Page - 319 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2016,9, 10 Figure14showssomecriticalwaveformsof thewirelesspower transfersystem,where thecyan curveshowstheoutputvoltageproducedbytheHBridge, thegreencurveshowsthevoltageacross the resonant capacitor in the transmitter and thepurple curve shows the charging current for the batterypack. Because thereductionscaleofhighvoltageprobe is200, themeasuredvoltagesneedto bemultipliedby200. Theamplitudeof thesquare-wavevoltageproducedbytheHBridge is400V. TheRMSvalueof thechargingcurrent is10.4A,andtherearesomeripplewaves, theamplitudeof whichdependsonthefiltercapacitors. Thebigger thefiltercapacitors, thesmaller theripplewaves. ȱ Figure 14. Purple curve: the charging current for the battery pack; cyan curve: the output voltage produced by theHBridge; green curve: the voltage across the resonant capacitor in the transmitter. Theyaremeasuredwhenthesystemworks in theratedstate (Vin=400V,VB=309.7V, Pcharging=3220W,Dtransfer=20cm). Thefollowingexperimental resultsaremeasuredwhentheq-Zsourceworks,andtwodifferent shoot-throughtimesareshowntoclearlydemonstrate theq-Zsourceprinciple. Figure15 indicates that differentshoot-throughtimesdeterminedifferentboost factors.Althoughthe inputvoltages (green curve)ofbothFigure15a,bare identical (200V), theiroutputvoltages (cyancurve)aredifferent.When theshoot-throughtimeis1μs, theboost factor isaround1.5, thus theoutputvoltage isaround300V, andthechargingcurrent is8.26A.Whentheshoot-throughtime is1.5μs, theboost factor isaround2, thus theoutputvoltage isaround400V,andthechargingcurrent is10.2A.Summarily, thecharging currentscanbeadjustedbycontrolling theshoot-throughtimes. ȱ (a)ȱ Figure15.Cont. 319