Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"Distance Relays"”.
-
Data-driven Protection of Transformers, Phase Angle Regulators, and Transmission Lines in Interconnected Power Systems
… their safety is a primary issue. Differential relays are commonly employed to protect transformers, whereas distance relays are utilized to protect transmission lines. Magnetizing inrush, overexcitation, and current transformer saturation make transformer protection a challenge. Furthermore, …
-
APPLICATION OF MODAL TRANSFORMATION FOR FAULT ANALYSIS AND DIGITAL DISTANCE RELAYING
Transmission lines are usually protected by distance relays that measure the apparent distances of faults and compare them with the relay settings to determine if the fault is inside the protected zone. The information required for setting relays is generally obtained from fault analysis studies. …
-
ACCELERATED ZONE-2 TRIP ALGORITHM FOR A NON-PILOT DISTANCE RELAY
Distance relays use time stepped protection zones for coordination purposes. The time delay introduced by zone-2 distance relays limits the use of these devices for extra high voltage (EHV) applications since the fast fault clearance requirement is not achieved. Transmission lines are normally …
-
A new method of utilising stability study results in applying out-of-step protection to allow observability of rotor angle unstable conditions
… conditions may cause undesired operation of distance relays, resulting in the unnecessary switching of lines. To prevent the possible undesired operation of distance relays, a protection type known as out-of-step blocking is used. This protection type is complemented by another type of …
-
Recommended protection scheme setting coordination for nine busbars transmission grid
… protection of transmission line three stepped distance protection can provide remote backup protection to transmission line by zone 2 and zone 3, but during the calculation of operation setting for different protection zones of the distance relays, some problems have been raised (overlap and …
-
Analysis of a Major Electric Grid – Stability and Adaptive Protection
… of faults and other disturbances that may occur. Distance relays are used extensively for the detection of faults on transmission lines. Out-of-step relays are used for generator protection to detect loss of synchronism conditions that result from disturbances on the electric grid. Also, when a …
-
Enabling Communication and Networking Technologies for Smart Grid
… lines are generally protected by distance relays. After a thorough analysis of U.S. historical blackouts, North American Electric Reliability Council (NERC) has concluded that the hidden failure induced tripping of distance relays is responsible for 70% of the U.S. blackouts. As a …
-
Design of a Distance Relay Using Adaptive Data Window Filters
Transmission lines are generally protected by distance relays. Most distance protection relays presently available use microprocessor technology. They estimate fundamental frequency phasors from the quantized values of voltage and current samples. The relays use filters that use fixed sample data …
-
Next-generation, phasor-based distance relay with fault-path resistance immunity
Distance relays are commonly utilized for the protection of transmission lines. A distance relay calculates the apparent impedance between the relay location and the fault location, and uses this value to determine the approximate location of the fault. Traditional distance relays, however, are …
-
Relay coordination with multiple breaker-in/breaker-out stations on the transmission line
… discusses the difficulty of setting up the zone distance relays and overcurrent relays when multiple breaker-in/breaker-out stations are added on the transmission line. It explains how many breakers can safely be added without compromising the zone 2 time delay of 50 cycles (limit imposed by …
-
Computer relaying for EHV/UHV transmission lines
… permissive. This requires a new generation of relays which have high security and dependability and high operating speed. With the advent of high speed microprocessor and fiber optic communication technologies, it is possible to develop high performance relays. In this dissertation, a new …
-
Distance Protection Aspects of Transmission Lines Equipped with Series Compensation Capacitors
… and better voltage regulation.1 Protective distance relays, which make use of impedance measurements in order to determine the presence and location of faults, are "fooled" by installed series capacitance on the line when the presence or absence of the capacitor in the fault circuit is not …
-
Design and implementation of ANN based phase comparators applied to transmission line protection
… various protective relaying functions including distance protection. The reliability and efficiency of ANN based distance relays is improving with the developing digital technologies. There are, however, some inherent deficiencies that still exist in the way these relays are designed. This …
-
Switch-on-to-fault scheme for transmission line protection
… (PTs) are used to polarize directional distance relays, there is no benefit to using memory voltage during an SOTF condition and the polarizing signal used is directly related to the amount of fault voltage available. Depending on the magnitude of fault voltage available, the speed of a …
-
An investigation into the importance of considering protection performance during power system out-of-step conditions
… conditions in that system. Protection relays such as distance relays may detect an out-of-step condition and consequently operate to trip unfaulted lines. The tripping of unfaulted lines interrupts supply to loads and exacerbates an already existing stability problem. To prevent …