Resilient Networks

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Recent Submissions

Now showing 1 - 5 of 9
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    Building Synthetic Power Transmission Networks of Many Voltage Levels, Spanning Multiple Areas
    ( 2018-01-03) Birchfield, Adam B. ; Xu, Ti ; Shetye, Komal ; Overbye, Thomas
    Synthetic power grids, that is, test cases designed to match realistic structural and statistical characteristics of actual grids, are useful for research, development, and demonstration of innovations, since the cases are fictitious and thus free from data confidentiality issues. Building on previous work, this paper addresses a couple of related problems in the transmission network synthesis process. These issues appear as created cases become larger and involve multiple areas and overlapping nominal voltage levels. A fast, scalable hierarchical clustering is designed to assign voltage levels to substations considering the needs of the system, the specific constraints of the area, and smooth interconnections between neighboring areas with different voltage levels. A line topology generation framework is considered that is appropriate for many networks of different voltage levels, constructed together for a useful, realistic grid. These methods are demonstrated in a new 2000 bus test case, validated and publicly released.
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    Interdependence of Transmission Branch Parameters on the Voltage Levels
    ( 2018-01-03) Athari, Mir Hadi ; Wang, Zhifang
    Transformers and transmission lines are critical components of a grid network. This paper analyzes the statistical properties of the electrical parameters of transmission branches and especially examines their interdependence on the voltage levels. Some interesting findings include: (a) with appropriate conversion of MVA rating, a transformer’s per unit reactance exhibits consistent statistical pattern independent of voltage levels and capacity; (b) the distributed reactance (ohms/km) of transmission lines also has some consistent patterns regardless of voltage levels; (c) other parameters such as the branch resistance, the MVA ratings, the transmission line length, etc, manifest strong interdependence on the voltage levels which can be approximated by a power function with different power constants. The results will be useful in both creation of synthetic power grid test cases and validation of existing grid models.
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    Assignment of Electrical Properties to Power Grid Topologies
    ( 2018-01-03) Schweitzer, Eran ; Scaglione, Anna ; Hedman, Kory
    Power systems are often described in terms of graphs, with various properties like load and impedance associated with the nodes and edges. These properties are coupled to the graph's topology, reflecting the great deal of engineering design in the power system. With the goal of automating the creation of usable synthetic cases, the problem of assigning these properties is considered. It is formulated as a Mixed Integer Program (MIP), which aims to minimize the angle differences between adjacent nodes in the system. Since the problem quickly balloons in size, a decomposition into smaller zones is explored, that enables scaling the problem to larger system sizes. Experiments demonstrate the efficacy and viability of the approach.
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    Systematic Framework for Integration of Weather Data into Prediction Models for the Electric Grid Outage and Asset Management Applications
    ( 2018-01-03) Kezunovic, Mladen ; Obradovic, Zoran ; Djokic, Tatjana ; Roychoudhury, Shoumik
    This paper describes a Weather Impact Model (WIM) capable of serving a variety of predictive applications ranging from real-time operation and day-ahead operation planning, to asset and outage management. The proposed model is capable of combining various weather parameters into different weather impact features of interest to a specific application. This work focuses on the development of a universal weather impacts model based on the logistic regression embedded in a Geographic Information System (GIS). It is capable of merging massive data sets from historical outage and weather data, to real-time weather forecast and network monitoring measurements, into a feature known as weather hazard probability. The examples of the outage and asset management applications are used to illustrate the model capabilities.
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    Exploring cascading outages and weather via processing historic data
    ( 2018-01-03) Dobson, Ian ; Carrington, Nichelle'Le ; Zhou, Kai ; Wang, Zhaoyu ; Carreras, Benjamin ; Reynolds-Barredo, Jose
    We describe some bulk statistics of historical initial line outages and the implications for forming contingency lists and understanding which initial outages are likely to lead to further cascading. We use historical outage data to estimate the effect of weather on cascading via cause codes and via NOAA storm data. Bad weather significantly increases outage rates and interacts with cascading effects, and should be accounted for in cascading models and simulations. We suggest how weather effects can be incorporated into the OPA cascading simulation and validated. There are very good prospects for improving data processing and models for the bulk statistics of historical outage data so that cascading can be better understood and quantified.