Enhanced Contingency Analysis—A Power System Operator Tool (original) (raw)

Contingency evaluation for voltage security assessment of power systems

2009

The demand for electricity is expected to continue to increase given the recent world population projection of about 30% increase in the next three decades. Consequently power systems are equally expected to be more heavily loaded than before. Unfortunately the environmental and economic constraints restrict the expansion of the existing power system facilities. This scenario requires a constant attention since it could result to voltage collapse which could in turn lead to a total blackout. This paper presents the procedure required to carry out a contingency assessment and ranking of the load buses and lines of power systems for voltage security. This would ensure that power systems are operated above a desired voltage stability margin to forestall voltage collapse. The impact of single line outage contingency on the static voltage stability margin, as well as the available transfer capability across the areas of the test system, are examined in the paper.

Power System Security Assessment under N-1 and N-1-1 Contingency Conditions

2019

The most important function in a power system planning and operation is the desire to keep the system in a secure state under normal and contingency conditions. Contingency is termed as a disturbance resulting from the components outages. This disturbance is a sudden change in the system configuration resulting in severe violations on the operating constraints. These violations may result in successive interruptions leading to partial or total blackout. The purpose of this paper is to study the effect of power system component outages in terms of their severity to select and rank all severe contingencies, and consequently to apply the Remedial Action Scheme (RAS) approach that is necessary to withstand these contingencies and return the system into a secure state. Both of RAS-1 and RAS-2 strategies are utilized to obtain a final system configuration which successfully recovers from any kind of N-1 contingency criterion. The most economical remedial scheme from RAS-1 and RAS-2 is dis...

Contingency Selection in the Context of Voltage Security Margin Determination

ICICCT 2019 – System Reliability, Quality Control, Safety, Maintenance and Management, 2019

The present day power utilities highly stressed and operate very close to the stability limit. Because of this, the power utilities are confronting the issue in keeping up the required bus voltages. The power system which happened to be limited by transient (angle) stability have now moved toward becoming voltage stability constrained. Henceforth, the focal point of this paper is being on voltage stability and voltage security analysis. The voltage security can be assessed by performing AC load flow for different outages. Practically in a Power System, number of contingencies is large to the point that they can't be investigated online by the AC load flow strategies. Subsequently the contingencies are, firstly, ranked according their relative degree of severity by implementing suitable selection algorithms. After this, the more severe contingencies are selected for full AC load flow analysis. This paper presents a functional link model based Artificial Neural Network (ANN) for the prediction of post-outage bus voltages. The contingencies are, then, ranked by implementing fuzzy logic approach by considering voltage deviation and voltage stability margin as well.

Linear and nonlinear methods for contingency analysis in on-line voltage security assessments

2009 IEEE Power & Energy Society General Meeting, 2009

The strategy of using an effective scheme to screen out a large number of stable contingencies and to apply detailed simulation programs only to potentially unstable contingencies is well recognized. This strategy is implemented in on-line voltage security assessment (VSA). This paper presents a hybrid of linear, quadratic and nonlinear methods for on-line VSA. Linear methods are fast but may not be sufficiently accurate while nonlinear methods are accurate but may not be sufficiently fast. To meet the demands of speed and accuracy for online application, the hybrid of three methods for performing screening, ranking and detailed analysis is thus developed and applied to the CAISO system with promising results.

An advanced tool for preventive voltage security assessment

2000

Summary. This paper deals with methods for the preventive assessment of voltage security with respect to contingencies. We describe a computing tool for the determination of secure operation limits, together with methods for contingency filtering. Examples from two very different real-life systems are provided. We outline extensions in the field of preventive control. ... Keywords. Voltage security assessment, contingency analysis, contingency filtering, preventive control ... In the recent past, a significant number of incidents throughout the world have resulted in ...

Ensuring power system security against contingencies

2007 International Conference on Industrial and Information Systems, 2007

A power system is secure against a given contingency if it operates within acceptable operating limits before and after the occurrence of the contingency. In practice, it is not possible to secure a power system against all possible contingencies. Therefore, only the most critical contingencies (imminent disturbances) are considered. The paper gives an overview of power system security and different ways of loosing stability. Then, a statistical learning based technique for determining the boundary of the secure operating region in terms of precontingent state of the power system is reviewed. The paper discusses possible applications of the boundary and some issues related to practical application of this method.

Power System Contingency Analysis to detect Network Weaknesses

Steady state power system insecurity such as transmission lines being overloaded causes transmission elements cascade outages which may lead to complete blackout. The power system operator must know the system state at any instant. The contingency analysis is used to predict which contingencies make system violations and rank the contingencies according to their relative severity. Contingency Analysis is useful both in the network design stages and for programmed maintenance or network expansion works to detect network weaknesses. The weaknesses can be strengthened by transmission capacity increase, transformers rating increase besides circuit breakers ratings increase. This work outlines mathematical models for the simulation of generator outages and transmission line and transformer outages so as to carry out a full AC load flow based contingency analysis and ranking. The method has been applied to Sudan National Grid (NG) and gives good results in determining the network weaknesses and suggesting the new transmission lines and transformers capacities which ensures better power system security.

?Contingency Ranking and Analysis using Power System Analysis Toolbox (PSAT)

Innovative Systems Design and Engineering, 2013

In this paper according to the increasing utilization in power system, the transmission lines and power plants often operate in stability boundary and system probably lose its stable condition by over loading or occurring disturbance. According to the reasons that are mentioned, the prediction and recognition of voltage instability in power system has particular importance and it makes the network security stronger. This paper, by considering of power system contingencies based on the maximum loading parameter point is focused in order to analyze the static voltage stability using continuation power flow method. The study has been carried out on IEEE 14-Bus Test System using Power System problem has been solved by using PSAT with Matlab and results are presented.

A Simple Contingency Selection for Voltage Stability Analysis

Electronics and Electrical Engineering, 2013

The paper deals with a selection of potentially critical contingencies from the voltage stability viewpoint. Consideration of all contingencies is impractical. Before contingency analysis starts, one can state, that certain contingencies need not be taken into account. In the paper, after a short overview of the existing papers, in which the problem of the selection of contingencies is considered, the new method for selection of contingencies is presented. A selection of contingencies is based on results of testing of possible power transfers in a power network after the contingencies occur. During the tests, assessments of extreme values of active and reactive power flows, which change when power system state changes, are taken into consideration. In the paper, a computational example of utilization of the described method is given. At the end, the most important features of the method are pointed out.