scholarly journals Vulnerability Analysis of Power Grids Using Modified Centrality Measures

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Francisco Gutierrez ◽  
E. Barocio ◽  
F. Uribe ◽  
P. Zuniga
Keyword(s):  
Power Flow ◽  
Power Grid ◽  
Electrical Power ◽  
Vulnerability Analysis ◽  
Active Power ◽  
Power Grids ◽  
Centrality Measures ◽  
Scale Free ◽  
Critical Nodes ◽  
Active Power Flow

The aim of this paper is to propose modified centrality measures as a tool to identify critical nodes before a vulnerability analysis is performed in an electrical power grid. Pair dependency centrality is weighted using the grid active power flow, and this becomes the basis to define closeness and betweenness of its nodes, and hence to identify the most critical ones. To support the idea of using modified centralities, four power grids are tested to be either exponential or scale-free. To evaluate the proposal, information obtained via modified centrality measures is used to calculate global efficiency of the power grids.

Determination of Marginal Power Flows Based on an Adaptive Gradual Load Increase Trajectory

Vestnik MEI ◽  
2021 ◽  
pp. 20-30
Author(s):  
Natalya L. Batseva ◽  
◽  
Vasiliy A. Sukhorukov ◽  
Keyword(s):  
Power Flow ◽  
Active Power ◽  
Power Grids ◽  
Small Signal ◽  
Mode Change ◽  
Operation Speed ◽  
Load Increase ◽  
Active Power Flow ◽  
Change Vector ◽  
The Difference

The aim of the study is to develop a technique for searching an adaptive gradual load increase trajectory for power grids with a chain structure and to test this technique on the monitored 500 kV backbone grid sections. The technique for searching an adaptive gradual load increase trajectory was developed proceeding from the theoretical data about the chain structures of power grids and about the specific features of their operation modes. The voltage levels at the 500 kV backbone grid nodes and normalized phase angles across the ties included in the studied section and in the adjacent monitored sections are adopted as criteria for monitoring loss of small-signal aperiodic stability in the section under study. Special attention is paid to active power flows through the monitored adjacent sections with respect to the section under study. The proposed technique was tested on two monitored sections of the backbone 500 kV grid. The numerical analysis results have shown that under certain grid configuration and mode conditions, the marginal active power flow determined according to the proposed technique is either higher than the marginal active power flow determined using the mode change vector with the difference between the values from 54 MW to 319 MW, or lower than the marginal flow, with the difference between the values from 121 MW to 228 MW. It has been established that the difference between the values is caused by higher or lower loading of the monitored adjacent sections with respect to the section under study. Grid configuration and mode conditions has also been found in which the marginal active power flows determined according to the proposed technique and the mode change vector are almost identical with one another with the difference making about 15 MW. The subsequent algorithmic implementation of the procedure and development of the relevant software will make it possible to apply it to a larger number of monitored sections and to study various grid configuration and mode conditions for accumulating statistical data. If the software operation speed requirements in a close-to-real-time mode are satisfied, the software will be adapted to the Stability Margin Monitoring System software package. On the whole, the testing of the proposed technique for chain-shaped grids allowed us to conclude that the procedure can be used for searching an adaptive gradual loading trajectory and determining marginal active power flows in regard of small-signal aperiodic stability using the power system analysis model corresponding to the current grid configuration and mode conditions.

scholarly journals Searching for small-world and scale-free behaviour in long-term historical data of a real-world power grid

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bálint Hartmann ◽  
Viktória Sugár
Keyword(s):  
Real World ◽  
Power Grid ◽  
Electrical Power ◽  
Small World ◽  
Network Evolution ◽  
Power Grids ◽  
Infrastructure Development ◽  
Real World Data ◽  
Scale Free

AbstractSince the introduction of small-world and scale-free properties, there is an ongoing discussion on how certain real-world networks fit into these network science categories. While the electrical power grid was among the most discussed examples of these real-word networks, published results are controversial, and studies usually fail to take the aspects of network evolution into consideration. Consequently, while there is a broad agreement that power grids are small-world networks and might show scale-free behaviour; although very few attempts have been made to find how these characteristics of the network are related to grid infrastructure development or other underlying phenomena. In this paper the authors use the 70-year-long historical dataset (1949–2019) of the Hungarian power grid to perform complex network analysis, which is the first attempt to evaluate small-world and scale-free properties on long-term real-world data. The results of the analysis suggest that power grids show small-world behaviour only after the introduction of multiple voltage levels. It is also demonstrated that the node distribution of the examined power grid does not show scale-free behaviour and that the scaling is stabilised around certain values after the initial phase of grid evolution.

Fast Evaluation Method on Thermal Stability Limit of Power Grid Cross-Section

2014 ◽  
Vol 986-987 ◽  
pp. 303-310
Author(s):  
Chun Zheng Tian ◽  
Lin Lin Yu ◽  
Jing Hui Huang ◽  
Yan Xie ◽  
Xu Hui Shen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Power Flow ◽  
Evaluation Method ◽  
Power Grid ◽  
Flow Distribution ◽  
Stability Limit ◽  
Active Power ◽  
Fast Evaluation ◽  
Active Power Flow ◽  
Summer Maximum

Enhanced grid structure makes the system thermal stability problems increasingly prominent. The thermal stability of grid section is deduced by use of DC power flow method in typical equivalent system, furthermore, the effect of section N-1 breaking on active power flow in operating equipment is analyzed. Based on the principle of active power flow distribution to meet the impedance proportional relationship, thermal stability limit section assessment methods and processes are presented, which can achieve fast assessment on thermal stability limits and restriction faults. Finally, the summer maximum loads mode of Henan Power Grid in 2014 is taken as example, and the thermal stability limit in northern sections is evaluated. The simulation results prove the feasibility of the proposed method. The research results can provide references for dispatchers and related software developers.

Active Power Flow Control in Inverter using Sliding Mode Controller

2021 ◽  
Author(s):  
Arpit Sharma ◽  
Adarsh Kashyap ◽  
Ayushi Saxena ◽  
Arunprasad Govindharaj ◽  
A Ambikapathy
Keyword(s):  
Flow Control ◽  
Power Flow ◽  
Sliding Mode ◽  
Active Power ◽  
Sliding Mode Controller ◽  
Power Flow Control ◽  
Active Power Flow
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