Research On Analysis Of Interaction Between FACTS And HVDC System And Control Strategy

High voltage direct current (HVDC) system and flexible AC transmission system(FACTS) devices are widely applied into modern power system because of their excellentcharacteristics. Interactions investigations among FACTS devices or between FACTS devicesand HVDC system in large scale AC/DC hybrid system are not enough mature due to shorttime of usage and complexity of controllers. Interactions between FACTS devices exist inactual power system at present. In addition， interactions between FACTS devices and othercontrol equipments can also cause negative influence on power system stability operation andcontrol. So investigations of interactions between FACTS devices and HVDC to ensurecoordinated operation have great realistic meaning.The thesis chooses AC/DC hybrid system installed FACTS devices as research objects.Time domain simulation， relative gain array (RGA) and small signal stability analysis wereadopted to quantitatively analyze interactions between FACTS devices and HVDC system.Realization and program process of RGA and small signal stability analysis， suitableselection of power system devics model， formation of whole AC/DC hybrid system modelwere described in detail. Then interactions among FACTS devices were investigated in IEEE2-area4-machine power system. The analysis result show that interactions among FACTSdevices exist. Negative interaction degree is related to electric distance of FACTS devices.500kV main network frame of southern power grid was investigated. All the500kVnodes and part of220kV nodes were preserved by equivalent detailed model of southernpower grid. Small signal stability analysis and RGA principle were used to analysisinteractions among FACTS device or between FACTS devices and HVDC. The result of RGAanalysis shows that there exist interactions between Yuguang HVDC and Chuxiong SVC.There is no negative interaction among other FACTS devices or between FACTS devices andother HVDC. Time domain simulation verifies correctness of RGA principle to analysisnegative interactions in power system.Finally， weak links of southern power grid were found out by means of sensitivityanalysis. The prevention and emergency response strategies when FACTS of cascading failurewere proposed by the results of RGA analysis and cascading failure time domain simulationof southern power grid.