Optimal Distribution Network Reconfiguration Research Articles

Optimal Network Reconfiguration and Distributed Generation Placement in Distribution System Using a Hybrid Algorithm

In this paper a method for solving optimal distribution network reconfiguration and optimal placement distributed generation (DG) with the objective of reducing power losses and improving voltage profile with the least amount of time using a combination of various techniques is offered. In the proposed method, first, a meta-heuristic algorithm (MHA) is used to solve the problem of optimal DG placement. The search space for using this technique has been reduced to the optimal scale which is why this technique is accurate and quick. After solving optimal DG placement using the abovementioned technique, a binary particular swarm optimization algorithm (BPSO) is presented for solving the network reconfiguration. In fact, by reducing the search space, the speed of the technique for solving the problem is improved. The proposed technique has been implemented with different scenarios on IEEE 33- and 69-node test systems. The comparison of the results with those of other methods indicates the effectiveness of this technique.

Reconfiguration of Distribution Network with Distributed Energy Resources Integration Using PSO Algorithm

This paper presents optimal reconfiguration of radial distribution network with integration of distributed energy resources (DER) using improved particle swarm optimization (PSO) algorithm. The benefits of DER integration in distribution system are reducing power losses, improving voltage profiles and load factors, eliminating system upgrades, and reducing environmental impacts. However, the presence of DER could also cause technical problems in voltage quality and system protection. Reconfiguration of distribution network is aimed to minimize power loss and to improve voltage quality in order to enhance the distribution system performance. In this study, reconfiguration method is based on an improved PSO. The method has been tested in a 60-bus Bantul distribution network of Yogyakarta Special Region province, Indonesia. The simulation results show the importance of reconfiguring the network for enhancing the distribution system performance in the presence of DER.

Optimal operation of energy storage devices with RESs to improve efficiency of distribution grids; technical and economical assessment

Abstract Electricity distribution grids are a crucial part of power systems as they are providing customers with the power demanded. This importance, absorbs a huge funding to be invested in this section. To reduce distribution grid losses, a wide variety of approaches are being deployed including optimal distribution substation placement and network reconfiguration. Introduction of higher storage capacities has made it possible to use them in power grids while it is highly appreciated to generate energy in a distributed manner and store it near customers due to environmental considerations. In this research, the idea of adding energy storage devices to the grid is investigated and its effect is studied on the efficiency of distribution grids. The objective function introduced in this paper calculates electricity grid losses while considering limitations of using energy storage devices. Dynamic programming is used to solve the problem on CIGRE low voltage grid as a standard benchmark. Several experiments show efficiency of the proposed method. In achieving results, simultaneous use of photovoltaic and energy storage devices is considered. Finally, the most economical solution is proposed after an economic evaluation of the solutions.

Novel methodology for optimal reconfiguration of distribution networks with distributed energy resources

This paper develops three novel methodologies for optimal reconfiguration of distribution networks in the presence of distributed energy resources (DERs). The novelty is in achieving a non-conservative and robust solution to grid reconfiguration. The optimal solution is the minimum-loss-configuration of the distribution network taking into account the cost of switching and the grid operational constraints. The methods are based on the concepts of receding horizon control (RHC) and scenario analysis (SA) which inherently optimize switching costs and losses. The salient feature of incorporating RHC and SA is that it avoids the need to pre-define the period of change of configuration. The methods vary in their degree of robustness and conservatism. A robust configuration will not violate the constraints under any of the predicted DER variations called scenarios. A non-conservative configuration exploits better benefits with respect to the objective of reconfiguration under all scenarios. Depending on the desired level of robustness and non-conservatism, one of the three methods developed in this paper can be used to find the optimal configuration. The methods can be used for planning as well as for operation of the distribution network since they indicate the most frequently open switches in the network and the time at which they are to be operated.

A novel codification and modified heuristic approaches for optimal reconfiguration of distribution networks considering losses cost and cost benefit from voltage profile improvement

Network reconfiguration is the process of changing the topology of distribution systems by altering the open/closed status of switches. Because there are many candidate-switching combinations in the distribution system, network reconfiguration is a complicated combinatorial, non-differentiable constrained optimization problem. In addition, the radiality constraint typically increases the intricacy of the problem. In this paper, to avoid create infeasible configuration, a new codification is proposed. The proposed codification is computationally efficient and guarantees to generate only feasible radial topologies all times. Also, in this paper, a modified heuristic approach for optimal reconfiguration in radial distribution systems is presented. Additionally, in order to economize voltage profile improvement, a number of new formulas have been represented. The effectiveness of the proposed method is demonstrated on balanced and unbalanced test distribution systems.

Distribution System Reconfiguration for Loss Minimization Using Modified Artificial Neural Network Approach of 16 Bus and 33 Bus Standard Test Systems with an Compensator

– This paper presents a new method for identifying the best switching option for the reconfiguration of Radial Distribution Systems (RDS). Feeder reconfiguration is the technique to alter the topological structure of the distribution feeder by changing the open/close status of sectionalizing and tie switches. The reconfiguration involves in selection of the set of sectionalizing switches to be opened and tie switch to be closed such that the resulting RDS has the desirable performance. Amongst the several criteria considered for optimal network configuration, loss minimization criterion is very widely used. In this project a novel method is presented which utilizes feeder reconfiguration as a planning and real time control tool in order to restructure the primary feeders for the loss minimization. The mathematical formulation of the proposed method is given; the solution procedure is illustrated with an example. Owing to the discrete nature of the solution space, a neural network approach for optimal reconfiguration of distribution network is proposed.

Application of binary group search optimization to distribution network reconfiguration

This paper presents the binary group search optimization algorithm (BGSO) for solving the optimal distribution network reconfiguration problem. The objective of the optimization is loss reduction in distribution system. The proposed GSO algorithm is introduced with fundamental modifications, such as introducing binary form of the GSO in order to be fit for reconfiguration and all binary form problems. All formulation of conventional GSO has been modified for accessing a novel powerful binary searching algorithm. Additionally, the forward–backward sweep, load flow is used in this paper, due to its accuracy. The Comparative studies are conducted on standard networks to verify the validity of the proposed algorithm. The simulations on different test cases confirm validity of the BGSO in solving optimal distribution network reconfiguration problem.

Reliability improvement in distribution systems employing an integrated voltage sag mitigation method using binary gravitational search algorithm

A method for improving the level of reliability of distribution systems is presented by employing an integrated voltage sag mitigation method that comprises a two-staged strategy, namely, distribution network reconfiguration (DNR) followed by DSTATCOM placement. Initially, an optimal DNR is applied to reduce the propagated voltage sags during the test period. The second stage involves optimal placement of the DSTATCOM to assist the already reconfigured network. The gravitational search algorithm is used in the process of optimal DNR and in placing DSTATCOM. Reliability assessment is performed using the well-known indices. The simulation results show that the proposed method is efficient and feasible for improving the level of system reliability.

Uniform voltage distribution based constructive algorithm for optimal reconfiguration of electric distribution networks

This paper introduces a new heuristic method called uniform voltage distribution based constructive algorithm (UVDA) especially intended for optimal reconfiguration of large-scale distribution networks. The algorithm starts with expanding a subnetwork through tracing maximum bus voltage and performing a series of branch exchange operation concurrently. By the aid of tracing nature of UVDA, no radial constraints are imposed. To exemplify the presented method, UVDA has been rigorously explained in details using a widely studied 33 bus test system. The validity of the proposed algorithm was confirmed through successful performance on numerous practical distribution networks, ranged from 16-bus system with 3 tie-switches up to 835-bus system with 146 tie-switches. Furthermore, comparisons are made with the other recent approaches available in the literatures. The test results demonstrate that the proposed algorithm successfully finds a globally optimal configuration for all the test systems in a conspicuously short time.

A rule based comprehensive approach for reconfiguration of electrical distribution network

This paper proposes a rule based comprehensive approach to study distribution network reconfiguration (DNRC). The DNRC model with line power constraints is set up, in which the objective is to minimize the system power loss. In order to get the precise branch current and system power loss, a power summation based radiation distribution network load flow (PSRDNLF) method is applied in the study. The rules that are used to select the optimal reconfiguration of distribution network are formed based on the system operation experiences. The proposed rule based comprehensive approach is implemented in distribution network in Guiyang South Power Supply Bureau. For the purpose of illustrating the proposed approach, two distribution network systems are tested and analyzed in the paper.

Minimization of Voltage Sag Costs by Optimal Reconfiguration of Distribution Network Using Genetic Algorithms

The paper describes genetic-algorithm (GA)-based optimization software for reconfiguration of a distribution network in order to minimize financial losses due to voltage sags. The developed methodology starts with a selected number of switches which generate various topologies. Load flows are then performed to evaluate the feasibility of topologies. For each feasible topology, fault analysis is performed to first calculate voltage sags at different buses in the network and then to calculate financial losses incurred by voltage sags at buses with sensitive industrial processes. The result of the optimization is the topology which yields the lowest voltage sag cost to customers. The main features of the GA include double-point crossover and adaptive mutation. The developed software tool is applied to the 295-bus generic distribution system.

Optimal service restoration and reconfiguration of network using Genetic-Tabu algorithm

This paper represents an approach for service restoration and optimal reconfiguration of distribution network using Genetic algorithm (GA) and Tabu search (TS) method. Restoration and reconfiguration problems in distribution network are difficult to solve within feasible times, because the distribution network is so complicated with the combination of many tie-line switches and sectionalizing switches and also has to satisfy radial operation conditions and reliability indices. Therefore, this paper applied Genetic-Tabu algorithm (GTA) to find optimum value with reasonable computation time. The Genetic-Tabu algorithm is a Tabu search combined with Genetic algorithm to find a global solution. The case studies with 7-feeder model showed that not only the loss reduction but also the reliability should be considered at the same time to achieve the optimal service restoration and reconfiguration in the distribution network.

Optimal service restoration and reconfiguration of network using Genetic-Tabu algorithm

This paper represents an approach for service restoration and optimal reconfiguration of distribution network using Genetic algorithm (GA) and Tabu search (TS) method. Restoration and reconfiguration problems in distribution network are difficult to solve within feasible times, because the distribution network is so complicated with the combination of many tie-line switches and sectionalizing switches and also has to satisfy radial operation conditions and reliability indices. Therefore, this paper applied Genetic-Tabu algorithm (GTA) to find optimum value with reasonable computation time. The Genetic-Tabu algorithm is a Tabu search combined with Genetic algorithm to find a global solution. The case studies with 7-feeder model showed that not only the loss reduction but also the reliability should be considered at the same time to achieve the optimal service restoration and reconfiguration in the distribution network.

Minimum Losses Reconfiguration of MV Distribution Networks through Local Control of Tie Switches

This paper deals with the problem of optimal reconfiguration of radial distribution networks for minimum loss operation. The proposed control strategy of the open-closed status of the tie switches is distributed, since every MV/LV node is provided with local controllers having some measured entities as input. It also does not prevent the system from the future implementation of centralized control; instead, it may represent the first step towards a complete automation of the distribution system. The proposed strategy is organized in hierarchic levels, the highest of which may be in the future a central control. After introducing the general problem of network reconfiguration, a review of the state of art on the subject is reported, even though the solution methodologies are usually related to the centralized formulation of the reconfiguration problem. The proposed local control strategy is outlined, and a detailed description of its different parts is reported with special attention to all the measures for a better performance of the system. Results of a number of simulation runs are reported in order to test the behavior of the proposed local control system in different possible operating conditions.

Optimal reconfiguration of electrical distribution network using the refined genetic algorithm

This paper proposes an improved method to study distribution network reconfiguration (DNRC) based on a refined genetic algorithm (GA). The DNRC model, in which the objective is to minimize the system power loss, is set up. In order to get the precise branch current and system power loss, a radiation distribution network load flow (RDNLF) method is presented in the study. The refined genetic algorithm is also set up, in which some improvements are made on chromosome coding, fitness function and mutation pattern. As a result, premature convergence is avoided. The proposed approach is tested on 16-bus and 33-bus distribution networks. Study results are given in the paper.

Genetic, simulated annealing and tabu search algorithms: Three heuristic methods for optimal reconfiguration and compensation of distribution networks

AbstractIn this paper three heuristic methods for radial distribution networks reconfiguration and capacitor control are presented. A Simulated Annealing algorithm (SA), a Genetic Algorithm (GA) and a Tabu Search algorithm (TS) with some adaptations have been applied and compared. Basic GA, SA and TS procedures, with particular reference to the combinatorial optimization problems, are presented and adaptations are described in detail. Three demonstration software have been developed to implement the three algorithms and the performances of the three methods are then compared in terms of computation time and statistical quality of obtained solutions. Test results demonstrate that the TS algorithm type outperform the other heuristics.

Application assessments of distribution network minimum loss reconfiguration

Application aspects of optimal distribution network reconfiguration are highlighted in this paper. The problem is raised from the theoretical solution level to the practical implementation assessment level. For this purpose, a complex methodology for operational and short-term planning analyses of distribution systems is created. It mainly regards nonautomated or low level automated distribution systems. Optimization of a distribution network configuration for a given loading condition is done by a heuristic method. However, the methodology appropriateness to practical applications is attained by introducing a method for load estimation in distribution systems with minimum information. Furthermore, the optimization results are evaluated throughout an appropriate cost/benefit analysis. In this way, the composed tool becomes flexible, allowing appraisal of the network reconfiguration potential benefits, as well as the economically approved frequency of switching. The results of the study on Skopje's distribution network are presented.