Synthetic Risk Assessment of Catastrophic Failures in Power System Based on Entropy Weight Method

Abstract

The synthetic risk assessment method incorporating the severity and the possibility is used to identify the catastrophic event sequences in power system. The weight setting of each severity index is determined by the proposed entropy weight method. Comparing with traditional methods, the entropy weight method can determine the weight coefficients objectively. The simulation results for the WSCC-9 buses system have proved the validity of the proposed method. This method can be used in the practice power system.

An Optimization Approach for Improving Comprehensive Performance of PHET Based on Evolutionary Many‐Objective Optimization

“…For eliminating the influence with the relative importance of each objective function by subjective factors, ω i is determined according to entropy weight method. [ 38 ] Supposing there are m evaluation schemes, n evaluation indexes, and the evaluation matrix is expressed as $$\begin{equation}R = \left[ { \def\eqcellsep{&}\begin{array}{@{}*{2}{c}@{}} { \def\eqcellsep{&}\begin{array}{@{}*{2}{c}@{}} {{r_{11}}}&\quad{{r_{12}}}\\[6pt] {{r_{21}}}&\quad{{r_{22}}} \end{array} }&\quad{ \def\eqcellsep{&}\begin{array}{@{}*{2}{c}@{}} \ldots &\quad{{r_{1n}}}\\[6pt] \ldots &\quad{{r_{2n}}} \end{array} }\\[6pt] { \def\eqcellsep{&}\begin{array}{@{}*{2}{c}@{}} \vdots &\quad \vdots \\[6pt] {{r_{m1}}}&\quad{{r_{m2}}} \end{array} }&\quad{ \def\eqcellsep{&}\begin{array}{@{}*{2}{c}@{}} \ddots &\quad \vdots \\[6pt] \ldots &\quad{{r_{mn}}} \end{array} } \end{array} } \right] \end{equation}$$where R = (r ij ) m×n , and r ij is the value of the j th evaluation index against the i th evaluation scheme, that is, the value of the j th normalized objective function against the i th evaluation scheme. Therefore, the entropy of the $$j$$th evaluation index can be expressed as $$\begin{equation}{e_j} = - k\mathop \sum \limits_{i = 1}^m {p_{ij}}{\rm{ln}}{p_{ij}}\end{equation}$$where k = 1 / ln m , p ij is a proportion of r ij against the j th evaluation index, and can be expressed as …”

“…For eliminating the influence with the relative importance of each objective function by subjective factors, 𝜔 i is determined according to entropy weight method. [38] Supposing there are m evaluation schemes, n evaluation indexes, and the evaluation matrix is expressed as…”

Research on the Spatio-Temporal Impacts of Environmental Factors on the Fresh Agricultural Product Supply Chain and the Spatial Differentiation Issue—An Empirical Research on 31 Chinese Provinces

“…The supply chain of fresh agricultural products features a complex structure with multiple links. Since different indicators have differently important roles to play in supply chain development, calculating the weighting coefficients of various indicators is prerequisite [42]. This paper combines Stata with the Entropy Weight Method (EWM) to determine specific weighting coefficients, and the smaller the entropy, the greater the weighting coefficient of an indicator [43].…”