Page - 237 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2016,9, 410 Figure 21 summarizes themeasured conversion efficiency of the studiedBDC in charge and discharge states. On the experimental porotype system, the conversionefficiency ismeasuredvia precisedigitalpowermeterWT310equipment,manufacturedbytheYokogawaElectricCorporation (Tokyo, Japan). Theaccuracyof themeasuredpower iswithin+/´0.1%. It canbe seen that from Figure21, themeasuredhighest conversionefficiency is 95%indischarge state and is around96% incharge state. Inorder to clarify theactualmeasuredconversionefficiency further, basedon the equations inTable 2, the calculatedpower lossdistributionat the rated load condition is listed in Table3,andfurthermore, thecalculated lossesbreakdowndiagramsof thestudiedBDCaredepicted inFigure22. FromTable3andFigure22,onecansee that thepower lossesmainlyoccur in thecopper lossof the inductors, switching lossandconduction lossof theMOSFETs. Thetotalpower losses in chargeanddischarge states are 28.5Wand28.6W,accounting for 5.70%and5.73%, in rated load condition, respectively. Thesematchwell themeasuredconversionefficiencyof thestudiedBDCin charge (94.29%)anddischarge (94.25%)states. 2XWSXW 3RZHU : &KDUJH 6WDWH 'LVFKDUJH 6WDWH Figure 21. Measuredconversionefficiencyof the studiedBDCfor low-sidevoltageVL=48Vand high-sidevoltageVH=385Vunderdifferent loads. (a) (b) Switching loss of MOSFETs 19% Conduction loss of MOSFETs 22% other loss 1% Loss of capacitors 12% Copper loss of inductors 46% Switching loss of MOSFETs 17% Conduction loss of MOSFETs 23% other loss 1% Loss of capacitors 12% Copper loss of inductors 47% Figure 22. Calculated losses breakdown diagrams at rated load condition: (a) in charge state; (b) indischargestate. 237