Masu ba da kayan aikin mai sauya mitar suna tunatar da ku cewa a cikin tsarin sarrafa mitar na gargajiya wanda ya ƙunshi na'urorin jujjuyawar mitar gabaɗaya, injinan asynchronous, da na'urorin inji, lokacin da aka sauke yuwuwar lodin da injin ke watsawa, motar na iya kasancewa cikin yanayin birki mai sabuntawa; Ko kuma lokacin da motar ke raguwa daga babban gudu zuwa ƙananan gudu (ciki har da filin ajiye motoci), mitar na iya raguwa ba zato ba tsammani, amma saboda inertia na injin, yana iya kasancewa a cikin yanayin samar da wutar lantarki. Ƙarfin injin da aka adana a cikin tsarin watsawa ana canza shi zuwa makamashin lantarki ta hanyar motar kuma a mayar da shi zuwa da'irar DC na inverter ta hanyar diodes masu motsi guda shida na inverter. A wannan lokacin, inverter yana cikin yanayin gyarawa. A wannan lokaci, idan ba a dauki matakan cinye makamashi a cikin mitar mai canzawa ba, wannan makamashi zai sa wutar lantarki ta capacitor na ajiyar makamashi a cikin tsaka-tsakin kewayawa ya tashi. Idan birki ya yi sauri sosai ko kuma nauyin injin yana da ƙarfi, wannan ɓangaren makamashi na iya haifar da lahani ga mai sauya mitar, don haka ya kamata mu yi la'akari da wannan ɓangaren makamashi.
A cikin masu sauya mitar gabaɗaya, akwai hanyoyin da aka fi amfani da su don sarrafa sabunta makamashi:
(1) Rushewa cikin "resissor" na wucin gadi da aka saita a layi daya tare da capacitor a cikin da'irar DC ana kiransa yanayin birki mai ƙarfi;
(2) Idan an mayar da ita zuwa grid ɗin wutar lantarki, ana kiranta yanayin birki na martani (wanda kuma aka sani da yanayin birki mai sabuntawa). Akwai wata hanyar birki, wato DC birki, wanda za'a iya amfani dashi a yanayin da ake buƙatar ingantaccen filin ajiye motoci ko lokacin da motar birki ke juyawa ba bisa ƙa'ida ba saboda abubuwan waje kafin farawa.
Masana da yawa sun tattauna yadda ake ƙira da amfani da birki na mitar mitar a cikin littattafai da wallafe-wallafe, musamman a cikin 'yan kwanakin nan, an sami kasidu da yawa kan "birking na makamashi". A yau, marubucin ya gabatar da wani sabon nau'in hanyar birki, wanda ke da fa'idodin aiki huɗu na huɗu tare da "birkin martani" da ingantaccen aiki, da kuma fa'idodin "ƙarashin amfani da makamashi" don grid ɗin wutar lantarki mara gurɓataccen gurɓataccen gurɓataccen iska da ingantaccen aminci.
Amfani da makamashin birki
Hanyar amfani da abin da aka saita na birki a cikin da'irar DC don ɗaukar makamashin lantarki mai sabuntawa na motar ana kiransa birki mai amfani da makamashi.
Amfaninsa shine gini mai sauƙi; Babu gurɓatawa ga grid ɗin wutar lantarki (idan aka kwatanta da sarrafa martani), ƙarancin farashi; Rashin lahani shine ƙarancin aikin aiki, musamman lokacin birki akai-akai, wanda zai cinye babban adadin kuzari kuma yana ƙara ƙarfin juzu'in birki.
Gabaɗaya, a gabaɗaya masu jujjuya mitar mitoci, masu juyawa masu ƙaramin ƙarfi (ƙasa da 22kW) suna sanye da na'urar birki da aka gina a ciki, wanda kawai ke buƙatar resistor na waje. Babban masu sauya wutar lantarki (sama da 22kW) suna buƙatar raka'a na birki na waje da masu birki.
Birkin martani
Don cimma nasarar mayar da martani na makamashi, ana buƙatar yanayi kamar sarrafa wutar lantarki a mitoci iri ɗaya da lokaci, sarrafa martani na yanzu, da sauransu. Yana ɗaukar fasahar inverter mai aiki don juyar da wutar lantarki da aka sabunta zuwa ƙarfin AC na mitoci da lokaci iri ɗaya da grid ɗin wuta da mayar da shi zuwa grid, ta yadda za a samu birki.
Amfanin birki na amsawa shine cewa yana iya aiki a cikin quadrant hudu, kuma amsawar makamashin lantarki yana inganta ingantaccen tsarin. Lalacewarsa shine:
(1) Wannan hanyar birkin martani ba za a iya amfani da ita kawai a ƙarƙashin tsayayyen wutar lantarki wanda ba shi da lahani ga kurakurai (tare da jujjuyawar wutar lantarki da ba ta wuce 10%) ba. Domin a lokacin da ake aiki da birki na samar da wutar lantarki, idan lokacin rashin wutar lantarki na grid ɗin ya fi 2ms, gazawar motsi na iya faruwa kuma abubuwan haɗin zasu iya lalacewa.
(2) Yayin amsawa, akwai gurɓataccen yanayi ga grid ɗin wutar lantarki.
(3) Kulawa yana da rikitarwa kuma farashin yana da yawa.
Sabuwar hanyar birki (birki mai karɓuwa)
Babban ka'idar kewayawa
Bangaren gyaran yana amfani da gada mai daidaitawa na gama gari don gyarawa, da'irar tacewa tana amfani da capacitor na duniya, kuma da'irar jinkiri tana amfani da ko dai mai lamba ko thyristor. Da'irar caji da amsawa ta ƙunshi tsarin wutar lantarki IGBT, caji da mai ba da amsa reactor L, da babban capacitor na electrolytic C (tare da ƙarfin kusan ƴan kashi goma na mita, wanda za'a iya ƙaddara bisa ga tsarin aiki na mai sauya mitar). Bangaren inverter ya ƙunshi ikon module IGBT. Da'irar kariyar ta ƙunshi IGBT da resistor.
1) Matsayin aikin samar da wutar lantarki na lantarki
CPU yana lura da shigar da wutar lantarki ta AC da wutar lantarki ta DC (μ d) a cikin ainihin lokaci, kuma tana ƙayyade ko aika siginar caji zuwa VT1. Da zarar μ d ya fi madaidaicin ƙimar wutar lantarki ta DC (kamar 380VAC -530VDC) na shigar da wutar AC, CPU tana kashe VT3 kuma tana cajin ƙarfin wutar lantarki C ta hanyar bugun bugun jini na VT1. A wannan lokacin, an raba reactor L da na'urar wutar lantarki C don tabbatar da cewa wutar lantarki ta C tana aiki a cikin kewayon aminci. Lokacin da wutar lantarki a kan electrolytic capacitor C ya kusanci darajar mai haɗari (kamar 370V) yayin da tsarin yana cikin yanayin samar da wutar lantarki, kuma ana ci gaba da aika wutar lantarki zuwa da'irar DC ta hanyar inverter, da'irar aminci tana taka rawa wajen cimma nasarar amfani da makamashin birki (braking juriya), sarrafa kashewa da kunna VT3, kuma hakan yana faruwa gabaɗayan ƙarfin kuzarin.
(2) Matsayin aikin motar lantarki
Lokacin da CPU ya gano cewa tsarin ba ya yin caji, bugun bugun jini yana gudanar da VT3, yana haifar da ingantaccen ƙarfin hagu na dama da ƙarancin wuta akan reactor L. Haɗe tare da ƙarfin lantarki akan capacitor C, tsarin amsawar makamashi daga capacitor zuwa da'irar DC za a iya cimma. CPU yana sarrafa mitar sauyawa da zagayowar aiki na VT3 ta hanyar gano ƙarfin lantarki akan capacitor C da ƙarfin lantarki a cikin da'irar DC, ta haka ne ke sarrafa ra'ayin halin yanzu da tabbatar da cewa ƙarfin lantarki na kewaye na DC ν d bai zama babba ba.
Matsalolin tsarin
(1) Zabi na reactors
(a) Muna la'akari da takamaiman yanayin aiki kuma muna ɗauka cewa wani kuskure yana faruwa a cikin tsarin, yana haifar da yuwuwar nauyin kuzarin da motar ke ɗauka don haɓaka cikin yardar kaina da faɗuwa. A wannan lokacin, motar tana cikin yanayin samar da wutar lantarki,
Ana mayar da makamashin da aka sabunta zuwa da'irar DC ta hanyar diodes masu motsa jiki guda shida, yana haifar da karuwa a cikin ∆ d kuma da sauri sanya inverter a cikin yanayin caji. A wannan lokacin, halin yanzu zai yi girma sosai. Don haka diamita na waya da aka zaɓa ya kamata ya zama babban isa ya wuce na yanzu a wannan lokacin.
(b) A cikin madauki na ra'ayi, domin a saki yawancin makamashin lantarki kamar yadda zai yiwu kafin cajin na gaba na capacitor na electrolytic, zaɓin ƙarfe na yau da kullum (silin karfe sheet) ba zai iya cimma burin ba. Zai fi kyau a zaɓi maɓallin ƙarfe da aka yi da kayan ferrite. Idan aka dubi darajar yanzu da aka yi la'akari a sama, ana iya ganin girman girman wannan ƙarfe. Ba a sani ba ko akwai irin wannan babban jigon ƙarfe na ferrite a kasuwa. Ko da akwai guda, tabbas farashinsa ba zai yi ƙasa sosai ba.
Don haka marubucin ya ba da shawarar yin amfani da reactor ɗaya don kowane caji da da'irar amsawa.
(2) Matsalolin sarrafawa
(a), A cikin da'irar DC na mai sauya mitar, ƙarfin lantarki ν d gabaɗaya yana sama da 500VDC, yayin da ƙarfin ƙarfin lantarki na capacitor C shine kawai 400VDC, yana nuna cewa sarrafa wannan tsarin caji baya kama hanyar sarrafa ƙarfin birki (braking juriya). Sautin wutar lantarki na gaggawa da aka haifar akan reactor shine, kuma saurin cajin wutar lantarki na electrolytic capacitor C shine ν c=ν d - ν L. Domin tabbatar da cewa wutar lantarki tana aiki a cikin amintaccen kewayon (≤ 400V), ya zama dole don sarrafa saurin jujjuyawar wutar lantarki ν L akan na'urar canzawa nan take.
(b) A yayin aiwatar da martani, ya kuma zama dole a hana fitar da makamashin lantarki daga electrolytic capacitor C daga haifar da matsanancin ƙarfin lantarki na DC ta hanyar reactor, wanda ke haifar da kariyar overvoltage a cikin tsarin.
Babban yanayin aikace-aikacen
Daidai saboda fifikon wannan sabuwar hanyar birki (capacitor feedback braking) na masu canza mitar ne kwanan nan da yawa masu amfani suka ba da shawarar samar da wannan tsarin dangane da halayen kayan aikinsu. Tare da fadada filin aikace-aikacen na masu sauya mitar, wannan fasahar aikace-aikacen za ta sami babban ci gaba. Musamman, ana amfani da shi a masana'antu irin su masu hawan ma'adinai (don ɗaukar mutane ko kayan lodi), motoci masu ma'ana (tubu ɗaya ko biyu), da injin ɗagawa. A kowane hali, ana iya amfani da na'urorin amsawar makamashi a cikin yanayin da ke buƙatar su.