Yuav ua li cas siv lub multimeter los kuaj diodes hauv lub zog hluav taws xob?

Ib, Lub hauv paus ntsiab lus ntawm kev kuaj diode: nkag siab txog PN junction yam ntxwv
Lub ntsiab ntawm lub diode yog PN kev sib tshuam, thiab nws cov yam ntxwv tseem ceeb suav nrog:

Unidirectional conductivity: pem hauv ntej conduction (tsis tshua muaj siab), rov qab txiav tawm (siab tsis kam).
Forward voltage poob (Vf): Tus nqi raug rau silicon diodes yog 0.6-0.7V, thiab rau Schottky diodes nws yog 0.2-0.4V.
Rov qab tawg voltage (Vbr): Tom qab tshaj qhov pib, lub diode puas lawm.
Lub ntsiab lus tseem ceeb ntawm multimeter los kuaj lub diode yog siv lub me me tam sim no (rau pem hauv ntej) lossis qhov hluav taws xob (rov qab), ntsuas nws qhov tsis kam lossis qhov hluav taws xob poob, thiab txiav txim siab seb PN junction puas lawm.

2, Kev npaj ua ntej kev sim: kev xaiv cov cuab yeej thiab ib puag ncig yuav tsum tau ua
1. Kev xaiv ntawm multimeter
Digital Multimeter (DMM): Nws raug nquahu kom siv cov qauv uas txhawb kev ntsuas diode, xws li Fluke 87V, UT61E, thiab lwm yam. Qhov ntsuas hluav taws xob feem ntau yog 2.8V (rau pem hauv ntej) thiab -3V (rov qab), nrog rau tam sim no txog 1mA, uas yuav tsis ua puas lub diode.
Analog multimeter: Nws yog ib qho tsim nyog los xaiv qhov kev tiv thaiv ntau yam (xws li x 1k Ω ntau), tab sis nws yuav tsum tau muab sau tseg tias qhov ntsuas qhov ntsuas hluav taws xob yuav dhau ntawm qhov pib diode, uas ua rau muaj kev pheej hmoo ntawm kev txiav txim tsis raug.
2. Kev ntsuas ib puag ncig yuav tsum tau ua
Kev tswj qhov kub thiab txias: Cov diode tsis sib txawv nrog qhov kub thiab txias (xws li Vf txo qis li 2mV rau txhua 10℃nce), thiab nws raug nquahu kom sim hauv ib puag ncig ntawm 25 degree.
Fais fab kev khiav hauj lwm: Lub hwj chim mov ntawm lub zog system yuav tsum raug txiav kom tsis txhob muaj kev pheej hmoo ntawm high -voltage hluav taws xob poob siab los yog luv luv Circuit Court.
Kev ntsuas kev tiv thaiv zoo li qub: Siv cov khoom siv tiv thaiv- cov dab teg zoo li qub los tiv thaiv hluav taws xob zoo li qub los ntawm kev nkag mus rau cov diodes rhiab heev (xws li MOSFET ua- hauv diodes).
3, Kauj ruam los ntawm kauj ruam Test Guide: Los ntawm Basic mus rau Advanced
Kauj Ruam 1: Kev tshuaj xyuas qhov tshwm sim ua ntej
Kev soj ntsuam pom: Saib seb lub diode pins puas yog oxidized, seb lub ntim puas tawg, thiab seb cov pob qij txha puas xoob.
Tag kev lees paub: Paub meej cov qauv diode (xws li 1N4007, MBR2045CT) thiab polarity (anode "+", cathode "-").
Kauj ruam 2: Multimeter nqis
Digital multimeter: Tig lub pob qhov rooj mus rau "diode test mode" (lub cim yog daim duab peb sab nrog tus xub).
Analog multimeter: Xaiv qhov "× 1k Ω" tsis kam ntau, txuas lub xov tooj liab mus rau lub davhlau ya nyob twg zoo thiab qhov kev sojntsuam dub rau qhov tsis zoo.
Kauj Ruam 3: Kev kuaj qhov zoo conductivity
Txuas cov probes: Txuas lub xov tooj liab mus rau lub anode ntawm lub diode thiab cov dub sojntsuam mus rau cathode.
Nyeem qhov muaj nuj nqis:
Digital multimeter: qhia rau pem hauv ntej voltage poob (Vf), silicon diode yuav tsum yog 0.5-0.7V, Schottky diode yuav tsum yog 0.2-0.4V.
Analog multimeter: Yog hais tias tus pointer deviates rau tus nqi qis (xws li ob peb puas ohms), tej zaum yuav muaj qhov qhib Circuit Court yog tias tus pointer tsis txav.
Cov qauv txiav txim:
Ib txwm: Vf nyob rau hauv qhov kev qhia tshwj xeeb thiab qhia "OL" (overload) thaum kuaj rov qab.
Exception: Vf=0V (short circuit) or Vf>1V (qhib Circuit Court lossis kev ua haujlwm tsis zoo).
Kauj Ruam 4: Rov qab Txiav tawm Kev Xeem
Rov qab sojntsuam: Txuas lub xov tooj liab mus rau cathode thiab cov tshuaj ntsuam dub rau lub anode.
Nyeem qhov muaj nuj nqis:
Digital multimeter: displays "OL" or high resistance value (usually>1M Ω).
Analog multimeter: Tus pointer tsis txav (siab tsis kam).
Cov qauv txiav txim:
Ib txwm: Qhov kev thim rov qab yog qhov siab heev thiab tsis muaj qhov cuam tshuam loj heev tam sim no.
Exception: Rov qab voltage poob<0.3V or resistance<100k Ω (large leakage current, possible breakdown).
Kauj ruam 5: Dynamic parameter kuaj (yeem)
Rau cov ntawv thov tseem ceeb xws li siab - lub zog diodes, yuav tsum tau kuaj ntxiv:

Lub sijhawm rov qab mus tom ntej (trr): Siv lub oscilloscope los soj ntsuam lub sijhawm hloov pauv ntawm lub diode los ntawm kev txiav tawm rov qab mus rau kev xa mus, trr yuav tsum tsawg dua 100ns (ceev rov qab diode).
Rov qab rov qab them nqi (Qrr): xam los ntawm kev sib koom ua ke ntawm qhov rov qab nkhaus tam sim no, qhov me dua Qrr, qhov qis dua qhov hloov pauv.
4, Cov xwm txheej ntawm daim ntawv thov thiab kev kuaj xyuas tsis raug hauv cov tshuab hluav taws xob
Scenario 1: PV module bypass diode xeem
Teeb meem tshwm sim: Cheebtsam kub qhov chaw thiab txo cov zis zog.
Cov kauj ruam xeem:
Disconnect tus tivthaiv los ntawm lub thawv combiner.
Test the forward voltage drop of the bypass diode. If Vf>0.7V (silicon tube) or>0.45V (Schottky raj), nws yuav tsum tau hloov.
Kev ntsuas rov qab yuav tsum tso saib "OL". Yog tias cov dej xau tam sim no ntau dua 10 μ A, nws yuav ua rau thermal khiav tawm.
Case: Nyob rau hauv 5MW photovoltaic fais fab chaw nres tsheb, 12% ntawm cov bypass diodes raug kev txom nyem ib tug tivthaiv efficiency poob ntawm ntau tshaj 5% vim yog nce nyob rau hauv Vf, uas tau rov qab los tom qab hloov.
Scenario 2: Kev ntsuam xyuas ntawm MOSFET ua- hauv diodes hauv lub zog cia
Cov teeb meem tshwm sim: Cov roj teeb tsis zoo them thiab tso tawm, BMS qhia txog kev ua haujlwm tsis zoo.
Cov kauj ruam xeem:
Disassemble lub MOSFET module thiab kuaj lub pem hauv ntej voltage poob ntawm lub cev diode.
Piv nrog rau cov khoom siv los ntawm tib lub batch, yog tias Vf sib txawv ntau dua 10%, tej zaum yuav muaj cov txheej txheem tsis raug.
Case: Nyob rau hauv ib lub hwj chim cia txee, tsis sib npaug tam sim no tshwm sim los ntawm inconsistent MOSFET diode Vf ua rau lub zos overheating.
Scenario 3: Kev ntsuam xyuas ntawm rectifier diodes hauv hluav taws xob tsheb them modules
Teeb meem tshwm sim: Txo kev them nqi hluav taws xob thiab diode burnout.
Cov kauj ruam xeem:
Siv lub tshuab ntsuas cua sov los nrhiav qhov siab -kub diode.
Test the Vf and reverse resistance of the high-temperature diode. If Vf>0.8V los yog rov qab tsis kam<500k Ω, replace it immediately.
Case: Ib lub chaw them nyiaj raug kev txom nyem los ntawm module burnout vim qhov rov qab xau loj tam sim no ntawm rectifier diode, ua rau cov nqi tu ntau tshaj 20000 yuan.
5, Tej teeb meem thiab kev daws teeb meem
Teeb meem 1: Cov nqi ntsuas tsis ruaj khov
Yog vim li cas: Kev sib cuag tsis zoo ntawm kev sojntsuam thiab thermal nyhuv ntawm lub diode.
Kev daws: Ntxuav cov kev sojntsuam thiab cov pins kom ua tiav qhov kev xeem sai sai (tsis txhob siv lub zog ntev ntawm cov cua sov).
Teeb meem 2: Analog multimeter misjudgment
Yog vim li cas: Qhov ntsuas hluav taws xob nyob rau hauv x 1k Ω ntau tshaj qhov pib diode.
Kev daws: Siv lub tshuab digital multimeter lossis txuas 1k Ω resistor hauv series rau kev txwv tam sim no.
Nqe lus nug 3: Dispersion ntawm diode tsis
Vim li cas: Muaj qhov sib txawv ntawm ± 5% hauv Vf ntawm cov khoom sib txawv ntawm cov khoom sib txawv.
Kev daws: Tsim ib lub tsev qiv ntawv parameter benchmark thiab sib piv cov txiaj ntsig kev xeem ntawm cov khoom los ntawm tib pawg.
6, Cov txheej txheem Advanced: Muab lwm yam cuab yeej los txhim kho kev kuaj mob
Thermal imaging pab: ceev nrooj nrhiav faulty diodes los ntawm qhov kub thiab txias (qhov txawv txav diode kub yog 10-20℃siab dua li qub).
LCR tester: ntsuas lub diode junction capacitance (Cj). Yog tias Cj cuam tshuam los ntawm tus nqi tshwj xeeb (xws li nce ntawm 100pF txog 500pF), tej zaum yuav muaj kev pheej hmoo ntawm kev tawg.
Curve tracker: Kos I-V tus yam ntxwv nkhaus kom raug txiav txim siab diode mos tawg lossis parameter drift.
7, Kev tswj hwm kev nyab xeeb thiab kev ua haujlwm taboos
Txwv tsis pub kuaj nyob: Lub zog siab ntawm lub zog hluav taws xob tuaj yeem ncav cuag 1000V lossis siab dua, thiab kev ua haujlwm nyob yuav ua rau arcing lossis hluav taws xob poob siab.
Tsis txhob thim rov qab high voltage: qhov rov qab voltage ntawm multimeter diode xeem ntau yog tsuas yog 3V, tab sis yog tias qhov siab voltage ntau (xws li 20V) siv yuam kev, lub diode yuav tawg.
Cov kev cai tiv thaiv zoo li qub: Thaum tuav cov diodes rhiab heev (xws li SiC MOSFET ua- hauv diodes), lawv yuav tsum tau ua haujlwm ntawm kev tiv thaiv - zoo li qub workbench.