Hluav taws xob nres ntawm peb theem asynchronous tsav
4.2 Hluav taws xob braking ntawm peb lub cev muaj zog asynchronous
a. Kev taw qhia
Nyob rau ntau lub tshuab, lub cav nres yog lub natural deceleration. Lub sij hawm ntawm kev siv ceev xwmphem nyob ntawm lub thev naus laus zis thiab lub zog ntawm lub tshuab tsav los ntawm lub tshuab. Txawm li cas los xij, feem ntau nws yog qhov yuav tsum tau ua kom luv luv no, thiab hluav taws xob braking yog ib qho yooj yim thiab siv tau zoo. Piv rau cov neeg kho tshuab thiab hydraulic nres cov tshuab, nws muaj qhov kom zoo dua ntawm kev ruaj khov thiab tsis tas yuav siv cov khoom seem twg.
b. Rov qab tswj hwm txoj cai tam sim no
Lub cav yog raug rho tawm los ntawm lub hwj huam khoom thaum nws tab tom khiav thiab rov qhib dua rau lub hwj huam ntawm lwm txoj hauv kev. Qhov no yog lub zog khiav ceev heev, lub tshuab nqus yog feem ntau tshaj qhov pib lub zog, nws yuav tsum tau braked li ntxov li sai tau kom tsis txhob muaj lub cav tawm hauv kev tawm tsam.
Thaum tus ceev yog nyob ze ntawm xoom, qhov kev siv ceev xwmphem yog tswj los ntawm ob peb yam khoom siv:
● Kev sib txhuam tsis sib haum, lub centrifuge stop detector.
● Cov khoom siv sij hawm txiav sij hawm.
● Kev ntsuas qhov ntsuas los yog rotor qhov hluav taws xob relay (txia nplhaib tsav).
Nas Lub Taub Hau Taub Hau
Lub thermal kev nyuab siab thaum lub caij braking ntau tshaj peb zaug siab dua thermal stress generated thaum muaj kev ua kom acceleration. Ntawm lub tshuab braking, cov tamsim no thiab cov taum qis siab tau siab dua qhov pib qhov tseem ceeb.
Yuav kom ntseeg tau tias txoj kev braking, txhua theem theem stator feem ntau muaj kev cob cog nrog ib qho uas tsis sib haum thaum hloov mus thim rov qab. Nyob rau hauv txoj kev no, lub zog thiab qhov tam sim no tuaj yeem raug txo kom zoo li nyob rau hauv rooj plaub pib ntawm tus qauv pib. Rov qab tam sim no braking nyob rau hauv squirrel cage motors muaj tseem ceeb drawbacks, yog li no system tsuas yog siv rau ib co qis zog tsav motors.
2. pob tw lub nplhaib
Tom qab qhov teeb meem tam sim no, qhov tiag tiag qhov rotor voltage yog ob zaug ntev li ntev, thiab qee qhov kev ntsuas qhov ntsuas yuav tsum tau ua. Xws li nrog lub cage cage tsav, ib qhov loj ntawm lub zog tso tawm rau hauv Circuit Court rotor. Nws yog tag nrho dissipated (tshwj tsis yog rau ib tug me me ntawm poob) nyob rau hauv lub resistor.
Lub cav yuav raug txiav tsis pub siv los ntawm ib qho ntawm cov khoom siv saum toj no lossis ib qho hluav taws xob los yog cov zaus tso tawm hauv qhov Circuit Court rotor. Qhov system no ua rau tsav tsheb ntawm nruab nrab ceev. Nws cov yam ntxwv tsis ruaj tsis khov (ntev li ntev raws li qhov kev hloov me ntsis, qhov ceev yuav hloov ntau heev).
c. Los ntawm txhaj koob tshuaj tiv thaiv kab mob DC tam sim no
Cov kev kho tam sim no ua ib qho kev sib nqus npliag deg uas nyob hauv cov pa nruab nrab ntawm lub tshuab. Txhawm rau tsim kom muaj qhov ua kom zoo thiab ua kom muaj kev txhuam cov nyom, qhov tam sim no yuav tsum yog 1.3 npaug tshaj li qhov tam sim no. Ib qho overcurrent ua rau kub hnyiab, uas yog compensated los ntawm ib ncua ntxiv tom qab braking.
Txij li thaum tus nqi tam sim no tau teev meej los ntawm tus stator winding tsis kam, qhov hluav taws xob ntawm qhov rectified yog qhov tsawg. Rectified source feem ntau yog muab los ntawm ib qho rectifier los yog kev tswj ceev. Lawv yuav tsum muaj peev xwm tiv tau lub sij hawm ntev ntawm cov hluav taws xob uas tsuas yog tawm ntawm cov hlua uas raug tawm ntawm AC qhov chaw xws li 380V rms. Muaj ib qho ntawv ntawm lub suab ntawm lub rotor thiab qhov chaw seem magnetic (magnetic teb tig rov qab rau hauv cov lus qhia rov qab mus rau qhov rov qab tam sim no). Tus cwj pwm ntawm lub tshuab yog zoo ib yam li ib lub tshuab hluav taws xob ua ke uas tawm hauv lub rotor. Muab piv rau cov kab ke tam sim no, cov yam ntxwv ntawm kev siv tshuaj txhaj tiv thaiv kabmob sib txawv:
• Lub zog tsis muaj zog yog tso rau hauv lub rotor resistor los yog tawb. Nws tsuas yog sib npaug ntawm cov tshuab hluav taws xob tso tawm los ntawm cov khoom siv. Lub zog ntawm lub zog uas tau txais los ntawm lub hwj chim tau siv tsuas yog siv los pib lub stator.
● Yog hais tias lub thauj tsis tsav tsheb, lub cav yuav tsis pib rau ntawm qhov kev coj ua.
● Yog hais tias lub thauj khoom tsav tsheb, qhov system yuav nres ntau zaus thiab khaws lub nra ntawm qhov qis qis. Qhov no yog lub zeeg nres tsis txhob nres nres nres. Nws cov yam ntxwv yog ntau ruaj khov tshaj qhov rov qab tam sim no.
Nyob rau hauv cov ntaub ntawv ntawm ib tug zis nplhaib engine, lub zog-torque yam ntxwv nyob ntawm lub xaiv resistor. Nyob rau hauv cov ntaub ntawv ntawm tus nas-cage tsav, lub system tau yooj yim kho lub braking torque los ntawm kev khiav hauj lwm ntawm DC pib tam sim no. Txawm li cas los xij, yog tias lub cav khiav ntawm kev kub ceev, lub braking torque yuav qis dua. Txhawm rau tiv thaiv kom tsis txhob kub hnyav heev, cov khoom siv yuav tsum raug siv los txiav tawm tam sim no hauv tus stator thaum kawg ntawm tus braking.
