Reliability Assessment Of Distribution Networks Research Articles

Multiple Data Sources in Reliability Assessment of Distribution Networks

Since distribution networks provide the regular and secure transmission of power to consumers, its dependability is essential to the smooth operation of modern society. Conventional techniques for evaluating these networks' dependability have depended on a single data source, such as historical outage statistics. The capacity to combine many data sources into dependability evaluation has been possible due to technological improvements and the abundance of available data. This allows for a more thorough and precise understanding of network performance. This technical abstract proposes a methodology for incorporating multiple data sources in the reliability assessment of distribution networks. It is to identify and collect various data sources such as weather data, customer complaints, equipment maintenance records, and outage data. These data sources are then integrated and analyzed using statistical and machine learning algorithms to identify patterns and correlations that can provide insights into the network's reliability.

Reliability Assessment of Distribution Network Considering Mobile Energy Storage Vehicles and Dynamic Zonal Coupling

Reliability Assessment of Distribution Network Considering Mobile Energy Storage Vehicles and Dynamic Zonal Coupling

RETRACTED: Economic, environmental, and reliability assessment of distribution network with liquid carbon-based energy storage using multi-objective group teaching optimization algorithm

In this paper, the optimum operation of a distribution network in the presence of renewable resources, and a new combined system of liquid carbon dioxide energy storage is investigated. A comprehensive structure is proposed for modeling and optimizing the combination of wind turbine and solar sources with the new energy storage system by considering their converters. Then, a multipurpose structure in the presence of these resources and the new storage resource is presented to overcome the uncertainty of the output power of renewable resources and improve the reliability of the grid. To this end, first, by considering the probabilistic nature of wind and solar resources, a relatively comprehensive modeling of the system is presented. Economic costs, including the cost of setting up units, cost of generation, and emission of these units, are presented as optimization problem. The effects of the storage system on the load curve are investigated and discussed. The proposed objective function is determined based on optimal load distribution and technical constraints. The multi-objective group teaching optimization algorithm is used to solve the microgrid optimal operation problem. The proposed model considering three cases, is successfully implemented on a 33-bus RBTS distribution network. The results indicated that the total cost of the proposed system in the first, second, and third case is decreased by about 2.88%, 21.78% and 21.2% compared to the base case study. The cost reduction in the first case is due to the use of renewable energy sources, and this reduction in the second case is more due to the use of new storage. Finally, in the third case, due to the consideration of uncertainty and reliability index, compared to the second case, the amount of cost has increased slightly, but compared to the main case, there is a significant decrease, which indicates the superiority of the proposed model.

Operational Reliability Assessment of Distribution Network With Energy Storage Systems

In this article, a novel approach that considers the time-varying load restoration capability is proposed for operational reliability assessment of distribution networks. To evaluate the operational reliability, two indices are firstly defined as the minimal load loss under the worst-case fault contingency in the upcoming time interval. To search for the optimal remedial actions for load restoration, a sequential network reconfiguration (NR) model is then proposed considering the reconfigurability of feeders and capability of emergent power support of energy storage systems (ESSs). Since this model is a complex nonlinear mixed integer programming model, an improved greedy searching-based algorithm is proposed to compute the optimal remedial actions and to further evaluate the risk of load loss. Comparative case studies are presented in this article to demonstrate that the load level, the expectation of the state-of-charge of ESS and the failure duration have the impacts on the system operational reliability. Besides, the proposed sequential NR model can be used to enhance the reliability of distribution networks by enabling an effective sequential load transfer strategy under emergent conditions. Unlike traditional reliability assessment, the proposed method provides the operators with the real-time awareness of the operational reliability level considering the real-time condition of distributed resource equipped feeders and worst-case emergency constraints.

Study on reliability assessment of distribution networks containing distributed power supplies

With a large number of distributed power sources connected to the distribution network, power supply reliability has always been one of the most concerned indicators for power supply companies. Fault mode and effect analysis (FMEA) can predict the impact of fault isolation and load switching diversity in active intelligent distribution networks. In this paper, a standardized model of reliability system evaluation is constructed by FEMA table, and the reliability index is solved by combining Monte Carlo analysis method. The simulation with IEEE-RBTS BUS6 as an example shows that the method can quantify the effect of distributed power supply on the reliability of active distribution network, which proves that the proposed method is effective and feasible to solve the index.

Reliability Assessment of Distribution Network Considering Multiple Types of Cyber Disturbances

The improvement of power grid intelligence depends on the development of communication technology. The wide application of communication technology in power grid has brought new security threats. In order to comprehensively and quantitatively evaluate the impact of external threats and cyber element failureson power supply reliability in the whole process of distribution network operation, reliability state models of different types of cyber disturbances are proposed, the impact of different types of cyber disturbance on the cyber availability is analyzed and a framework of distribution network reliability evaluation considering multiple types of cyber disturbance is constructed. Finally, the simulation test of IEEE33 bus distribution system verifies the feasibility and effectiveness of the proposed model and method.

Reliability assessment of distribution network considering differentiated end-users demand for reliability

In view of the importance of the distribution network in the power system and the current problem of the fragmentation of the reliability assessment of distribution network considering differentiated end-users demand for reliability index of the distribution network, this paper proposes a comprehensive assessment method for the reliability of the distribution network. Based on the distribution network data obtained from the perception layer of the Internet of Things, the main assessment indices for the reliability of the distribution network based on the power supply capacity and the number of users, and the reference assessment indices for the reliability of the distribution network based on the reliability price are calculated respectively. Then according to the index scoring standards, the reliability assessment result of the distribution network is obtained. A case study is used in this paper to verify the effectiveness of the proposed comprehensive assessment method.

Reliability Assessment of Distribution Network with Distributed Generation based on BP Neural Network

The distributed power supply is developing rapidly to realize the energy conservation and consumption reduction of the whole society. But the development of distributed generation (DG) will affect the reliable operation of distribution network. A novel reliability assessment model for distribution network with DG was integrated. A series of essential criteria can be extracted by Principal Component Analysis (PCA). And their weights can be obtained based on the entropy method. The assessment results can be calculated by applying BP neural network. Example analysis were implemented to prove the validity of the comprehensive reliability assessment model.

Linear Formulations for Topology-Variable-Based Distribution System Reliability Assessment Considering Switching Interruptions

Continuity of supply plays a significant role in modern distribution system planning and operational studies. Accordingly, various techniques have been developed for reliability assessment of distribution networks. However, owing to the complexities and restrictions of these methods, many researchers have resorted to several heuristic optimization algorithms for solving reliability-constrained optimization problems. Therefore, solution quality and convergence to global optimality cannot be guaranteed. Aiming to address this issue, two salient mathematical models are introduced in this paper for topology-variable-based reliability evaluation of both radial and radially-operated meshed distribution networks. Cast as a set of linear expressions, the first model is suitable for radial networks. The second model relies on mixed-integer linear programming and allows handling not only radial networks but also radially-operated meshed distribution grids. Therefore, the proposed formulations can be readily incorporated into various mathematical programming models for distribution system planning and operation. Numerical results from several case studies back the scalability of the developed models, which is promising for their further application in distribution system optimization studies. Moreover, the benefits of the proposed formulations in terms of solution quality are empirically evidenced.

Reliability evaluation of distribution network based on fuzzy spiking neural P system with self-synapse

This paper proposes a fuzzy spiking neural P system with self-synapse (in short, FSNPSS) which is applied to the reliability assessment of distribution networks. The method maps the operation or fault states of the distribution network component and the load to the excited or resting states of neurons, and converts electrical relationships among components, loads and targeted systems into a synaptic connection relationship. Then, the occurrence probabilities of the states are transmitted by spikes, and reliability indices are computed by accumulating pulse values of the spikes. Finally, the feasibility and effectiveness of solving reliability assessment of distribution networks by membrane systems are verified in case studies.

Power Supply Reliability Assessment of Distribution Network Considering by Operation, Maintenance and Repair

In order to realize automation and intelligence of power system, it is essential to improve the power supply reliability assessment of distribution network. A comprehensive evaluation system for the reliability was proposed in the paper. An overall index system was integrated to introduce the criteria of the operation, maintenance and repair, which are important for the reliability. Entropy weight method and fuzzy TOPSIS method were combined to propose the evaluation model. Empirical analysis was implemented to verify the practicality of the evaluation system.

Fast Reliability Assessment Algorithm of Distribution Network based on Topological Similarity Analysis

In this paper, the concept of topological similarity is introduced to realize a fast and accurate reliability assessment of distribution network. Based on the singular value sequence as the similarity index, the mathematical relationship between similarity of network topology and power supply reliability of distribution network is developed. Firstly, the matrix representation, similarity index and its determination method of distribution network topology are presented, while the compression and reconstruction of matrix are analyzed to ensure the topological characteristics of adjacent matrix. Then, a fast reliability assessment algorithm of distribution network based on topological similarity is proposed, which uses root mean square method to determine similarity according to topology database and updates reliability indexes, together with the calculation flow. Lastly, case study of IEEE 33-node distribution network is undertaken, which shows that the calculation efficiency of the proposed algorithm is seven times higher than that of other conventional algorithms under the same calculation accuracy.

Water Distribution Network Reliability Assessment and Isolation Valve System

Mechanical reliability analysis of water distribution networks (WDNs) refers to the assessment to provide correct service to customers under abnormal functioning conditions due to system component failures. Mechanical reliability depends on the isolation valve system (IVS) effectiveness in isolating a network segment and on the failure probability. The main aim of this work was the formal development of reliability indicators considering pressure-driven analysis (PDA) for customer demand and topological changes. Three factors influencing reliability were identified: (1) the hydraulic behavior of the still-connected network; (2) the topological performance of the IVS; and (3) the topological performance of the IVS with respect to unintended isolation. The reliability performance assessment of the network over time depends on the hydraulic capacity of the WDN under abnormal functioning conditions and on two IVS performance topological indicators of the risk of disconnection and unintended isolations. The hydraulic capacity was computed using PDA, whereas the topological risks were computed considering the unsupplied demand in the isolated segment and the normalized failure probability, i.e., the probability of a segment disconnection for an assumed failure occurrence in the network. The development of a modularity index for an IVS was achieved in a consistent framework and the integrated design of an IVS and district metering areas was introduced. The framework allows the analysis of the isolation valve failure. A real Apulian WDN was used to discuss and demonstrate the theoretical findings.

Reliability Assessment of Distribution Networks with Optimal Coordination of Distributed Generation, Energy Storage and Demand Management

Modern power distribution networks assume the connection of Distributed Generators (DGs) and energy storage systems as well as the application of advanced demand management techniques. After a network fault these technologies and techniques can contribute individually to the supply restoration of the interrupted areas and help improve the network reliability. However, the optimal coordination of control actions between these resources will lead to their most efficient use, maximizing the network reliability improvement. Until now, the effect of such networks with optimal coordination has not been considered in reliability studies. In this paper, DGs, energy storage and demand management techniques are jointly modelled and evaluated for reliability assessment. A novel methodology is proposed for the calculation of the reliability indices. It evaluates the optimal coordination of energy storage and demand management in order to reduce the energy-not-supplied during outages. The formulation proposed for the calculation of the reliability indices (including the modelling of optimal coordination) is described in detail. The methodology is applied to two distribution systems combining DGs, energy storage and demand management. Results demonstrate the capability of the proposed method to assess the reliability of such type of networks and emphasise the impact of the optimal coordination on reliability.

Analytical methodology for reliability assessment of distribution networks with energy storage in islanded and emergency-tie restoration modes

A wide scale deployment of energy storage systems in power networks for energy balancing applications will lead to network reliability improvements. After a fault occurs in a network, energy storage will be able to help restore supply in the network areas isolated from the primary substation or in those re-connected to adjacent feeders of limited transfer capacity by emergency-ties. The reliability improvements introduced by energy storage need to be evaluated and quantified for both restoration modes. The objective of this paper is to assess the energy storage contribution in these restoration modes and to seek analytical, less computationally intensive solutions for such evaluation. The proposed analytical technique uses a probabilistic model of energy storage to assess the charge and discharge processes over a fault duration and the related operational strategy. In this way, reliability indices are calculated by taking into account the energy storage actions during a fault as well as the time-evolution of renewable generation and demand. These features lead to more realistic modelling of energy storage in analytical techniques. The proposed analytical technique was firstly validated by using a case study where the results obtained by Monte Carlo Simulation were used as a reference. Then, the proposed technique was applied to a distribution network to assess the reliability improvement provided by energy storage and to demonstrate the effectiveness and accuracy of the proposed approach.

Reliability Assessment of Distribution Network and Electric Vehicle Considering Quasi-Dynamic Traffic Flow and Vehicle-to-Grid

With the increasing number of electric vehicles and the emergence of vehicle-to-grid technology, electric vehicles have become distributed loads and power sources with random movement characteristics in the distribution network. In order to evaluate the reliability of the distribution network incorporating electric vehicles, firstly, this paper uses the trip chain theory to describe the travel of electric vehicles. Based on the static traffic flow distribution, a high efficiency quasi-dynamic travel simulation method is proposed to consider the influence of traffic congestion on the path selection. Then, the simulation time advancement of the Monte Carlo method is improved, which makes the reliability assessment of the distribution network containing a large amount of electric vehicles' charging and discharging behaviors realizable. Finally, the practicality of the method is verified by the modified IEEE-RBTS Bus-6 test system. The effects of electric vehicles penetration, discharging threshold, and battery capacity on reliability of both distribution networks and electric vehicles are studied.

Reliability assessment of distribution networks through graph theory, topology similarity and statistical analysis

This study aims to investigate the topology characteristic indices which have a close relationship with reliability of distribution networks via mathematical tools. First, a practical network is extracted into a topology and presented by weighted adjacency matrix associated with a failure degree matrix, which contains more significant information than that of original adjacency matrix. Second, singular value sequence and vertex/edge sharing are proposed as two similarity indices. Finally, similarity functions are applied on two cases to establish the relationship with reliability by curve fitting and clustering. optimisation strategy based on modified contingency-load-loss index is elaborated to improve the reliability and guide to distribution network planning.

Analysis and Suggestions for Power Supply Reliability Assessment Index of Distribution Network

The application of micro-grid affects distribution network, while the existing power supply reliability assessment index of distribution network cannot reflect its specific contribution. Based on an analysis of the shortages with the existing power supply reliability assessment index, a new index considering the time and power for evaluating the power supply reliability is proposed. The example indicates that the index proposed can be simply calculated and quantitatively measures the contribution to power supply reliability assessment of distribution network.

The Short-Term Reliability Assessment of Distribution Network Based on Conditions Dependent Element Failure Rate

Specific to the demand for the actual operation, this paper calculates short-term failure rates of various types of elements by adopting improved conditions dependent model: temperature-dependent element aging failure model, weather-dependent occasional failure model, current-dependent overload protection model, and processes a short-term reliability assessment by forward failure diffusion algorithm. Example analysis is simulated by 11kV distribution network of IEEE RBTS Bus-2 system to prove the reliability assessment model, the reliability assessment process are effective and provide on-site operation and maintenance personnel with guidance for decision making in the short-term scheduling and online operation.

Distribution Network Reliability Calculation Base on Improved Minimal Path Method

Distribution network reliability calculation is an important function for distribution network planning and operating system software. It is also one of the earliest core function modules for distribution network calculating. This paper investigates into general-purpose distribution network reliability assessment technique. The paper improves the minimal path method for reliability assessment and solves the precision problem using general-purpose minimal path technique; the paper demonstrates an example to verify the validity of this method.