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.
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Showing 1 to 15 of 15 for “"Protective Relays"”.
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Hidden Failure in Protective Relays: Supervision and Control
… works passively in conjunction with the existing protective relaying system at a substation. During normal system operating conditions, the RSS supervises the relay system to prevent trips due to hidden failures. During wide area network disturbances, it adapts the relay system to increase …
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Analyzing voltage sag direction using protective relays and deep-learning methods
… and the location of the fault. Traditional relays effectively locate, detect, and isolate faults. Circuit breakers, fuses, and relays, these devices work together to ensure the power system remains stable and reliable, under various conditions including system failures. Smart Intelligent …
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BEHAVIOR OF BUSBAR DIFFERENTIAL RELAYS WITH AIR-GAP CORE CURRENT TRANSFORMERS
Protective relays normally estimate the magnitude and phase angle of current. Since the level of current is normally too high to permit a direct connection to the power system, a Current Transformer (CT) is used to scale down the current value. A CT should faithfully replicate waveform of the …
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A Novel Inverter Based Resource Control Strategy to Facilitate Utility-Scale Renewable Integration and Retain Existing Transmission Protection Infrastructure
… faulted conditions may change to the point where protective relays may fail to accurately detect the location of a fault. This thesis proposes a novel control strategy for utility-scale inverter-based resources designed to ensure proper operation of the existing transmission-line protection …
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Impact of MHD-E3 on power system equipment and loads.
… of elevated levels of harmonics on power system protective relays, and the impact of harmonic-rich voltages on information technology equipment. A benchtop transformer DC injection testing apparatus was designed and constructed, and these laboratory transformer test results are analyzed and …
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Software framework for protection relay testing
… automated testing of power system protection relays. This application was implemented using a model protection system that was designed to simulate actual relaying operations performed in the electric power system. The implemented application provided automated testing functionality that …
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Current transformers transient response modelling using electromagnetic transient program (EMTP)
… These limitations might lead to mal operation of protective relays due to distorted inputs from current transformers particularly in transient periods. This thesis involved studying the behaviour of current transformers in both steady state and transient periods. An emphasis being put on transient …
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Cascading Events in the Aftermath of a Targeted Physical Attack on the Power Grid
… k. The consideration of hidden failures in the protective relays has revealed that the outage of certain lines/buses in the course of cascading events can save the power grid from a system collapse. Finally, a comparison with the DC steady state analysis of cascading events shows that a …
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Cogeneration in distribution system : planning, operation, transients
… duty on circuit breakers, effect on response of protective relays and automatic control systems are pointed out. It also considers security to personnel and protection of metering equipment. The thesis also offers guide for contractual matters between the utility and the private generation.
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Assessment Of Overcurrent Relay Coordination In A Microgrid With High PV Penetration Deployment
… and dependability of the distribution network. Protective device coordination is considered as a critical challenge for a microgrid with high deployment of PV power. This is mainly due to the dynamically changing configuration of the microgrid, addition of fault current due to presence of DERs, …
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Electricity distribution networks’ analysis with particular references to distributed generation and protection
… identification of power system signals used by protective relays is developed in an effort to contribute in the deterrence and reduction of faults. Finally, extensive studies in a distribution network have been conducted, with and without DGs, which aimed to identify the influence of several …
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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 …
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Fault Location in High Voltage Shunt Capacitor Banks
… sensitive protection available in numerical relays these failures will be detected and SCBs will be taken out of service. But determining the phase and section in which capacitor elements have failed is important for utilities to decrease downtime of SCBs. This thesis proposes methods to …
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Analysis of a Major Electric Grid – Stability and Adaptive Protection
Protective systems of the electric grid are designed to detect and mitigate the effects 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 …
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Fault Identification of UPFC-Compensated Transmission Lines in Complex Microgrids Using an Intelligent Relaying Scheme Based on Discrete Wavelet Transform and ANN Classifier
Transformation of traditional power infrastructures to modern inter-connected electrical grids has resulted in the emergence of microgrids as modernization of the existing aging transmission and distribution systems. Microgrids allow integration of distributed energy resources (DER) such as wind …