when a distribution network consisting of distributed generations (dgs) is disconnected from upstream network, the system may be exposed to severe power imbalance. in order to prevent the damage of power plants, frequency relays operate and remove dgs from the network. in contrast to traditional methods, the main objective in new methods is to keep dg units in service in the islanded distributi...

Modern society depends on a reliable energy distribution network. Recent incidents such as the infiltration of a U.S. nuclear power plant together with the impacts of big power outages call for security measures to guarantee supply with energy. This article deals with security goals, attacks, and protection mechanisms for energy automation systems. Nevertheless many of the discussed issues and ...

Economical harvesting of electrical energy on a large scale considering the environmental issues is a challenge. As a solution, Microgrids (MGs) promise to facilitate the widely penetration of renewable energy sources (RESs) and energy storage devices into the power systems, reduce system losses and greenhouse gas emissions, and increase the reliability of the electricity supply to the customer...

Power transformer is one of the most important equipment in a power transmission and distribution system. This paper presents a technology to simulate differential relay in Matlab Simulink based environment for determining its behavior during various operating conditions. The results show that this simulation method can work properly and this will allow rapid modeling and testing of new algorit...

 Protective relays work in concert with sensing and control devices to accomplish their function. Under normal power system operation, a protective relay remains idle and serves no active function. But when fault or undesirable condition arrives Relay must be operated and function correctly.  A Power System consists of various electrical components like Generator, transformers, transmission l...

One of the key challenges for future orthogonal frequency division multiple access-based networks is inter-cell interference coordination. With full frequency reuse and small inter-site distances, coping with co-channel interference (CCI) in such networks has become increasingly important. In this article, an uplink interference protection (ULIP) technique to combat CCI is introduced and invest...

Recent power quality studies have been focused on the source-identification of voltage disturbances at distribution network busses. This paper describes a method aimed at correlating indirect-lightning events with power systems relay operations, associated with voltage dips. The proposed method, based on the coordinated use of the Italian lightning location system CESI-SIRF, the Italian monitor...

abstract: one the most important problems in recent sensitive loads is the quality of voltage. for this challenge custom power devices are used in distribution systems. dynamic voltage restorer (dvr) is a custom power device that improves voltage, decrease power distortion, filter harmonics and balance distributed generations (dgs) with low voltage distribution system. in this paper, a new algo...

Because of the special fault-current characteristics of the inverter-interfaced distribution generator (IIDG) , the conventional fault-analysis method based on the synchronous generator cannot be used for the power grid with IIDGs. The paper points out the problems of using the conventional fault-analysis method for the power grid with IIDGs and proposes a novel fault-analysis method for the po...