"Ukungahambelani kusho ukuthi kunzima ukukuxazulula," kusho u-Arthur Mattuck, isazi sezibalo eMassachusetts Institute of Technology (MIT).Kodwa kufanele kubhekwe lapho i-nonlinearity isetshenziswa emithwalweni kagesi, ngoba ikhiqiza ama-harmonic currents futhi ithinte kabi ukusatshalaliswa kwamandla-futhi kuyabiza.Lapha, u-Marek Lukaszczyk, uMphathi Wokumaketha waseYurophu naseMpumalanga Ephakathi we-WEG, umkhiqizi womhlaba wonke kanye nomphakeli wobuchwepheshe bezimoto nokushayela, uchaza indlela yokunciphisa i-harmonics kuzinhlelo zokusebenza ze-inverter.
Amalambu e-Fluorescent, izinsiza zamandla ezishintshayo, amafurnace e-arc kagesi, izihlungi zokulungisa kanye neziguquli zefrikhwensi.Konke lokhu kuyizibonelo zamadivayisi anemithwalo engaqondile, okusho ukuthi idivayisi idonsa i-voltage kanye namanje ngendlela yama-pulses amafushane angazelelwe.Ahlukile emishinini enemithwalo emigqeni—njengamamotho, izifudumezi zasemkhathini, ama-transformer anamandla, nama-incandescent bulb.Ngemithwalo yomugqa, ubudlelwano phakathi kwe-voltage kanye ne-waveform yamanje i-sinusoidal, futhi yamanje nganoma yisiphi isikhathi ilingana ne-voltage-evezwa umthetho we-Ohm.
Inkinga eyodwa ngayo yonke imithwalo engaqondile ukuthi ikhiqiza ama-harmonic currents.I-Harmonics izakhi zemvamisa ngokuvamile eziphakeme kunemvamisa eyisisekelo yokuphakelwa kwamandla, phakathi kuka-50 noma 60 Hertz (Hz), futhi zengezwa kumanje oyisisekelo.Lawa magagasi engeziwe azodala ukuhlanekezelwa kwe-voltage waveform yesistimu futhi anciphise isici sawo samandla.
Ama-harmonic currents ageleza ohlelweni lukagesi angaveza eminye imiphumela engathandeki, njengokuhlanekezelwa kwamandla kagesi ezindaweni zokuxhumanisa neminye imithwalo, kanye nokushisisa ngokweqile kwezintambo.Kulezi zimo, isilinganiso esiphelele sokuhlanekezelwa kwe-harmonic (THD) singasitshela ukuthi ingakanani i-voltage noma ukuhlanekezeka kwamanje okubangelwa ama-harmonics.
Kulesi sihloko, sizofunda ukuthi singanciphisa kanjani ama-harmonics kuzinhlelo zokusebenza ze-inverter ngokusekelwe ezincomo zemboni zokuqapha okulungile nokuchazwa kwezenzakalo ezibangela izinkinga zekhwalithi yamandla.
I-UK isebenzisa i-Engineering Recommendation (EREC) G5 ye-Energy Network Association (ENA) njengomkhuba omuhle wokulawula ukuhlanekezelwa kwamandla kagesi e-harmonic ezinhlelweni zokudlulisa kanye namanethiwekhi okusabalalisa.E-European Union, lezi zincomo ngokuvamile ziqukethwe kuziqondiso ze-electromagnetic comppatibility (EMC), ezihlanganisa amazinga ahlukahlukene we-International Electrotechnical Commission (IEC), njenge-IEC 60050. I-IEEE 519 ivamise ukuba izinga laseNyakatho Melika, kodwa kubalulekile ukuqaphela ukuthi i-IEEE 519 igxile ezinhlelweni zokusabalalisa esikhundleni semishini ngayinye.
Uma amazinga e-harmonic enqunywa ngokulingisa noma ukulinganisa, kunezindlela eziningi zokuwanciphisa ukuze uwagcine ngaphakathi kwemikhawulo eyamukelekayo.Kodwa yimuphi umkhawulo owamukelekayo?
Njengoba kungenzeki ngokwezomnotho noma kungenzeki ukuqeda wonke ama-harmonics, kunezindinganiso ezimbili zamazwe ngamazwe ze-EMC ezikhawulela ukuhlanekezelwa kwamandla kagesi ngokucacisa inani eliphezulu le-harmonic current.Ziyizinga le-IEC 61000-3-2, elifanele okokusebenza okunomthamo wamanje olinganiselwe ofika ku-16 A (A) no-≤ 75 A ngesigaba ngasinye, kanye nezinga le-IEC 61000-3-12, elifanele imishini engaphezu kuka-16 A.
Umkhawulo wama-harmonics we-voltage kufanele kube ukugcina iTHD (V) yephuzu le-common coupling (PCC) iku-≤ 5%.I-PCC iyindawo lapho amakhondakta kagesi esistimu yokusabalalisa amandla exhunywe kumakhondatha amakhasimende nanoma yikuphi ukudluliswa kwamandla phakathi kwekhasimende nohlelo lokusabalalisa amandla.
Isincomo esingu-≤ 5% sisetshenziswe njengemfuneko kuphela yezinhlelo zokusebenza eziningi.Yingakho ezimweni eziningi, ukusebenzisa nje inverter ene-6-pulse rectifier kanye nokusabela okokufaka noma i-inductor yesixhumanisi yamanje (DC) eqondile kwanele ukuhlangabezana nesincomo esiphezulu sokuhlanekezelwa kwamandla kagesi.Kunjalo, uma kuqhathaniswa ne-6-pulse inverter engenakho i-inductor kusixhumanisi, ukusebenzisa inverter ene-DC link inductor (njenge-WEG's own CFW11, CFW700, kanye ne-CFW500) inganciphisa kakhulu imisebe ye-harmonic.
Uma kungenjalo, kunezinye izinketho ezimbalwa zokunciphisa i-harmonics yesistimu kuzinhlelo zokusebenza ze-inverter, esizozethula lapha.
Isixazululo esisodwa sokunciphisa i-harmonics ukusebenzisa i-inverter ene-12-pulse rectifier.Kodwa-ke, le ndlela ivame ukusetshenziswa kuphela lapho i-transformer isivele ifakiwe;kuma-inverter amaningi axhunywe kusixhumanisi esifanayo se-DC;noma uma ukufakwa okusha kudinga i-transformer enikezelwe ku-inverter.Ngaphezu kwalokho, lesi sixazululo sifanele amandla kagesi ngokuvamile angaphezu kuka-500 kilowatts (kW).
Enye indlela ukusebenzisa i-6-pulse active current (AC) drive inverter ene-passive filter kokokufaka.Le ndlela ingaxhumanisa amazinga kagesi ahlukene-ama-harmonic voltages phakathi kwe-medium (MV), i-voltage ephezulu (HV) kanye ne-voltage ephezulu eyengeziwe (EHV)-futhi isekele ukuhambisana futhi iqede imiphumela emibi emishinini ebucayi yamakhasimende.Nakuba lokhu kuyisixazululo sendabuko sokunciphisa ama-harmonics, kuzokwandisa ukulahlekelwa ukushisa futhi kunciphise isici samandla.
Lokhu kusiletha endleleni engabizi kakhulu yokunciphisa ama-harmonics: sebenzisa i-inverter ene-18-pulse rectifier, noma ikakhulukazi idrayivu ye-DC-AC enikwa amandla isixhumanisi se-DC ngesilungisi se-pulse engu-18 kanye nesiguquli esishintshayo sesigaba.I-pulse rectifier iyisixazululo esifanayo noma ngabe i-12-pulse noma i-18-pulse.Nakuba lokhu kuyisixazululo sendabuko sokunciphisa ama-harmonics, ngenxa yezindleko zayo eziphakeme, ngokuvamile sisetshenziswa kuphela lapho i-transformer ifakiwe noma i-transformer ekhethekile ye-inverter iyadingeka ukuze kufakwe ukufakwa okusha.Amandla ngokuvamile angaphezu kuka-500 kW.
Ezinye izindlela zokucindezela i-harmonic zandisa ukulahlekelwa ukushisa futhi zinciphisa isici samandla, kuyilapho ezinye izindlela zingathuthukisa ukusebenza kwesistimu.Isixazululo esihle esisincomayo ukusebenzisa izihlungi ezisebenzayo ze-WEG ezinamadrayivu angu-6-pulse AC.Lesi yisixazululo esihle kakhulu sokuqeda ama-harmonics akhiqizwa amadivaysi ahlukahlukene
Ekugcineni, lapho amandla engenziwa kabusha kugridi, noma lapho amamotho amaningi eqhutshwa isixhumanisi esisodwa se-DC, esinye isisombululo siyakhanga.Okusho ukuthi, idrayivu evuselelayo yangaphambili (AFE) nesihlungi se-LCL kusetshenziswa.Kulesi simo, umshayeli une-rectifier esebenzayo kokokufaka futhi uhambisana nemikhawulo enconyiwe.
Kuma-inverter angenaso isixhumanisi se-DC-njenge-WEG's own CFW500, CFW300, CFW100 kanye nama-inverters angu-MW500-isihluthulelo sokunciphisa ama-harmonics ukusabela kwenethiwekhi.Lokhu akuxazululi kuphela inkinga ye-harmonic, kodwa futhi kuxazulula inkinga yamandla agcinwe engxenyeni esebenzayo ye-inverter futhi ingasebenzi.Ngosizo lokusabela kwenethiwekhi, i-inverter ye-high-frequency single-phase elayishwe inethiwekhi ye-resonant ingasetshenziswa ukubona ukusabela okulawulwayo.Inzuzo yale ndlela ukuthi amandla agcinwe ku-reactance element aphansi futhi ukuhlanekezela kwe-harmonic kuphansi.
Kukhona ezinye izindlela ezisebenzayo zokubhekana nama-harmonics.Enye iwukuba kwandiswe inani lemithwalo yomugqa ngokuhlobene nemithwalo engeyona yomugqa.Enye indlela iwukuhlukanisa amasistimu okuphakela amandla emithwalweni eqondile nengaqondile ukuze kube nemikhawulo ehlukene ye-voltage ye-THD phakathi kuka-5% no-10%.Le ndlela ihambisana nezincomo zobunjiniyela ezibalulwe ngenhla (EREC) G5 kanye ne-EREC G97, esetshenziselwa ukuhlola ukuhlanekezelwa kwamandla kagesi we-harmonic wezitshalo nemishini engaqondile kanye ne-resonant.
Enye indlela ukusebenzisa i-rectifier enenani elikhulu lama-pulses futhi uyifake ku-transformer enezigaba eziningi zesibili.Ama-multi-winding transformers anama-winding amaningi ayisisekelo noma esibili angaxhunywa komunye nomunye ngohlobo olukhethekile lokucushwa ukuze anikeze izinga le-voltage elidingekayo elidingekayo noma ukushayela imithwalo eminingi ekuphumeni, ngaleyo ndlela anikeze izinketho eziningi ekusabalaliseni amandla kanye nohlelo lokuguquguquka.
Ekugcineni, kukhona ukusebenza kokuvuselela kabusha kwe-AFE okukhulunywe ngenhla.Amadrayivu e-AC ayisisekelo awavuseleleki, okusho ukuthi awakwazi ukubuyisela amandla kumthombo wamandla-lokhu akwanele ikakhulukazi, ngoba kwezinye izinhlelo zokusebenza, ukubuyisela amandla abuyisiwe kuyimfuneko ethile.Uma amandla okukhiqiza kabusha adinga ukubuyiselwa kumthombo wamandla we-AC, lena indima yedrayivu yokuvuselela.Ama-rectifiers alula athathelwa indawo yi-AFE inverters, futhi amandla angatholwa ngale ndlela.
Lezi zindlela zinikeza izinketho ezihlukahlukene zokulwa nama-harmonics futhi zifanele izinhlobo ezahlukene zezinhlelo zokusabalalisa amandla.Kodwa futhi angakwazi ukonga amandla futhi abize kakhulu ezinhlelweni ezihlukahlukene futhi ahambisane nezindinganiso zamazwe ngamazwe.Lezi zibonelo zibonisa ukuthi inqobo nje uma kusetshenziswa ubuchwepheshe obufanele be-inverter, inkinga engeyona yomugqa ngeke kube nzima ukuyixazulula.
For more information, please contact: WEG (UK) LtdBroad Ground RoadLakesideRedditch WorcestershireB98 8YPT Tel: +44 (0)1527 513800 Email: info-uk@weg.net Website: https://www.weg.net
Inqubo nokulawula Namuhla akunasibopho sokuqukethwe kwezindatshana ezithunyelwe noma ezikhiqizwe ngaphandle nezithombe.Chofoza lapha ukuze usithumele i-imeyili esazisa nganoma yimaphi amaphutha noma ukweqiwa okuqukethwe kulesi sihloko.