Seite - 312 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2016,9, 10 (a) (b) 40 60 80 100 120 0 100 200 300 400 500 Input Voltage VS (V) PLC-LC (VB=75V) PLCL-LCL (VB=75V) PLC-LC (VB=50V) PLCL-LCL (VB=50V) 40 60 80 100 120 0.86 0.88 0.90 0.92 Ș LC-LC (VB=75V) Ș LCL-LCL (VB=75V) Ș LC-LC (VB=50V) Ș LCL-LCL (VB=50V) Input Voltage VS (V) Figure4.Experimentaltransferpower(a) andefficiencies (b)of theLC-LCseriesandLCL-LCLtopologies. The results in Figure 4a show a good agreement with those in Figure 3a. However, the experimental transferefficienciesdeclinesharplycomparedwith those inFigure3b,which ismainly because theHBridgeandrectifier introduceadditional losses. Still, it isobvious that theefficiencyof theLC-LCseries topology is superior to thatof theLCL-LCLtopology, so thispaperadopts theLC-LC series topologyas thepower transfercarrier. 3.OnlinePowerRegulation 3.1. Principles of q-Zsource Z-source isaunique impedancenetworkwith twopairsof inductorsandcapacitorsconnected in anXshape [33]asshowninFigure5a,and itwas initiallyusedforstabilizing thewidelychanging voltageproducedbyfuelcell stacks.Comparedwith theZ-source, theq-ZsourceshowninFigure5b has better performance [34]. Themost obvious twovirtues are as follows: first, there is an input inductor L1, which enables the input current to be continuous and thus limits the transient peak loss. Second, thewithstandvoltageforC1 is lowered, forC1 alwayscombineswithpowersource to chargeordischargeL1. ThisallowsthevolumeandweightofC1 tobereduced,andimprovessystem powerdensity. 312