طراحي هماهنگ PSS و كنترل كننده ي TCSC به هدف بهبود ميرايي نوسانات الكترومكانيكي در سيستم هاي قدرت

چكيده انگليسي :

107 Coordinated Design of PSS and TCSC controller for Improving the Damping of Electro mechanical Oscillations in Power Systems Seyyed Abbas Rahimi sa rahimi@ec iut ac ir Date of Submission 1 21 2013 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Gholamreza Yousefi yousefi@cc iut ac irAbstract Power systems are increasingly being more stressed due to the need for more power transfer over tielines The competitive environment of power markets has made utilities to deploy the maximum capacity ofthe transfer system to trade power with the neighbouring power pools This has pushed power systemstoward their stability margins When huge amount of power is transferred over weak tie lines inter areaoscillations are likely to happen Many incidents of power system instability due to low damped oscillationshave been reported The most common method to damp power systems low frequency oscillations has beenthe use of Power System Stabilizers PSS for a long time Conventional PSSs have proved to be quiteeffective in damping local oscillatory modes but when it comes to damping of inter area modes they seem tolack the desirable efficiency This is mainly due to the low observability of inter area oscillatory modes inPSS local signals such as rotor speed deviations or generator s power deviations Flexible AC TransmissionSystem FACTS devices were initially devised for mitigating power system s steady state performance suchas voltage regulation and power flow capacity increase Later they proved to be efficient in damping powersystems oscillatory modes Considering all PSSs FACTS and HVDC controllers there are lots of controllersin a typical power system Coordination of these controllers is essential for their efficient performance Theconventional method for tuning different controllers in a power system is the linear sequential method LSM in which controllers are tuned and installed one after another considering a specific oscillatory mode to bedamped by each single controller The main shortcoming of the LSM is that controllers are tuned disregardingthe effect of the next controllers Installation of a new controller inevitably affects the performance ofpreviously installed controllers and may decline the damping performance of a specific controller Optimization based coordination of controllers has been proposed for amelioration of this drawback In thismethod the optimum performance of all controllers of a system is sought through optimization of anobjective function The coordinated design of PSSs and TCSC controllers based on the optimization of aproper objective function using the Genetic Algorithms is presented in this thesis Furthermore since thecontrollers designed by the conventional linear methods suffer a lack of robustness by change in the systemworking point or in the presence of different disturbances a wide area controller based on the robustcontroller design method is presented in this thesis The performance of the controller is then comparedwith the residue based controller for verification of the robustness of the controller design The resultsshow that the controller designed by the technique although more complicated in design and structure has much better damping performance compared to the conventional lead lag controllers Keywords Coordinated design of power system controllers Genetic Algorithmsbased optimization PSS design TCSC damping controller Wide area controllerdesign for power systems

رحيمي، عباس

طراحي هماهنگ PSS و كنترل كننده ي TCSC به هدف بهبود ميرايي نوسانات الكترومكانيكي در سيستم هاي قدرت

پايدارساز شبكه ي قدرت , كنترل كننده ي پايداري براي TCSC , تنظيم هماهنگ پايدار سازهاي شبكه , بهينه سازي با الگوريتم ژنتيك , طراحي كنترل كننده ي ∞H براي سيستم قدرت