Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu.
Kuhlongozwe uxhumano lwe-inverter yesigaba sesithathu ngoxhumo olungathathi hlangothi okungukuthi, isigaba sesithathu se-wire inverter siyaphakanyiswa. Uhlelo lwe-UPS luphakelwa i-inverter yezintambo zesigaba sesine kanye ne-voltage yephoyinti engathathi hlangothi yomthwalo iphansi ukuze ihlangabezane nemfuneko yesistimu. Ama-inverter emilenze emine ahlinzeka ngempumelelo ukuxhumana okungathathi hlangothi kusistimu yezintambo zesigaba sesine. Zisetshenziswa ezinhlelweni eziningi zokuphatha amandla amanje angathathi hlangothi okubangelwa umthwalo ongalingani futhi ongawumugqa. Umthwalo ongalinganiseli uba ongewona umugqa lapho ukungathathi hlangothi kwemithwalo kufinyeleleka khona. I-inverter yemilenze emine ikhiqiza ama-voltage amathathu okukhiphayo ngokuzimela ngomlenze owodwa owengeziwe. Isici esiyinhloko se-inverter yezigaba ezintathu ezinomlenze owengeziwe ongathathi hlangothi yikhono layo lokubhekana nokungalingani komthwalo ohlelweni. Umgomo we-inverter yesigaba sesine sesigaba sesine ukugcina i-waveform ye-voltage ye-sinusoidal oyifunayo kuzo zonke izimo zokulayisha nezidlulayo. Uxhumo oluphakathi nendawo lukhona ukuphatha amandla aphansi ngenxa yemithwalo engalingani. Ukuba nokwenzeka kwenqubo ehlongozwayo yokuguquguquka kuqinisekiswa nguMatlab/Simulink.
Indlela entsha yokulungisa isilawuli samandla aqondile esijwayelekile (i-DPC) kuzinhlelo zokusebenza zamandla aphezulu, lapho isihlungi se-LCL ye-oda lesithathu sidingeka njalo. Isihlungi se-LCL singabangela ukuzwakala okunamandla futhi sidinga umzamo owengeziwe wokulawula isistimu. Ukusetshenziswa kwe-DPC yokulawula isiguquli somthombo wamandla kagesi wokuxhumeka kwesigaba sesithathu esixhunywe kugridi ngesihlungi akukakacatshangelwa. Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu.Ukwengezwa kwesu elisebenzayo lokudambisa, kanye neluphu yokulawula ukwenqatshwa kwe-harmonic, ku-DPC evamile kuhlongozwa futhi kuhlaziywe kuleli phepha. Isimo sokuzinza, kanye nokusebenza okuguquguqukayo kwesistimu ehlongozwayo, kuqinisekiswa ngemiphumela yokulingisa nezilinganiso zokuhlola.
Ukulawula okuqondile kwe-current-space-vector yesihlungi samandla asebenzayo (APF) okusekelwe ekuxhumekeni kwe-inverter yezigaba ezintathu. Indlela ehlongozwayo yakha inkomba yamanje yesinxephezelo ngokungaqondile ngokusebenzisa indlela efanayo yokwenziwa kwengxenye ebalulekile kusetshenziswa isilawuli sikagesi se-dc-link se-APF. Isilawuli esihlongozwayo singakhetha ngokukhetha izingxenye zamanje ezivumelanayo ngenguquko yesikhathi sangempela ye-Fourier esheshayo ukuze kukhiqizwe isinxephezelo samanje. Imali yesinxephezelo imelwe kusistimu yokuxhumanisa eshintshayo enezimo ezikhethiwe zokushintsha kusuka kuthebula elishintshayo elisetshenziswe kuhlelo lwesango elihlelekayo. Ukwengeza, i-APF yezigaba ezine ezinezintambo ezisekelwe ku-inverter enamaleveli amathathu angathathi hlangothi nendawo eboshwe nayo iye yethulwa. I-APF ehlongozwayo iqeda ama-harmonics kuzo zontathu izigaba kanye ne-neutral current. Isistimu ye-inverter ye-NPC yezigaba ezintathu enezintambo ezintathu ingasetshenziswa njengesistimu yezintambo ezine zezigaba ezintathu kusukela ama-split dc capacitor ahlinzeka ngokuxhuma okungathathi hlangothi.
Ukuba khona okwandayo kwamajeneretha asabalalisiwe esigaba esisodwa kanye nemithwalo engalingani ohlelweni lwamandla kagesi kungase kuholele ekungalinganini kwama-voltage ezigaba ezintathu, okuholela ekwenyukeni kokulahlekelwa nokushisa. Ama-opharetha enethiwekhi yokusabalalisa (ama-DNO) aya ngokuya ephonselwa inselelo yokugcina ikhwalithi yamandla edingekayo. Ukunciphisa ukungalingani kwamandla kagesi ama-DNO afuna ukuxhuma amayunithi amakhulu e-DG ezigabeni ezintathu esikhundleni soxhumano lwesigaba esisodwa. Uxhumano lwe-inverter yezigaba ezintathu lungabonakala ngokuxhuma kwe-inverter yezigaba ezintathu noma nge-inverter yezigaba ezintathu. I-inverter topology ngayinye ingasetshenziswa ngamasu ahlukene okulawula. Isilawuli singahlonyiswa ngemisebenzi yokuhlunga amandla asebenzayo engathuthukisa ikhwalithi yamandla. Kuleli phepha, umphumela wokuxhuma amayunithi e-DG ngokusebenzisa uxhumano lwe-inverter yezigaba ezintathu zokuxhuma kwesigaba esisodwa ekungalinganini kwe-voltage kuyafundwa.
Uxhumano lochungechunge lwamaseli wamandla ekucushweni kwe-asymmetrical cascaded kusiza ukukhansela amaleveli okukhiphayo angafuneki futhi kwandise inani lamaleveli ahlukene akhiqizwe isiguquli. Ukucushwa okusha kokuxhumeka kwe-inverter yezigaba ezintathu ze-asymmetrical cascaded voltage source inverter kuvezwa. Lesi sakhiwo siqukethe amabhulokhi ama-inverters axhumeke kuchungechunge axhunywe ku-sub-multilevel. Inani lamaswishi asetshenzisiwe, amasekhethi abashayeli bamasango avaleleke, ukuma kwamandla kagesi kumaswishi, indawo yokufaka kanye nezindleko zehliswe kakhulu. Ama-voltage e-DC e-Cascaded-cell emlenzeni ngamunye we-inverter akha ukulandelana kwe-arithmetic nomehluko ovamile we-E. Ngemithombo ekhethiwe ye-inverter DC, izindlela zokulawula ze-high-frequency pulse-width modulation (PWM) zingasetshenziswa ngempumelelo ngaphandle kokulahlekelwa imodularity. Amasu we-low-frequency kanye ne-sinusoidal PWM asetshenziswe ngempumelelo. Ngakho-ke, ukuguquguquka okuphezulu ekuguquguqukeni kwe-inverter ehlongozwayo kuyaboniswa.
I-inverter encane futhi enamandla kakhulu ekwazi ukubona isigaba samanje ngaphandle kokudinga ukuthuthukiswa kwesofthiwe yokulawula eyinkimbinkimbi futhi ngaphandle kokubangela noma yikuphi ukuhlanekezela kwamanje kunikezwa. Izinqamuleli ze-Shunt ezisebenza njengohlobo lomtshina wamanje zinikezwa, ngokulandelanayo, phakathi kwezinto ezishintsha izingalo eziphansi ezigabeni ezimbili kuphela—kanye nohlangothi lokususa lomthombo wamandla we-DC.Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu. Isikhathi esifanayo se-ON sincishisiwe kusukela kuzikhathi zoku-ON ze-elementi yokushintsha ingalo ephezulu kumjikelezo wenkampani yenethiwekhi ngokuphelele izigaba ezintathu. Ngakho, isigaba samanje sitholwa ezigabeni ezimbili ezinikezwe izithasiselo ze-shunt. I-inverter ingakwazi ukubona isigaba samanje ngaphandle kokwenza inkimbinkimbi isofthiwe yokulawula futhi ngaphandle kokubangela noma yikuphi ukuphazamiseka kwamanje, ngokulawula i-inverter circuit nge-software yokulawula ehlanganiswe kumjikelezo wokulawula ngokusebenzisa imigqa yokuxhuma.
Iziguquli zamandla ezinhlelweni zokuxhuma kugridi ngokuvamile zisebenzisa indlela ye-Sinusoidal Pulse-Width Modulation (SPWM). Izihlungi ze-Passive zisetshenziswa ukuze kuncishiswe ama-ripples amanje ashintshayo futhi kunciphise ukukhala phakathi kwegridi nesiguquli. I-oda lokuqala, i-oda lesibili, kanye nokuxhumeka kwe-inverter yezigaba ezintathu kuyizihlungi ezijwayelekile zamagridi axhumeke kwi-Voltage Source Inverters. Empeleni, ngenxa yosayizi wesistimu, isisindo, nezidingo zezindleko, isihlungi se-LCL sisetshenziswa kakhulu phakathi kwezinye ukuze kuhlanganiswe i-VSI yezigaba ezintathu kugridi. Kodwa-ke, ukuzinza kwesistimu yokulawula kuthintwa isici sokunciphisa isihlungi se-LCL ngakho-ke, sethula izinselele zenkinga yokulawula. Amasu amaningi okulawula afana nokuphindaphinda, ukubikezela, ukulawula i-multiloop, nokulawulwa kwe-hysteresis kuphakanyiswe ukuze kuthuthukiswe ukuzinza kwama-VSI axhunywe kugridi.
Isistimu ye-inverter yemodi ephindwe kabili yezigaba ezintathu yacwaningwa kuleli phepha, okufakwe kuyo kwakuyisistimu yebhange yebhethri ene-PV generation. Lolu hlelo lungasetshenziswa ngemodi yokuma yodwa ngokuxhuma kumthwalo wasendaweni futhi nangemodi exhunywe kugridi ngokuhambisana negridi. Uma ikwimodi yokuma yodwa, isistimu yayisebenza njengomthombo wamandla kagesi, kuyilapho lapho ikumodi exhunywe kugridi, ukuphuma kwe-inverter kwakulawulwa kulandelwa ngegridi. I-algorithm yenguquko yokuvimbela ukungena ngaphakathi kwamanje kanye nokutholwa okusheshayo kwesimo seswishi kanye negridi qinisekisa ukuthi uguquko olungenazihibe phakathi kokuxhunywa kwegridi nokuma wodwa. Lolu hlelo lwe-inverter lunenzuzo yesakhiwo esilula futhi kulula ukusisebenzisa, kangangokuthi belufaneleka kugridi encane.
Umsebenzi ohlongozwayo owokuklama isiguquli sikagesi samandla ukuze kwehliswe izindaba zekhwalithi yamandla. Ngenxa yokusetshenziswa okwandisiwe kweziguquli zikagesi zamandla okucubungula amandla, izinkinga zekhwalithi yamandla ziba isihloko esishisayo socwaningo esikhathini esidlule. Njengoba izinga lamandla likhula, izinga likagesi liyakhuphuka ngokufanele ukuze kutholwe ukusebenza kahle okugculisayo. Phakathi namashumi eminyaka adlule, isilinganiso samandla kagesi sokushintshwa ngokushesha kwama-semiconductors kagesi aphezulu njengeSango Elingafakwanga i-Bipolar Transistor (IGBT) sinyukile. Noma kunjalo, kunesidingo sokuxhuma kochungechunge lokushintshwa kwamadivaysi. Kule ndawo yezinhlelo zokusebenza, isiguquli samandla esinezinga eliphezulu sibonise ukuthandwa okukhulayo. Izinzuzo ezibalulekile zama-multilevel converter topology amaza okukhiphayo ahlanekezelwe aphansi kanye nengcindezi kagesi elinganiselwe kumadivayisi ashintshayo yingakho nokuphazamiseka kazibuthe kagesi okuncishisiwe kumagagasi okukhiphayo. Ububi obuyinhloko buyinkimbinkimbi ephakeme kanye nokulawula okunzima kakhulu kodwa kunganqotshwa ngokusebenzisa izilawuli zesimanje zedijithali.
Inokwakhiwa okufanayo ne-inverter yokuxhumana yezigaba ezintathu ezivamile exhunywe ohlelweni olulodwa lokusabalalisa lwezintambo ezintathu. Yize isifunda esihlongozwayo singenaso isiguquli esiphumayo, singenziwa ngokulinganayo njengesiguquli sesigaba esisodwa esiphindwe kabili se-cascade ngokuphambukisa isiguquli sesigxobo ohlelweni lokusetshenziswa. Ngokulawula uhlelo olufanele, ama-currents okukhiphayo angatholakala njengoba ama-waveforms anamazinga amahlanu kanye nokuhlanekezela kwawo kungancishiswa ngokwanele. Isetshenziswa kusistimu yokugcina amandla kagesi esebenzisanayo namabhethri futhi izici eziyisisekelo zokulahla kuxoxwa ngazo ngokuhlola.
Ngokukhula kokusetshenziswa kwemithombo evuselelekayo, ucwaningo lwezinhlelo zokulawula zokulawula kangcono amasistimu okukhiqiza asabalalisiwe kanye noxhumo lwegridi selubaluleke kakhulu ukuze kuzuzwe ukuzinza okungcono kohlelo. Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu.Le thesis ihlinzeka ngocwaningo lohlelo lokulawula lokuxhumana phakathi komthombo we-DC kanye negridi ye-AC. Isikimu sokulawula esingase sibe khona siyafundwa futhi silingiswe ku-Simulink. Ukuziphatha kwesistimu kuhlaziywa ngokuyifaka ngaphansi kwezinguquko ezihlukene kumapharamitha nezimo zegridi. Ukuqaliswa kohlelo kwenziwa kusetshenziswa imodeli ye-dSpace neSimulink. Ukuqaliswa kwe-Low Voltage kuphela kwenziwa futhi kuhlolwe kule thesis.
Ukusetshenziswa kwama-voltage ezigaba ezintathu (iziguquli ze-DC kuya ku-AC) kuvame ukuhlangatshezwana nazo ohlelweni lwamandla kagesi, njengakuxhumano lwe-photovoltaics nayo yonke igridi. Iphepha lihlongoza indlela yokulawula impendulo engaqondile yokuxhumeka kwe-inverter yezigaba ezintathu, esekelwe kumbono wokuhluka okucaba kanye nendlela entsha yokuhlunga engaqondile ngaphansi kwegama Isihlungi se-Derivative-free nonlinear Kalman. Okokuqala, kuboniswa ukuthi imodeli eguquguqukayo ye-inverter iyisicaba esihlukile. Lokhu kusho ukuthi zonke izinto eziguquguqukayo zesimo kanye nokokufaka kokulawula kungabhalwa njengemisebenzi yokuguquguquka okukodwa kwe-algebra okuwumphumela oyisicaba. Ngokuxhashazwa kwezakhiwo ezihlukanisiwe ze-flatness kuboniswa ukuthi imodeli ye-inverter ingashintshwa ibe yifomu le-canonical (kaBrunovsky). Ukuze uthole incazelo yakamuva ukwakheka kwesilawuli sempendulo yombuso kungenzeka, isb ukusebenzisa izindlela zokubeka izigxobo. Ngaphezu kwalokho, ukuze ulinganisele okuguquguqukayo kwesimo esingalinganiseki sokulingana komugqa kwesiguquli, Kusetshenziswa Isihlungi se-Kalman esingenayo i-Derivative-free nonlinear siyasetshenziswa.
Imodeli yezibalo esekelwe kumbono wePaki ivumela ukuhlaziywa kwe-spectrum yonke (imoto kagesi ; i-frequency inverter) ukushayela ibhasi yetroli kagesi eyenziwe ku-ASTRA Bus Arad. Ukususa ama-harmonics we-oda eliphakeme, i-waveform ye-PWM ye-voltage yokunikezela isetshenziswa, isethwe esimweni esijwayelekile. Izici zokusebenza ze-electric motor drive zisethelwe ku-sub-nominal frequency kanye nama-engeli ahlukene wezinto ezishintshayo zokulawula ekwakhiweni kwe-inverter. Ukungezwani ku-stator yomshini olinganayo kunqunywa izingxenye ezintathu: ingxenye eyisisekelo; ingxenye yesibili ehambisana ne-harmonics yezinga eliphakeme, elijikelezayo ngokuxhuma okuqondile; kanye nengxenye yesithathu efanelekile yama-harmonics wezinga eliphakeme, azungeziswa ngokuhlehla. Imodeli yezibalo eyenziwe izosiza ukunquma ama-harmonics anethonya elibi ekusebenzeni.
Ithesis iphathelene nokusetshenziswa kwesistimu yokugcina amandla e-flywheel kuhlelo lokusebenza lokulinganisa umthwalo. Umsebenzi owethulwe uqukethe izingxenye ezimbili, okokuqala, ukuhlolwa kwezinhlelo zokukala umthwalo wensiza nge-FESS njengendawo yokugcina amandla, futhi okwesibili, ukuthuthukiswa kokusebenzelana kwe-elekthronikhi kwamandla e-FESS kunsizakalo. Ithesis yethula ucwaningo lokuhlola izikimu zokulinganisa umthwalo we-FESS enkampanini yase-UK yokuphakela nokusabalalisa ugesi. Ihlonza futhi ilinganise izindleko nezinzuzo zezinhlelo, futhi yenza ukuhlolwa kwezimali okusekelwe Kuvelu Yamanje Yamanje kanye Nesilinganiso Sangaphakathi Sezindlela Zokubuyisela. Imiphumela ibonisa ukuthi izikimu ze-DSM ezisebenzisa i-FESS zingasebenza ngokwezimali ibhizinisi lase-UK lokuphakela nokusatshalaliswa kukagesi esimweni se-FESS esikhiqizwa ngobuningi, futhi sinikeze abakhiqizi nabathuthukisi be-FESS imigomo yezindleko zezicelo ezinjalo. Iziphetho ezifinyelelwe zinikeza ugqozi lolunye ucwaningo lobuchwepheshe olwenziwa ngaphakathi kohlelo lomsebenzi.
Uma kuqhathaniswa nezilawuli zendabuko ezifana ne-PI esekelwe kokuthiyori yokulawula yakudala, i-athikili isebenzisa ithiyori yokulawula yokwenziwa ekwakhiweni kwezilawuli ze-inverter ezixhunywe kugridi ye-LCL yezigaba ezintathu. Imodeli yezibalo yesistimu esekelwe ku-Euler-Lagrange iyasungulwa, futhi indlela yokudambisa isicupho isetshenziselwa ukucindezela ama-resonance spikes akhiqizwa uhlelo, ukuze uhlelo luhlangabezane nezidingo zokuxhuma kwegridi. Imiphumela yokulingisa iqinisekisa ukuba nokwenzeka kwesikimu.
Njengesixhumi esibonakalayo sezentengiso, ama-voltage-source inverters (VSI) ezigaba ezintathu ajwayele ukuhlonyiselwa ukuguqulwa kwamandla ukuze athekelise amandla e-DC ukusuka esizukulwaneni esisabalaliswe kakhulu (i-DG) ukuya ensizeni ye-AC. Akukhona nje kuphela ukuthi iziguquli zomthombo wamandla kagesi zithatha umthwalo wokuguqula amandla emithwalo kodwa zisekela i-voltage yegridi endaweni yokuxhumana okuvamile (PCC) futhi, okuncike esimweni semithwalo exhunywe kugridi. Leli phepha lihlola ukungqubuzana komngcele kanye nendlela yakho yokusebenzisana phakathi kwe-VSI, imithwalo ehlanganayo ephikisayo namagridi, okubonisa njengokuvela okushintshanayo kwemisebenzi yokuguqula nokulungisa, lapho ukusebenza okuvamile kunqanyulwa futhi kucatshangwe okusha.Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu. Umthelela wazo ofanayo kwikhwalithi yamandla ephenywayo uzodala inkinga yokuzinza kwesekhethi bese uwohloka nakakhulu amandla okulawula amandla kagesi e-VSI ngokukhuphula ngendlela emangalisayo ama-harmonic kagesi wegridi. Kutholakala ngombono ogxile ekuklanyweni ukuthi ukusebenza kokushayisana komngcele kuzokwenziwa ngaphakathi kwendawo yepharamitha engafanele mayelana nezintambo zokudlulisela.
Namuhla ama-inverter asezingeni eliphezulu asetshenziswa kabanzi ezinhlelweni zikagesi zamandla. Ama-inverters ama-multilevel anconyelwe ukusetshenziswa kwamandla kagesi aphakathi nendawo naphezulu. Ama-inverters ama-multilevel asethandwa kakhulu ngenxa yokunciphisa ukulahlekelwa kokushintsha, izindleko eziphansi, ukuhlanekezela okuphansi kwe-harmonic namandla aphezulu kagesi uma kuqhathaniswa neziguquli ze-PWM zendabuko. Leli phepha likhuluma nge-hybrid multilevel converter ehlanganiswe yephoyinti elingathathi hlangothi elicishiwe kanye ne-cascaded inverter yamaleveli amaningi. Isiguquli se-multilevel esihlanganisiwe sihlongozwa ngezilinganiso zamandla amakhulu kagesi amaphakathi. Isiguquli esihlongozwayo esihlanganisa isiguquli somthombo wamandla kagesi esixhunywe namamojula angamahhafu ebhuloho esigabeni ngasinye. Ngoxhumano oluhlongozwayo ingxenye enkulu yamandla ingandulelwa yi-VSI ngokuxhuma isilungisi se-multipulse esisodwa. Amasheya amancane wamandla acutshungulwa ngaphakathi kwamamojula webhuloho elinguhhafu. Uhlelo lokumodulisa lwe-hybrid multilevel inverter lutholakala ngokwemvelo ngokusebenzisa i-logic circuit.
Ngokusetshenziswa okukhulayo kwama-inverters esizukulwaneni esisabalalisiwe, inkinga yama-harmonics ajovwe iba bucayi. Lawa ma-harmonics adinga ukuxhumeka kwezihlungi zokudlula okuphansi phakathi kwe-inverter nenethiwekhi. Leli phepha libonisa indlela yokuklama yesihlungi se-LC esiphumayo kuzinhlelo zokusebenza ezihlanganiswe negridi ezinhlelweni zokukhiqiza ezisabalalisiwe. Idizayini ihambisana namazinga e-harmonics anquma izinga lama-harmonics amanje afakwe kunethiwekhi yegridi. Izinkulumo zokuhlaziya ze-inductor ripple current ephezulu zithathwa. Idizayini ye-capacitor yesihlungi incike ezingeni elivumelekile lokushintshwa kwezingxenye ezifakwe kugridi. Kuphenywa futhi kucutshungulwe izindlela ezihlukene zokwehlisa isihlungi ukuze kuncishwe imithelela ye-resonance. Imiphumela efanisiwe ifakiwe ukuze kuqinisekiswe izinkulumo ezitholiwe.
I-inverter enamazinga amabili emilenze emine yenzelwe izinxephezelo zekhwalithi yamandla ezigaba ezintathu ezinezintambo ezine. Uma isetshenziswa kuzinxephezelo zomthamo ophakathi nendawo omkhulu, ingcindezi kagesi kuwo wonke iswishi ngayinye iphezulu kangangokuthi i-dv/dt ehambisanayo ibangela ukuphazamiseka okukhulu kozibuthe. I-multilevel voltage source inverter topology ithatha indawo enhle, ngoba inganciphisa ingcindezi kagesi futhi ithuthukise okuqukethwe kwe-harmonic okukhiphayo. I-inverter ekhona enamazinga amathathu e-neutral point clamped (NPC) ezimisweni zezintambo ezintathu zezintambo ezintathu ingasetshenziswa ezinhlelweni ezinezintambo ezine zezigaba ezintathu futhi, ngenxa yokuthi ama-dc capacitor ahlukanisayo ahlinzeka ngokuxhuma okungathathi hlangothi. Leli phepha lethula ucwaningo lokuqhathanisa phakathi kwe-inverter ye-NPC yemilenze emine enezinga ezintathu kanye ne-NPC eguquguqukayo enamazinga amathathu. Ukushintshwa kwevekhtha yasemkhathini okunezinhlangothi ezintathu (3DSVM) okusebenzayo okusheshayo nokujwayelekile okusebenzayo (XNUMXDSVM) kuphakanyiswe ukuze kulawulwe inverter ye-NPC enezigaba ezintathu kusistimu yezintambo ezine zezigaba ezintathu. Ingxenye yokulandelana kukaziro yevekhtha ngayinye icatshangelwa ukuze kusetshenziswe isinxephezelo samanje esimaphakathi.
Isiguquli esinezinhlangothi ezimbili singagcwalisa kokubili ukuxhumeka kwegridi nezindlela zokulungisa ngokulungisa isici samandla. Ukulawulwa okuhlongozwayo kuhlanganisa izindlela ezimbili, indlela eyodwa yokulawula umjikelezo womugqa (OLCRA) kanye nendlela yokulawula umugqa womugqa wesithupha (OSLCRA), ebhekelela amandla e-DC-bus kanye nokulawula amandla kagesi e-dc-bhasi ukulandelela ubudlelwano phakathi I-dc-bus voltage kanye ne-inverter inductor yamanje. Njengoba zombili lezi zindlela zokwenza zidinga ipharamitha yomthamo webhasi le-dc, leli phepha lethula kuqala ukunqunywa kosayizi we-dc-bus capacitor kanye nendlela yokulinganisa umthamo we-inthanethi. Nge-OLCRA, i-inverter ishuna i-voltage ye-dc-bhasi yonke imijikelezo yomugqa, enganciphisa imvamisa yoshintsho lwemodi yokusebenza kanye nokuhlanekezela kwamanje. I-OSLCRA ilungisa umyalo wamanje wonke umjikelezo womugqa owodwa wesithupha ukuze uvumelane nokuhlukahluka kwe-voltage yebhasi ye-dc.
Ukuxhumeka kwemithombo yamandla esabalalisiwe negridi yensiza ngokuvamile kudinga isiguquli samandla we-elekthronikhi ukuze kucutshungulwe amandla akhiqizwe endaweni kanye namandla afakayo kusistimu. Uma umthombo uhlinzeka nge-voltage ye-dc, isiguquli kufanele sikwazi ukukhiqiza i-ac current enokuhlanekezelwa okuphansi kwe-high-power-factor ac current. Izici ezifanayo ezihlobene ne-voltage kanye nokuhlanekezelwa kwamanje okukhiqizwa yimithwalo engaqondile kungacatshangelwa ukuze kufakwe amandla kugridi. Uma kungekho izinga elithile, leli phepha lithatha njengereferensi imikhawulo yama-harmonics amanje anikezwe izindinganiso zamazwe ngamazwe. Isizathu sale ndlela ukuthi, kusukela ekuwohlokeni kwe-voltage yomugqa, akukho mehluko phakathi kwama-currents ajovwe namuncwe. Leli phepha lethula i-inverter yezigaba ezintathu esebenzisa ukuguquguquka kwe-low-frequency. Isekethe eyisizayo yengezwa ku-inverter topology ukuze kuncishiswe ukuhlanekezelwa kwamandla kagesi, ngaleyo ndlela kuthuthukiswe i-waveform yamanje.
Ukuze kuphenywe ukusebenza kwesistimu yokuxhunywa kwegridi, isistimu yokuphehla amandla e-photovoltaic engu-50 kW okuhlanganisa ne-inverter yezigaba ezintathu ze-DC/AC iyaklanywa, yenziwe futhi yakhiwe. Leli phepha lichaza ukwakheka kwesistimu nokusebenza kweplanti ye-PV eboshwe ngegridi engu-50 kW, ehlanganisa amaseli elanga, i-DC/AC inverter, igridi yokusetshenziswa. Ikakhulukazi, uhlelo lokulawula lwesiguquli se-PWM esilawulwa manje sezigaba ezintathu sisebenzisa ukuguqulwa kwe-axis ye-dq siyethulwa, bese imiphumela yokuhlola ikhombisa ukuthi uhlelo oluhlongozwayo lunokuziphatha okuzinzile okuphezulu okunamandla okubumbana ekusebenzeni okusebenzisanayo. Futhi imiphumela yokuhlolwa kwenkundla ikhombisa ukuthi izinga lokusebenzisa uhlelo licishe libe ngu-13.4%.
Ukuzinza kwamasignali amancane kuwukukhathazeka okubalulekile ezigabeni ezintathu ze-inverter-based AC power systems. Indlela esekelwe ku-impedance esekelwe kumbandela ojwayelekile wokuqina we-Nyquist (GNC) ingahlaziya ukuzinza okuhlobene nezindlela ezimaphakathi neziphezulu zamasistimu. Nokho, i-GNC ibandakanya ukubalwa kwesigxobo sendiza eyingxenye yesokudla (i-RHP) yamatrices omsebenzi wokudlulisa isilinganiso sokubuya, angenakugwenywa ukuze kuhlaziywe ukuzinza kwezinhlelo zamandla e-ac eziyinkimbinkimbi. Ngakho-ke, idinga ulwazi oluningiliziwe lokulawula kwangaphakathi lwama-inverters, olungavamile ukutholakala kuma-inverters ezentengiselwano. Ukuze kubhekwane nalolu daba, leli phepha lethula Indlela Yokuxhumanisa Ingxenye (CCM) kusizinda semvamisa sokuhlaziywa kokuzinza kuhlaka lwe-dq oluvumelanisiwe, ngokuphakamisa indlela yokuthola i-matrix ye-impedance yamanethiwekhi oxhumano wezinhlelo zamandla we-ac asekelwe ku-inverter.
Amakhodi egridi ayabuyekezwa ukuze afake izidingo ezengeziwe zamandla avuselelekayo, njengoba amandla afakiwe enyuka. Ngakho-ke kuyadingeka ukuthuthukisa izinhlelo zokulawula ezikwazi ukufeza lezo zidingo ezintsha, ngokuvamile ezihlanganisa amandla okusebenza ngaphansi kwama-voltage egridi angalingani ngaphandle kokungcolisa igridi, phakathi kokunye. Leli phepha lethula i-inverter yezigaba ezintathu ukuze kuxhunywe amajeneretha e-photovoltaic kugridi, enephoyinti lamandla eliphakeme elifiphele kanye nekhono lokulawula amandla asebenzayo. Isici esiyinhloko se-inverter ukuthi uhlelo lokulawula lwenzelwe ukubhekana nezimo ze-voltage ezingalingani.
I-inverter ye-thyristor enamagatsha ahambisanayo angu-N ilawulwa umthombo wokuhlinzekwa kwe-impulse ngokuvamile ojabulisa ama-thyristors angawodwana egatsheni ngalinye ngokulandelana kwe-cyclic. Lapho kukhona ukugcwala ngokweqile egatsheni, umthombo we-impulse ushintshelwa kumodi yokukhipha ejabulisa ngesikhathi esisodwa wonke ama-thyristors e-inverter. Ikhoyili elahliwe egatsheni ngalinye le-inverter ichaza, ngesekethe esebenzayo ehlanganisa i-capacitor yokugcina exhunywe kuwo wonke amagatsha, i-oscillatory circuit. I-inductance yamakhoyili egatsha ikhethwa ngendlela yokuthi ngesikhathi semodi yokukhipha, i-oscillatory current inkulu ngobukhulu kune-overload yamanje. Ngakho-ke ama-thyristors e-inverter ayacinywa phakathi nomjikelezo wesigamu we-oscillation lapho i-polarity ye-oscillation iphikisana nalokho kwamandla okulayisha ngokweqile. Ngemuva kokucisha okunjalo, umthombo we-impulses ungase ukhutshazwe ukuvimbela ukuvutha kabusha kwama-thyristors, noma ushintshele kumodi yawo evamile.
I-DC kuya kwezigaba ezimbili ze-AC inverter ehlanganisa amasekhethi amathathu emodi yokushintsha umlenze owodwa noma isekethe yebhuloho enezigaba ezintathu kanye nesekethe yesilawuli/yomshayeli. Umjikelezo wesilawuli/womshayeli uhlanganisa ijeneretha ye-waveform engunxantathu kanye namajeneretha amabili ereferensi yereferensi ye-sinusoidal aphume esigabeni omunye komunye, ama-waveform e-sinusoidal akhiqizwa imvamisa yokuphuma kwe-AC oyifunayo, kanye ne-waveform engunxantathu ekhiqizwa imvamisa ephezulu. Isekhethi yesilawuli/yomshayeli ilungiselelwe ukuthi ishayele umlenze owodwa wesekethe yebhuloho ngomjikelezo womsebenzi ongu-50% kufrikhwensi ye-waveform engunxantathu kanye neminye imilenze emibili kufrikhwensi ye-waveform engunxantathu enamasignali aguquliwe obubanzi be-pulse, ububanzi be-pulse yesiginali ngayinye ehluka nge i-discrete eyodwa ye-waveforms ye-sinusoidal. Isigaba ngasinye se-AC yezigaba ezimbili sihlinzekwa yi-inverter phakathi komlenze oshayelwa kumjikelezo we-50% we-duty kanye ne-discrete yeminye imilenze.
Iziguquli zamandla ezinhlelweni zokuxhuma kugridi ngokuvamile zisebenzisa indlela ye-Sinusoidal Pulse-Width Modulation. Izihlungi ze-Passive zisetshenziswa ukuze kuncishiswe ama-ripples amanje ashintshayo futhi kunciphise ukukhala phakathi kwegridi nesiguquli. I-oda lokuqala, i-oda lesibili, kanye ne-topology yesihlungi se-oda lesithathu izihlungi ezijwayelekile zegridi exhunywe I-Voltage Source Inverters . Empeleni, ngenxa yosayizi wesistimu, isisindo, nezidingo zezindleko, isihlungi se-LCL sisetshenziswa kakhulu phakathi kwezinye ukuze kuhlanganiswe i-VSI yezigaba ezintathu kugridi. Kodwa-ke, ukuzinza kwesistimu yokulawula kuthintwa isici sokunciphisa isihlungi se-LCL ngakho-ke, sethula izinselele zenkinga yokulawula.Ukuhlaziywa kokuxhumeka kwe-inverter yezigaba ezintathu. Amasu amaningi okulawula afana nokuphindaphinda, ukubikezela, ukulawula i-multiloop, nokulawulwa kwe-hysteresis kuphakanyiswe ukuze kuthuthukiswe ukuzinza kwama-VSI axhunywe kugridi.
Ukusetshenziswa okwandayo kwezizukulwane ezisabalalisiwe ohlelweni lwamandla kungaholela ezinkingeni zokuvikela. Ngakho-ke, ezindleleni ezivamile, ama-DG kufanele anqanyulwe kugridi esimweni sephutha. Esimeni sokungena okuphezulu kwama-DG, leli su liholela enkingeni yokwehla kwamandla kagesi. Kuleli phepha, ama-DG asekelwe ku-inverter alawulwa kahle esimweni sephutha esikhundleni sokunqanyulwa kugridi. Le ndlela ibizwa ngokuthi i-fault ride through strategy. Imiphumela yokulingisa ibonisa ukuthi iphutha lamanje ligcinwa kububanzi obufunekayo kusetshenziswa i-algorithm ehlongozwayo kanye nokuxhumana kokuvikela ngaphambi kokuxhumeka kwe-DG kuhlala kungashintshi ngisho nangemva kokuxhumeka kwe-DG. Ngaphezu kwalokho, i-voltage sag ithuthukisiwe ngenxa yomjovo wamandla asebenzayo we-DG ngesikhathi sephutha. Ngaphezu kwalokho, le ndlela ayinazo izindleko ezengeziwe ngoba isu lokulawula elihlongozwayo lenziwa ku-inverter ehlanganisiwe futhi asikho isidingo sokusebenzisa izakhi ezengeziwe.
