Contingency Analysis Method Research Articles

Reliability assessment of composite power systems containing sea wave slot‐coned generators

The generated power of the Sea-wave slot-coned generator (SSG), as one of the high capacity wave energy converters, is dependent on the period and height of the waves. The generated power of this energy-converter changes due to the variation in these parameters. Thus, different aspects of the power systems may be affected that must be investigated by increasing the share of these converters for electricity production in the power-systems. In this paper reliability assessment of composite power-systems containing large-scale SSG is performed. The Xie and Beni (XB) index is calculated for obtaining the optimum number of states in the reliability model of the SSG and fuzzy c-means clustering technique is proposed for reducing the number of states of the model. The contingency analysis method is proposed for calculating the reliability indices of the composite power-system incorporating large-scale SSG. DC load-flow method, which considers line capacity, is used to perform load-flow in the composite power-system including generation and transmission networks. In the proposed technique, a load-shedding program with the goal of minimizing the value of lost load is solved using of the linear programming method based on the interior-point-approach for contingency states leading to the load curtailment.

Online contingency analysis method for multi‐terminal DC distribution networks with renewable resources

In this study, an interval arithmetic-based method has been proposed for contingency analysis of line outage in DC distribution networks. This method incorporates the uncertainties in source/load which become considerable in the system with increasing renewable generations and time-varying loads. Two-stage contingency analysis approach is adopted in this method. For the first stage of contingency screening, a contingency filter has been developed based on interval matrix norm to quickly estimate the bounds of operating state in the post-outage period. For the second stage of detailed analysis to the selected contingencies, the interval analytical model is first transformed into a non-linear programming-based equivalent model. To solve this model accurately and efficiently, successive linear programming and reformulation-linearisation techniques are employed. The proposed method is benchmarked against Monte Carlo simulations and line outage distribution factor-based method.

Estudio de caso diagnosticado como desorden obsesivo compulsivo desde el análisis contingencial

Introducción: en este trabajo se presenta un estudio de caso de un comportamiento diagnosticado como trastorno obsesivo compulsivo.Metodología: el caso se analiza y se trata con una metodología surgida de la aproximación interconductual que se denomina “análisis contingencial”. Se ilustra la aplicación de la metodología al presentar el análisis de dos dimensiones básicas para este propósito: microcontingencial y macrocontingencial. Se describen algunos aspectos importantes de la génesis de este comportamiento, así como el análisis de las soluciones seleccionadas. Igualmente, se presentan los objetivos de intervención y las técnicas empleadas.Resultados: como resultado de la intervención se obtuvieron cambios en el comportamiento de la usuaria del servicio (quien era la madre de la persona diagnosticada con el trastorno y del hijo diagnosticado de esta manera).Conclusiones: se detallan las ventajas de abordar un estudio de caso con la metodología del análisis contingencial.

Contingency Analysis of South Bandung Electric Power System

Electric power transmission system must operate reliably and continuously, but in fact there are many disturbance that affect the reliability and stability of the power system. This study aims to determine the weak elements of power system when release of components occur. This study uses simulation with Newton Raphson power flow method for contingency analysis. The study is located in South Bandung electric power system with voltage of 150 kV. In this study, the object of contingency analysis is IBT-II 500/150 KV at peak periods load in 2013 to evaluate the system reliability when release of the Inter bus Transformer (IBT). Selection of the component is based that IBT is the most important component in the power supply that should be maintain continuously. The results of the study and analysis show that in the event of contingency almost all bus voltage has decreased below the limit allowable voltage and IBT-I get overloaded, then the maneuver is performed according to the procedures of specified load. The results of this study can be use as a reference for the electric power operating system which has conditions similar to the simulated cases.

정전복구에 대한 배전계통 상정사고 해석법

This paper identifies the issues of contingency analysis for restoration in distribution systems. Contingency analysis has been applied to transmission systems but not to distribution systems. The distribution system is different from transmission system. So it is hard to apply for existing contingency analysis to distribution system. In this paper, a new contingency analysis method for distribution systems is proposed. The proposed method is based on service restoration capability. It aims to minimize outage left after service restoration in case of a fault in advance. The method estimates the vulnerability which is represented by zone restoration index proposed in. Applying the proposed method, operators could change the system so that it does not leave any outage left after restoration. Case study has been carried out on a five feeder system and its results show effectiveness of the method.

A Method for the Evaluation of the Effectiveness of Turboelectric Distributed Propulsion Power System Architectures

Radical new electrically propelled aircraft are being considered to meet strict future performance goals. One concept design proposed is a Turboelectric Distributed Propulsion (TeDP) aircraft that utilises a number of electrically driven propulsors. Such concepts place a new and significant reliance on an aircraft's electrical system for safe and efficient flight. Accordingly, in addition to providing certainty that supply reliability targets are being met, a contingency analysis, evaluating the probability of component failure within the electrical network and the impact of that failure upon the available thrust must also be undertaken for architecture designs. Solutions that meet specified thrust requirements at a minimum associated weight are desired as these will likely achieve the greatest performance against the proposed emissions targets. This paper presents a Fault Tree Analysis (FTA) based design approach for the electrical system and thrust reliability analysis of TeDP aircraft architectures. This approach extends beyond the single failure rate provided by traditional FTA methods by profiling the reliability and thrust provision of each possible system configuration (i.e. following the failure of one or more components), which combined with a measure of total system weight and volume provides an effective design capability. The paper presents a case study for a TeDP design configuration showing how Thrust - Reliability (TR) dispatch targets may be achieved using a contingency analysis method utilising k-out-of-n probability and concludes by discussing plans to build upon the described work and utilise the method for more complex studies.

Analisis Kontingensi Sistem Tenaga Listrik dengan Metode Bounding

The bounding method is one of the contingency analysis method for detecting branch flow violations. Three subnetworks in the bounding method namely N1, N2, and N3 will give information regarding those subnetworks that may not go overload and those that may. This research compared the results from contingency analysis that has been done to the 30 bus system using the bounding method and software PowerWorld Simulator 15 GSO. The result by using the bounding method is 12 lines can go overload for the outage of line 1-2. As well as for the outage of line 1-3 and the outage of line 2-5. Meanwhile, the output of using PowerWorld Simulator 15 GSO with DC power flow method, there are three overloads exist for the outage of line 1-2, three overloads exist for the outage of line 1-3, and five overloads exist for the outage of line 2-5. The overload lines are included in the group of lines that can overload from bounding result.

Contingencies Ranking for Voltage Stability Analysis using Continuation Power Flow Method

A screening method and continuation power flow program to analyze contingencies and their impact on static voltage stability in power systems is proposed. The proposed method for contingency analysis and voltage stability studies and is based on the impact of the contingency on the load, the Mega Watt Margin (MWM) and maximum loading point. The Method provides initially a ranking scheme for first level contingencies by comparing their loadability with the maximum loadability of the system. It then makes a short list of important contingencies for detailed analysis. The proposed method is tested by the IEEE 14-bus Test System. Bibl. 14 (in English; summaries in English, Russian and Lithuanian).

A risk based contingency analysis method incorporating load and generation characteristics

This paper presents an efficient and realistic contingency analysis method. The contingencies are ranked based on their risk index value which incorporates both the probability and the severity of the contingency. Severity for each contingency is computed based on load loss, equipment overloads, voltage magnitude violation at nodes and system frequency deviation from the nominal value. The proposed method considers line/transformer outages as well as generator outage contingencies. A modified Fast Decoupled Power Flow method which considers frequency and voltage dependent characteristic of loads, generator regulation characteristics and sensitivity based transformer tap adjustments is used to evaluate the contingencies. The power flow method is suitable for any AC/DC power system and can carry out contingency analysis even if the system gets islanded.

An efficient method for assessing security on a daily basis [power systems

The daily planning function aims to optimize the day-to-day operation of power systems. Most of the time these plans are constructed without any information regarding the system security (power flow limits). In order to consider the system security constraints in such planning studies, a planning system architecture including a fast cyclic contingency analysis method and an optimal power flow and daily generation management procedure is presented. Tests have been performed on the French 225-400 kV grid containing 462 nodes and 855 branches with the generation and load planning recorded on the 29 February 1996 at the French National Dispatching Center. For this day, 48 states, corresponding to a 24-hour-period in 30-minute-steps, were analyzed. Tests confirm that the authors' approach is applicable, accurate and faster than the existing approaches.

An improved linearized method for evaluation of bus voltage for line outage contingency

This paper presents an improved linearized method for contingency analysis which computes load-bus voltage following line outage. This method requires one base case AC load-flow and subsequently one DC load-flow for each contingency to determine the bus voltages. This proposed non-iterative method is applied to 14 and 30 bus IEEE test systems and compared with the existing method to show its superiority over it.

Efficient bounding method for linear contingency analysis

A very efficient contingency analysis method for detecting branch megawatt flow violation is presented. The efficiency stems from the use of a bounding criterion that drastically reduces the number of branch-flow computations and limits checking, and the use of state-of-the-art compensation and sparse matrix/vector methods. The method requires no offline setup, is highly efficient, and can handle contingencies with any time of network topology and load/generation changes. The method is based on the linear incremental-power-flow model and consequently does not consider reactive power.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A fast method for contingency analysis based on P‐Q decoupled model

A fast method for contingency analysis based on P‐Q decoupled model

ＰＱ分離等価回路による高速想定事故解析手法

ＰＱ分離等価回路による高速想定事故解析手法

Redistribution of Reactive Power Flow in Contingency Studies

During recent years, problems associated with reactive power flow and bus voltages have acquired greater importance. The transmission capacity may sometimes be limited by reactive power considerations. In a few instances collapse of transmission network has been attributed to abnormal reactive power flow patterns. Some recent papers have addressed the question of improving the contingency study techniques for the reactive power flow problem. A commonly used method for contingency analysis is based upon the use of distribution factors. The distribution factor method of contingency analysis is very fast in its execution time, and for this reason is widely used in real time applications as well as planning studies. This technique is known to be particularly suited to the study of real power redistribution following an outage. It is not as accurate in dealing with problems of reactive power flow redistribution and accompanying effects on bus voltages. The inaccuracies are particularly significant when voltage controlled buses are present in the power system. The distribution factors are based on approximating active power injections by current injections under the assumption that voltage magnitudes throughout the system are kept constant. This is an unacceptable assumption for reactive power. This paper develops a new formulation of distribution factors which is suitable for the analysis of the reactive power problem. The new formulation is based on the S-E (complex power - complex bus voltage) representation of a power network instead of the usual I-E (complex current - complex bus voltage) formulation.