Mining the inherent persistence property of the time series of wind power is crucial for forecasting and controlling wind power.Few common methods exist that can fully depict and quantify the persistence property.Base...Mining the inherent persistence property of the time series of wind power is crucial for forecasting and controlling wind power.Few common methods exist that can fully depict and quantify the persistence property.Based on the definition of the active power output state of a wind farm,this paper describes the statistical persistence property of the duration time and state transition.Based on the results of our analysis of significant amounts of wind power field measurements,it is found that the duration time of wind power conforms to an inverse Gaussian distribution.Additionally,the state transition matrix of wind power is discovered to yield a ridge property,the gradient of which is related to the time scale of interest.A systemaic methodology is proposed accordingly,allowing the statistical characteristics of the wind power series to be represented appropriately.展开更多
This paper presents the behavior analysis of modular multilevel converter under DC pole-to-pole short-circuit fault, which is an important issue in fault management, electrical system design and MMC based power system...This paper presents the behavior analysis of modular multilevel converter under DC pole-to-pole short-circuit fault, which is an important issue in fault management, electrical system design and MMC based power system protection and control. Firstly, the transient behavior is analyzed and the conduction overlap- ping angle γ, is defined. Secondly, seven possible short-circuit current paths induced by different γ values are identified, and the corresponding engineering short-circuit current calculation methods for both AC and DC sides are proposed. And then, the influences of impedance distribution factor κ and equivalent short-circuit resistance Rsc on short-circuit currents are elaborated the proposed analysis methods. Finally, case study is used to verify the effectiveness of展开更多
Energy storage plays an increasingly important role in modem power systems. It can add value to power systems in various aspects. This paper discusses possible energy storage system （ESS） applications and their bene...Energy storage plays an increasingly important role in modem power systems. It can add value to power systems in various aspects. This paper discusses possible energy storage system （ESS） applications and their benefits to power systems. The system configuration, converter design, and recent field installations of an LV converter based ESS are presented.展开更多
基金supported by the Natural High Technology Research and Development of China(863 Program)(Grant No.2011AA05A112)the National Natural Science Foundation of China(Grant No.51377027)ABB(China)Ltd.
文摘Mining the inherent persistence property of the time series of wind power is crucial for forecasting and controlling wind power.Few common methods exist that can fully depict and quantify the persistence property.Based on the definition of the active power output state of a wind farm,this paper describes the statistical persistence property of the duration time and state transition.Based on the results of our analysis of significant amounts of wind power field measurements,it is found that the duration time of wind power conforms to an inverse Gaussian distribution.Additionally,the state transition matrix of wind power is discovered to yield a ridge property,the gradient of which is related to the time scale of interest.A systemaic methodology is proposed accordingly,allowing the statistical characteristics of the wind power series to be represented appropriately.
文摘This paper presents the behavior analysis of modular multilevel converter under DC pole-to-pole short-circuit fault, which is an important issue in fault management, electrical system design and MMC based power system protection and control. Firstly, the transient behavior is analyzed and the conduction overlap- ping angle γ, is defined. Secondly, seven possible short-circuit current paths induced by different γ values are identified, and the corresponding engineering short-circuit current calculation methods for both AC and DC sides are proposed. And then, the influences of impedance distribution factor κ and equivalent short-circuit resistance Rsc on short-circuit currents are elaborated the proposed analysis methods. Finally, case study is used to verify the effectiveness of
文摘Energy storage plays an increasingly important role in modem power systems. It can add value to power systems in various aspects. This paper discusses possible energy storage system （ESS） applications and their benefits to power systems. The system configuration, converter design, and recent field installations of an LV converter based ESS are presented.
