Mai ba da amsa naúrar yana tunatar da ku cewa tun bullowar induction induction na atomatik, nau'in janareta na AC ya rigaya ya fara aiki mai sauƙi. Canja saurin janareta kuma daidaita mitar fitarwa. Kafin bullar transistor masu saurin gaske, wannan na daya daga cikin manyan hanyoyin da ake canza saurin motar, amma saboda saurin janareto da ke rage yawan fitarwa a maimakon wutar lantarki, an takaita yawan mitar.
Saboda haka, bari mu dubi abubuwan da ke cikin na'urar canza mitar mu ga yadda suke aiki tare don canza mita da saurin mota.
Inverter sassa - gyarawa
Saboda wahala wajen canza mitar igiyoyin AC sine a yanayin AC, aikin farko na mai sauya mitar shine ya canza tsarin kalaman zuwa DC. Don yin kama da AC, yana da sauƙin sarrafa DC. Bangaren farko na duk masu sauya mitar na'ura shine na'urar da ake kira rectifier ko Converter. Da'irar mai gyara mitar mai sauya mitar tana canza canjin halin yanzu zuwa halin yanzu kai tsaye, kuma yanayin aikinsa kusan iri ɗaya ne da na cajar baturi ko na'urar walda ta baka. Yana amfani da gadar diode don taƙaita igiyar AC sine daga motsi zuwa hanya ɗaya kawai. Sakamakon haka shine cikakken gyaran fuska na AC ana fassara shi ta hanyar da'irar DC azaman sigar motsi na gida na DC. Mai sauya mitar mitoci uku yana karɓar matakan shigarwar AC masu zaman kansu guda uku kuma yana canza su zuwa fitowar DC guda ɗaya.
Yawancin masu sauya mitar mitoci uku kuma za su iya karɓar wutar lantarki na lokaci-lokaci (230V ko 460V), amma saboda rassan shigarwa guda biyu kawai, abin da ake fitarwa (HP) na mai sauya mitar dole ne a lalatar da shi saboda ƙarancin wutar lantarki na DC da aka ƙirƙira daidai gwargwado. A gefe guda kuma, inverter na gaskiya guda-ɗaya (mai juyawa na lokaci-lokaci guda ɗaya wanda ke sarrafa motar motsa jiki guda ɗaya) yana amfani da shigarwar lokaci ɗaya kuma yana haifar da fitarwar DC daidai da shigarwar.
Akwai dalilai guda biyu da ya sa aka fi amfani da injuna masu hawa uku fiye da abubuwan da ake amfani da su na lokaci-lokaci idan aka zo ga aiki mai saurin canzawa. Da fari dai, suna da kewayon iko mai faɗi. A wani bangaren kuma, injinan hawa guda ɗaya yawanci suna buƙatar wasu saƙon waje don fara juyawa.
Abubuwan inverter - bas na DC
Ba za a iya ganin ɓangaren na biyu na bas ɗin DC a kowane mai sauya mitar ba saboda ba ya shafar aikin mai sauya mitar kai tsaye. Koyaya, koyaushe yana kasancewa a cikin manyan masu canza mitar maƙasudi na gabaɗaya. Bus ɗin DC yana amfani da capacitors da inductor don tace wutar lantarki ta AC "ripple" a cikin wutar DC da aka canza, sannan ta shiga sashin inverter. Hakanan ya haɗa da tacewa don hana murdiya masu jituwa, wanda za'a iya mayar da shi zuwa wutar lantarki ta inverter. Tsofaffin masu sauya mitoci suna buƙatar matatun layi daban don kammala wannan tsari.
Inverter sassa - Inverter
A gefen dama na hoton akwai "gabobin ciki" na mai sauya mitar. Mai jujjuyawar yana amfani da manyan juzu'i uku na transistor masu saurin canzawa don ƙirƙirar dukkan "pulses" guda uku na DC waɗanda ke daidaita raƙuman ruwa na AC. Waɗannan ƙwanƙwasa ba wai kawai ƙayyade ƙarfin wutar lantarki ba ne, har ma da mitar sa. Kalmar 'inverter' na nufin' juyowa ', wanda kawai ke nufin motsi sama da ƙasa na sigar igiyar ruwa da aka haifar. Masu canza mitar na zamani suna amfani da wata dabara mai suna "pulse width modulation" (PWM) don daidaita wutar lantarki da mita.
Sannan muyi magana akan IGBT. IGBT yana nufin "kofar bipolar transistor mai ɓoye", wanda shine ɓangaren canzawa (ko bugun jini) na inverter. Transistor (maye gurbin vacuum tubes) suna taka rawa biyu a duniyar lantarki ta mu. Yana iya aiki kamar amplifier kuma yana ƙara siginar, ko kuma yana iya aiki azaman canji ta hanyar kunnawa da kashe siginar kawai. IGBT sigar zamani ce wacce ke ba da saurin sauyawa (3000-16000 Hz) kuma yana rage haɓakar zafi. Maɗaukakin saurin sauyawa zai iya inganta daidaiton simintin igiyar AC kuma ya rage hayaniyar mota. Rage zafi da aka haifar yana nufin cewa zafin zafi ya fi ƙanƙanta, don haka mai sauya mitar ya mamaye ƙaramin yanki.
Inverter PWM waveform
Siffar igiyar igiyar ruwa da mai juyawa na PWM inverter ya haifar idan aka kwatanta da igiyar AC na gaskiya. Fitarwar Inverter ta ƙunshi jerin abubuwa masu kusurwa huɗu tare da tsayayyen tsayi da nisa mai daidaitawa.
A cikin wannan takamaiman yanayin, akwai saiti guda uku na pungeses - a saiti mai faɗi a tsakiya da kuma kunkuntar saiti da mara kyau da mara kyau sassa na tsarin curin.
Jimlar yankunan bugun jini daidai yake da ingantaccen ƙarfin lantarki na igiyoyin AC na gaskiya. Idan kana so ka yanke sassan bugun jini a sama (ko ƙasa) ainihin yanayin yanayin sadarwa kuma ka cika sararin da ke ƙasa da lanƙwasa tare da su, za ka ga cewa sun kusan daidaita daidai. Daidai ta wannan hanyar ne mai sauya mitar zai iya sarrafa wutar lantarkin motar. Jimlar faɗin bugun bugun jini da nisa mara kyau a tsakanin su yana ƙayyadad da mitar nau'in motsin da motar ke gani (saboda haka PWM ko daidaita girman bugun bugun jini). Idan bugun bugun jini yana ci gaba (watau ba tare da komai ba), mitar zata kasance daidai, amma ƙarfin wutar lantarki zai fi girma fiye da igiyoyin AC na gaskiya.
Dangane da irin ƙarfin lantarki da mitar da ake buƙata, mai sauya mitar zai canza tsayi da faɗin bugun bugun jini, da kuma faɗin da ba komai a tsakanin su biyun. Wasu mutane na iya yin mamakin yadda wannan 'AC na karya (a zahiri DC) ke aiki da injin shigar da AC.
Bayan haka, shin alternating current yana buƙatar "jawo" filin maganadisu na yanzu da daidai a cikin na'ura mai juyi? Don haka, AC a zahiri za ta haifar da induction saboda tana canzawa koyaushe, yayin da DC ba za ta yi aiki akai-akai ba da zarar an kunna da'irar.
Koyaya, idan an kunna DC kuma a kashe, yana iya jin halin yanzu. Ga waɗanda suka manyanta, tsarin kunna wutan mota (kafin ƙwaƙƙwaran ƙasa) ya kasance yana da saitin maki a cikin mai rarrabawa. Manufar waɗannan maki shine don tafiya daga baturi "pulses" zuwa coils (transformers). Wannan yana haifar da caji a cikin nada sannan ya ɗaga wutar lantarki zuwa matakin da zai ba da damar walƙiya don kunna wuta. Faɗin bugun bugun DC da aka gani a cikin wannan adadi na sama a zahiri ya ƙunshi ɗaruruwan bugun jini guda ɗaya, kuma buɗewa da rufe motsi na fitarwar inverter yana ba da damar shigar da DC.
Ingantacciyar wutar lantarki
Ɗaya daga cikin abubuwan da ke haifar da alternating current shine cewa yana canza wutar lantarki kullum, daga sifili zuwa matsakaicin matsakaicin ƙarfin lantarki, sannan ya koma sifili, sannan zuwa wani matsakaicin matsakaicin ƙarfin lantarki, sannan ya koma zero. Yadda za a ƙayyade ainihin ƙarfin lantarki da aka yi amfani da shi a kewaye? Hoton da ke ƙasa shine 60Hz, 120V na sine. Amma ya kamata a lura cewa iyakar ƙarfinsa shine 170V. Idan ainihin ƙarfinsa shine 170V, ta yaya za mu kira shi igiyar 120V?
Wani abu da ke sanya alternating current complex shine sauyinsa akai-akai a wutar lantarki, daga sifili zuwa madaidaicin wutar lantarki, sannan ya koma sifili, sannan zuwa wani matsakaicin matsakaicin wutar lantarki, sannan ya koma sifili. Yadda za a ƙayyade ainihin ƙarfin lantarki da aka yi amfani da shi a kewaye?
Ya kamata a lura cewa kalaman sine na 60Hz, 120V cewa ƙarfin ƙarfinsa shine 170V. Idan ainihin ƙarfinsa shine 170V, ta yaya za mu kira shi igiyar 120V?
A cikin sake zagayowar daya, yana farawa a 0V, ya tashi zuwa 170V, sa'an nan kuma ya sake saukewa zuwa 0. Yana ci gaba da saukewa zuwa -170, sa'an nan kuma ya sake tashi zuwa 0. Yankin rectangle na kore tare da babban iyaka na 120V yana daidai da jimlar yankunan wurare masu kyau da korau na lankwasa.
Don haka 120V shine matsakaicin matakin? Da kyau, idan za mu matsakaita duk ƙimar ƙarfin lantarki a kowane maƙasudi a cikin duka zagayowar, sakamakon zai zama kusan 108V, don haka ba zai iya zama amsar ba. Don haka me yasa aka auna wannan ƙimar ta VOM a 120V? Yana da alaƙa da abin da muke kira 'effective voltage'.
Idan ana son auna zafin da wutar lantarkin da ke gudana ta hanyar resistor, za ka ga ya fi zafin da ake samu ta hanyar alternating current. Wannan saboda AC baya kula da ƙima akai-akai a duk tsawon zagayowar. Idan an gudanar da shi a ƙarƙashin yanayin sarrafawa a cikin dakin gwaje-gwaje, an gano cewa wani ƙayyadaddun halin yanzu na DC yana haifar da karuwar zafi na digiri 100, wanda ya haifar da karuwar digiri 70.7 a AC daidai ko 70.7% DC darajar.
Don haka ingancin ingancin AC shine 70.7% na DC. Hakanan za'a iya ganin ƙimar ingancin wutar lantarki ta AC daidai yake da tushen murabba'in jimillar ma'auni na ƙarfin lantarki a farkon rabin lanƙwasa. Idan mafi girman ƙarfin lantarki shine 1 kuma ana buƙatar auna nau'ikan ƙarfin lantarki daban-daban daga digiri 0 zuwa digiri 180, ingantaccen ƙarfin lantarki zai zama matsakaicin ƙarfin ƙarfin digiri na 0-707. Sau 0.707 mafi girman ƙarfin lantarki na 170 a cikin adadi yana daidai da 120V. Wannan ingantaccen ƙarfin lantarki kuma ana kiransa da tushen ma'anar murabba'i ko ƙarfin lantarki na RMS.
Saboda haka, mafi girman ƙarfin lantarki koyaushe shine 1.414 na ingantaccen ƙarfin lantarki. 230V AC halin yanzu yana da mafi girman ƙarfin lantarki na 325V, yayin da 460 yana da ƙarfin ƙarfin 650V. Baya ga bambance-bambancen mita, ko da ƙarfin lantarki ya kasance mai zaman kansa da saurin aiki na injin AC, mai sauya mitar kuma dole ne ya canza ƙarfin lantarki. Biyu 460V AC sine taguwar ruwa. Tsarin ja shine 60Hz, kuma shuɗin shuɗi shine 50Hz. Dukansu suna da mafi girman ƙarfin lantarki na 650V, amma 50Hz ya fi fadi. Kuna iya gani cikin sauƙi cewa yankin da ke cikin rabin farko na lanƙwan 50Hz (0-10ms) ya fi rabin farkon lanƙwan 60Hz (0-8.3ms). Bugu da ƙari, kamar yadda yankin da ke ƙarƙashin lanƙwasa yana daidai da daidaitattun ƙarfin lantarki, ƙarfin ƙarfinsa ya fi girma. Yayin da mitar ke raguwa, haɓaka ingantaccen ƙarfin lantarki ya zama mai tsanani.
Idan aka ba da damar 460V Motors suyi aiki akan waɗannan manyan ƙarfin lantarki, za a iya rage rayuwarsu sosai. Don haka, dole ne mai jujjuya mitar ya zama koyaushe ya canza ƙarfin wutar lantarki na "kololuwa" dangane da mitar don kula da ingantaccen ƙarfin lantarki. Ƙananan mitar aiki, ƙananan ƙarfin wutar lantarki, da kuma akasin haka. Ya kamata yanzu ku sami kyakkyawar fahimtar ƙa'idar aiki na mai sauya mitar da yadda ake sarrafa saurin motar. Yawancin masu sauya mitar mitoci suna ba masu amfani damar saita saurin mota da hannu ta hanyar maɓalli masu yawa ko maɓallan madannai, ko amfani da na'urori masu auna firikwensin (matsi, kwarara, zafin jiki, matakin ruwa, da sauransu) don sarrafa aikin.