Optimized Overcurrent Relay Coordination in a Microgrid System

2019 ◽  
Vol 13 ◽  
Author(s):  
O.V.Gnana Swathika ◽  
K.T.M.U. Hemapala
Keyword(s):  
Simplex Algorithm ◽  
Protection Scheme ◽  
Distributed Generators ◽  
Fault Currents ◽  
Relay Coordination ◽  
Protection Strategies ◽  
Overcurrent Relays ◽  
Overcurrent Relay ◽  
Dual Simplex ◽  
Dual Simplex Algorithm

: Microgrids are a conglomeration of loads and distributed generators at a distribution level network. Since this network is no longer a single source fed network, the typical protection strategies may not be deployed. Reconfiguration is a topology changing feature that is visible in microgrid. This is also another factor that is to be considered while protecting the microgrid setup. This paper proposes a protection scheme that has normal and fault currents captured for all topologies of the microgrid. For each topology, the optimized time multiplier settings of overcurrent relays are computed using Dual Simplex Algorithm. This aids in clearing the fault as fast as possible from the network. A 21-bus microgrid system is considered and the optimized overcurrent relay coordination scheme is realized for the same.

Sensitivity Analysis on Linear Programming Problems with Trapezoidal Fuzzy Variables

2013 ◽  
pp. 64-82
Author(s):  
Seyed Hadi Nasseri ◽  
Ali Ebrahimnejad
Keyword(s):  
Linear Programming ◽  
Simplex Algorithm ◽  
Programming Models ◽  
Fuzzy Data ◽  
Fuzzy Variables ◽  
Fuzzy Environment ◽  
Dual Simplex ◽  
Linear Programming Problems ◽  
Simplex Tableau ◽  
Dual Simplex Algorithm

In the real word, there are many problems which have linear programming models and sometimes it is necessary to formulate these models with parameters of uncertainty. Many numbers from these problems are linear programming problems with fuzzy variables. Some authors considered these problems and have developed various methods for solving these problems. Recently, Mahdavi-Amiri and Nasseri (2007) considered linear programming problems with trapezoidal fuzzy data and/or variables and stated a fuzzy simplex algorithm to solve these problems. Moreover, they developed the duality results in fuzzy environment and presented a dual simplex algorithm for solving linear programming problems with trapezoidal fuzzy variables. Here, the authors show that this presented dual simplex algorithm directly using the primal simplex tableau algorithm tenders the capability for sensitivity (or post optimality) analysis using primal simplex tableaus.

Time-Overcurrent Relay Coordination: A Review

2005 ◽  
Vol 2 (2) ◽  
Author(s):  
Dinesh Birla ◽  
Rudra Prakash Maheshwari ◽  
Hari Om Gupta
Keyword(s):  
Power System ◽  
Research Work ◽  
Future Generation ◽  
Relay Coordination ◽  
Complex Power ◽  
Coordination Process ◽  
Overcurrent Relays ◽  
Overcurrent Relay ◽  
In Series

When two protective apparatus installed in series have characteristics, which provide a specified operating sequence, they are said to be coordinated or selective. The coordination of directional overcurrent relays poses serious problems in the modern complex power system networks, which are interconnected. Researchers have looked upon the problem of coordination from different considerations by making use of computer aids. Many efforts have been made to the automation of the coordination process in the area of relay coordination. This paper compiles the most of the significant developments in the area of time-overcurrent relay coordination using different techniques and methodologies. It is hoped that this work will be useful for future generation researchers to find the relevant references to advance the research work in future.

scholarly journals Smart Protection Scheme For Radial Distribution System

2019 ◽  
Vol 8 (6) ◽  
pp. 3621-3624
Keyword(s):  
Power System ◽  
Differential Evolution ◽  
Distribution System ◽  
Coordination Problem ◽  
Radial Distribution System ◽  
Protection Scheme ◽  
Relay Coordination ◽  
Overcurrent Relays ◽  
Optimal Coordination ◽  
Real Time Simulations

In this paper,the study of optimal coordination of directional overcurrent relays along with relay communication in HV substations is proposed. The relay coordination problem is non linear.It typically consist of two groups of control variables(Time Dial Settings:TDS and Plug Settings:PS). The purpose of relay coordination is to propose the suitable settings for all releases and ensure the coordination. The differential evolution is employed to solve for solutions of optimal relay coordination. The relay coordination is mainly done to improve selectivity of the relay to particular fault. ETAP is so popular for its capability for modelling of power system networks and analyzing various studies and Real Time simulations.

Sensitivity Analysis on Linear Programming Problems with Trapezoidal Fuzzy Variables

2011 ◽  
Vol 2 (2) ◽  
pp. 22-39 ◽  
Author(s):  
Seyed Hadi Nasseri ◽  
Ali Ebrahimnejad
Keyword(s):  
Linear Programming ◽  
Simplex Algorithm ◽  
Fuzzy Data ◽  
Fuzzy Variables ◽  
Fuzzy Environment ◽  
Tableau Algorithm ◽  
Dual Simplex ◽  
Linear Programming Problems ◽  
Simplex Tableau ◽  
Dual Simplex Algorithm

In the real word, there are many problems which have linear programming models and sometimes it is necessary to formulate these models with parameters of uncertainty. Many numbers from these problems are linear programming problems with fuzzy variables. Some authors considered these problems and have developed various methods for solving these problems. Recently, Mahdavi-Amiri and Nasseri (2007) considered linear programming problems with trapezoidal fuzzy data and/or variables and stated a fuzzy simplex algorithm to solve these problems. Moreover, they developed the duality results in fuzzy environment and presented a dual simplex algorithm for solving linear programming problems with trapezoidal fuzzy variables. Here, the authors show that this presented dual simplex algorithm directly using the primal simplex tableau algorithm tenders the capability for sensitivity (or post optimality) analysis using primal simplex tableaus.

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