This paper presents a simple and efficient reconfiguration approach for balanced and unbalanced distribution networks with DG. The proposed approach that is based on load flow, begins with meshed networks by closing all tie switches. Branch currents were used as switching index to determine the open/closed states of the tie and sectionalizing switches with an objective of system losses reduction. The radial configuration was restored by opening the switch with smallest switching index in each loop. The proposed method has been tested on one balanced and two unbalanced systems with and without distributed generation, and compared with those reported in the literature

This paper presents a simple and efficient reconfiguration approach for balanced and unbalanced distribution networks with DG. The proposed approach that is based on load flow, begins with meshed networks by closing all tie switches. Branch currents were used as switching index to determine the open/closed states of the tie and sectionalizing switches with an objective of system losses reduction. The radial configuration was restored by opening the switch with smallest switching index in each loop. The proposed method has been tested on one balanced and two unbalanced systems with and without distributed generation, and compared with those reported in the literature

This paper presents a simple yet efficient service restoration algorithm for balanced and unbalanced radial distribution networks including Distributed Generators DG. The proposed algorithm that is based on load flow, begins with identifying the de-energized loads group due to fault isolation. All tie switches connecting this group with the rest of the network are the candidate switches for restoration. Branch currents from meshed network (i.e. closing all tie switches) were used as switching index to determine which one of these candidate tie switches should be closed for restoration. The restoration is carried out with objectives of maximizing the restored loads and minimizing the number of switching operations under line current limits, bus voltage limits and radial topology constraints. Each out-of-service group restored by closing the candidate tie switch with highest switching index. The proposed method has been tested on one balanced and two unbalanced systems with and without distributed generation, and compared with those reported in the literature.

This paper presents a simple and efficient multi-objective reconfiguration approach for balanced distribution networks. Two types of power quality indicators are minimized: (i) power losses and (ii) average system interruption frequency. The proposed approach starts with meshed networks by closing all tie switches. Three switching indices were defined for reconfiguration using branch failure rates and apparent power flow in lines. The radial configuration was restored by opening the switch with the highest switching index in each loop subjected to system operational constraints. The time varying nature of loads through using daily load profiles in each node of the system was considered. The results concluded the effectiveness of the fixed configuration compared to hourly reconfiguration in terms of energy losses and number of switching operations. The proposed method has been tested on two systems and compared with those reported in the literature

This paper presents a simple and efficient reconfiguration approach for balanced distribution networks with Distributed Generation (DG). The proposed approach starts with meshed networks by closing all tie switches. A switching index is defined for reconfiguration using apparent power flow in lines. The radial configuration was restored by opening the switch with the highest switching index in each loop subjected to system operational constraints. The time varying nature of loads through using daily load profiles in each node of the system was considered. The results concluded the effectiveness of the fixed configuration compared to hourly reconfiguration in terms of energy losses and number of switching operations. The proposed method has been tested on three systems with and without distributed generation, and compared with those reported in the literature.

Plug-in electric vehicles (PEVs) have uncertain penetration in electric grids due to uncertainties in charging and discharging patterns. This uncertainty together with various driving habits makes it difficult to accurately assess the effects on local distribution network. Extra electrical loads due uncoordinated charging of electric vehicles have different impacts on the local distribution grid. This paper proposes a method to evaluate the impacts of uncoordinated PEVs charging on the distribution grid during peak period. Two PEVs charging scenarios are studied, including normal and fast charging. The impact analysis is evaluated in terms of voltage violations, power losses and line loading, which is implemented on a real distribution system in Canada. The results of the analysis indicate that there are significant impacts on distribution networks due to PEVs charging, which limits the accommodation of desired penetration levels of PEVs.

There is increasing interest in renewable energy sources interconnections in distribution systems since they are inexhaustible and nonpolluting. Wind and photovoltaic are among most mature renewable energy sources, and their penetration continues to increase. This paper proposes a method for distribution network reconfiguration to minimize annual energy losses by determining the optimal configuration for each season of the year. Uncertainties including the daily time varying load and stochastic power generation of renewable distributed generators (DGs) are modeled and taken into account. The method is based on generating a probabilistic generation-load model that combines all possible operating conditions of the renewable DGs with their probabilities of occurrence, then accommodating this model in the reconfiguration problem. The reconfiguration problem, based on Genetic Algorithm, aims at achieving minimum annual energy losses. The constraints include the voltage limits, line current limits, radial topology, and feeding of all loads. The proposed method has been tested on two systems. Simulation results show significant reductions in the seasonal and annual energy losses for all the studied cases.

This paper presents a simple and efficient reconfiguration approach for balanced and unbalanced radial distribution networks with Distributed Generators. The proposed approach starts with meshed networks by closing all tie switches. A switching index is defined for reconfiguration using apparent power flow in lines. The radial configuration was restored by opening one switch in each loop subjected to system operational constraints. The switching index can be used for both loss reduction and service restoration during normal and emergency situations respectively. The time varying nature of loads through using daily load profiles was considered. The results concluded the effectiveness of: (i) fixed configuration compared to hourly reconfiguration in terms of energy losses and number of switching operations during normal operation; and (ii) building restoration plans with the consideration of load variation compared to plans based on pre-fault or peak load values. The proposed method has been tested on one balanced and one unbalanced systems

Effect of load variation on network reconfiguration and service restoration plans in balanced and unbalanced distribution systems is studied. Comprehensive survey of the conceptual aspect as well as published algorithms for distribution network reconfiguration is presented. Different reconfiguration networks and scenarios are discussed. Results showed the effectiveness of building restoration plans with the consideration of load variation compared to plans based on pre-fault or peak load values.

Until now, distribution systems have radial structure with unidirectional power flows and a simple protection scheme. As one of the smart grid objectives and in order to face the continuous demand growth, there is a trend to connect more distributed generation (DG units) to distribution networks. In order to realize this aim and to increase the maximum loadability, meshed network architecture has been suggested. For this reason, in this paper three possible arrangements for distribution networks (i.e., base radial configuration, radial configuration obtained from a reconfiguration problem, and meshed network) have been investigated and compared with each other. The three network configurations are compared in terms of feeder losses, maximum loadability, voltage profile and maximum DG penetration level. The comparison has been tested on the 33 bus balanced and 19 bus unbalanced systems