8463

7843

كارشناسي ارشد

قدرت

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1392

دوازده،190ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمداسماعيل همداني گلشن

7/11/92

حميدرضا كارشناس، محمد امين لطيفي

مهندسي برق و كامپيوتر

ID7843

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Islanding Detection of Synchronous Distributed Generation in Distribution Systems Babak Ahmadzadeh Shooshtari b ahmadzadeh@ec iut ac ir Date of Submission 9 22 2013 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohamad Esmail Hamedani Golshan hgolshan@cc iut ac irAbstract Distribution networks are commonly passive so their disconnection from upstream network wouldmake the loads and network components de energized By connection of the Distributed Generation DG tothe distribution feeders these networks are not passive anymore and if they lose their connection with theupstream network loads are still supplied by distributed generation thus islanding occurs in the system Considering that usually in islanding distribution systems do not have voltage and frequency controlfacilities system s operating in islanding is not acceptable and in order to prevent network loads anddistributed generation damages it would be necessary to disconnect these sources from the network as soonas possible For this purpose distributed generation will be equipped by the anti islanding protection system This system can be formed based on a communication infrastructure or designed according to the measuredlocal parameters at the distributed generation terminal Local methods are classified in three groups passive active and hybrid Islanding detection of synchronous distributed generation is more challenging thaninverter based one because of relatively high output power sometimes more than 30 MW high inertiaconstant and less flexibility in control of the output parameters such as terminal voltage rotor speed outputactive and reactive power This thesis introduces and investigates different aspects of the most widely used passive methods inislanding detection of synchronous distributed generation such as frequency rate of change of frequency vector surge and voltage relays In this regard the theoretical basics and algorithms of each relay areanalyzed Furthermore relays performance in islanding detection is investigated with using the performancecurve and the Non Detection Zone NDZ The behavior of these relays against occurrence of the non islanding disturbances in system is studied also In order to satisfy these purposes two test networks isemployed one of them is common in related studies and the other one is a small part of Isfahan network Transient interval simulations for the various islanding and non islanding disturbances have been done inMATLAB Simulink software Finally setting of various relays by means of the application region is donefor the test networks considering the following goals islanding detection in appropriate time satisfaction ofthe requirements related to the safe and abnormal frequency and voltage variations and ability indiscrimination between islanding and non islanding disturbances Then relays performance is investigated byusage of the power imbalance application region Key WordsFrequency relay islanding detection non detection zone passive methods performancecurve synchronous distributed generation voltage relay

محمداسماعيل همداني گلشن

حميدرضا كارشناس، محمد امين لطيفي