Efficiencyimprovement inwind turbines by increasingspeedrangeusingatandemconnection scheme

Thepaperdescribes theuseofa tandempower electronic configuration invariable speedwindturbines to improveefficiency by allowing anincrease inbothrotational speedandmaximumpowersenttothegrid. First, thepossible increment inpowerisdetermined, limiting bothcurrent andlosses inthemachine totheir ratedvalues, but allowing anincrease interminal voltage. Next,theincrement in captured energy fordifferent winddistributions isassessed. Finally, therequired powerrating oftheconverters inthe secondary systemisestimated, taking intoaccount thatinthe proposed systemtheyhavetheextrataskofextracting fromthe generator andsending totheutility theextra generated power.