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The access of wind power will bring frequency fluctuation to power system, the performance of system's primary frequency regulation (PFR) has an important effect on the stable operation of the grid. In this paper, the ability of system's primary frequency regulation is studyed after wind farm connected to grid. First, the paper forecasts wind speed by time sequence method, and establishes ARMA model...
As a green energy, wind is widely used around the world in recent decades. And reliable operation of wind turbines is closely related to the safe operation of power grid. In this paper, factors which cause wind turbine outage are analysed to establish the outage rate model of a wind turbine, from the point of assessing wind turbine operation reliability. First,factors which cause outage of wind turbine...
Currently the development of large scale electric vehicles have become governments' focus of attention. Based on the research of charging and discharging power models, the paper puts forward the island formation strategy and establishes the distribution system reliability model with the electric vehicles. The Monte Carlo time sequential simulation is used to evaluate the effects of different vehicle...
With the rapid development of wind power generation, it is significant to study the impacts of wind farms on power system reliability. A general probabilistic model of a wind farm is proposed in this paper. The wind farm is modeled as a conventional unit with multiple states. The model could be used in conventional power system adequacy assessment utilizing analytical or simulation methods without...
The paper focuses on the study of environmental effects that electric vehicle might cause if they were connected to the distribution grid. A comprehensive evaluation index system is proposed in a quantitative way to describe the environmental effects, such as the pollutant reduction validity and greenhouse gas reduction validity. In order to ensure the economical efficiency of the system, the comprehensive...
Abstract - Wide Area Measurement System has increasingly become an important part of wide-area interconnected power system, the reliable transmission of real-time measurement data is essential. This paper creates WAMS delay model from perspectives of the stratification of system functionality and communication structure. It also analyses influences to WAMS communication delay caused by different protection...
The usage of cemented paste backfill (CPB) in the underground by mining industry is becoming increasingly. In this study, three kinds of CPB with waste rock content of 15%, 20% and 25% respectively were tested, and their stress-strain curves were obtained. According to the damage mechanism of CPB during the uniaxial compressive failure process, this paper further established the damage constitutive...
There will be quite a large amount of smart meters used in AMI, which may be produced by many different manufacturers. Therefore, it's very important to maintain interoperability among different devices, and reduce or even avoid the overhead of protocol conversion. Using a general standard might be a very good way to accomplish interoperability. This paper attempts to use IEC 61850, which will be...
Installing subsection switches on distribution network feeders is an effective measure to improve system reliability. In this paper, based on value engineering, a new method is presented to determine optimal subsection scheme. By application of value engineering theory, a new objective function is constructed. The new objective function, based on cost-benefit analysis, is constructed by reference...
The Substation Automation System (SAS) is a crucial element of power system control. The devices of SAS with remote-control functions are one of the main target of cyber attack. The vulnerability assessment for communication network of SASs that supporting the analysis of control process, is an unsolved problem. Combined with the characteristics of SAS and the vulnerability assessment of the distributed...
In this paper a general reliability evaluation algorithm for complex medium voltage distribution networks (MVDN) is proposed, in which each feeder is a basic unit and without simplifying the network equivalent, the depth-first search algorithm and breadth-first search algorithm is used to search each feeder in topologies. Then circuit breakers oriented first-class zone based on the same influences...
The location and sizing of distribution substations integrated with urban spatial information is a optimization problem which primary characteristics are the existence of many suboptimal cost peaks and the solution space is on a discrete floating-point variables rage with some unfeasible area constraints. To solve this problem, a spatial information based parameter self-adaptive schema of DE (ISADE)...
Bacterial colony chemotaxis (BCC) algorithm is a new colony intelligence optimization algorithm. In this paper through a mass of experiments on the standard test function, the impact of the algorithm parameters on the performance of algorithm is demonstrated, and then the parameter control strategies are given, which lay the foundation for further study of the algorithm. In older to enhance the success...
The IEC 61400-25 standard has defined mapping of power plant information model to Web services. How to ensure the security of Web services-based communication for wind power plants is a unsolved problem. WS-Security is a standard used to deal with the security requirement in application of Web services, while username/password and X.509 certificates are security tokens most commonly used in electric...
Substation planning is an important component of urban power networks. In this paper, a new mathematics model for unified substation planning of two voltage levels is presented, which makes the total cost of two voltage levels as objective function and the geographical information as restrictive condition, introduces the penalty function to ensure the uniformity of the load distribution. Bacterial...
It has been long recognized that high cost of denture design and manufacture are the main obstacles standing in the way of dental restoration treatment. It is expected to develop a cost-efficient method and a relatively intelligent system to satisfy the growing requirements from ordinary people who are not capable of affording high expenditures aroused by traditional approaches or even some modern...
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