Sökning: "digital protective relays"
Hittade 5 avhandlingar innehållade orden digital protective relays.
1. Power Quality Disturbances and Protective Relays
Sammanfattning : This thesis combines knowledge from two areas: power quality and power system protection. Power quality concerns the effect of voltage disturbances on end-user equipment and of current disturbances on network components. Power system protection concerns the detection of faults in the system from measured voltages and currents. LÄS MER
2. On power quality and protection
Sammanfattning : .... 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. Electromagnetic Modelling of Power Transformers with DC Magnetization
Sammanfattning : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. LÄS MER
5. Electromagnetic Modelling of Power Transformers for Study and Mitigation of Effects of GICs
Sammanfattning : Geomagnetic disturbances that result from solar activities can affect technological systems such as power networks. They may cause DC currents in power networks and saturation of the core in power transformers that leads to destruction in the transformer performance. LÄS MER