Sökning: "Hans Edin"
Visar resultat 1 - 5 av 20 avhandlingar innehållade orden Hans Edin.
1. Partial Discharges Studied with Variable Frequency of the Applied Voltage
Sammanfattning : This thesis concerns partial discharge (PD) diagnostics withvariable frequency of applied voltage in the frequency range 1mHz - 400 Hz. The exploration of a new type of spectroscopythat combines partial discharge analysis and dielectricresponse is demonstrated. LÄS MER
2. Essays in Labor and Demographic Economics
Sammanfattning : Essay 1: (co-written with Olof Åslund) We study the impact of family size on intermediate and long-term outcomes using twin births as an exogenous source of varia¬tion in family size in an unusually rich dataset. Similar to recent studies, we find no evidence of a causal effect on long-term outcomes and show that not taking selection effects into account will likely overstate the effects. LÄS MER
3. 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
4. On the polymer-based nanocomposites for electrical switching applications
Sammanfattning : Recent research demonstrated that polymer based nanocomposites (PNCs) have been engineered in order to improve the arc interruption capability of the circuit breakers. PNCs are the combination of nano-sized inorganic nanoparticles (NPs) and polymers, opened up new developments in materials science and engineering applications. LÄS MER
5. Development of on-line diagnostic methods for medium voltage XLPE power cables
Sammanfattning : On-line diagnostics of power system components is an important area since it allows the diagnostics to be performed at regular intervals during the normal operation of the components. This combined with reliability centered maintenance could lead to reduced customer outages. LÄS MER