Vim li cas APF amplify load harmonics?

Thaum xub thawj siab ib muag, ib txhia yuav tsis ntseeg lub npe, xav tsis thoob yog tias muaj yuam kev. Cov lim dej ua kom muaj zog (APFs) yog ib txwm xav kom txo qis kev sib haum xeeb thiab txo cov khoom sib haum xeeb hauv kev sib koom tes, yog li lawv yuav ua li cas thiaj li txhawb nqa kev sib haum xeeb? Koj nyeem qhov ntawd, thiab kuv tsis tau ua yuam kev ib yam nkaus. APFs tiag tiag txo cov kev sib haum xeeb, tab sis lawv kuj ua kom nrov rau lawv. Lawv txo cov kev sib haum xeeb ntws mus rau sab kab sib chaws thiab ua kom muaj kev sib haum xeeb los ntawm sab load! Yog tsis nkag siab qhov no, nws tsis yooj yim sua kom raug teeb tsa APF lub peev xwm thiab siv nws yam xyuam xim. Hauv qab no, kuv yuav sim piav qhia qhov tshwm sim nthuav.

Daim duab saum toj no qhia txog ib qho kev thauj khoom uas tsis yog linear txuas nrog lub network faib. Nyob rau hauv daim duab, Ls sawv cev rau qhov sib npaug sab hauv impedance ntawm kev faib network transformer, L1 yog input impedance ntawm lub nonlinear load, thiab APF kev twb kev txuas taw tes yog nruab nrab ntawm Ls thiab L1. Nrog rau qhov ruaj khov, qhov loj ntawm cov khoom sib haum xeeb ncaj qha cuam tshuam nrog cov lej ntawm Ls thiab L1; qhov loj Ls + L1 yog, qhov me me ntawm cov load harmonics, thiab vice versa. Thaum lub APF tsis txuas, lub input impedance rau load harmonics yog Ls + L1. Txawm li cas los xij, tom qab APF txuas nrog thiab theoretically mitigates tag nrho cov harmonics ntws mus rau lub transformer tis, qhov zoo tagnrho peb -theem voltage qhov chaw rau harmonics hloov mus rau nruab nrab txoj hauj lwm ntawm Ls thiab L1. Nyob rau ntawm lub sijhawm no, lub tswv yim impedance rau load harmonics yog L1, yog li cov load- sab harmonics yuav amplify synchronously, nrog rau amplification magnitude yuav luag sib npaug rau (Ls + L1) / L1.

Raws li kev soj ntsuam saum toj no, APF kev sib txuas feem ntau ua kom muaj kev sib haum xeeb ntawm sab load. Thaum Ls thiab L1 sib npaug sib npaug, qhov kev sib haum xeeb yog qhov tseem ceeb. Txij li thaum lub load input reactance ntawm ib tug raug zaus converter yog piv rau lub internal impedance ntawm lub tis transformer, configuring ib APF mus suppress input harmonics tseem yuav ua rau ib tug ceeb amplification ntawm zaus converter lub input harmonics. Qhov no yog qhov tseeb tshwj xeeb tshaj yog rau qee qhov siab - fais fab zaus converters uas tsis siv lub input inductor, es tsis txhob siv lub transformer qhov sib npaug hauv impedance raws li input inductance. Nyob rau hauv cov ntaub ntawv no, theoretically, tom qab siv ib tug APF los suppress lub zaus converter lub input harmonics, lub load (ie, zaus converter) input tam sim no harmonics yuav ua infinite, lub ntsiab lus tag nrho cov input tam sim no yuav ua infinite, muaj peev xwm ua puas lub zaus converter. Hauv kev xyaum, kev soj ntsuam daim phiaj hluav taws xob ntawm APF kev sib txuas taw tes qhia tawm qhov kev poob qis thiab nce hauv qhov hluav taws xob, uas tuaj yeem ua rau lwm yam khoom puas tsuaj hauv kab sib chaws! Yog li ntawd, nyob rau hauv cov xwm txheej zoo li no, ib qho kev tawm tswv yim ntxiv yuav tsum tau txuas nrog hauv series nrog lub zaus converter.

Rov qab mus rau lo lus nug thawj zaug, hais txog kev nthuav dav ntawm cov khoom sib haum xeeb los ntawm kev sib txuas APF, qhov kev nthuav dav no yuav tsum tau txiav txim siab tag nrho thaum teeb tsa lub peev xwm APF. Lub peev xwm APF tiag tiag yuav tsum yog tsawg kawg (Ls + L1) / L1 zaug ntawm qhov sib haum xeeb ua ntej APF kev sib txuas kom ntseeg tau tias APF muaj peev xwm txaus los txo cov kev sib haum xeeb ntws mus rau daim phiaj los ntawm kev thauj khoom. Rau inverter loads nrog tsawg input impedance, xws li cov uas tsis muaj input reactance, ib tug reactance yuav tsum tau kev cob cog rua nyob rau hauv series ntawm lub APF kev twb kev txuas taw tes thiab lub load. Tus nqi reactance feem ntau yuav tsum tau txiav txim siab tsawg kawg yog 3% reactance tus nqi, thiab tom qab ntawd APF kev teeb tsa muaj peev xwm yuav tsum raug xam raws li qhov piv ntawm Ls rau qhov inductance ntawm cov koob - txuas input reactance.