1,721,039 research outputs found
Genetic Algorithm for Distribution Network Planning in presence of Distributed Generation
No full text
Adaptive relays for overhead line protection
No full textIn the liberalized energy market scenario protective relays play an important role in assuring continuous service in the power system where a malfunctioning could lead to serious damages to a wide number of operators having access to the power system. Considering that power lines are operated many times below a rated load current, in this paper an adaptive procedure is presented in order to manage power distribution systems according to dependability or security requirements. In particular, a procedure to obtain an inverse time trip curve by means of a microprocessor, connected to a relay, is presented. The procedure adapts the trip characteristic depending on the conductor temperature, wind speed, emissivity and solar absorbity and is implemented on a microprocessor Rabbit 2200 considering a Drake conductor, 795 kcmil 26/7 ACSR
Optimal Switch Placement by Alliance Algorithm for Improving Microgrids Reliability
No full textA method for optimal switches placement in distribution systems with distributed generation is presented in this paper. According to both technical and economical issues, the method allows minimizing the unsupplied loads in case of permanent faults, while limiting the number of installed switches. The problem is formulated as a mixed integer non linear programming problem (MINLP) and the solution is obtained by a new metaheuristic algorithm, i.e., the Alliance Algorithm. The method is based on self-microgrids forming and allows improving the continuity of the service as confirmed by simulation results on both an IEEE standard and a real test network
Coordinated local reactive power control in smart distribution grids for voltage regulation using sensitivity method to maximize active power
No full textDistributed generation (DG) integrated into Smart grid is the future of distribution systems. The expected impact is wide in terms of control, management, supply and use. In particular, in
order to integrate DG based on renewable sources in distribution networks without
compromising the integrity of the grid, it needs to develop proper control techniques to allow power delivery to customers in compliance with power quality and reliability standards. This
paper proposes a coordinate local control approach based on a mixed distribution network (DN)
sensitivity analysis to maintain voltage levels within regulatory limits. The proposed control is based on a reactive/active power regulation able to offer voltage regulation as ancillary services
to the DN, and to maximize the produced active power of the DGs. The validation of the
proposed control technique has been conducted through a several number of simulations on a
real MV Italian distribution system
A Petri net based protection monitoring system for distribution networks with distributed generation
No full textConnection of distributed generation (DG) essentially changes distribution network operation and creates a range of well-documented effects varying voltage levels and short circuit currents. Among others, DG can alter protection system operations in distribution networks, leading to failure of reclosing, disconnection of healthy feeder or prevention of protection operation. This paper proposes a procedure, based on Petri nets and supported by a centralized monitoring architecture for monitoring failures of the protection systems in radial distribution networks. Some case studies applied to a real Italian distribution network proved the effectiveness of the proposed procedure that can therefore represent an effective solution to improve distribution systems reliability in presence of DG. © 2009 Elsevier B.V. All rights reserved
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