Hauv kev sib txawv zaus tsav (VFD) lub cev muaj zog, braking tsis tsuas yog hloov pauv hauv lub cev muaj zog, tab sis kuj hloov pauv ntawm cov tshuab hluav taws xob rau hauv hluav taws xob. Thaum lub cev muaj zog yuav tsum decelerate sai sai, nres, los yog ua hauj lwm nyob rau hauv lub zog ntawm ib tug sab nraud load, nws yuav ua tau regenerative hluav taws xob zog. Yog tias lub zog no tsis ua haujlwm zoo, nws tuaj yeem ua rau lub tsheb npav DC voltage hauv VFD nce, cuam tshuam rau kev ua haujlwm ntawm lub cev. Yog li ntawd, Braking Resistor Boxes feem ntau yog siv rau hauv cov ntawv thov uas xav tau kev ua haujlwm zoo ntawm kev sib tsoo.
Ua ntej, nws yog ib qho tseem ceeb kom nkag siab txog lub zog hloov dua siab tshiab uas tshwm sim thaum lub cev muaj zog deceleration. Thaum lub sijhawm ua haujlwm ib txwm muaj, VFD muab cov khoom siv hluav taws xob rau lub cev muaj zog, tso cai rau nws los tsim lub zog thiab tsav cov cuab yeej siv tshuab. Thaum lub cev muaj zog nkag mus rau hauv lub xeev deceleration, lub tshuab tshuab tseem khaws lub zog kinetic vim inertia. Raws li kev tswj xyuas tsim nyog, lub cev muaj zog tuaj yeem nkag mus rau hauv lub xeev tsim, hloov ib feem ntawm lub tshuab hluav taws xob no rau hauv lub zog hluav taws xob thiab pub nws rov qab rau hauv VFD lub tsheb npav DC.
Qhov thib ob, lub zog regenerative tuaj yeem ua rau DC tsheb npav voltage nce. Thaum lub sijhawm ua haujlwm, VFD yuav tsum tswj hwm nws cov tsheb npav hauv DC nyob rau hauv qhov kev lees paub. Thaum lub cev muaj zog pub lub zog hluav taws xob rov qab rau hauv lub cev thiab lub zog tsis tuaj yeem siv los yog rov qab mus rau lub zog hluav taws xob, nws nkag mus rau hauv lub tsheb npav DC, ua rau lub zog nce ntxiv. Yog tias qhov hluav taws xob ntau dhau ntawm VFD qhov kev tiv thaiv kev txwv, lub tswb overvoltage lossis kev tiv thaiv kaw yuav tshwm sim, cuam tshuam cov khoom siv ib txwm siv.
Lub luag haujlwm tseem ceeb ntawm Braking Resistor Box yog los tswj lub zog hluav taws xob ntau dhau. Thaum lub tsheb npav DC voltage nce mus txog qhov pib tswj kev nres, lub braking unit activates lub braking Circuit Court raws li nws tswj logic, tso cai rau regenerative zog ntws los ntawm lub braking resistor. Lub resistor hloov cov hluav taws xob ntau dhau mus rau hauv tshav kub thiab tso tawm rau hauv ib puag ncig ib puag ncig, pab txo qhov hluav taws xob DC.
Thib peb, siv Braking Resistor Box txhim kho qhov yooj yim ntawm lub cev muaj zog deceleration tswj. Hauv qee daim ntawv thov kev lag luam, cov motors yuav tsum nres sai sai raws li preset deceleration curves. Yog hais tias lub zog regenerative tsis tuaj yeem ua haujlwm tau zoo, VFD yuav tsum tau ncua lub sij hawm deceleration los tiv thaiv DC lub tsheb npav ntau dhau. Nrog rau kev teeb tsa kom haum rau Braking Resistor Box, lub kaw lus muaj txoj hauv kev ntxiv rau dissipating regenerative zog, tso cai rau kev hloov pauv hloov pauv ntau dua nyob rau hauv kev tso cai ua haujlwm.
Plaub, Braking Resistor Box pab txo cov khoom siv kaw los ntawm DC tsheb npav overvoltage. Hauv cov khoom nqa nqa, elevator, tshuab centrifugal, thiab cov tshuab loj conveyor, lub cev muaj zog tuaj yeem ua haujlwm nyob rau hauv ntau inertia lossis load quab yuam. Thaum lub sij hawm deceleration ceev los yog load qis, tseem ceeb regenerative zog yuav raug generated. Yog tias lub zog no tsis tuaj yeem ploj mus sai, VFD tuaj yeem qhib nws txoj haujlwm tiv thaiv thiab cuam tshuam cov khoom siv.
Tsis tas li ntawd, Braking Resistor Boxes muab kev txhawb nqa rau ntau hom kev tsav tsheb. Rau cov khoom siv uas nquag pib thiab nres, ceev deceleration, los yog loj inertial loads, kho kom zoo lub Braking Resistor Box pab txhim kho lub cev muaj peev xwm los tuav regenerative zog.
Nws yuav tsum tau muab sau tseg tias tsis yog txhua txhua VFD system yuav tsum muaj ib tug Braking Resistor Box. Txawm hais tias ib qho yuav tsum tau nyob ntawm cov yam ntxwv xws li lub cev muaj zog, cov yam ntxwv ntawm kev thauj khoom, kev sib tsoo zaus, kev xav tau qeeb, thiab VFD tus kheej lub zog tuav lub peev xwm. Qee lub tshuab tuaj yeem tswj xyuas lub zog rov qab los ntawm lwm txoj kev daws teeb meem, xws li cov khoom siv hluav taws xob rov ua dua tshiab.
Zuag qhia tag nrho, Braking Resistor Box yog siv thaum lub sij hawm VFD braking kom dissipate tshaj regenerative zog, tiv thaiv ntau tshaj DC tsheb npav voltage, thiab pab lub kaw lus ua kom ruaj khov thiab txhim khu kev qha deceleration thiab braking tswj.