Ndemanga pa Topology ndi Control Applications za Medium-High Voltage Power Electronic Transformers III

3.3 Topology Yokhala ndi Magawo Ambiri Okhala ndi Magawo Ambiri

Topology ya Neutral Point Clamped (NPC) multilevel ikuwonetsedwa. Kupatula topology ya NPC yokhala ndi diode-clamped, ma topology a NPC akuphatikizaponso flying capacitor type ndi hybrid clamped type, pakati pa ena. Komabe, chifukwa cha kuchuluka kwa capacitor, ma topology a NPC amagwiritsabe ntchito zida zosinthira zosagwira ntchito kapena zogwira ntchito poyimitsa. Potengera topology ya diode-clamped multilevel monga chitsanzo, mu topology ya magawo atatu yoyimitsa, gawo lililonse limapangidwa ndi ma transistors osinthira ndi ma clamping diode, olumikizidwa motsatira basi imodzi ya DC yamagetsi amphamvu. Mabuku adapereka topology ya gawo limodzi la PET yokhala ndi gawo loyimitsa pogwiritsa ntchito dera la magawo anayi loyimitsa diode. Basi imodzi yamagetsi amphamvu ya DC imatsatiridwa ndi ma DAB olowera-mndandanda-wotulutsa-wofanana, monga momwe zasonyezedwera. Topology iyi ikhoza kukulitsidwa kukhala kapangidwe ka magawo atatu, ndipo kuchuluka kwa milingo yamagetsi kumatha kusinthidwa kutengera milingo yamagetsi yopirira chipangizo komanso mulingo wamagetsi amphamvu. Monga topology ya MMC, topology ya NPC ingagwiritsidwenso ntchito pagawo lodzipatula, kulumikiza basi ya DC yamagetsi okwera kwambiri ku Chosinthira Chodzipatula, monga momwe zasonyezedwera. Mabuku adagwiritsa ntchito chosinthira cha NPC chokhala ndi ma diode atatu mbali yamagetsi amphamvu kwambiri ya chosinthira cha resonant cha LLC, ndikuchitsimikizira pa prototype ya 166kW/2kV ~ 400V. Mabuku adagwiritsa ntchito dera la NPC lokhala ndi ma diode atatu ku DAB ya magawo atatu, zomwe zidapangitsa kuti magetsi ndi magetsi a DAB akhale abwino kwambiri.

Pamene NPC topology ikugwiritsidwa ntchito ngati gawo lokonzanso, siifuna mabasi a DC okhaokha, zomwe zimachepetsa chiwerengero cha ma transformer a sitepe yodzipatula. Kuphatikiza apo, m'magawo atatu, palibe ma voltage ripple a mizere iwiri pa basi. Komabe, chifukwa topology yolumikizidwa imafuna zida zambiri zolumikizira, chiwerengero cha zida zolumikizira chimawonjezeka pamene kuchuluka kwa milingo kukukwera, zomwe zimapangitsa kuti kukulitsa milingo kukhale kovuta komanso kuwonjezereka kumakhala kovuta kukwaniritsa. Ponena za kulamulira, mafunde omwe akuyenda mu capacitor iliyonse ya NPC converter ndi osiyana, zomwe zimapangitsa kuti capacitor voltage isagwirizane. Pa ma NPC topology opitilira milingo itatu, palibe algorithm yogwira ntchito yolinganiza magetsi. Kuphatikiza apo, nthawi yogwirira ntchito yosasinthasintha ya ma switch mkati ndi kunja kwa mikono imabweretsa kutentha kosagwirizana, komwe kumatha kuthetsedwa kokha posintha topology yonse ya dera.

Mavuto ambiri omwe amadza chifukwa cha kukula kwa ma level amatanthauza kuti ma NPC topology amatha kugwiritsidwa ntchito kokha pa ma voltage apakatikati/apamwamba kudzera mu kulumikizana kwa zida kapena kugwiritsa ntchito zida za SiC zamphamvu kwambiri. Komabe, pa ma voltage otsika, poyerekeza ndi ma H-bridge topology amodzi, NPC ya magawo atatu imakhala ndi theka lokha la mphamvu yopirira ma voltage ndi mphamvu ya voltage pa transistor iliyonse yosinthira, pomwe imatulutsa ma voltage ambiri, zomwe zimapangitsa kuti pakhale zofunikira zochepa zosefera. Ili ndi ubwino waukulu wogwiritsidwa ntchito ngati inverter siteji kumbali ya PET yamagetsi otsika. Mwachitsanzo, mabuku adagwiritsa ntchito NPC ya magawo atatu yokhala ndi diode-clamped ngati inverter siteji ya PET kuyendetsa mota ya magawo atatu, kuchita kutsimikizira koyesera ndikupeza magwiridwe antchito abwino a motor drive ndi phokoso.