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Visar resultat 1 - 5 av 100 avhandlingar som matchar ovanstående sökkriterier.
1. A calibration system for instrument transformers with digital output
Sammanfattning : .... LÄS MER
2. Lifetime modeling and management of transformers
Sammanfattning : This work have studied and developed lifetime estimation methods for the power transformer and how these could be used for asset management purposes. It is researchperformed in the intersection of the fields of reliability theory, statistical analysis, and stochastic process theory applied to lifetime estimations and management of transformers. LÄS MER
3. Differential Protection for Arbitrary Three-Phase Power Transformers
Sammanfattning : This thesis describes how to provide standardized, current based, differential protection for any three-phase power transformer, including phase-shifting transformers with variable phase angle shift and transformers of all construction types and internal on-load tap-changer configurations. The use of standard transformer differential protection for such applications is considered impossible in the protective relaying standards and practices currently applied. LÄS MER
4. Magnetizing Currents in Power Transformers : Measurements, Simulations, and Diagnostic Methods
Sammanfattning : This thesis demonstrates a method for transformer core diagnostics. The method uses the no-load current of the transformer as an indicator, and gives different characteristic signatures for different types of faults or defects. Using the no-load current for the diagnostic gives high sensitivity. LÄS MER
5. Multiple Aspects of Dynamic Rating in the Power System
Sammanfattning : Increased consumption and increased use of renewable energy make overhead lines and transformers more often congested. Dynamic rating (DR) uses a time-depending maximum permissible current instead of a long-term-fixed rating; it is an effective solution to upgrade the capacity of existing grid assets to minimize this congestion. LÄS MER