Fast contingency screening and evaluation for voltage security analysis
TL;DR: In this article, a fast security-analysis technique for voltage security assessment in an energy-management system is described, which identifies the location of buses with potential voltage problems and thereby defines a voltage-sensitive subnetwork for contingency screening.
Abstract: The authors describe a fast security-analysis technique for voltage security assessment in an energy-management system. The proposed method identifies the location of buses with potential voltage problems and thereby defines a voltage-sensitive subnetwork for contingency screening. This allows the evaluation of a large number of contingencies. The efficiency of this method is derived from the use of a voltage subnetwork to drastically reduce the number of bus voltages to be solved; and subsequently from the use of compensation techniques and sparse-vector methods (including adaptive reduction) for screening and final solution of contingencies. Results demonstrating the effectiveness of the method on a small and a large power system are presented. >
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TL;DR: A comprehensive list of books, reports, workshops and technical papers related to voltage stability and security can be found in this article, where the authors provide a comprehensive overview of the literature.
Abstract: This paper provides a comprehensive list of books, reports, workshops and technical papers related to voltage stability and security
212Â citations
TL;DR: In this paper, an effective ac corrective/preventive contingency dispatch over a 24-hour period is proposed based on security-constrained unit commitment (SCUC) model.
Abstract: In this paper, an effective ac corrective/preventive contingency dispatch over a 24-h period is proposed based on security-constrained unit commitment (SCUC) model. The SCUC model includes unit commitment, ac security-constrained optimal power flow (SCOPF), and load shedding (LS) for steady state and contingencies. The objective of this SCUC model is to obtain the minimum bid-based system operating cost while maintaining the system security. The prevailing generation constraints, such as hourly power demand, system reserves, fuel and emission limits, ramp up/down limits, and minimum up/down time limits, are included in this model. In addition, system constraints such as time-limited emergency controls for a given contingency and ac network security limits are taken into account. The proposed ac solution for the hourly scheduling of generating units is based on Benders decomposition. Case studies with the six-bus system, the IEEE 118-bus test system, and 1168-bus system are presented in detail in this paper.
199Â citations
TL;DR: In this paper, the change in the loading margin to voltage collapse when line outages occur is estimated, and the results show the effective ranking of contingencies and the very fast computation of the linear estimates.
Abstract: The change in the loading margin to voltage collapse when line outages occur is estimated. First a nose curve is computed by continuation to obtain a nominal loading margin. Then linear and quadratic sensitivities of the loading margin to each contingency are computed and used to estimate the resulting change in the loading margin. The method is tested on a critical area of a 1390 bus system and all the line outages of the IEEE 118 bus system. The results show the effective ranking of contingencies and the very fast computation of the linear estimates.
189Â citations
Cites methods from "Fast contingency screening and eval..."
...Changes in generator VAR limits were computed during both the procedure to find the post-contingency operating point and the subsequent continuation....
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TL;DR: The security measure captures nonlinear effects such as VAR limits on generators that can influence the systems vulnerability to collapse and the behavior of the index with respect to network load increases is nearly linear over a wide range of load variation, facilitating prediction of the onset of collapse.
Abstract: A security measure is defined to indicate vulnerability to voltage collapse based on an energy function for system models that includes voltage variation and reactive loads. The system dynamic model, the energy function, and the security measure are first illustrated in a simple radial system. Application of the security measure and its computational aspects are then examined in a standard 30-bus example (New England System). The security measure captures nonlinear effects such as VAR limits on generators that can influence the systems vulnerability to collapse. The behavior of the index with respect to network load increases is nearly linear over a wide range of load variation, facilitating prediction of the onset of collapse. >
168Â citations
TL;DR: In this article, a linear programming model for generation rescheduling and minimization of the amount of load shed is presented for correcting the voltage problem, and the composite system is classified into different system states for which probabilistic indices are calculated.
Abstract: An electric power network containing generation and transmission facilities can be divided into several states in terms of the degree to which adequacy and security constraints are satisfied in a reliability evaluation of the composite system. The composite system is classified into different system states for which probabilistic indices are calculated. Both annualized and annual indices using a seven-step load model are presented for two test systems. Selection methods are used to detect problem-creating contingencies. A linear programming model for generation rescheduling and minimization of the amount of load shed is presented. A linear programming model for correcting the voltage problem is presented. >
162Â citations
References
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TL;DR: This paper describes a simple, very reliable and extremely fast load-flow solution method that is attractive for accurate or approximate off-and on-line routine and contingency calculations for networks of any size, and can be implemented efficiently on computers with restrictive core-store capacities.
Abstract: This paper describes a simple, very reliable and extremely fast load-flow solution method with a wide range of practical application. It is attractive for accurate or approximate off-and on-line routine and contingency calculations for networks of any size, and can be implemented efficiently on computers with restrictive core-store capacities. The method is a development on other recent work employing the MW-?/ MVAR-V decoupling principle, and its precise algorithmic form has been determined by extensive numerical studies. The paper gives details of the method's performance on a series of practical problems of up to 1080 buses. A solution to within 0.01 MW/MVAR maximum bus mismatches is normally obtained in 4 to 7 iterations, each iteration being equal in speed to 1? Gauss-Seidel iterations or 1/5th of a Newton iteration. Correlations of general interest between the power-mismatch convergence criterion and actual solution accuracy are obtained.
1,447Â citations
TL;DR: A fast technique has been developed for the automatic ranking and selection of contingency cases for a power system contingency analysis study and results of this technique applied to different test systems are presented.
Abstract: A fast technique has been developed for the automatic ranking and selection of contingency cases for a power system contingency analysis study. A contingency list is built containing line and generator outages which are ranked according to their expected severity as reflected in voltage level degradation and circuit overloads. An adaptive contingency processorcan be set up by performing sequential contingency tests starting with the most severe contingencies at the top of the list and proceeding down the list, stopping when the severity goes below a threshold. Computational results of this technique applied to different test systems are presented.
466Â citations
TL;DR: The efficiency of the sparse vector methods is verified by tests on a 156-bus, a 1598-bus and a 2265-bus system and the new methods are significantly faster than the established sparse matrix techniques.
Abstract: Sparse vector methods enhance the efficiency of matrix solution algorithms by exploiting the sparsity of the independent vector and/or the desire to know only a subset of the unknown vector. This paper shows how these methods can be efficiently implemented for sparse matrices. The efficiency of the sparse vector methods is verified by tests on a 156-bus, a 1598-bus and a 2265-bus system. In all cases tested, the new methods are significantly faster than the established sparse matrix techniques.
338Â citations
TL;DR: The paper gives a unified derivation and analysis of compensation methods for the efficient solution of network problems involving matrix modifications, including the removal, addition and splitting of tiodes.
Abstract: The paper gives a unified derivation and analysis of compensation methods for the efficient solution of network problems involving matrix modifications. These methods have a very wide range of practical application, and many of the better ones appear tobe little known in the power field. General and specific cases are dealt with, including the removal, addition and splitting of tiodes. The choice between themany compensation versions is seen to be highly problem dependent, and although space precludes the treatment of specific applications, guidelines are offered for the comparison of versions with each other and with matrix refactorization.
200Â citations
TL;DR: In this article, the authors present an advanced contingency selection algorithm, which is essentially equivalent to a ranking based on the results of a DC load flow of each case, only at a fraction of the calculation time.
Abstract: This paper reports on the development of an advanced contingency selection algorithm giving superior results compared to earlier techniques. Problems inherent in the earlier algorithm resulted in occasional misranked contingency cases. The new algorithm gives results which are essentially equivalent to a ranking based on the results of a DC load flow of each case, only at a fraction of the calculation time. A complete derivation, test results and applications are given in the paper.
186Â citations