7853

7318

كارشناسي ارشد

قدرت

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1391

ده،153ص.: مصور،جدول،نمودار﴿رنگي﴾

ص.ع.به فارسي و انگليسي

محمد اسماعيل همداني گلشن

22/4/92

حميدرضا كارشناس، غلامرضا يوسفي

مهندسي برق و كامپيوتر

ID7318

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Improvement and Complement of Some Protective Schemes Performance Using Wide Area Protection Concept Milad Rouhinia a rouhinia@ec iut ac ir Date of Submission 2013 02 24 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan Iran 84156 83111 Degree M Sc Language Farsi Supervisor Mohammad Esmaeil Hamedani Golshan hgolshan@cc iut ac irAbstractPower system designers and operators have been always looking for solutions to preventthe expansion of normal disturbances and also to prevent cascading outages in case of anemergency situation Backup protections most of the times play an effective role inpreventing small disturbances to spread all over the system Changes in the operatingpoint of the power systems affects the access area of the protection relays and this lead toinappropriate protection system functions especially in backup relays Due to the changeof power transfer in the major tie lines after the outage of a faulted line cascading tripscounts as an important menace to the stability and security of power systems The inherentdelay of the existing backup relay protection systems along with the effects of faultresistance on pushing the observed fault out of the range of the main protection relaysettings and the conventional backup protection relay could lead to expansion of thedisturbances cascading line outages and ultimately a blackout in the systems The mainpurpose of this thesis is to investigate the drawbacks of the existing conventional backuprelaying systems and using wide area protection for obviating these drawbacks The mainstructures and facilities necessary for implementation of wide area backup relayingsystems are introduced and as examples two wide are backup protection relaying schemesare investigated and introduced in detail One of these schemes works based on themeasurement of the positive sequence of bus voltages and difference in line currentangles and the other one works based on some expert algorithms which use the results ofconventional protection schemes The performance of these two schemes is comparedwith each other by simulation of different fault scenarios on the well known 39 bus NewEngland standard test system Simulation results show that the proposed protectionscheme has a good capacity for reducing wide area disturbances system blackouts andcan result in a more secure operation of power systems Keywords Wide area measurement systems Phasor measurement unit Wide area Backup protection systems Cascading outage

محمد اسماعيل همداني گلشن

حميدرضا كارشناس، غلامرضا يوسفي