WindTurbine Generator Interaction WithDiesel Generators onanIsolated PowerSystem

TheBlockIsland PowerCompany (BIPCO), onBlockIsland, RhodeIsland, operates anisolated electric powersystemconsisting of dieselgeneration andanexperimental windturbine.The150-kWwind turbine, designated MOD-OAbytheU.S.Department ofEnergyistypically operated inparallel withtwodieselgenerators to servean average winterloadof350kW. Aspartofanexperimental program toevaluate windturbine generator performance ontheisolated dieselpowersystem, therecordings froman extensive datameasurement effortwerereviewed andanalyzed todefinethenatureofthedynamicinteraction effects. Thedatawerecollected overa three-month period onthesystemtowhich theDOE/NASA experimental windturbine wasconnected. Duringthistime, thedieselunitswerelightly loadedresulting inupto60%ofthetotal loaddemandbeingsupplied bytheMOD-OAinperiods of severely gusting winds.Inthreeof themodesofnormalMOD-OAoperation -- startup- synchronization, shutdown/cutout, andcontinuous fixedpitchrunning-- power,frequency andvoltagetransients werecomparable withthose produced bytypical loadchangeson thedieselsystemalone.Inthe fourthmode,variable pitch(constant power) control,a significant reduction in systemdampingsometimes occurredwhichgaveriseto increasedfrequency and voltageperturbations undergustywind conditions. Basedon a linearmodelof thesystemitisshownthat changes incontrol systemsettings couldbemadeto improve damping. Themainstudyconclusion isthatwindturbinegeneration, evenwhen providing a largeportion ofthepowerrequired byanisolated utility, canbea practical option resulting insystemdisturbances no greater thanthosefoundinconventional dieselsystems.