Search for dissertations about: "protective relays"

Showing result 1 - 5 of 8 swedish dissertations containing the words protective relays.

2. 1. Power Quality Disturbances and Protective Relays

   Author : Fan Wang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; overcurrent relays; component switching; frequency deviation; power system disturbance; protection algorithms; power quality; digital protective relays; impedance relays;

   Abstract : 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. READ MORE

4. 2. On power quality and protection

   Author : Fan Wang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power system protection; distance protection; power system disturbance; overcurrent protection; protection algorithms; power quality; digital protective relays;

   Abstract : .... READ MORE

5. 3. Methods for Synchrophasor-Based Power SystemInstability Detection and HVDC Control

   Author : Rujiroj Leelaruji; Luigi Vanfretti; Jean Mahseredjian; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wide-Area Monitoring Protection and Control Systems; Synchrophasor applications; Wide-Area Voltage Instability Detection; Wide-Area EarlyWarning Systems; Automatic Voltage Stabilizer;

   Abstract : The recent availability Phasor Measurement Unit (PMU) functionalities in relay technology has opened up new opportunities for power system protection, allowing this microprocessor-based technology to be used beyond traditional protection purposes. This technology now also considers the computation and communication mechanisms that allow the transmission of synchronized phasor measurements. READ MORE

6. 4. Differential Protection for Arbitrary Three-Phase Power Transformers

   Author : Zoran Gajic; Industriell elektroteknik och automation; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric power systems; power transformers; differential protection; power system protection;

   Abstract : 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. READ MORE

7. 5. Electromagnetic Modelling of Power Transformers with DC Magnetization

   Author : Seyed Ali Mousavi; Göran Engdahl; S. V. Kulkarni; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

   Abstract : 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. READ MORE