1. Introduction to Lithium Ion Battery

1.1 State-of-Charge (SOC)

Mamiriro ekuchajiswa anogona kutsanangurwa senzvimbo yesimba rinowanikwa remagetsi mubhatiri, rinowanzoratidzwa sechikamu. Nekuda kwekuti simba remagetsi riripo rinosiyana nechaji uye yekuburitsa ikozvino, tembiricha, uye kuchembera, tsananguro yenzvimbo yekuchaja yakakamurwawo mumhando mbiri: Absolute State-Of-Charge (ASOC) uye Relative State-of-Charge (Relative State. -Yekubhadharisa ASOC) State-of-Charge; RSOC). Kazhinji iyo inowirirana mamiriro ekuchajisa 0% -100%, nepo bhatiri riri 100% kana razara uye 0% kana rabuditswa. Mhedziso yemamiriro ekuchajisa ireferensi ukoshi inoverengerwa zvichienderana neyakagadzirirwa yakatarwa simba kukosha kana bhatiri rinogadzirwa. Mhedziso yekuchaja bhatiri nyowani rakazara 100%; uye kunyange kana bhatiri rekukwegura rakazara zvakakwana, haigoni kusvika 100% pasi pemamiriro akasiyana-siyana ekuchaja uye ekubvisa.

Nhamba iri pazasi inoratidza hukama pakati pevoltage uye bhatiri huwandu pamitengo yakasiyana yekuburitsa. Kukwira kwehuwandu hwekubuda, kuderera kwebhatiri. Kana tembiricha yadzikira, simba rebhatiri richadererawo.

Mufananidzo 1.

Hukama huri pakati pevoltage uye huwandu pamitengo yakasiyana yekuburitsa uye tembiricha

1.2 Max Charging Voltage

The maximum charging voltage is related to the chemical composition and characteristics of the battery. The charging voltage of lithium battery is usually 4.2V and 4.35V, and the voltage value will be different if the cathode and anode materials are different.

1.3 Yakachajwa Yakazara

Kana mutsauko uripo pakati pebhatiri voltage uye yakanyanya kuchaja voltage iri pasi pe100mV, uye yekuchaja ikozvino inodonha kusvika kuC/10, bhatiri rinogona kutorwa serakachajiwa zvizere. Maitiro ebhatiri akasiyana, uye iyo yakazara yekuchaja mamiriro zvakare akasiyana.

Mufananidzo uri pazasi unoratidza yakajairika lithium bhatiri yekuchaja hunhu curve. Kana bhatiri yemagetsi yakaenzana nepamusoro-soro yekuchaja voltage uye yekuchaja ikozvino inodonha kusvika kuC / 10, bhatiri inoonekwa seyakazara.

Mufananidzo 2. Lithium bhatiri yekuchaja hunhu curve

1.4 Mini Discharging Voltage

The minimum discharge voltage can be defined by the cut-off discharge voltage, which is usually the voltage when the state of charge is 0%. This voltage value is not a fixed value, but changes with load, temperature, aging degree, or other factors.

1.5 Kuburitsa Kwakazara

Kana iyo bhatiri voltage iri pasi kana yakaenzana neiyo shoma yekuburitsa voltage, inogona kunzi kuburitsa kwakazara.

1.6 Charge uye discharge rate (C-Rate)

Chiyero chekuchaja-chiyero chiratidziro chekuchaja-kuburitsa ikozvino maererano nehukuru hwebhatiri. Semuenzaniso, kana 1C ikashandiswa kubudisa kweawa imwe chete, zvakanaka, bhatiri rinopera zvachose. Yakasiyana yekuchaja uye yekuburitsa mitengo inozokonzera akasiyana anogona kushandiswa. Kazhinji, iyo yakakura yechaji-yekuburitsa mwero, idiki iyo inowanikwa.

1.7 Hupenyu hwekutenderera

Huwandu hwematenderedzwa ndiyo nhamba yenguva iyo bhatiri rakazadzwa kuchaja uye kuburitsa, izvo zvinogona kufungidzirwa kubva paiyo chaiyo yekuburitsa simba uye dhizaini yekugadzira. Pese apo iyo yakaunganidzwa yekuburitsa simba yakaenzana neiyo dhizaini dhizaini, iyo nhamba yekutenderera kamwe chete. Kazhinji mushure memazana mashanu ekuchajisa-kuburitsa, huwandu hwebhatiri rakazara rinodonha ne500% ~ 10%.

Figure 3. The relationship between the number of cycles and battery capacity

1.8 Kuzvibvisa

Kuzviburitsa kwemabhatiri ese kunowedzera sezvo tembiricha inokwira. Kuzvibvisa pachako hakusi kukanganisa kwekugadzira, asi maitiro ebheteri pachayo. Zvisinei, kubata kusina kunaka mukugadzirwa kwekugadzira kunogonawo kukonzera kuwedzera kwekuzvibudisa. Kazhinji, mwero wekuzviburitsa unopeta kaviri kune yega yega 10 ° C kuwedzera kwekushisa kwebhatiri. Mwedzi wega wega wega-kuzviburitsa mabhatiri e-lithium-ion inenge 1 ~ 2%, nepo mwedzi wega wega wega-kuzviburitsa mabhatiri akasiyana-siyana-nickel-based ari 10-15%.

Figure 4. The performance of the self-discharge rate of lithium batteries at different temperatures

2. Nhanganyaya yeBattery Fuel Gauge

2.1 Nhanganyaya kune Fuel Gauge Basa

Battery management can be regarded as part of power management. In battery management, the fuel gauge is responsible for estimating battery capacity. Its basic function is to monitor the voltage, charge/discharge current and battery temperature, and estimate the battery state of charge (SOC) and the battery’s full charge capacity (FCC). There are two typical methods for estimating the state of charge of a battery: the open circuit voltage method (OCV) and the coulometric method. Another method is the dynamic voltage algorithm designed by RICHTEK.

2.2 Vhura dunhu voltage nzira

Iyo mita yemagetsi uchishandisa yakavhurika yedunhu voltage nzira iri nyore kuita, uye inogona kuwanikwa nekutarisa kumusoro tafura inoenderana nenzvimbo yekuchaja yemhepo yakavhurika yedunhu. Mamiriro ekufungidzira emhepo yakavhurika yedunhu ndiyo bhatiri terminal voltage kana bhatiri richizorora kwemaminitsi makumi matatu.

Pasi pemutoro wakasiyana, tembiricha, uye kuchembera kwebhatiri, bhatiri voltage curve ichave yakasiyana. Nokudaro, yakagadziriswa yakazaruka-circuit voltmeter haigoni kumiririra zvakakwana mamiriro ekubhadhara; mamiriro emutero haagone kufungidzirwa nekutarisa kumusoro kwetafura chete. Mune mamwe mazwi, kana mamiriro ekubhadhara achifungidzirwa chete nekutarisa kumusoro kwetafura, kukanganisa kuchave kwakakura kwazvo.

Nhamba inotevera inoratidza kuti iyo bhatiri voltage iri pasi pechaji uye kubuda, uye mamiriro ekuchaja anowanikwa neyakavhurika yedunhu voltage nzira yakasiyana zvakanyanya.

Mufananidzo 5. Battery voltage pasi pekutengesa uye kubvisa

Nhamba iri pasi apa inoratidza kuti mamiriro ekubhadhara anosiyana zvakanyanya pasi pemitoro yakasiyana panguva yekubuda. Saka zvakanyanya, iyo yakavhurika yedunhu voltage nzira inokodzera chete masisitimu ane zvakaderera zvinodiwa pakurongeka kwenzvimbo yekuchaja, sekushandisa mabhatiri e-lead-asidhi kana magetsi asingachinjike mumotokari.

Mufananidzo 6. Battery voltage pasi pemitoro yakasiyana panguva yekubuda

2.3 Coulomb kuyerwa nzira

Nheyo yekushanda yenzira yekuyeresa coulomb ndeyekubatanidza chidziviriro chekuona pane yekuchaja/kuburitsa nzira yebhatiri. Iyo ADC inoyera voltage pane yekuona resistor uye inoishandura kuita kukosha kwazvino kwebhatiri ririkuchajwa kana kuburitswa. Iyo chaiyo-nguva counter (RTC) inopa kubatanidzwa kweiyo kukosha kwazvino nenguva, kuti uzive kuti mangani coulombs anoyerera nepakati.

Mufananidzo 7. Nzira yekutanga yekushanda yeCoulomb yekuyera nzira

Coulomb kuyerwa nzira inogona kuverengera chaiyo-nguva mamiriro ekuchaja panguva yekuchaja kana kuburitsa. Nechaji coulomb counter uye discharge coulomb counter, inogona kuverenga iyo yasara chiyero (RM) uye yakazara kuchaja huwandu (FCC). Panguva imwecheteyo, iyo yakasara chiyero (RM) uye yakazara chaja huwandu (FCC) inogona zvakare kushandiswa kuverenga mamiriro ekuchaja, kureva (SOC = RM / FCC). Mukuwedzera, inogonawo kufungidzira nguva yasara, yakadai sekupera simba (TTE) uye simba rakazara (TTF).

Figure 8. Calculation formula of Coulomb measurement method

Pane zvinhu zviviri zvikuru zvinokonzeresa kutsauka mukukodzera kweiyo nzira yekuyera yeCoulomb. Yekutanga ndeyekuunganidzwa kwekukanganisa kwekukanganisa mukunzwa kwazvino uye kuyerwa kweADC. Kunyange zvazvo kukanganisa kwekuyera ne teknolojia yemazuva ano ichiri duku, kana pasina nzira yakanaka yekuibvisa, kukanganisa kuchawedzera nekufamba kwenguva. Nhamba iri pazasi inoratidza kuti mune zvinoshanda zvekushandisa, kana pasina kururamisa munguva yenguva, iyo yakaunganidzwa kukanganisa haina muganho.

Mufananidzo 9. Cumulative kukanganisa kweCoulomb kuyerwa nzira

In order to eliminate the accumulated error, there are three possible useable time points in normal battery operation: end of charge (EOC), end of discharge (EOD) and rest (Relax). When the charging end condition is reached, it means that the battery is fully charged and the state of charge (SOC) should be 100%. The discharge end condition means that the battery has been completely discharged and the state of charge (SOC) should be 0%; it can be an absolute voltage value or change with the load. When it reaches the resting state, the battery is neither charged nor discharged, and it remains in this state for a long time. If the user wants to use the rest state of the battery to correct the error of the coulomb measurement method, an open-circuit voltmeter must be used at this time. The figure below shows that the state of charge error can be corrected in the above state.

Mufananidzo 10. Mamiriro ekubvisa kukanganisa kwekuwedzera kweCoulomb kuyerwa nzira

Chinhu chechipiri chikuru chinokonzera kutsauka kwekururama kwenzira yekuyeresa coulomb ndeye full charge capacity (FCC) kukanganisa, ndiwo mutsauko uripo pakati pekukosha kwebhatiri rekugadzira dhizaini uye yechokwadi yakazara chaji yebhatiri. Yakazara yekuchaja huwandu (FCC) ichakanganiswa nekupisa, kuchembera, mutoro uye zvimwe zvinhu. Naizvozvo, iyo yekudzidza zvakare uye nzira yekubhadhara yehuwandu hwekuchaja huwandu hwakakosha zvakanyanya kune coulomb kuyerwa nzira. Iyi inotevera nhamba inoratidza chiitiko chemamiriro echaji chikanganiso kana iyo yakazara kuchaja huwandu hwakawandisa uye isingatarisirwe.

Mufananidzo 11. Chikanganiso chinokanganisa apo huwandu hwehuwandu hwehuwandu hunowedzerwa uye husingatarisirwi

2.4 Dynamic voltage algorithm mafuta geji

Iyo dynamic voltage algorithm peturu geji inogona kuverenga mamiriro ekuchaja yelithium bhatiri zvichienderana chete nebhatiri voltage. Iyi nzira ndeyekufungidzira kuwedzera kana kudzikira kwechaji zvichienderana nemusiyano uripo pakati pebhatiri voltage neyakavhurika yedunhu voltage yebhatiri. Ruzivo rwemagetsi emagetsi runogona kunyatso kutevedzera maitiro ebhatiri re lithium kuona mamiriro ekuchaja SOC (%), asi iyi nzira haigone kufungidzira kukosha kwebhatiri (mAh).

Nzira yekuverenga yakavakirwa pamusiyano uripo pakati pebhatiri voltage uye yakavhurika yedunhu voltage, nekushandisa iterative algorithm kuverengera kuwedzera kwega kwega kana kudzikira kwenzvimbo yekuchaja kufungidzira mamiriro ekuchaja. Kuenzaniswa nemhinduro ye coulomb metering mafuta geji, iyo dynamic voltage algorithm mafuta geji haizounganidze zvikanganiso nekufamba kwenguva uye zvazvino. Coulomb metering mageji emafuta anowanzo kukonzera fungidziro isiriyo yenzvimbo yekuchaja nekuda kwekukanganisa kwekunzwa uye bhatiri rinozviburitsa. Kunyangwe iko iko iko kukanganisa kwekunzwa kuri kudiki kwazvo, iyo coulomb counter icharamba ichiunganidza chikanganiso, uye chikanganiso chakaunganidzwa chinogona kubviswa chete kana chachajwa zvizere kana kuburitswa.

Iyo dynamic voltage algorithm fuel gauge inofungidzira mamiriro ekuchajisa kwebhatiri chete neruzivo rwevoltage; nekuti haina kufungidzirwa neruzivo rwazvino rwebhatiri, haina kuunganidza zvikanganiso. Kuti uvandudze iko kurongeka kwenzvimbo yekuchaja, iyo dynamic voltage algorithm inoda kushandisa chaiyo mudziyo, uye gadzirisa maparamita eiyo yakagadziridzwa algorithm inoenderana neiyo chaiyo bhatiri voltage curve kana yazara uye yaburitswa zvizere.

Mufananidzo 12. Kuita kwe dynamic voltage algorithm fuel gauge uye kuwana optimization

Izvi zvinotevera kuita kweiyo dynamic voltage algorithm pasi peakasiyana discharge rate mamiriro. Inogona kuonekwa kubva pamufananidzo kuti mamiriro ayo ekubhadhara ane kunaka kwakanaka. Pasinei nemamiriro ekubudiswa kweC / 2, C / 4, C / 7 uye C / 10, iyo yose yemhosva yekukanganisa nzira iyi iri pasi pe3%.

Mufananidzo 13. Kuitwa kwemamiriro ekutonga kweiyo dynamic voltage algorithm pasi pemamiriro akasiyana ekubuda.

Mufananidzo uri pasi apa unoratidza kushanda kwemamiriro ekubhadhara apo bhatiri iri pfupi-yakazara uye ipfupi-yakabudiswa. Mamiriro ekuchaja kukanganisa kuchiri kudiki, uye kukanganisa kwakanyanya kunongova 3%.

Mufananidzo 14. Kuitwa kwemamiriro ekutonga kweiyo dynamic voltage algorithm kana bhatiri iri pfupi-chaji uye pfupi-yakadzikiswa.

Kuenzaniswa nemamiriro ezvinhu apo iyo Coulomb metering geji yemafuta inowanzokonzera isina kurongeka yekuchaja nekuda kwezvino zvikanganiso zvekunzwa uye bhatiri kuzviburitsa, iyo dynamic voltage algorithm haina kuunganidza zvikanganiso nekufamba kwenguva uye ikozvino, inova mukana mukuru. Nekuti hapana ruzivo nezve kuchaja / kuburitsa ikozvino, iyo dynamic voltage algorithm ine hurombo hwenguva pfupi yechokwadi uye inononoka yekupindura nguva. Pamusoro pezvo, haikwanise kufungidzira huwandu hwakazara hwekuchaja. Zvisinei, inoita zvakanaka maererano nekureba kwenguva refu, nokuti magetsi ebheteri anozopedzisira aratidza zvakananga mamiriro ayo ekubhadhara.