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 20 of 42 for “"circuit breakers"”.
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Z-source circuit breakers in naval power systems
… on future vessels. Integrating the z-source circuit breaker into a "typical" naval MVDC power system requires understanding system dynamics that may cause the circuit breaker to inadvertently energize a circuit through regenerative turn-on of the thyristor. An electrically-scaled model and a …
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DC thyristor circuit breakers: An investigation of current interruption ability
… of the project were to investigate DC Thyristor Circuit Breaker (TCB) current interruption and appraise the current interruption performance in simulated systems. A generalized analysis was developed which enabled succinct assessment of the current interruption performance of different thyristor …
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Modeling of AC circuit breakers in the electromagnetic transients program
… was to develop and implement a model for an A.C circuit breaker in the Electromagnetic Transients Program (EMTP). Various models for the arcing process were evaluated, and the modified Mayr equation was chosen for the model. Other equations were added to demonstrate the generality of the …
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Development of Solid State Circuit Breakers for 380V DC Microgrid Protection.
North Carolina State University Theses Electrical and Computer Engineering.
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Insulation-Constrained Design of Power Electronics Converters and DC Circuit Breakers
… Power electronics converters and DC circuit breakers (DCCBs) are the key components of a DC system and are hence the focus of this work. The combination of growing power density requirements and higher voltages can result in enhanced electric field (E-field) intensities, leaving the …
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Modeling and Design of a Railgun-Driven Actuator for Ultrafast LVDC Circuit Breakers
L'abstract è presente nell'allegato / the abstract is in the attachment
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Supercapacitor-assisted Arc Management (SCA2M) technique for DC circuit breakers in low-voltage applications
Direct Current (DC) circuits are gaining popularity due to their compatibility with renewable energy. However, their development is hindered by the lack of mature DC protection, such as circuit breakers. Unlike alternating current (AC), DC lacks natural zero-crossing points, making arc extinction …
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Analysis of asset health : an approach to monitoring and diagnostics for medium voltage circuit breakers
… smart-grid. With an emphasis on medium voltage circuit breakers, the purpose of this thesis was to identify sensor technology and analytics that will allow electric utilities in North America-primarily the United States-to assess the health of their equipment and utilize this information for …
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A study of the effect of harmonics in the system on the performance of residual current-operated circuit-breakers and electromechanical overcurrent relays
Residual current-operated circuit-breakers (RCCBs) have proved useful devices for the protection of both human beings against ventricular fibrillation and installations against fire. Although they work well with sinusoidal waveforms, there is little published information on their characteristics. …
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Design, Simulation, and Hardware Construction of a 600 W Solid State DC Circuit Breaker for the DC House Project
<p>DC circuit breakers must be able to arrest overcurrent conditions to prevent electrical equipment and wiring from causing building fires or other hazards from occurring. With more DC renewable sourced structures such as Cal Poly’s DC House, an inexpensive and reliable protection system is …
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Einfluss des Elektrodenabbrandes auf das Schaltverhalten eines SF 6-Selbstblasschalters
Due to the fact that high voltage circuit breakers are able to work under short current conditions, too, they are the important security elements in electrical power systems. During the switching operation an electrical arc exists between the switching contacts. The operation method of all circuit …
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Vergleich von Strahlungs- und Turbulenzmodellen zur Modellierung von Lichtbögen in SF -6-Selbstblasleistungsschaltern
High voltage circuit breakers are important elements in the transfer of energy between the power plant and the consumer. Circuit breakers of the third generation, so-called SF6-selfblast-circuit-breakers, use the energy set free by the switching arc in case of a fault to build up the pressure …
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Analysis in circuit breaker performance requirements for high-voltage DC networks
… system is unable to transfer power. Prototype dc circuit breakers have been developed by manufacturers to, in theory, allow seamless operation of the healthy areas of the network when a fault occurs. In order to do this they operate extremely fast; opening in less than 5ms. To achieve this the …
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Modellierung des typspezifischen Störungsaufkommens von Hochspannungs-Schaltgeräten
… specific failure occurrences of high voltage circuit breakers is the objective of this dissertation. First, based on a comprehensive database of minor and major failures as well as empiric findings, the failure model in case of current maintenance actions will be developed and applied on a …
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Market microstructure issues related to the Greek capital market
… from drastic fluctuations. For their concerns, circuit breakers have been recommended as the mechanisms for the market stabilisation and for reducing the volatility of the stock market. Empirical and theoretical studies carried out so far have not been able to conclusively resolve the debate on …
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Modellierung des Plasmas im Vakuum-Leistungsschalter unter Berücksichtigung axialer Magnetfelder
The main task of vacuum circuit breakers is the switching of short circuit currents, which can reach values of about 50 kA in medium voltage systems. In the medium voltage area the vacuum technique is the dominant switching principle and is mostly used worldwide whereas the market share amounts 60 …
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Widerstandsverteilung in Schaltlichtbögen von Selbstblasleistungsschaltern während der Stromnulldurchgangsphase
SF6 self-blast circuit breakers are widely used as switching elements in electrical power systems. In case of a short-circuit fault the breaker contacts are separated leading to an ignition of an electric arc. Hence, the current flow is carried by the electric arc itself. Due to a cooling of the …
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A feasibility study of an adaptive reclosing relay
… (b) The logic is applicable only for circuit breakers which. have reclosing on individual phases. (c) The relay works correctly in the case of both (shunt) compensated and uncompensated lines.
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Specification, Placement, and Control of Fault Current Limiters In Power Systems
… connection eliminates the need to upgrade the circuit breakers at the feeder of the bus connected to the new DG. A dual-FCL controller determines the fault location and then trips the appropriate FCL device. In this connection, it costs one more FCL to enhance the synchronism between the new DG …
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Adaptive out of step relay algorithm
… For stable oscillations following a disturbance, circuit breakers at the 500 kV interconnections are blocked from tripping. For separations these circuit breakers are tripped. EEAC requires synchronized voltage phasor measurements at two specific locations within the overall electrical power …
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