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 11 of 11 for “"Geomagnetic Disturbances"”.
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Enhanced power system resiliency to high-impact, low-frequency events with emphasis on geomagnetic disturbances
… we focus on cyber-physical attacks and geomagnetic disturbances (GMDs). Corrective control through generation redispatch is proposed to protect the system from cyber-physical attacks. A modification of the optimal power flow (OPF) is proposed which optimizes the system resiliency instead …
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Power distribution feeder response to the asymmetric saturation of substation transformers caused by significant high-side DC currents.
High-altitude electromagnetic-pulse and geomagnetic disturbances can lead to asymmetric saturation of utility transformer cores by causing significant DC current to flow through the transformer windings. Transformer secondary voltage and current waveforms are distorted by core saturation and this …
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Precise orbit determination and analysis from satellite altimetry and laser ranging
… the modelling of density changes associated with geomagnetic disturbances comes under scrutiny in this section. By introducing persistence modelling of a geomagnetic event and solving for certain geomagnetic parameters, a new density model is derived which performs significantly better than the …
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Duality derived topological model of single phase four limb transformers for GIC and DC bias studies
Geomagnetic disturbances brought about by solar activity cause geo-electric fields in the Earth that drive geomagnetically induced currents through the earthed neutrals of transformers and through power transmission networks. The flow of these currents causes the magnetic cores of transformers to …
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Synchronous generator and excitation system response to GIC
… physicists, and power engineers. The resultant Geomagnetically Induced Currents (GIC) lead to periodic part wave saturation of transformers, harmonic pollution, increased non-active power demand and potential voltage collapse. While most power system studies have focussed on the transformer's …
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Characterization and Modeling of Solar Flare Effects in the Ionosphere Observed by HF Instruments
… solar flares and those co-occurring with other geomagnetic disturbances during the 2017 solar storm. We found successive solar flares can extend the ionospheric relaxation time and the variation of HF absorption with latitude is different depending on the type of disturbance. In Chapter 4, we …
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Measurements and finite element modelling of transformer flux with dc and power frequency current
Geomagnetically induced currents (GIC’s) caused by solar storms or other sources of dc excitation in the presence of ac energization can disturb the normal operation of power transformers. If large enough, they cause half-cycle saturation of a power transformer’s core which could lead to …
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Modeling, simulation, and mitigation of the impacts of the late time (E3) high-altitude electromagnetic pulse on power systems
The student, Trevor Hutchins, accepted the attached license on 2015-11-24 at 10:07.
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High-performance computing for smart grid analysis and optimization
… addressing OPF related problems, we also study geomagnetic disturbances (GMDs) and how to mitigate their threat to the reliability of power grids. Geomagnetically induced currents (GICs) introduced by GMDs can damage transformers, increase reactive power losses and cause reliability issues in …