Ib qho ntawm qhov sib txawv loj tshaj plaws ntawm cov nroj tsuag tsim dua tshiab- hnub ci ua liaj ua teb thiab cov phiaj xwm cua, piv txwv li- thiab cov khoom siv ib txwm muaj - lub zog hluav taws xob nyob hauv cov khoom siv hluav taws xob. Cov nroj tsuag no vam khom ntau ntawm cov kab faus, tsis yog cov kab hluav taws xob. Thiab cov kab hluav taws xob ntawd tso ncaj qha ntawm lub hwj chim kim - cov khoom siv hluav taws xob: inverters, DC cov khoom sib txuas, thiab cov ncoo- mounted transformers.
Qhov teeb meem tiag tiag pib nrog ib zaug -theem- mus rau - av faults - qhov peb hu ua qis - qhov ua txhaum hauv av tam sim no. Tus cwj pwm tsis muaj dab tsi zoo li qhov koj xav pom ntawm cov kab lus siv dav dav. Nyob rau hauv kev xyaum, cov faults no feem ntau tshwm sim raws li intermittent arcing. Lub ntsiab lus txhaum tsis nyob ruaj khov; Hloov chaw, nws tawg thiab rov zoo dua, tawm tsam ib qho arc ntau dua. Txhua retrike txhaj ib qho overvoltage nyob rau hauv lub system-feem ntau ob peb zaug nominal voltage. Qhov zoo ntawm kev rov ua dua tshiab yog kev puas tsuaj rau lub zog hluav taws xob. IGBT modules thiab DC- txuas capacitors hauv inverters tsuas yog tsis muaj qhov overvoltage margin uas ib txwm hloov pauv ua. Ob peb lub zog muaj zog tuaj yeem xuas nrig los ntawm cov rwb thaiv tsev, ua rau DC- sab yuam kev, thiab qhov phem tshaj plaws, ua rau muaj kev puas tsuaj loj - hluav taws thiab tawg nrog. Qhov ntawd tsis yog alarmist; nws yog qhov yooj yim physics.
Ntau cov nroj tsuag siv tsawg- tsis kam grounding, uas txhais tau hais tias kev tiv thaiv relay mus ncig ua si tam sim ntawd ntawm ib qho kev ua txhaum theem -. Suab huv si, tab sis nws ua rau mob taub hau sib txawv: koj yuav ua li cas thiaj paub qhov twg feeder lossis qhov sib koom ua tsis tau zoo? Ib qho nruab nrab - hnub ci ua liaj ua teb muaj peev xwm muaj tshaj li ib puas kilometers ntawm faus cable, nrog ntau pua splices. Thaum kev tiv thaiv tshem tawm tag nrho cov khoom noj khoom haus, cov neeg coob tau sab laug ntsia ntawm txoj hauv av ntev uas tsis muaj qhov pom tseeb. Qhov txhaum tuaj yeem yog kaum mais deb, faus rau hauv ib lub trench lossis ncaj qha - faus ntawm qee qhov nruab nrab -span splice. Yog tsis muaj qhov chaw meej, koj cov kev xaiv nkaus xwb yog txhawm rau txhawm rau khiav tag nrho lossis sim ua kom muaj kev pheej hmoo rov ua dua - zog. Thiab rov- ua kom lub zog ua haujlwm tsis raug cai hauv qhov tseem ceeb uas tsis muaj zog taw tes rau lwm qhov arc loj heev- tig dab tsi yuav yog qhov teeb meem me me rau hauv qhov chaw ruaj khov.
Qhov ntawd coj peb mus rau qhov yuav tsum tau ua tseem ceeb: cov nroj tsuag xav tau ib lub cuab yeej uas tuaj yeem txheeb xyuas cov khoom noj tsis raug thiab txheeb xyuas qhov chaw ua ntej kev mus ncig ua si ntawm kev sib tsoo - qhov zoo tshaj plaws, txawm tias thaum lub sijhawm tso tawm tsis tu ncua. Cov pa kaw qhov tsis raug thiab qhov kev ncua deb yuav luag tsis muaj txiaj ntsig ntawm no. Cable impedance tsawg dhau, thiab tus cwj pwm hloov pauv thaum lub sij hawm arcing yog qhov nyuaj heev rau txhua qhov kev ua haujlwm raws li qhov tseem ceeb - zaus kom muaj qhov chaw ruaj ntseg. Qhov kev sib tw tiag tiag rau qhov me me -tam sim no hauv av- qhov chaw txhaum yog nyob rau hauv kev ntes siab -frequency transient travel waves or transient zero-sequence current direction during the fault. Qhov ntawd yuav siv qhov piv txwv siab heev thiab cov yam ntxwv zoo tshaj -extraction algorithms- cov uas tuaj yeem xaiv qhov tsis raug kos npe los ntawm lub suab nrov tom qab uas muaj kev sib haum xeeb ntawm inverter thiab ambient hloov suab nrov.
Yog tias koj tsis daws qhov no, qhov kev tshwm sim raug cuam tshuam rau peb lub hauv ntej: poob tiam, khoom siv puas tsuaj, thiab kev nyab xeeb. Ib qho hluav taws kub hnyiab hauv qhov chaw nyob hauv av tuaj yeem ua rau hluav taws kub hnyiab tau sai, thiab hluav taws tuaj yeem sib tw hauv lub trench, tshem tawm txhua qhov hluav taws xob hauv txoj kev hauv tsev. Thiab rau ib qhov project uas tau them los ntawm megawatt- teev, qhov tsis tsim nyog txuas ntxiv yog qhov cuam tshuam ncaj qha rau cov nyiaj tau los. Yog li lub kaw lus uas tuaj yeem ua ob qho tib si - xaiv cov khoom noj kom raug thiab nrhiav qhov txhaum hauv meters- tsis yog kev tiv thaiv kev hloov kho ntxiv lawm. Nws yog ib qho tseem ceeb uas yuav tsum tau muaj rau kev tiv thaiv cov cuab yeej cuab tam thiab kev ua haujlwm tau txiaj ntsig hauv cov nroj tsuag hluav taws xob tauj dua tshiab.
