Distribution Reconfiguration Research Articles

Braking Torque Distribution Reconfiguration Strategy of Vehicle With Faults of In-Wheel Motor Drive System

Braking Torque Distribution Reconfiguration Strategy of Vehicle With Faults of In-Wheel Motor Drive System

Active and Reactive Power loss Minimization Along with Voltage profile Improvement for Distribution Reconfiguration

Optimal distribution network reconfiguration (DNR), distributed generations location and sizing (DGs-LS), tap changer adjustment (TCA), and capacitors bank location and sizing (CAs-SL) are different methodologies used to reduce loss and enhance the voltage profile of distribution systems. DNR is the process of changing the network topography by changing both sectionalized and tie switch states. The optimal location looks to find the optimal setting of the DG and CA within the distribution network. Optimal size seeks to find the optimal output generation of both DG and CA. The TCA looks to find the optimal position for TC. These methods are challenging optimization problems and resort to meta-heuristic techniques to find a globally optimal solution. This paper presents a new methodology with which to simultaneously solve the problem of DNR, DGs-LS, TCA, and CAs-SL in distribution networks. This work aims to minimize active and reactive power losses, including voltage profile improvement using a multi-objective decision approach. The firefly algorithm (FA) and analytic hierarchy process (AHP) are used to optimize the fitness function and determine the function weight factors through the use of MATLAB software. Several scenarios were considered on the IEEE 69-bus network. In terms of active power and reactive losses, reductions in the test system of 96.16% and 92.7%, respectively, were achieved, evidencing the positive impact of the proposed methodology on distribution networks.

On the explicit formulation of reliability assessment of distribution systems with unknown network topology: Incorporation of DG, switching interruptions, and customer-interruption quantification

This paper presents an original approach for the evaluation of reliability of active distribution networks with unknown topology. Built upon novel reformulations of conventional definitions for distribution reliability indices, the dependence of system-oriented reliability metrics on network topology is explicitly formulated using a set of mixed-integer linear expressions. Unlike previously reported works also modeling mathematically the relationship between reliability assessment and network topology, the proposed approach allows considering the impact of distributed generation (DG) while accounting for switching interruptions. Moreover, for the first time in the emerging closely related literature, the nonlinearity and nonconvexity of the customer average interruption duration index are precisely characterized. The proposed mixed-integer linear model is suitable for various distribution optimization problems in which the operational topology of the network is not specified a priori. Aiming to exemplify its potential applicability, the proposed formulation is incorporated into a distribution reconfiguration optimization problem. The effectiveness and practicality of the proposed approach are numerically illustrated using various test networks.

Effect of Endogenous Failure Events on the Survivability of Turboelectric Distributed Propulsion System

Recent advancements in aircraft electrification have led to the introduction of turboelectric distributed propulsion (TeDP). For instance, NASA's N3X airplane aims to curb jet fuel emissions with the aid of TeDP. However, it is crucial to analyze the survivability of the TeDP system during extreme conditions. The endogenous failure events are of specific interest as they were found to cause a significant number of accidents for commercial aircraft. While the distribution reconfiguration is necessary to meet the critical load demands under extreme failure events, it can also create a transient overload condition in the turboshaft engine. The power system survivability is further deteriorated in the presence of constant power loads. In this article, a mathematical analysis of the survivability of the system is presented to make the aircraft power system highly resilient to endogenous failure events. A power system collapse mitigation strategy is proposed by adding an energy storage system. Moreover, the analytical expressions are formulated to size the energy storage unit to prevent the system collapse. Various failure conditions are modeled using PSCAD/EMTDC to study the minimum energy storage required to prevent system collapse.

Distribution Network Reconfiguration for Loss Reduction and Voltage Stability With Random Fuzzy Uncertainties of Renewable Energy Generation and Load

This paper presents a distribution reconfiguration framework to adapt to the distribution network considering the twofold random and fuzzy uncertainties of the wind, photovoltaic power generation, and load demand and considering the power loss reduction and voltage stability. First, the random fuzzy power output models of distributed generation and load are built based on the random fuzzy theory. Second, the corresponding objective functions are established, which are the random fuzzy expected value of active power loss and maximum probability of voltage limit. Third, the modified particle swarm optimization (MPSO) algorithm based on Kruskal algorithm is introduced for the first time to determine the optimal network topology. The Kruskal algorithm is employed to generate a radial network topology directly without checking the loops and islands. Lastly, the proposed method is applied to the IEEE33, PG&E 69-bus distribution systems, 25-bus unbalanced distribution system, as well as a real 109-bus distribution system. The results show that the proposed method has a good performance to solve distribution network reconfiguration problem.

Distribution System Reconfiguration Considering DGs’ Small Signal Stability

The emerging of the distributed generations in the distribution network changes the structure of the network, which used to operate without generations. However, the locations of these DGs are fixed when performing the distribution reconfiguration, which may contribute to the stability problem. The small signal stability of theses DGs in the distribution reconfiguration hasn’t been well considered in the literature. This paper establishes the small signal model of the distribution system considering the dynamic model of these DGs, and proposes a model which aims to decrease the power loss of the system on the basis of guaranteeing the small signal stability. The IEEE 33 system is used to verify the rationality of this model.

Plasma spatial distribution manipulation and electrical property enhancement through plasma coupling effect

Plasma pattern transition in a symmetric hybrid structure cavity device at micrometer scale is researched through microplasma interaction in intervening microchannel between adjacent cavities while manipulating electric field strength. Plasma distribution reconfiguration in central (objective) cavity is observed when sidearm (donor) cavities are ignited. As long as coupling effect occurred by modulating the electric field strength in the sidearm cavities, stable plasma pattern transition in objective cavity is obtained, exhibiting plasma pattern split from one circular spot (initial pattern) to two small circular spots (transited pattern), along with plasma peak emission intensity displacement over 100 μm to its equilibrium position. The shape of transited plasma patterns are depending on the coupling effect from sidearm cavities. The two circular spots unsymmetrically distributed if either donor cavity is ignited, and the ratio of average emission intensity between the two plasma spots is over 30%, however, which is less than 4% if coupling symmetrically occurred. The electrical and optical properties of central microplasma are also modulated, that the breakthrough voltage is decreased by 22% and emission intensity is improved by ∼30%, by means of plasma coupling. The microplasma pattern formation at micrometre scale and manipulation of the electrical properties in microscale cavity implies significant value in the application of plasma transistor and signal processing.

Optimal distribution reconfiguration considering high penetration of electric vehicles

The appearance of Plug-in Electric Vehicles (PEVs) in the electric grids is providing new opportunities when some new challenges are also created. Technically, PEVs are movable loads that can benefit to both owners and utilities in case of using Vehicle-to-Grid (V2G) technology. Therefore, this art icle aims to investigate the Distribution Feeder Reconfiguration (DFR) effect to optimally manage PEV performance in a probabilistic framework. The proposed stochastic framework will capture the uncertainties of location of PEVs as well as driving pattern and battery State-of-Charge (SOC). In addition, a new self-adaptive evolutionary swarm algorithm based on Social Spider Optimization (SSO) algorithm is proposed that will search the problem space globally. The simulation results on the IEEE standard test system shows the high performance of the proposed method.

Distribution Network Efficiency Improvement Based on Fuzzy Multi-objective Method

This paper presents a reconfiguration methodology based on a fuzzy multi-objective approach for achieving the minimum active power loss and the maximum voltage magnitude of radial distribution networks with distributed generations in order to improve the distribution system efficiency. Multi-objective function are considered for load balancing among the feeders, minimization of the real power loss, and deviation of bus voltage, while subject to a radial network structure in which all loads must be energized. These objective functions are modeled with fuzzy sets to evaluate the imprecise nature of each objective. Originality of the research is that the fuzzy-based multi-objective optimization in reconfiguration of distribution network including the distributed generation. The implementation of the fuzzy multi-objective for distribution reconfiguration on a 77 bus distribution network with distributed generation is described. The simulation results show that a 1.80% of electric power distribution network efficiency improvement is achieved by the method

The Distribution Network Reconfiguration Based on Spatial Data Mining

Distribution network reconfiguration is one of the essential functions of the DMS system; it can be attributed to a number of constraints of large-scale nonlinear combinatorial optimization problem in mathematics. The characteristic of load change of time and space will affect the results of load forecasting. Distribution network reconfiguration relies on the load forecasting results. This paper proposes the more realistic distribution reconfiguration scheme based on the GIS system with space information through spatial data mining. For the real-time and efficiency of effective assurance data, the interface design in GIS system and distribution automation system are also proposed. The geographical information and real-time information are connected seamlessly, so that this two system information is highly unified. The solution can provide the data basis for distribution reconfiguration scheme accurately, and improve power supply reliability of distribution network. It shows that through the example: GIS based on the spatial data mining can provide load in quantity, time, space prediction for the deeper research of distribution network reconfiguration.

A practical codification and its analysis for the generalized reconfiguration problem

Distribution network reconfiguration problem is simply aimed at finding the best set of radial configurations among a huge number of possibilities. Each solution of this set ensures optimal operation of the system without violating any prescribed constraint. To solve such problem, it is important to count on efficient procedure to enforce radiality. In this paper, we propose a reliable approach to deal properly with topology constraint enabling algorithm convergence toward optimal or quasi-optimal solutions. A simple and practical codification of individuals used in evolutionary algorithms to solve the generalized reconfiguration problem is detailed in this paper. Mathematical formulation, algorithm, and simulation results are presented for the distribution reconfiguration problem, incorporating a new representation scheme which is immune to topologically unfeasible possibilities. The individual interpretation procedure is straight and it demands no additional data structure or graph preprocessing. Comparisons are made for five well-known distribution systems to demonstrate the efficacy of the proposed methodology. It is also demonstrated that optimal configurations are properly surveyed when single or multiple sources are dealt.

Load type impact on distribution system reconfiguration

An analysis establishing the significant impact of load type, and problem reformulation have been carried out for distribution reconfiguration problem. The process of changing one radial configuration to other using tie lines, as and when required, to meet a particular objective is called reconfiguration. Simulation study on a practical test system has been carried out to show the quantitative significance of load models in reconfiguration studies. A weighted sum of objective functions representing operational cost of the distribution system is investigated in such a scenario. The paper highlights the importance of considering voltage dependence of loads in reconfiguration problem. It is shown that if the loads are not modelled as voltage dependent and instead modelled as constant power, a system configuration may result yielding higher system intakes and higher financial losses.

A Selecting Method of Optimal Load on Time Varying Distribution System for Network Reconfiguration considering DG

This Paper presents about selecting the most suitable load used for distribution optimization considering time-varying load demand and generation of DG. The objective of this paper is to find optimal load which obtain best network reconfiguration result according to time-varying load demand and DG generation. Many researches about distribution reconfiguration for optimization have been studied for ages and they have used constant loads only for reconfiguration. To get the best result, however, at least for 24 hours time-varying load demand and generation of DG should be considered. Four daily load curves and one PV generation curve have been decomposed into sequential levels. But, the optimal distribution reconfiguration considering time-varying load demand and PV generation should not to be the only scheme. Because, the reconfiguration result may demand hourly switching operation of electric devices and it might cause deterioration of switches lifespan. Therefore, the method of how to select the most optimal load considering not only time-varying loads demand and DGs generation but also the number of switching for maximizing income is researched. The method of selecting optimal load is proved by adapting to a simple model system and the more efficient result is also confirmed in this paper.

A novel closed‐loop reconfiguration for radial distribution systems with dispersed generation

Currently, Tai‐power Company is attempting to change its power distribution systems from radial distribution configurations to closed‐loop configurations in order to enhance the quality of the supply of electricity. Besides, the dispersed generation (DG) should be considered in making the reconfiguration suitable for present circumstances. To form a closed‐loop configuration, a new tie‐line is added in this paper to interconnect two different feeders of the original radial power distribution systems. The multi‐objective is, not only to reduce power transmission loss, but also reduce the cost representative of power distribution reconfiguration. Assuming that the cost representative is a linear function of the system's short‐circuit capacity, line current and bus voltage. The problem solution procedure in this paper is mainly divided into two steps. The first step is to form objective function by determining the weighting factor of each objective term based on the cost‐benefit analysis scheme. Then, the optimum solution is pursued for the objective function by means of refined genetic algorithm (RGA). An example is studied by using the proposed methodology. The results show that the cost‐benefit analysis scheme is verified capable of finding the weighting factors, that the RGA can render stable solutions and that the transmission loss reduction ratio is satisfactory.

Formulation of distribution reconfiguration problem using network topology: a generalized approach

Radial distribution reconfiguration problem formulation is rather difficult from the computer simulation point of view. Complexity of distribution network increases with increase in numbers of laterals and sublaterals. This needs a generalized approach, by which any radial distribution system can be solved. This paper describes the formulation of the reconfiguration problem using network topology approach. Algorithm developed can be used in general to radial system with any number of bifurcations. A modified iterative load flow method is also discussed to assist the reconfiguration problem. Simple and efficient technique is described to detect the loops formed during reconfiguration process. Formulation of single loop optimization problem is implemented to obtain network reconfiguration under normal operation.

DAME: an environment for preserving the efficiency of data-parallel computations on distributed systems

DAME (Data Migration Environment) uses transparent supports to overcome inefficiencies in data parallel programming. These supports hide irregular network topology, dynamically adapt the data distribution to platform conditions, and mask the consequent nonuniform distribution to the programmer. The authors compare DAME's performance with that of some popular frameworks. They begin by discussing DAME's three main design goals: efficiency, transparency, and scalability. Next, they describe the five supports that DAME gives the programmer: virtual topology, data distribution, data management, interprocess communication, and workload reconfiguration. Then, they present the results they obtained from experiments using 10 workstations that provide a hardware heterogeneous, data homogeneous, nonuniform platform. The results show that DAME provides a virtual single program, multiple data machine that overcomes most of the differences that distinguish a parallel virtual machine from an ideal SPMD machine.

Automatic Power Distribution Reconfiguration Algorithm Including Operating Constraints

A generalized reconfiguration algorithm applied to automated remote control of power distribution systems is described. The algorithm combines two independent processes: a Service Restoration to dark zones and a Load Balance between feeders. Electrical opera ting cons traints are included in the analysis using an appropriate fast decoupled load flow. Simulation results obtained with a real distribution system data base are presented showing the influence of operating restrictions. The way of interchange the restoration and balance processes is also discussed.