svpwm

Chapter7SpaceVectorPWMElectricaldrivesandcontrolsSpacephasorabcFaibiciIdqFdiqiI)2121(32cbadiiii)(2332cbqiiicbajcjbacbacbcbaqdiaaiieieiiijijiiijiiijiiI234323232)2321()2321(32)](23)2121[(32SpacephasorThesameforthevoltage:abcUaubucujcbacbcbaqdUeuaauuuujuuujuuU232)](23)2121[(32isthespacephaseangleUisthespacephasorSpacephasorIfthevoltagesarethreephasesymmetry:abcU)(atu)(btu)(ctuThelocusofthevoltagespacephasorwillmovealongacirclewhenthe“t”variesaperiod.)34cos()32cos(costUutUutUumcmbmatjmcbaeUuaauuU232SpacephasortAnalysisforthethree-phasebridgeinverter+abcnloaddVCfLfiai1Q3Q5Q2Q4Q6Q1D3D5D4D6D2DAnalysisforthethree-phasebridgeinverterOperatingstateforsquarewave(orSix-Step)2241//iOAiOAUuSUuSOOOCCOOOOBBOOOOAAOuuuuuuuuu)()(COBOAOOCOBOAOOuuuuuuu3131)(OCOBOAOOuuuu310UiD2S1S2D1iiRLUi/2Ui/2D3S3S5D5S6S4D6D4O'ABCOS1tOAu?S2S3S4S5S6OBuOCuOOuAOuCOuBOuABuiipiiBiAiCIii1+5i1+3i3+5i1+5i1i3i5i1TPiUi/2Ui/6Ui/32Ui/3Ui1-42-53-6OCOAOBBOuuuu313132OCOBOAAOuuuu313132OBOAOCCOuuuu313132Operatingstateforsquarewave(orSix-Step)Analysisforthe23=8permissibleswitchingstates.numberSwitchingstatecodeSpacevector1VT6VT1VT21001U2VT1VT2VT31102U2VT2VT3VT40103U4VT3VT4VT50114U5VT4VT5VT60015U6VT5VT6VT11016U7VT1VT3VT51117U8VT2VT4VT60000UForexample:)100(1UdAUu210dBBUuu2100dOCOBOAAOUuuuu32313132dOCOAOBBOUuuuu31313132dOBOAOCCOUuuuu3131313200213232)100(jdCOBOAOeUuaauuUAnalysisforthethree-phasebridgeinverter)100(1U)110(2U)010(3U)011(4U)001(5U)101(6U)000(0U)111(7UeRmI060223232)110(jdCOBOAOeUuaauuUAnalysisforthe28=8permissibleswitchingstates.aubucu1t2t1132)()()(32)(12111jjdcbaeUeUmtuataututU2232)()()(32)(22222jjdcbaeUeUmtuataututURelationshipofsinusoidalphasorwithswitchphasorHowtousetheswitchphasorstorealizethesinusoidalphasors?tocalculatethedutyratio)100(1U)110(2U)010(3U)011(4U)001(5U)101(6U)000(0U)111(7UeRmIbUaUU060baUUU11UTtUPWMa22UTtUPWMb0120sinsinUUb00120sin)60sin(UUa21022011sin32)60sin(32ttTtTUUtTUUtPWMPWMPWMAccordingtothesin-principle:then:Relationshipofsinusoidalphasorwithswitchphasortopartitionthesectors)100(1U)110(2U)010(3U)011(4U)001(5U)101(6U)000(0U)111(7UeRmIbUaUUUU0sector1sector2sector3sector4sector5sectorUUU1.accordingto2.accordingtoUU,jUUU)(sign)(sign2)(sign430sin60sin30sin60sin0120020010BBBPUUBUUBUB0)(sign,0;1)(sign,0:)(signxxxxxP1234560sector12345practicalmethod:Relationshipofsinusoidalphasorwithswitchphasortodeterminethelinear(orundermodulation)region)100(1U)110(2U)010(3U)011(4U)001(5U)101(6UeRmIbUaUU0sector1sector2sector3sector4sector5sectorUReferencevoltagelimit002121tTttUUUUPWMbaInsidethecirclearea,thesynthesizedoutputsignalissinusoidalwave,otherwise,thewaveisnotsinusoidal.overmodulationregion)100(1U)110(2U)010(3U)011(4U)001(5U)101(6UeRmIbUaUU0sector1sector2sector3sector4sector5sectorUReferencevoltagelimitPWMbaTttUUUU2121Howtorealize?switchingtimeofeachphase(eachup-legswitch))100(1U)110(2U)010(3U)011(4U)001(5U)101(6U)000(0U)111(7UeRmIbUaUU06021022011sin32)60sin(32ttTtTUUtTUUtPWMPWMPWM0c02b021atttttttttforsector-0:switchingtimeofeachphase(eachup-legswitch))100(1U)110(2U)010(3U)011(4U)001(5U)101(6U)000(0U)111(7UeRmIbUaUU0600c02b021atttttttttforthecentersymmetricalPWM:)4(*2)42(*2)422(*20H-02H-021H-aHcHbHttttttttt40t0U1U2U7U2U7U1U0U21t22t40t2PWMT2PWMTtttPhaseaPhasebPhasec000triggersignalproducedbyspacevectorHowtoproducethePWMinCPU?N_max--themaxofthecounter,thehighofthetrianglemaxPWMmaxPWMmaxPWMaabbccNntTNntTNntTHowtoproducethePWMinCPU?