Reliability Analysis Of Distribution Systems Research Articles

A Solution to Investigate Uncertainties in Reliability Analysis of Distribution System Based on Fuzzy Logic Method

A Solution to Investigate Uncertainties in Reliability Analysis of Distribution System Based on Fuzzy Logic Method

Power Supply Reliability Analysis of Distribution Systems Considering Data Transmission Quality of Distribution Automation Terminals

A distribution automation system is the integration of physical power distribution systems and information systems. Its information system guarantees the safe operation and reliable power supply of physical systems by monitoring, collecting and transmitting information. In the information system, the remote terminal unit of distribution automation is the hub of the information system, connecting it to the physical power system. Considering the unreliability of terminal information transmission in the information system, this paper aims to build a model to quantitatively evaluate the impact of unreliable transmission information on the power supply reliability of distribution systems. Firstly, the m-segment and n-connection unit model of distribution feeders is established, and then, the power supply reliability indices in the process of handling feeder terminal unit error are analyzed and calculated under the configuration modes of “three-remote” and “two-remote” of remote terminals. Then, considering the impact of a transmission error in the information system, the reliability index calibration model under the condition of unreliable information transmission is established. Finally, a case study is presented to illustrate how the proposed model is implemented.

Reliability Analysis of Power Distribution System

Electrical distribution system is a component of electrical power system that is very important because it is closest to the customer. In its operation, the distribution system often suffers that causes the flow of electricity to the customer is interrupted. This situation is not expected by customers or by electric power companies. The more frequent and longer the occurrence of electrical power flow interruption, the lower the system reliability, and vice versa. Reliability of a distribution system can be analyzed based on SAIDI and SAIFI parameters. In this research, reliability analysis of distribution system on Gejayan substation. The analysis result using SAIDI and SAIFI parameters shows that Gejayan substation is reliable enough to national standard, while based on international standard still not reliable.

Impact of Distributed Generation on the Reliability of Local Distribution System

With the growth of distributed generation (DG) and renewable energy resources the power sector is becoming more sophisticated, distributed generation technologies with its diverse impacts on power system is becoming attractive area for researchers. Reliability is one of the vital area in electric power system which defines continuous supply of power and customer satisfaction. Around the world many power generation and distribution companies conduct reliability tests to ensure continues supply of power to its customers. Uttermost reliability problems in power system are due to distribution network. In this research reliability analysis of distribution system is done. The interruption frequency and interruption duration increases as the distance of load points increase from feeder. Injection of single DG unit into distribution system increase reliability of distribution system, injecting multiple DG at different locations and near to load points in distribution network further increases reliability of distribution system, while introducing multiple DG at single location improves reliability of distribution system. The reliability of distribution system remains unchanged while varying the size of DG unit. Different reliability tests were done to find the optimum location to plant DG in distribution system. For these analyses distribution feeder bus 2 of RBTS is selected as case study. The distribution feeder is modeled in ETAP, ETAP is software tool used for electrical power system modeling, analysis, design, optimization, operation, control, and automation. These results can be helpful for power utilities and power producer companies to conduct reliability tests and to properly utilize the distributed generation sources for future expansion of power systems.

Optimization of Distribution System Reliability

Reliability analysis of distribution systems has been attracting increasing attention. A special concern pertains to the distribution networks on which most failures occurs. The optimization of distribution system of breakers and power switches is a possible strategy to improve reliability. The paper describes development procedure for modelling restoring after a fault and calculating associated reliability indices and customers’ outage costs. The developed model of the network and reliability and outage costs calculating algorithm is suitable for multi-criteria analysis of the network. Proposed reliability and outage costs calculation algorithm is based on Monte Carlo simulation and genetic algorithm.

Reliability Analysis of Distribution Systems with Photovoltaic Generation Using a Power Flow Simulator and a Parallel Monte Carlo Approach

This paper presents a Monte Carlo approach for reliability assessment of distribution systems with distributed generation using parallel computing. The calculations are carried out with a royalty-free power flow simulator, OpenDSS (Open Distribution System Simulator). The procedure has been implemented in an environment in which OpenDSS is driven from MATLAB. The test system is an overhead distribution system represented by means of a three-phase model that includes protective devices. The paper details the implemented procedure, which can be applied to systems with or without distributed generation, includes an illustrative case study and summarizes the results derived from the analysis of the test system during one year. The goal is to evaluate the test system performance considering different scenarios with different level of system automation and reconfiguration, and assess the impact that distributed photovoltaic generation can have on that performance. Several reliability indices, including those related to the impact of distributed generation, are obtained for every scenario.

A New Reliability Evaluating Method for Distribution Network

In order to improve the reliability evaluation to the distribution network, uncertainty factors about aging of components are considered under conventional reliability analysis of distribution system in the paper. The relationship between unavailability of aging of components and time (or limit age of components) is analyzed. Then the reliability indices are calculated by FMEA (Failure Mode and Effect Analysis). Finally distribution network reliability level is distinguished and the measures on improving the power distribution system reliability are presented.

The Reliability Evaluating Method Considering Component Aging for Distribution Network

In order to improve the reliability evaluation to the distribution network, uncertainty factors about aging of components are considered under conventional reliability analysis of distribution system in the paper. The relationship between unavailability of aging of components and time (or limit age of components) is analyzed. Then the reliability indices are calculated by FMEA (Failure Mode and Effect Analysis). Finally distribution network reliability level is distinguished and the measures on improving the power distribution system reliability are presented.

Evaluation of the Probability Density Functions of Distribution System Reliability Indices With a Characteristic Functions-Based Approach

In reliability analysis of distribution systems, random events like the occurrence of a fault or the time to restore the service after a fault are represented by using random variables (RVs), so that the reliability indices built on the basis of these RVs also become RVs. Existing techniques for the evaluation of the probability distributions of reliability indices are typically based on Monte Carlo and analytical simulations. This paper presents a new method for computing the probability distribution of reliability indices. The random sums introduced by the randomness of the number of fault occurrences in the time interval of analysis are handled by using a characteristic functions-based approach. The direct convolution of the probability density functions is avoided by resorting to the properties of the compound Poisson process. In addition, the direct and inverse discrete Fourier transforms are used to allow for handling any type of probability distribution. The proposed method is an effective alternative to the existing methods, providing a fast and simple computation of probability distributions and moments for local and global reliability indices. Results obtained for large real urban distribution systems are presented.

Quantitative reliability analysis of distribution systems: automation

Great importance is attached to improving the performance of the electricity distribution network by reducing the number of interruptions and the time during which customers are off supply. This article reviews some of the means which are used to bring about these improvements and considers in particular the potential benefits that may be achieved by automation. The results of an analysis using the network simulation computer program eaNSF are used to illustrate the level of improvement which may be achieved and also to illustrate the sensitivity to the variation in the fault rate of a circuit.

Quantitative reliability analysis of distribution systems: repair times

This article analyses the impact of repair times on the performance of the distribution network in an isolated rural community using the eaNSF program which was developed specifically to aid in the economic and strategic evaluation of capital investment and technical developments in distribution networks. The study investigates the impact on system availability caused by changing the repair times. The sensitivity of the results is evaluated for a range of networks with similar characteristics and varying reliability data.

Determination and Analysis of Data for Reliability Studies

Methods for transmission and distribution system reliability analysis currently being developed and used require that the expected values of component outage rates and outage durations be known. The paper describes how the required component parameters can be estimated from field data. Also described are methods of placing confidence limits on the parameters estimated. The methods presented were developed through a study of six years of field records provided by a utility company. Sample expected outage rates and outage durations for various components such as transmission lines, substation transformers, and circuit breakers are presented. Also presented are data which tend to confirm the distributional assumptions made in system reliability analysis methods.