitude can be modulated via controlling the coefficients of the linear term, cross-product term and squared term simultaneously or respectively, and the phase of x3 can be modulated by the product of the coefficients of the linear term and cross-product term. Furthermore, scaling chaotic attractors of this system are achieved by modified projective synchronization with an optimization-based linear coupling method, which is safer for secure communications than the existed synchronization scheme since the scaling factors can be regarded as the security encoding key.
