A second order method for contingency severity assessment with respect to voltage collapse

Contingency ranking is one of the methods used in power system operations and planning to foresee the behavior of a system when there is a large disturbance in the system. Several indices have been proposed in the literature for estimating the severity of a particular contingency but mostly in the area of static security assessment. Therefore, in order to effectively capture the performance of a large power system under contingencies, dynamic security assessment (DSA) indices would be more desirable. In this paper, a score is presented with relatively less computational burden and used to determine the severity of a large disturbance in the power system for the purpose of contingency ranking. This score is formulated from the algebraic state variables that are related to the machines in a multi-machine power system modeled with differential algebraic equations (DAE). The proposed score is used with the angle stability criteria and applied on the IEEE 14-Bus test system in Matlab environment to determine the critical transmission lines in the system.

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“…The stator algebraic equations are obtained from the synchronous machine two-axis model dynamic circuit [8], [9] and are given in (10) and (11).…”

Section: B Algebraic Equationsmentioning

confidence: 99%

“…Author in [9] gives various models of synchronous machines necessary to carry out transient stability studies. In [10]- [12], various indices were presented for voltage collapse studies and transient stability analysis.…”

Section: Introductionmentioning

confidence: 99%

Power system contingency ranking based on the generator algebraic state variables score in dynamic security assessment

Oyekanmi

Radman

Uzoechi

2014

2014 IEEE 6th International Conference on Adaptive Science &Amp; Technology (ICAST)

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“…Then, the fault condition is substituted into the resulting equations to obtain the following equations [3]: (8) where where : dimension of the power flow (5). Matrix is a constant square matrix and is independent of contingencies, while vector depends on contingency k. The dimension of (8) is…”

Section: A Linear Estimations Based On Sensitivitiesmentioning

confidence: 99%

“…The use of the reactive power reserves has been proposed as an index to eval- uate the voltage stability of postcontingency systems [6], [7]. Other stability indices have been proposed based on the second order information derived from the singular value analysis of the power flow Jacobian in [8]. Furthermore, the relations between voltages and local reactive supports have been utilized to propose a stability index in [9].…”

Section: Introductionmentioning

confidence: 99%

A Method of Voltage Stability Evaluation for Branch and Generator Outage Contingencies

Yorino

Harada

et al. 2004

IEEE Trans. Power Syst.

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This paper proposes a fast computation method to evaluate the load power margins with respect to saddle node bifurcations under branch outage as well as generator outage contingencies. The voltage stability evaluation for generator outages is a new topic, while there exist various studies for the branch outage contingencies. The proposed method is based on the conventional linear sensitivity method. The linear estimations are improved by taking into account nonlinearities of the power flow equations and by using a fast line search technique. Compared with existing methods, the accuracy is considerably improved. The effectiveness of the proposed method is demonstrated through IEEE 14-, 30-, and 57-bus systems. The estimation errors in load power margins are not more than 5% for generator outage and 15% for all branch outage (route open outage) contingencies.Index Terms-Contingency, load power margin, saddle node bifurcation, voltage stability.

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“…In this context, two types of approaches may be distinguished : those in which the contingency is simulated explicitly and post-contingency system information is used [11], [12], [13] and those relying on first or second order sensitivity information [14], [15], [16]. Reference [14], for instance, proposed to estimate the PCLL through a wellknown formula giving the sensitivity of load power margin to parameters.…”

Section: Introductionmentioning

confidence: 99%

Fast contingency filtering based on linear voltage drop estimates

Otomega

Cutsem

2005

2005 IEEE Russia Power Tech

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Abstract-This paper deals with the filtering of harmless contingencies in voltage stability and security analyses. In many systems, a post-contingency load flow allows to identify the contingencies with severe impact on voltage stability, as causing either divergence or large voltage drops. However, for filtering purposes, accurate voltage drops need not be computed; linear estimates obtained from sensitivity formulas are appropriate. For a given contingency, the method used in this paper solves a sparse linear system to update the phase angles, assuming constant voltage magnitudes. Then, assuming constant active power flows in the branches, a second sparse system is solved to update the voltage magnitudes. This yields better accuracy than one full load flow iteration while retaining the sparse structure of a decoupled formulation. For contingency analysis, the incidents are filtered by comparing the voltage drops to a threshold. For secure power margin computations, the same procedure is used after stressing the system in the specified direction. The method has been tested on a real system where it has been found to combine simplicity of implementation, quality of filtering and computational efficiency.Index Terms-Voltage stability, voltage security assessment, contingency filtering, sensitivity analysis, electrical decoupling, CRIC method.

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A second order method for contingency severity assessment with respect to voltage collapse

Cited by 24 publications

References 14 publications

Power system contingency ranking based on the generator algebraic state variables score in dynamic security assessment

Power system contingency ranking based on the generator algebraic state variables score in dynamic security assessment

A Method of Voltage Stability Evaluation for Branch and Generator Outage Contingencies

Fast contingency filtering based on linear voltage drop estimates

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