VW-80149-EN原版完整文件

Groupstandard VW80149

Issue2021-08

Class.No.: 8MA

Descriptors: 12volts,alternator,converter,energysupply,highcurrent,high-currentloads,load

High-CurrentLoads

AdditionalRequirementsandTests

Preface

Thelimitedcapacity(staticanddynamic)ofthevehicleelectricalsystemisconfrontedwiththein-creasingdemandforelectricalenergy.Anelectricalsystemoverloadcanresultinvoltagefluctua-tionsthatarenoticeableinthecomfortarea(e.g.,fluctuatinginteriorblowerspeed,lightflickering)aswellasinvoltagefluctuationsthatleadtofunctionallimitations/failuresinthevehicle(e.g.,lossofelectricalsteeringassistance).

Thispartofthestandarddescribesthetestreportthatthecontractormustprepareincollaborationwiththepurchaser.Thepurposeofthetestreportistogivethepurchaseranoverviewofthedy-namicbehavioroftherespectiveload.

Previousissues

VW80149:2009-11,2013-09,2018-02

Changes

ThefollowingchangeshavebeenmadetoVW80149:2018-02:

Nomenclatureedited

Section4restructured

Section4.3.1expanded

Section4.3.2expanded

Section5restructured

Section5.2.1added

Section5.4expandedandrestructured

Section6restructured

Section7.8restructured

Section7.8.3expanded

AppendixAupdated

Alwaysusethelatestversionofthisstandard.

Thiselectronicallygeneratedstandardisauthenticandvalidwithoutsignature.Acommaisusedasthedecimalsign.TheEnglishtranslationisbelievedtobeaccurate.Incaseofdiscrepancies,theGermanversioncontrols.

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Contents

1

2

3

4

4.1

4.2

4.3

4.3.1

4.3.2

4.3.3

5

5.1

5.2

5.2.1

5.2.2

5.2.3

5.2.4

5.3

5.3.1

5.3.2

5.4

6

6.1

6.2

6.3

6.4

7

7.1

7.2

7.3

7.4

7.5

7.6

7.7

7.8

7.8.1

7.8.2

7.8.3

7.8.4

7.9

8

8.1

8.2

9

AppendixAA.1

Page

Scope 3

Definitions 3

Abbreviations 3

General 3

Generalsupplyrequirements 3

Identificationofhigh-currentloads 3

Energysupply 4

12Venergysupplythroughaclassicalalternator(conventionalvehicle) 4

12-VenergysupplybyDC-DCconverter(MHEV,HEV,PHEV,BEV) 4

Systemuseinthetwoarchitectures 4

Limitsandtestspecifications 4

General 4

Generallimitsandtestspecifications 4

Currentthresholdforclassificationasahigh-currentload 4

Testvoltagespecifications 5

Voltagelevels 5

Maximumpowerconsumptionandenergybackfeed 5

Limitsandtestspecifications(vehicleswithaconventionalpowertrain) 6

Maximumpermittedhigh-currentloadgradients 6

Controlfrequencyrange 6

Limitsandtestspecifications(MHEV,HEV,PHEV,BEV) 7

Testingandevaluationforclassification 7

Test 7

Measurementsetup 7

Evaluationofloadstep 8

Evaluationofloaddump 10

Requirementsforthedesignofhigh-currentloads 12

Obligationtoreport 12

Maximumtotalpowerofthehigh-currentload 12

Designspecificationsformultiple-actuatorsystems 12

Voltagesensing 12

Reportingofpowerconsumption 13

Currentinput 13

Efficiency 14

Stabilizationmeasures 15

General 15

Overvoltage/undervoltagecontrolstrategies 15

Degradationstrategy 15

Informationon12Vstartduringdriving 18

SWmodelforsimulation 18

Testsforverificationofimplementedmeasures 19

Efficiencyverification 19

Measurementforverificationofthedegradationconcept 20

Applicabledocuments 20

21

High-currentloadtestreport 21

Scope

Thisstandarddescribesrequirementsandlimits,aswellastestconditionsandtests,thatmustbeadheredto/performedwhendevelopinghigh-currentloads.Itdefinesspecificationsforthedesignofelectricalcomponentstoensurevoltagestabilityinthevehicle.

ThisstandarddoesnotsupersedetherequirementsofVolkswagenstandardVW80000,norVDA320publishedbytheGermanAssociationoftheAutomotiveIndustry(VDA).

Definitions

SmartActuator Intelligentbrakeactuator

Terminal15on-to-offcycle Timefrom"ignitionsystemon"to"ignitionsystemoff"

Abbreviations

48-VMHEVBEV

ECUEPSESCEVHALHEVHWKFLVPEPEPPF

PHEVPPSCUSWVESeBKV

48-Vmildhybrid(electricvehicle)Batteryelectricvehicle

ElectroniccontrolunitElectromechanicalpowersteeringElectronicStabilityControlElectricvehicle

Four-wheelsteeringHybridelectricvehicleHardware

ConceptFreezeLow-voltagePowerelectronics

ProductEmergenceProcessProjectFeasibility

Plug-inhybridelectricvehicleProjectPremises

SteeringcontrolunitSoftware

VehicleelectricalsystemElectromechanicalbrakebooster

General

Generalsupplyrequirements

ApprovaloffirstsupplyandchangesasperVW01155ThegeneralrequirementsasperVW80000apply.

AvoidanceofharmfulsubstancesasperVW91101

Identificationofhigh-currentloads

Ahigh-currentloadisidentifiedbythelimitsandparametersdescribedinthefollowingsectionsbe-ingexceeded.Whentheseareexceeded,thecomponentisidentifiedasahigh-currentloadand,therefore,thereisanobligationtoreportittothepurchaser.

Energysupply

12Venergysupplythroughaclassicalalternator(conventionalvehicle)

Inconventionalvehiclesystems,energyisconvertedbyclawpolealternators.Fromaphysicalstandpoint,onlylowcurrentgradients(<300A/s)canberealizedusingthistypeofenergyconver-sion.

Inordertoensureastableenergysupplyandlowvoltagefluctuation,theremustbeanobligationtoreporthigh-currentloadswhentheramp-up,control,orramp-downgradientsare>300A/sandwhenthecurrentthresholdisexceeded(seealsosection5).

12-VenergysupplybyDC-DCconverter(MHEV,HEV,PHEV,BEV)

Invehiclesystemswithanintegratedmedium-voltageorhigh-voltagebatterypack(MHEV,HEV,PHEV,BEV),the12-VenergygenerationisrealizedbyadynamicallyregulatingDC-DCconverter.Thequantityofenergydemandedissuppliedfromthemedium-voltageorhigh-voltagebatterypackthroughtheDC-DCconverteronthelow-voltageside.Fromaphysicalstandpoint,forthistypeofenergysupply,theconverter'speakflowis,inmostcases,thedesign-relevantparameter.

Inordertoensureastablevoltagesupply,theremustbeanobligationtoreporthigh-currentloadswhentheramp-up,control,orramp-downgradientsare>15kA/sandwhenthecurrentthresholdisexceeded(seealsosection5).

Systemuseinthetwoarchitectures

Ifahigh-currentloadisusedinthetwovehicleelectricalsystemarchitectures(describedinsection4.3.1andsection4.3.2),thereisanobligationtoreportanyexceedingofthespecificationsdetailedinsection4.3.1.

Forconfigurablesystems,adesignforthecorrespondingscopeofapplicationcanbecreated.Theobligationtoreportparametersdescribedinsection4.3.1andsection4.3.2remainunchanged.

Configurablesystemsmustbeprotectedinthecorrespondingvehiclearchitectures.

Limitsandtestspecifications

General

Thissectionsummarizesallthelimitsandtestspecificationsthatmustbecompliedwith.Iftheyareexceeded,thepurchasermustbeinformeddirectly.High-currentloadsmustpreferablybede-signedwithohmicbehavior.Inthecaseofdeviatingbehavior(current/powercontrol),aseparateagreementmustbereachedwiththepurchaser.

Generallimitsandtestspecifications

Currentthresholdforclassificationasahigh-currentload

Anelectricalloadmustbeclassifiedasahigh-currentloadifitexceedsthecurrentthresholdIX,max(seetable1)andthemaximumpermittedcurrentgradients(seetable5andtable7).

Table1–Currentthresholdofthehigh-currentload

Parameter

Value

Tolerance

Description

IX,max

30A

—

Currentthresholdforclassificationasahigh-currentload(regardlessofelectrical-systemtopology)

Testvoltagespecifications

Thetestsdescribedinsection6mustbeperformedatthreevoltages(seetable2)withanidealcurrentsource(Ri=0Ω).

Table2–Testvoltagespecifications

Parameter

Value

Tolerance

Description

VA,min

11,8V

±100mV

Testvoltageminimumsetting

VA,max

15,6V

±100mV

Testvoltagemaximumsetting

VA,crit

9,8V

±100mV

Minimumcriticaltestvoltage

Ri,source

0Ω

—

Idealvoltage/currentsource

Voltagelevels

Aloadidentifiedasadynamichigh-currentloadmustswitchtothespecifiedfunctionmodesfortheself-protectionofthevehicleelectricalsystemintheeventthatthedefinedvoltagelevels(seetable3)areexceeded/notreached(seealsosection7.8).

Table3–Voltagelevels

Parameter

Value

Tolerance

Description

VA,min_conventional

12,2V

±100mV

MinimumvoltagespecificationinLVvehicleelectricalsystem

VA,min_derate_100%

10,8V

±100mV

VoltageatECUatthestartofderating

VA,min_derate_0%

9,0V

±100mV

VoltageatECUduringmaximumderating

VA,low_active

6,0V

±100mV

VoltageatwhichtheECU

canconsumeamaximum10W(1,67Aat6,0V)andcontinuestobeactive

TheindividualvoltagevaluesVA,min_derate_100%andVA,min_derate_0%(seetable3)aretransmittedtothehigh-currentloadonthevehiclebusoragreeduponwiththepurchaser.

Maximumpowerconsumptionandenergybackfeed

Theloadmustnotexceedaspecifiedmaximumpowerconsumption(seetable4)inthe12-Velec-tricalsystem.Ifthehigh-currentloadcanactivelybackfeedenergyintothevehicleelectricalsys-tem,functionalconditions(seetable4)mustbetakenintoaccount.Thefunctionalbehaviormustbeagreeduponwiththepurchaser.

Table4–Powerconsumptionandenergybackfeed

Parameter

Value

Tolerance

Description

Powerconsumption

Pmax,A00-A

1200W

—

PmaxatVA,minforvehiclesuptoA-class(modulartransversematrix(MQB)A,Golf,Po-lo,etc.)

Pmax,B-D

1500W

—

PmaxatVA,minforvehiclesfromB-class(modularlongitudinalmatrix(MLB),Passat,etc.)

Pmax,individualactuator

400W

—

Insystemswithseveralactivesinks

Voltagesensing

tsense

≤2ms

—

CalculationtasksfortheanalysisofVsense

Sinkenergybackfeed

Imax,backfeed

15A

±5%

Maximumpermissiblebackfeedcurrentofthecomponent(doesnotapplytocomponentswithanactivebackfeedinordertorealizeCO2re-ductionpotentials)

Ifexceeded,anagreementwiththepurchaserisalwaysrequired.

Limitsandtestspecifications(vehicleswithaconventionalpowertrain)

Maximumpermittedhigh-currentloadgradients

Thegradientsspecifiedmustbedeterminedaspersection6.Deviationsfromthesespecifications(table5)mustbeagreeduponwiththepurchaser.

Table5–High-currentloadgradients

Parameter

Value

Tolerance

Description

Loadimposition

f´(lX)

300A/s

—

Maximumpermittedpositivegradientatthecomponents

tt

5ms

—

Deadtimeuntilalternatorprovidesenergy

Loaddump

|f´(lX)|

300A/s

—

Maximumpermittednegativegradientatthecomponents

Controlfrequencyrange

Topreventalternatorcontrolleroscillationswithactivelycontrolledhigh-currentloads,thefrequen-cyrangeaspertable6isnotpermitted.

Table6–Non-permittedfrequencyrangefordynamicclosed-loopcontrol

Parameter

Value

Tolerance

Description

fcontrol

10Hzto

100Hz

—

Preventionofalternatorcontrolleroscillations

Limitsandtestspecifications(MHEV,HEV,PHEV,BEV)

Thegradientsspecifiedmustbedeterminedaspersection6.Deviationsfromthesespecifications(seetable7)mustbeagreeduponwiththepurchaser.

Table7–High-currentloadgradients

Parameter

Value

Tolerance

Description

Loadimposition

f´(IX)

15kA/s

—

Maximumpermittedpositivegradientatthecomponents

tt

1ms

—

DeadtimeuntilDC-DCconvertersuppliesener-gy

Loaddump

|f´(IX)|

15kA/s

—

Maximumpermittednegativegradientatthecomponents

Ifanundervoltageisdetectedintheelectricalsystem(Vcomponent<9,8V),agradientof300A/smustbemaintainedinordertoprotecttheelectricalsystemagainstanotherundervoltage.Thisstatemustbemaintainedforthisterminal15on-to-offcycle.

Testingandevaluationforclassification

Test

Atleastthefunctionofthecomponentintermsofthecurrentandvoltagecurvesatwhichthehigh-estpowersareconsumedorfedintotheelectricalsystem(recordingofvehiclestate,voltages,cur-rents,temperature)mustbemeasured.Multiplemeasurementsmayneedtobeperformed/ana-lyzed,ofwhichthemostcriticalmatters.

Themeasurementsareperformedinearlyprojectphasesasacomponenttestbythecontractor.Ifthecomponentisinstalledinthevehicle,theoverallvalidationandelectrical-systemstabilityre-leaseareperformedbythepurchaser.

Measurementsetup

Torecordthecharacteristicelectricalvaluesfortheclassificationoftheload,themeasurementset-upasperfigure1mustbeusedforthemeasurementstobeperformed.

Themeasurementsetupconsistsofanidealdirect-currentvoltagesource,theloadtobemeas-ured(consistingofaswitchS1andaloadresistorRX),aswellameasuringdevicewithpotentiallyseparatedinputs(e.g.,oscilloscope)torecordthevoltageandcurrent.

Thevoltagesourcemustbedesignedsothattheload'smaximumrequiredpoweraswellasitsmaximumdynamicscanbesupplied.Themeasurementisperformedonthecomponentatthreedifferentsupplyvoltages(seesection5).

Theloaddiagram,consistingofaswitchandaloadresistor,isofsymboliccharacter.Theinternalsetupandtypeoftheconnectionarecomponent-specificandcandeviatefromtheequivalentcir-cuit.

Themeasuringdeviceforrecordingtheloadcurrentandthevoltageatthecomponentmustbeatleastoftheaccuracyclass0,5andhaveaminimumsamplingrateof10kHz.

Legend

Idealvoltagesource

load

RX Symbolicloadresistor

S1 Symbolicswitch,closingattimeT0(activationoftheload)

M1 Measuringdevice(preferablyoscilloscope)

VX Voltageattheloadinput

T0 Timeatwhichtheswitchisclosed

Figure1–Measurementsetupfordeterminingthecharacteristicelectricalvalues

Evaluationofloadstep

Fortheclassificationoftheload,diagramswithvaluesasperfigure2mustbegeneratedforthemeasuredcurrentprofiles.Bothstart-upandclosed-loopcontrolmustbeconsideredinthesedia-grams.

Legend

IinA

tins

Peakcurrentabovethealternatorcharacteristiccurve

X

QB- ChargetakenfromtheSLIbattery

f´(IX) Positivegradientofthecurrentcurve(gradientfortheloadstep)IX(t) Measuredcurrentcurveoftheloadovertime

IDC/DC+(t) CurrentcurveoftheDC-DCconverterovertime(currentoutput)IG+(t) Currentcurveofthealternatorovertime(currentoutput)

t0 Switch-ontimeoftheload

t1 DC-DCconverterenergyoutputtimepointt2 Alternatorenergyoutputtimepoint

t3 TimeatwhichtheloadstepiscompensatedbytheDC-DCconvertert4 Timeatwhichtheloadstepiscompensatedbythealternator

ta Timeatwhichthecurrentisat10%ofthepeaktb Timeatwhichthecurrentisat90%ofthepeak

Figure2–Determinationofthecharacteristicsduringloadstep

CalculatingtheSLIbatterypowerdrawandsinkcurrentgradient

formula(1)describesthebatterypowerdrawcalculationinsystemswithalternatorenergygenera-tion.formula(2)describesthepowerdrawwithsupplyfromaDC-DCconverter.

Batterypowerdrawinvehicleswitha12-Valternator

BatterypowerdrawinvehicleswithaDC-DCconverter

(1)

(2)

ThechargequantityQB-istheareabelowthemeasuredcurrentcurveIX(t),lessthearearesultingfromthecurrentcurveofthepositivealternatorgradientIG+(t)(informula(1))andlesstheareare-sultingfromthecurrentcurveoftheDC-DCconverterIDC/DC(t)(informula(2)).Thelowerlimitforcalculatingtheintegralistheswitch-ontimeoftheloadt0,theupperlimitisthetimet4(alternator)andt3(DC-DCconverter),atwhichthecurrentcurveoftheloadandthecurrentcurveofthealter-nator/DC-DCconverterintersect.

Thegradientfortheloadstepiscalculatedusingformula(3).

Gradientforloadstep

(3)

Thepositivegradientofthecurrentcurvef´(lX)resultsfromthedifferencebetweenthe0,1-foldpeakcurrentandthe0,9-foldvalue.Thisvaluemustbedividedbythetimethatisrequiredforthecurrentcurvetoincreasefromthe0,1-foldvaluetothe0,9-foldvalue.

Evaluationofloaddump

Fortheclassificationoftheload,diagramswithvaluesasperfigure3mustbegeneratedforthemeasuredcurrentprofiles.Bothclosed-loopcontrolandpowerdownmustbeconsideredinthesediagrams.

Legend

IinA

tins

X,switch-off

PeakcurrenttobeswitchedoffIX,switch-off(t)Currentcurveoftheloadovertime

IG-(t) Currentcurveofthealternatorovertime(withdrawalofthecurrentoutput)

f´(lX,switch-off)Negativegradientofthecurrentcurve(gradientfortheloaddump)

IDC/DC-(t) CurrentcurveoftheDC-DCconverterovertime(withdrawalofthecurrentoutput)tc Timeatwhichthecurrentisat90%ofthepeak

td Timeatwhichthecurrentisat10%ofthepeak

Figure3–Determinationofthecharacteristicsduringloaddump

Calculatingthesinkcurrentgradient

Whenevaluatingtheloaddump,thegradientofthepeakcurrenttobeswitchedoffintherange0,9×X,switch-offto0,1×X,switch-offissignificantassoonasitexceedsthevalueofthenegativegradi-entofthealternatorcurrent/DC-DCconverter.

Thevalueofthegradientfortheloaddumpiscalculatedusingformula(4).

Gradientforloaddump

(4)

Thenegativegradientofthecurrentcurvef´(lX,switch-off)resultsfromthedifferencebetweenthe0,9-foldpeakcurrentandthe0,1-foldvalue.Thisvaluemustbedividedbythetimethatisrequiredforthecurrentcurvetodecreasefromthe0,9-foldvaluetothe0,1-foldvalue.

Requirementsforthedesignofhigh-currentloads

Obligationtoreport

Ifaloadisdefinedasadynamichigh-currentload,thepurchasermustbeinformedimmediately.

Theidentificationisapparentattheparameterlimitsdescribedinsection5.AsperthePEP,andbythe"KFmilestone"atthelatest,thesystemparametersofeachhigh-currentloadmustbere-portedtothepurchasersothattheenergysupplysystemdesigncanbeadaptedtothevehiclere-quirements.

Ifacomponentidentifiedasahigh-currentloadplacesanAutomotiveSafetyIntegrityLevel(ASIL)requirementontheenergysupplyintheelectricalsystem,thismustalsobereportedindetailtothepurchaserbythe"PPmilestone"atthelatest.

Maximumtotalpowerofthehigh-currentload

FromapeakpowerofPmaxatVA,min(seesection5),asystemevaluationthatteststheconversionofthecomponentstoahighervoltagelevelmustbesubmittedduringtheconceptphase(e.g.,nominalvoltagelevelVnominal=24V/48V/.../400V).Thisvoltagelevelmustbeagreedwiththepur-chaserintherun-uptothequotation.

NOTE: Aseparationofpowerunit(V>>12V)andlogicunit(Vnominal=12V)canbeusedwhenlookingatthesystem.

Designspecificationsformultiple-actuatorsystems

Ifanoverallsystemcontainsmorethanonehigh-currentactuatorwithPmax,individualactuator(seesection5),theremustbeafunctionalallowanceforequalizingasimultaneouspeak-currentre-quirement.

Voltagesensing

Aninternalvoltagesensingmustbeeffectedbothforthepowerunitandthelogicunit.Apotentiallyredundantdesignofthevoltagesensingmustbedefinedbythesystemengineer.

Calculationtasksfortheevaluationandfurtherprocessingofthesensedvoltage(Vsense)mustruninatimeloopof≤2ms.

Adegradationstrategybasedonthevoltagesensingmustbeactivatedatintegrationlevel2atthelatestandmustbeagreedwiththepurchaser.

Activationofthehigh-currentload'spowerunit

TheactivationoftheelectricmachineormotororactuatorviathePEmustbecontrolledsothat,forexample,asoftstart-up/softrundown/softclosed-loopcontrol(seefigure4,A)canbeimple-mented.

Anactivationthathasacurrentcurvewithsteepcontrolramps,shortcircuitstart-up,andhardshutdown(seefigure4,B)isnotpermitted.Functionssuchassoftstart-up,softrundown,orsoft

closed-loopcontrolmustbeagreeduponwiththepurchaserinthecourseoftheprojectandduringtheB-sampledefinitionphaseatthelatest.

A"quasi"shortcircuit,ascanoccuronenginestart-up,isnotpermittedinnormaloperation.Theenginestart-upcurrentsmustbelimitablethroughcalibration.Inthecaseofuseinconventionalvehicles,thefrequencyrangeof10Hzto100Hzisnotpermittedforpermanentactivationinthepowerunit.Thisfrequencybandcaninteractwiththealternatorcontrollerandcauseoscillations.

Legend

Start-up

Closed-loopcontrol

Rundown

Softstart-up,softrundownandsoftclosed-loopcontrol

Shortcircuitstart-up,steepcontrolrampsandhardshutoff

Figure4–Schematicrepresentationofthehigh-currentloadactivation

Reportingofpowerconsumption

Ateveryoperatingpoint,thecomponentmustdetermineandreportitscurrentpowerinput.Aspartofapossiblepredictionofthepowerthatwillshortlyberequiredbythehigh-currentcomponent,apowerrequirementsignalmustbegenerated(e.g.,airspring:"compressorwillrunshortly",EPSpowerrequirementbitwhenparking,earlydangerdetectiontominimizetheeffectsof/topreventacrashbythepre-collisionsystem).

Currentinput

Ifaloadisabletoactivelyfeedcurrentviaitssupplyconnectionsintothevehicleelectricalsystem,thiscurrentmustbelimitedtoamaximumofImax,backfeed.

Forthis,thefollowingapproachcanbefollowed:

– Storageofthebackfeedenergyinthehigh-currentcomponent(e.g.,inanintermediatecircuitcapacitor).

Ifacomponentfeedsenergybackintotheelectricalsystem,thiscomponentmustnotexceedtheECUoperatingvoltagelimitsasperVW80000.

Thebackfeedmustbeagreeduponwiththepurchaser.

Efficiency

Theefficiencyofthecomponentmustaverage80%overtheentireoperatingrange.Thepurchaserwilldisclosetheexactvaluetothecontractor.

Theefficiencyiscalculatedfromthesumofindividualoperatingpointsinthecomponent'scharac-teristicmapandcorrespondingweighting.Itiscalculatedusingformula(5).

Efficiency

(5)

Legend

j Index

n Numberofoperatingpointsonthecharacteristicmaptobeusedfortheefficiencycalculation

Meanefficiency

ηj EfficiencyattheoperatingpointusedPoutj PoweroutputattheoperatingpointusedPinj Powerinputattheoperatingpointused

Pmechj Mechanicalpoweroutputofthecomponentatthetransitionpointinthevehicleattheoperatingpointused

Pelj Electricalpowerinputofthecomponentacrossallelectricalconnec-tionsforpowerandlogicattheoperatingpointused

wj Weightingoftheoperatingpoint(consideringfrequencyincustomeroperation)

Themeanefficiencyiscalculatedfromthesumofindividualefficiencies,whereeachindividualeffi-ciencymustbeallocatedaweighting.Theindividualefficiencyiscalculatedfromtheratioofthepoweroutputtothepowerinput,inthiscaseofthemechanicalpowertotheelectricalpower.

Thepurchaserwilldefinetheoperatingpointsandtheirweightinginsimilarform(seetable8).

Table8–Operatingpointsandtheirweighting

Operatingpoint

Mechanicalvariable1

Mechanicalvariable2

Electricalvariable1

Electricalvariable2

Weighting

1

2

3

Stabilizationmeasures

General

High-currentloadsmustnotifytheirdesiretoswitchontotheenergymanagementsystem(withtheexceptionofloadsthataffectsafety:ESC,EPS,eBKV,SmartActuator,SCU,HAL).

Iftheelectricalsystemhassufficientpowerreserves,theloadisgivenapprovaltoswitchon(pow-ercontrolbussignalLR_Komponente_xy_Freigabe(PC_component_xy_approval)).

Thissectiondescribeswhichfunctionalcharacteristicsthecomponentmustadoptintheeventthatanovervoltage/undervoltageisdetected.

Overvoltage/undervoltagecontrolstrategies

Iftheenergymanagementsystemdetectsanovervoltage/undervoltageandsendsacorrespond-ingsignaltothevehiclebus(bussignalLR_Komponente_xy_Freigabe),thecomponentmustre-duceitsownpowerrequirementtoanagreedmaximumvalue.Thecomponentmustenterasafestatethroughastill-to-be-developeddegradationprocessuptohardshutdownwhenpowercon-sumptionhasdecreasedto"low".Forpulsedactivation,themeanvalueofthecurrentisdecisive.Inthiscase,thecontrolfrequencymustnotbeinthealternator'sfrequencyband(10Hzto100Hz)(seesection7.4).Thedegradationprocessmustbeagreeduponwiththepurchaser.

Thedegradationprocesswillbeseparatelydefinedineachvehicleproject,astheramp(seefigure5)dependsontheenergysource(DC-DCconverteroralternator)usedinthevehicle.

Whenanundervoltagedirectlylinkedtothecomponent'sownpowerconsumptionwithinatermi-nal15on-to-offcycleisfrequentlydetected,thismustbereportedonavehiclebus.Thetypeofmessageandthefrequencymustbeagreedwiththepurchaser.

Legend

IinA

tinms

Degradationofnon-pulsedload

Degradationofpulsedload

Figure5–Exampleswitch-offbehavioracrosscurrentramp

Degradationstrategy

Deepervoltagesagsshouldbecounteractedbyapowerdegradationinthelowervoltagerange,startingatVA,min_derate_100%,inwhichthecomponentmuststillfulfillitsfunction(seefigure6).

Legend

Power(P)

Voltage(V)

A Specifieddesignvalue

PD Designpowerrating

Pdeg Reducedpowerrating

Vmin MinimaldesignvoltagewithreducedpowerratingVA,min Lowestdesignvoltageforpowerrating

Figure6–Schematicrepresentationofadegradationstrategy

ThedesignvoltageVA,ministhevoltageuptowhichthecomponentshouldperformitsrequiredop-eratingcharacteristicscorrectlyandthusalsoconsumeitsdesignpowerPA.Itisheavilydependentonthefunctionofthecomponentandmustbeselectedsystem-specifically.

FromthevoltageVA,mindowntoalowerdesignvoltageVA,min_derate_0%,apowerdegradationtoPdegmustoccur.ThepowerPdegmustbeselectedsothatperformancecharacteristicsthatarestilltoler-ableforcustomersaredelivered(e.g.,forheaters,averylowpowercanbeselectedastheeffectsareonlynoticeableforthecustomeroveraverylargetimeconstant).Incontrast,incomponentssuchaslightingdevices,theeffectsofachangeinpowerareimmediatelynoticeableforthecus-tomer.Inthiscase,theremustbenopowerdegradation(Pdeg=PA)requested.

Ifthecomponentdetectsthatitsown,alreadyreducedpowerconsumptiondecreasesthevoltagelevelinthevehicleelectricalsystemfurther,itmustcheckwhetherthepowerc