نتایج جستجو برای ' Relay '

 Based on study on propagation characteristics of traveling wave in transmission lines, a novel power grid fault traveling wave network protection scheme was proposed in this paper. When a line fault occurs, all traveling wave protection relays (TWPR) record arrival time of initial traveling wave using the precise timing signals from Global Positioning System (GPS). Then the ineffective arrival time of initial traveling wave is eliminated and modified, while the effective arrival time of in...

 This work presents the development and implementation of an artificial neural network based algorithm for transmission lines distance protection. This algorithm was developed to be used in any transmission line regardless of its configuration or voltage level. The described ANN-based algorithm does not need any topology adaptation or ANN parameters adjustment when applied to different electrical systems. This feature makes this solution unique since all ANN-based solutions presented until ...

 This paper presents a new protection scheme for improving the performance of the distance protective relays in transmission systems. The determination of fault zone by the proposed scheme is based on data sheared locally with other distance relays at the same station, in addition to a command from the distance relay on the other end of the protected line. Based on analyzing this information the relay decides the correct fault zone. With the proposed scheme, the first zone in the distance r...

 This paper proposes a novel adaptive load blinder for distance protection. A distance relay can provide remote backup protection by zones 2 and 3, but it may mal-operate under heavy loading conditions and cause cascading trips in the network, which could further lead to a widespread blackout. To prevent cascading outages, load blinders or load encroachment elements are generally used to block the distance relay when there is heavy load in the system. However, these elements are not always ...

 Protective relay performance analysis is only feasible by first formulating the hypothesis of expected relay operations beforehand. Traditionally, the process involved in discovering the relay operation characteristics is bogged down by the issues of differing knowledge of protection experts, meticulous manual understanding of complex relay event report and the need to have supplementary data from diverse intelligent electronic devices. This paper investigates the implementation of a novel...

 In this paper a new auto-tuning algorithm for PI and PID controllers based on relay experiments is proposed to minimize the load disturbance integral error (IE) by maximizing the integral gain, subject to a desired phase margin, and a minimum required gain margin constraint. The main advantage of the proposed auto-tuning algorithm with respect to previous works is that it leads, for most of the processes, to PID tuning with close loop performance similar to PID designed using off-line nume...

 This paper focuses on a graphical approach to determine the region of proportional-integral-derivative (PID) controllers in the parameter space for which the closed-loop system is internally stable and the H∞optimization criteria are satisfied for a class of single-input single-output arbitrary order plant with or without dead time. Unlike conventional methods which the analytical models, such as transfer functions and state space models, are needed, the design information of th...

 Bluetooth is a low power wireless technology designed to connect various short-range devices such as laptops, cameras, cell-phones, head-phones, navigators, etc. Bluetooth has limited resources and its devices are connected in ad hoc fashion. The Bluetooth specification allows only eight active devices to communicate within its smallest networking unit known as piconet. Multiple piconets can be connected together through at least one common device, known as relay to form a bigger network c...

 A common operation in wireless ad hoc networks is the flooding of broadcast messages to establish network topologies and routing tables. The flooding of broadcast messages is, however, a resource consuming process. It might require the retransmission of messages by most network nodes. It is, therefore, very important to optimize this operation. In this paper, we first analyze the multipoint relaying(MPR) flooding mechanism used by the Optimized Link State Routing (...

 Improving power coupling efficiency of beam uplink propagation in a relay mirror system is under extensive research in recent years. A typical model of the relay mirror system is established and theory of beam shaping used to improve power coupling efficiency of the relay mirror system is analyzed in detail. A reduced-scale experimental relay mirror system is founded, which has the same Fresnel number as uplink propagation in the relay mirror system with 1.0 m-caliber transmitter and 30&nb...