In power system protection, the need to know the load current together with the fault level detected by a relay is important. This is due to the fact that the relay is required to isolate the equipment being protected if a fault is present and keep the breaker associated with it closed if the current level is lower than the maximum load level. This is not an issue for a radial system. This is n...

This study proposes an intelligent protection relay design that uses artificial neural networks to secure electrical parts in power infrastructure from different faults. Electrical transformer and transmission lines are protected using differential distance relay, respectively. Faults categorized, their locations pinpointed three-phase current values zero-current characteristics differentiate b...

This paper presents a new fast-acting backup protection strategy for future hybrid ac-dc distribution networks. By examining the impedance measured by distance relay measuring from “ac-side” of network, unique characteristic is established faults occurring on “dc-side” an embedded medium-voltage dc (MVDC) link, interconnecting two 33 kV network sections. Based identified characteristic, appropr...

In this channel,we study rate region of a Gaussian two-way diamond channel which operates in half-duplex mode. In this channel, two transceiver (TR) nodes exchange their messages with the help of two relay nodes. We consider a special case of the Gaussian two-way diamond channels which is called Compute-and-Forward Multiple Access Channel (CF-MAC). In the CF-MAC, the TR nodes transmit their mes...

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...

Abstract: This paper proposes a novel protection method for single line-to-ground (SLG) faults in ungrounded low-inertia microgrids. The proposed method includes microgrid interface protection and unit protection. The microgrid interface protection is based on the difference between the zero-sequence voltage angle and the zero-sequence current angle at the microgrid interconnection transformer ...

Maximum availability is essential in the power generation and transmission sector. Faults in transmission lines, substations etc. can cause very serious damage. Therefore it is important to have means to examine each type of fault and the relay performance for different point on wave instant in detail using a relay testing simulator, in order to detect malfunction of the relay. “Point on wave f...

The article examines four basic theses about the ostensibly extremely high reliability of microprocessor-based relay protection (MP) touted by supporters of MP. Through detailed analysis based on many references it is shown that the basis of these theses are widespread myths, and actually MP reliability is lower than the reliability of electromechanical and electronic protective relays on discr...

Utility engineers and consultants use relay models to select the relay types suited for a particular application, and to analyze the performance of relays that appear to either operate incorrectly or fail to operate on the occurrence of a fault. Instead of using actual prototypes, manufacturers use relay model designing to expedite and economize the process of developing new relays. Electric po...

Abstract: This paper is concerned with the analysis of exact symbol error probability (SEP) for cooperative diversity using amplify-and-forward (AF) relaying over independent and non-identical Nakagami-m fading channels. The mathematical formulations for Probability Density Function (pdf) and Moment Generating Function (MGF) of a cooperative link have been derived for calculating symbol error p...