Sökning: "numerical relays"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden numerical relays.

  1. 1. Channel Estimation for Amplify and Forward Relay Networks

    Författare :Panagiota Lioliou; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel estimation; relay networks; Multiple-input-multiple-output MIMO ; Cramer-Rao Lower Bound CRB .; least squares LS ;

    Sammanfattning : The use of intermediate-relaying nodes has been identified as a promising technique for enhancing coverage and combating the impairments of Multiple-Input-Multiple-Output (MIMO) wireless channels. The main ideais to introduce relays that forward the data to the destination which isotherwise out of the reach of the source. LÄS MER

  3. 2. Differential Protection for Arbitrary Three-Phase Power Transformers

    Detta är en avhandling från Department of Industrial Electrical Engineering and Automation, Lund Institute of Technology

    Författare :Zoran Gajic; Lunds universitet.; Lund University.; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric power systems; power transformers; differential protection; power system protection;

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

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Seyedali Mousavi; KTH.; [2015]
    Nyckelord :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;

    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

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

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Seyed Ali Mousavi; KTH.; [2012]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

    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

  7. 5. IoT Networking Resource Allocation and Cooperation

    Detta är en avhandling från Linköping : Linköping University Electronic Press

    Författare :Ioannis Avgouleas; Linköpings universitet.; Linköpings universitet.; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The Internet of Things (IoT) promises that "anything that can be connected, will be connected". It comprises of Information and Communication Technologies that interconnect billions of physical and visual things with some "basic" intelligence. LÄS MER