6 research outputs found

    Algorithms for Graph Connectivity and Cut Problems - Connectivity Augmentation, All-Pairs Minimum Cut, and Cut-Based Clustering

    Get PDF
    We address a collection of related connectivity and cut problems in simple graphs that reach from the augmentation of planar graphs to be k-regular and c-connected to new data structures representing minimum separating cuts and algorithms that smoothly maintain Gomory-Hu trees in evolving graphs, and finally to an analysis of the cut-based clustering approach of Flake et al. and its adaption to dynamic scenarios

    Advanced methods for offshore windfarm planning

    Full text link
    There have been increasing interests and projects of Offshore wind farm (OWF) development across the world given the rich wind resources in order to achieve carbon neutral objectives. Appropriate electrical system design of OWF is of key importance in terms of cost saving and improving system efficiency. Two novel electric system layout optimization models for OWF planning are proposed to optimize the topology of collector system and connected transmission system simultaneously in OWFs with single and multiple substations. For OWF with single-substation, a novel mathematical model to represent the system topology is proposed to reduce the number of variables so as to effectively decrease the search space of the optimisation problem, where the continuous substation sitting problem is discretized by a 2-step rasterization method. For large-scale OWFs, the overall electric system optimization problem has been classified into 3 levels: substation optimization, feeder selection, and cable determination. Fuzzy clustering technique and wind turbine allocation method has been proposed to effectively divide the large offshore windfarms into partitions. Both HVDC and HVAC cables are considered as alternatives used in the associated transmission system, which can be optimized at the substation level. The concept of clustering is further applied in feeder level to cluster wind turbines into appropriate feeders. The proposed model and the optimization algorithms are tested and validated in two large-scale offshore winds. A comprehensive decision support model is proposed which covers three key factors that characterize OWF integration: investment cost, system stability and the interactions between MTDC and local AC system, all of which are concerned to characterize the optimal integration location of wind turbines into AC bus location and appropriate converter size installed at the corresponding MTDC terminals. To better fit into the real-world situation, various wind speed and load scenarios have been considered. Validity and effectiveness of the proposed model has been tested to integrate two wind farms to a benchmark AC system via a MTDC grid. The research methodologies presented in the thesis form a rather comprehensive approach for OWF design and planning. With the rapid development in OWF technologies, future research needs are also identified and presented in the thesis

    Cumulative index to NASA Tech Briefs, 1963-1967

    Get PDF
    Cumulative index to NASA survey on technology utilization of aerospace research outpu

    Reliability Abstracts and Technical Reviews January-December 1968

    Get PDF
    No abstract availabl
    corecore