Search for dissertations about: "digital protective relays"

Found 5 swedish dissertations containing the words digital 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. 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

6. 4. 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

7. 5. Electromagnetic Modelling of Power Transformers for Study and Mitigation of Effects of GICs

   Author : Seyedali Mousavi; Göran Engdahl; Ebrahim Rahimpour; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transformer; hysteresis; DC magnetization; GMD; GICs; FEM; reluctance network method; low frequency transients; core losses; winding losses; eddy current losses; transformator; hysteresis; DC; likströmsmagnetisering; GMD; GIC; FEM; reluktansnätverksmodell; lågfrekventa transienter; kärnförluster; lindningsförluster; virvelströmsförluster; Electrical Engineering; Elektro- och systemteknik;

   Abstract : 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. READ MORE