Protection of compensated lines with FACTS devices using artificial intelligence techniques

The use of power electronic devices to improve the power systemperformance forms concepts of Flexible Alternating Current TransmissionSystems FACTS. The study focused on two different types of FACTSdevices. the first device is the thyristor controlled series capacitor TCSC.The other one is the most recent developed FACTS devices that dependson voltage source converters, namely the static synchronous compensatorSTATCOM. The contribution of these devices which may be presented inthis work from point of view of power system protection.Distance protection relays have been widely applied for protectingtransmission lines because of their simple operating principle andcapabilities to work independently under most circumstances. These relaysstill provide very good protection for transmission lines. Presence ofFACTS devices like TCSC and STATCOM implemented with its controlstrategies in the fault loop affects both the steady state and transientcomponents in the voltage and current. Therefore, apparent impedancecalculations may be affected.Todays Artificial Neural Networks (ANN) have been trained toperform complex functions in various applications, including patternrecognition, identification, classification, speech, vision, and controlsystems. ANN can be trained to solve problems that are difficult forconventional computers or human beings. This work uses ANN as anadvanced tool to protect the compensated lines with FACTS devices.SimPowerSystems is a modern design tool that allows scientistsand engineers to rapidly and easily build models that simulate powersystems. SimPower under Matlab-Simulink environment allows the userto build a model using simple click and drag procedures. Not only it candraw the circuit topology rapidly, but the required analysis of the circuitcan be included. The thesis uses this tool to simulate samples of powersystem networks equipped with TCSC and ST ATCOM. The simulatedmodels take into account all components of control circuits required in theautomatic operation of the concerned FACTS devices.