Performance Of Power Distribution System Research Articles

Risk Assessment of Radial Distribution Systems using Modified Jelly Fish Search Algorithm to analyse the Performance Indices

One of the essential techniques for figuring out Power Distribution System performance is reliability evaluation. With time, the range of methods for assessing reliability has grown, and the distribution system's evolution has also become more intricate. The likelihood of a network failing grows with time once it begins to function, especially if it is used for an extended period. Reliability indices have been evaluated using different algorithms such as Particle Swarm Optimization (PSO), Genetic Algorithm (GA) and various modified versions of algorithms. The Jelly Fish Search Algorithm has been used in various power system applications such as to determine the most cost-effective way to dispatch generating units' loads, integrate Distributed Generation (DG) units, track the maximum power of photovoltaic systems, and determine optimal power flow solutions, among other uses. The performance indices for the Radial Distribution System (RDS) have not been evaluated using JFSA.Variation of performance indices with respect to unavailability has not been discussed in the literature. Here an attempt is made to analyse the variation of the indices with the unavailability. The proposed algorithm is evaluated first on 3 load point radial distribution system and the computations are performed on the popular IEEE-RBTS Bus2 test system. Based on the output it is observed that for the both the systems the behaviour of the indices with respect to the unavailability is in similar fashion. The equations are derived for the performance indices using the Minitab. With the equations obtained the Performance indices values can be predicted for the given unavailability value. It is the better appropriate method for the assessing the performance indices of Radia Distribution System.

Optimal Capacitor Placement and Rating for Large-Scale Utility Power Distribution Systems Employing Load-Tap-Changing Transformer Control

Significant opportunity for savings in energy and investment through improved performance of power distribution systems exists in the optimal placement and rating of capacitors, a conventionally cost-effective and popular reactive power compensating technology. A novel optimal capacitor planning (OCP) procedure is proposed for large-scale utility power distribution systems, which is exemplified on an existing utility circuit of approximately 4,000 buses. An initial sensitivity analysis is employed to intelligently reduce OCP computation time and maintain quality of optimal configurations. Three optimization objectives are considered, including the minimization of total system active power losses, standard deviation of node voltages, and investment in total capacitor power rating. Eight multi-objective optimization methods that employ the non-dominated sorting algorithm III (NSGA-III) concept are compared to determine individual merits. Differences between the methods include the incorporation of a penalty constraint for voltage violations and the automatic readjustment of load-tap-changing (LTC) transformer tap settings for proposed capacitor re-configurations concurrently within the optimizer, which ensures peak system performance and fair comparison to the reference case. A multi-step model conversion process was developed with OpenDSS to enable the OCP procedure to be generally applicable to real large-scale utility circuits. OCP is performed for three example sub-circuits served by a substation with a 48MW, 9Mvar peak load, which represents the most extreme case and offers the best opportunity for savings. Example configurations from the resulting Pareto sets through a pseudo-weight vector approach are also analyzed through a systematic procedure of comparison between the most extreme configuration types to inform configuration selection.

Probabilistic reliability evaluation of distribution systems considering the spatial and temporal distribution of electric vehicles

Fast-growing electric vehicles load can impose various reliability concerns and peak demand increase in electric power systems, particularly distribution networks. From a power system point of view, electric vehicles can be considered as random moving loads. A new probabilistic approach is, therefore, proposed in this paper to evaluate the impact of electric vehicles on the reliability performance of power distribution systems. A two-layer stochastic electric vehicle charging demand estimation model is proposed. The model comprises of a traffic layer representing the spatial-temporal distributions of electric vehicles and an electrical network layer describing the electric vehicles charging demand. A Dynamic Hidden Markov Model is used to capture the electric vehicle movements in the traffic layer. Electric vehicle travel patterns and charging demand are simulated using a sequential Monte Carlo simulation approach considering the vehicle distance traveled, the type of charging location and the driver class. The proposed approach and the models are used to perform reliability studies on an example test system, and a series of analysis results are presented.

A new model for reliability-centered maintenance prioritisation of distribution feeders

Maintenance of distribution systems has become more important due to the need to increase energy availability, quality and safety, and also reduce operation cost. Accordingly, the maintenance strategy in distribution systems is one of the most important decision-making activities. One of the most important evaluations for deciding the adequate performance of power distribution system is the identification of the critical components. On the other hand, the budget for maintenance of components is limited, so the maintenance should only be performed on critical components. Identifying the critical components is used to achieve the objective of minimising the cost for maintenance actions. This paper presents a new weighted importance (WI) reliability index model and proposes an appropriate method in order to prioritise the elements of distribution system for reliability-centered maintenance (RCM) at two different levels. At the first level, the feeders of a sample distribution substation are prioritised for the RCM actions. The second level is more detailed than the first level. At the second level, the components of a sample feeder are prioritised for the RCM actions. The reliability of system can be increased to as much as required level while minimal maintenance to be done by the maintenance prioritisation of the system components and performing the maintenance actions on the critical components. Appropriate maintenance decision-making for the critical components of distribution system can lead to the improvement in the reliability of distribution system.

Two stage residential energy management under distribution locational marginal pricing

This paper proposes a new optimization model for Smart Home Management Systems (SHMS) in order to increase the profits of Load Serve Entities (LSEs) and customers from technical and financial points of view. In the recent decades, performing Demand Response (DR) is one of the most efficient ways to improve the performance of power distribution systems in terms of power loss, and investment costs. The LSEs can implements some strategies like offering incentives to customers to change their consumption pattern with the aim of reducing power loss, improving asset management and increasing the profits. On the other hand, the end users can participate in DR programs to decrease electricity bills and earn monetary incentives from LSEs proportionate to their contributions to the energy loss reduction. In this paper, Distribution Locational Marginal Price (DLMP) instead of time-based pricing mechanism is applied to bill the customers. In the proposed strategy, the energy bill of customers and power loss of the system are simultaneously decreased. For dealing with uncertainties, stochastic variables computation module is designed which generates several scenarios by Monte Carlo simulation at each hour. The operation of household resources and appliances are optimized through a Mixed Integer Linear Programming (MILP), which has a two-stage stochastic model. The results explicitly show benefits of the proposed stochastic model since it provides accuracy in scheduling and decreases the operation cost. Besides, the superiority of DLMP and the proposed method over existing pricing mechanism is demonstrated.

Multi-microgrid energy systems operation incorporating distribution-interline power flow controller

Innovative power electronic devices such as distribution-interline power flow controller (D-IPFC) can be utilized to improve the operating performance of power distribution systems. In this paper, a power injection model is presented to formulate the D-IPFC operation in distribution grids. The proposed power injection model keeps original symmetry of the impedance matrix as well as system equations which facilitates power flow calculations. Then, a centralized multi-objective optimization algorithm is formulated to optimally coordinate multi-microgrids (MMGs) through D-IPFC. The final optimal operating point of MMG is a trade-off between minimization of operating cost, voltage profile deviation, and feeder congestion. To guarantee voltage stability of the system, a voltage security constraint is considered in the optimization problem. The proposed algorithm improves flexibility of the active distribution grids which is essential for resilient smart power grids. A typical MMG and a spider diagram are applied to show the effectiveness of the proposed algorithm.

The Software Design for an Automation Intelligent Distribution Terminal Unit in Electric Power Systems Based on C and Assembly Language

Electric power distribution systems play an important role in electric power systems, in which automation intelligent distribution terminal units are critical for the performance of power distribution systems. The software of an automation intelligent electric power distribution terminal unit based on digital signal processor is designed in the paper, a way of admixture programming with C language and assembly language. In this manner, real-time requirement on the electric power distribution system will be satisfied, the reliability and stability of the software are ensured as while. It has a broad application prospects in electric power systems.

Impact of supply restoration procedures on the reliability performance of power distribution systems

The purpose of this paper is to describe an efficient computational methodology that models supply restoration procedures, which are available in power distribution systems, and calculates their impact on the reliability performance of system load-points. This methodology recognizes various practical operating features of the distribution systems under consideration and deduces the switching operations that are available to be executed, following the occurrence of a failure event. A set of five probabilistic indices is also obtained for each affected load-point taking into account the component reliability parameters and the system operational and maintenance practices being applied. The unavailability indices of the system standby components are calculated separately and their effect on the system reliability performance is established. Finally, the analysis of a typical 150 kV/20 kV system based on a real Greek urban distribution system is included.

DOE tests new equipment to study lightning

The Department of Energy (DOE) Lightning Protection Program to improve methods for predicting the performance of power distribution systems in lightning storms began recently with the installation of instruments on electric power lines in Tampa, St. Petersburg, and Sarasota, Florida.The instruments are designed to measure and record information on the surge of electric current in power distribution lines and other equipment struck by lightning. If the initial tests are successful, plans call for at least 400 similar devices to be installed on utility systems across the country over the next few years.