The ANALYSIS iOF iAN iH6 iINVERTER iFOR iTRANSFORMERLESS iTHREE-PHASE iPV iSYSTEMS
Abstract
Eliminating ithe ileakage icurrent iis ione iof ithe imost iimportant iissues ifor itransformerless ithree iphase iphotovoltaic i(PV) isystems. iIn ithis ipaper, ithe ileakage icurrent ielimination iof ia ithree-phase ifour-leg iPV iinverter iis iinvestigated. iWith ithe icommon imode iloop imodel iestablished, ithe igeneration imechanism iof ithe ileakage icurrent iis iclearly iidentified. iDifferent itypical icarrier-based imodulation imethods iand itheir icorresponding icommon imode ivoltages iare idiscussed. iA inew imodulation istrategy iwith iBoolean ilogic ifunction iis iproposed ito iachieve ithe iconstantcommon imode ivoltagefor ithe ileakage icurrent ireduction.Finally ithe idifferentmodulation imethods iareimplemented iand itestedonthe iTMS320F28335DSP i+XC3S400FPGAdigital icontrol iplatform. iThe iexperimental iresults.The itransformer iless iinverter itopologies iSolar icells iproduce idirect icurrent ielectricity ifrom isun ilight iwhich ican ibe iused ito ipower iequipment ior ito irecharge ia ibattery. iThe ifirst ipractical iapplication iof iphotovoltaic iwas ito ipower iorbiting isatellites iand iother ispacecraft, ibut itodaythe imajority iof iphotovoltaic imodules iare iused ifor igrid iconnected ipower igeneration. iIn ithis icase ian iinverter iis irequired ito iconvert ithe iDC ito iAC. iThere iis ia ismaller imarket ifor ioff-grid ipower ifor iremote ihave isuperior iefficiency ithanks ito isaving itransformer ibut ithere isemiconductor idevices istill ihardswitching istated ipresent i.A ifamily iof iZCT itransformer iless iinverterwithsinusoidal iPWM imodulation iis ideduced iby iusing ifuzzy ilogic icontroller i.
