in this paper, an interval approach is presented to achieve perfect selectivity and maximum sensitivity in distance relay zones, considering uncertainties. for this purpose, first, the uncertainties affecting the settings of the three zones of a distance relay are discussed. then, by using the monte-carlo simulation, the uncertainties are modelled and the impedances seen by the distance relay a...

Abstract—In this paper, the problem of secure transmission in two-hop amplify-and-forward (AF) systems with an untrusted relay is investigated. To prevent the untrusted relay from intercepting the source message and to achieve positive secrecy rate, the destination-based cooperative jamming (DBCJ) technique is used. In this method the destination sends an intended jamming signal to the relay. T...

in this paper, design and application of a new digital protective relay based on fuzzy logicand value estimation to a radial power system protection was presented. a novel approach based onvalue estimation was investigated for the proposed fuzzy logic based protective relay. in addition to thetheoretical aspect of fuzzy logic, mathematical definition of value estimation, detection andmeasuremen...

In this paper, our objective is maximizing total sum-rate subject to power constraints on total relay transmit power or individual relay powers, for amplify-and-forward single-antenna relay-based wireless communication networks. We derive a closed-form solution for the total power constraint optimization problem and show that the individual relay power constraints optimization problem is a quad...

power system blackouts have become a serious problem for electric utilities especially in recent years. different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. to counteract each form of system instability, special algorithms have been designed in the protection system, e.g. under frequency load shedding (ufls) and under vol...

in order to study the effects of cropping systems and mulch application in relay intercropped styrian pumpkin (cucurbita pepo l.) with chickpea (cicer arietinum l.), a field experiment was conducted as factorial layout based on a randomized complete block design with three replications at the agricultural research station, college of agriculture, ferdowsi university of mashhad, during growing s...

Power reserves are usually scheduled in day-ahead unit commitment (UC) to minimize operating costs while maintaining system security. In applying basic UC (bUC) after a contingency, the frequency may fall upon activation of load-shedding global control (under-frequency or UFLS) limits. Small isolated microgrids more sensitive this issue due their lack inertia. Including dynamic considerations i...

This paper concerns power allocation in relay-assisted wireless channels for two-hop transmission. First, the transmitter sends the information to both the relay and receiver parts. Next, in the second hop, the transmitter cooperates with the relay to increase the received signal to noise ratio (SNR), assuming the relay makes use of the Amplify and Forward (AF) strategy. Moreover, it is assumed...

in this paper two different rateless transmissionschemes are developed. in the proposed scheme, relay node candecode and forward the message to the destination if they areable to decode it, or amplify and forward the message to thedestination. based on the analysis and simulation resultsprovided in this paper, the proposed method has bettertransmission time than the scheme which only the relay ...

The aim of the relay coordination is that protection systems detect and isolate the faulted part as fast and selective as possible. On the other hand, in order to reduce the fault clearing time, distance protection relays are usually equipped with pilot protection schemes. Such schemes can be considered in the distance and directional overcurrent relays (D&DOCRs) coordination to achieve faster ...