Kusankha Zipangizo Zoteteza Kukwera kwa Machitidwe a PV - Mitundu ya SPDs

Kupanga magetsi a Photovoltaic (PV) ndi gwero lofunika kwambiri la mphamvu zongowonjezedwanso ndipo ndi kopikisana kwambiri pazachuma poyerekeza ndi kupanga magetsi kwachikhalidwe. Makina ang'onoang'ono a PV ogawidwa, monga mapanelo a dzuwa padenga, akutchuka kwambiri. Makina a PV pamwamba pa denga amagwiritsa ntchito kugawa kwa AC ndi DC komwe ma voltage amafika mpaka 1500V. Mbali ya DC, makamaka mapanelo a PV, amatha kukumana mwachindunji ndi mphezi m'malo omwe ali pachiwopsezo chachikulu, zomwe zimapangitsa kuti azivutika ndi kuwonongeka kwa mphezi.

Chitetezo cha mphezi cha nyumba chimagawidwa m'magulu awiri: chitetezo chakunja (LPS) ndi chitetezo chamkati (Surge Protective Measures, SPM), kutengera chiopsezo cha mphezi. Zipangizo Zoteteza Kugwedezeka (SPDs), monga gawo la chitetezo chamkati, zimateteza ku ma voltage osakhalitsa omwe amayambitsidwa ndi mphezi yamlengalenga kapena ntchito zosinthira. Ma SPD amayikidwa kunja kwa zida zotetezedwa ndipo makamaka amagwira ntchito motere: pamene palibe kugwedezeka mu dongosolo lamagetsi, SPD simakhudza kwambiri magwiridwe antchito abwinobwino a dongosolo lomwe limateteza. Pamene kugwedezeka kumachitika, SPD imapereka kugwedezeka kochepa, kutembenuza mphamvu ya kugwedezeka kudzera yokha ndikuchepetsa mphamvu yamagetsi kufika pamlingo wotetezeka. Kugwedezeka kwadutsa ndipo mphamvu yotsala iliyonse yatha, SPD imabwerera ku mkhalidwe wapamwamba wa kugwedezeka.

1. Malo Okhazikitsira Zipangizo Zoteteza Kuthamanga (SPD)

Malo oyika ma SPD amatsimikiziridwa malinga ndi kuchuluka kwa chiwopsezo cha mphezi komanso kutengera lingaliro la Lightning Protection Zones (LPZ) mu IEC 62305. Ma overvoltage osakhalitsa amachepetsedwa pang'onopang'ono kufika pamlingo wotetezeka, womwe uyenera kukhala pansi pa voltage yolimba ya zida zotetezedwa. Monga momwe zasonyezedwera pachithunzichi, ma SPD amayikidwa m'malire a madera awa, zomwe zimapangitsa kuti pakhale lingaliro la chitetezo cha ma surge cha magawo ambiri chomwe chimagwiritsidwa ntchito m'makina otsika mphamvu zamagetsi. Pa makina a PV, cholinga chachikulu ndikuletsa ma surge a mphezi kulowa m'mbali mwa AC ndi DC, potero kuteteza zigawo zofunika monga ma inverter.

2. Makalasi Oyesera Zipangizo Zoteteza (SPD)

Malinga ndi IEC 61643-11, ma SPD amagawidwa m'magulu atatu oyesera kutengera mtundu wa mphamvu yamagetsi yomwe adapangidwira kuti ipirire. Mayeso a Type I (olembedwa ngati T1) cholinga chake ndi kutsanzira mafunde amagetsi ochepa omwe angachitike mnyumba. Izi zimagwiritsa ntchito mawonekedwe a mafunde a 10/350 µs, monga momwe zasonyezedwera pachithunzi, ndipo nthawi zambiri amagwiritsidwa ntchito pamalire pakati pa LPZ0 ndi LPZ1—monga pama board ogawa main kapena ma transformer otsika mphamvu. Ma SPD a mulingo uwu nthawi zambiri amakhala amtundu wosinthira mphamvu zamagetsi, okhala ndi zinthu monga machubu otulutsa mpweya kapena mipata ya spark (monga, mipata ya nyanga kapena mipata ya graphite).

Mayeso a Mtundu Wachiwiri (T2) ndi Mtundu Wachitatu (T3) amagwiritsa ntchito ma impulses a nthawi yochepa. Ma SPD a Mtundu Wachiwiri nthawi zambiri ndi zida zochepetsera mphamvu zamagetsi zomwe zimagwiritsa ntchito zigawo monga metal oxide varistors (MOVs). Amayesedwa ndi nominal discharge current pogwiritsa ntchito 8/20 µs current waveform (onani Chithunzi chophulika), ndipo ali ndi udindo wochepetsa mphamvu ya ma surge voltage yotsalira kuchokera ku chipangizo choteteza cham'mwamba. Mayeso a Mtundu Wachitatu amagwiritsa ntchito jenereta ya mafunde ophatikizana yokhala ndi 1.2/50 µs voltage ndi 8/20 µs current impulse (onani Chithunzi pansipa), zomwe zimayesa ma surges pafupi ndi zida zogwiritsidwa ntchito kumapeto.

3. Mtundu Wolumikizira wa Chipangizo Choteteza Kuthamanga (SPDs)

Pali njira ziwiri zazikulu zodzitetezera ku ma voltage opitilira nthawi. Choyamba ndi chitetezo cha common-mode (CT1), chomwe chimapangidwa kuti chiteteze ku ma surges pakati pa ma conductor amoyo ndi PE (protective earth). Mwachitsanzo, kugunda kwa mphezi kungayambitse ma voltage apamwamba poyerekeza ndi nthaka mu dongosolo. Chitetezo cha common-mode chimathandiza kuchepetsa kukhudzidwa kwa zosokoneza zakunja, monga mphezi, monga momwe zasonyezedwera pansipa.

Chachiwiri ndi chitetezo cha differential-mode (CT2), chomwe chimateteza ku mafunde pakati pa conductor wa mzere (L) ndi conductor wa neutral (N). Chitetezo chamtunduwu ndi chofunikira kwambiri pothana ndi mavuto amkati, monga phokoso lamagetsi kapena kusokoneza komwe kumachitika mkati mwa makinawo, monga momwe zasonyezedwera pachithunzichi pansipa.

Mwa kugwiritsa ntchito njira imodzi kapena zonse ziwiri zotetezerazi, makina amagetsi amatha kutetezedwa bwino ku magwero omwe angagwere, zomwe zimapangitsa kuti zida zolumikizidwa zikhale zokhalitsa komanso zodalirika.

Ndikofunika kudziwa kuti kusankha njira zotetezera za SPD kuyenera kugwirizana ndi njira yokhazikitsira pansi yomwe ilipo. Pa makina a TN, njira zonse zotetezera za CT1 ndi CT2 zingagwiritsidwe ntchito. Komabe, mu makina a TT, CT1 ingagwiritsidwe ntchito pansi pa RCD. Mu makina a IT—makamaka omwe alibe conductor wa neutral—chitetezo cha CT2 sichigwira ntchito. Ichi ndi chinthu chofunikira kwambiri chomwe chiyenera kuganiziridwa mu makina ogawa a DC omwe amagwiritsa ntchito makina okhazikitsira pansi a IT. Zambiri zingapezeke mu tebulo ili m'munsimu.

4. Ma Parameters Ofunika a Zida Zoteteza Zowonjezereka (SPD)

Malinga ndi muyezo wapadziko lonse wa IEC 61643-11, makhalidwe ndi mayeso a ma SPD olumikizidwa ku machitidwe ogawa mphamvu zamagetsi otsika afotokozedwa, monga momwe zasonyezedwera pa Chithunzi 7.

(1) Mlingo Woteteza Voltage (Kukwera)

Chofunika kwambiri posankha SPD ndi mulingo wake woteteza magetsi (Mmwamba), womwe umadziwika ndi magwiridwe antchito a SPD pochepetsa magetsi pakati pa ma terminal. Mtengo uwu uyenera kukhala wapamwamba kuposa mphamvu yayikulu yolumikizira magetsi. Umafikiridwa pamene mphamvu yodutsa mu SPD ikufanana ndi mphamvu yotulutsa magetsi ya nominal. Mulingo woteteza magetsi wosankhidwa uyenera kukhala wotsika kuposa mphamvu yolimbana ndi mphamvu ya Uw ya katundu. Pankhani ya kugunda kwa mphezi, mphamvu yodutsa ma terminal a SPD nthawi zambiri imakhala pansi pa Up. Pa makina a PV DC, katundu nthawi zambiri amatanthauza ma module a PV ndi ma inverter.

(2) Voltage Yogwira Ntchito Yopitirira (Uc)

Uc ndiye mphamvu yayikulu kwambiri ya DC yomwe ingagwiritsidwe ntchito mosalekeza ku SPD protection mode. Imasankhidwa kutengera mphamvu yovotera ndi kasinthidwe ka grounding ya system ndipo imagwira ntchito ngati gawo loyatsa magetsi la SPD. Pa mbali ya DC ya PV systems, Uc iyenera kukhala yayikulu kuposa kapena yofanana ndi Uoc Max ya PV array. Uoc Max imatanthauza mphamvu yayikulu kwambiri yotseguka pakati pa ma live terminals ndi pakati pa live terminal ndi ground pamalo osankhidwa a PV array.

(3) Kutulutsa Kwadzina (Mu)

Iyi ndi mtengo wapamwamba kwambiri wa mphamvu ya mafunde ya 8/20 μs yomwe ikuyenda kudzera mu SPD, yomwe imagwiritsidwa ntchito poyesa Mtundu Wachiwiri komanso poyesa kukonza zinthu mu Mtundu Woyamba ndi Mtundu WachiwiriIEC imafuna kuti SPD ikhale yolimba ndi mphamvu yamagetsi ya 8/20 μs yosachepera 19. Mtengo wa In ukakwera, nthawi ya moyo wa SPD imakhala yayitali, koma mtengo wake umawonjezekanso.

(4) Mphamvu ya Mphamvu (Iimp)

Potanthauzidwa ndi magawo atatu: current peak (Ipeak), charge (Q), ndi specific energy (W/R), current iyi imagwiritsidwa ntchito mu Mtundu Woyamba Mayeso. Mafunde achizolowezi ndi 10/350 μs.