SE542927C2 - Power supply arrangement for a vehicle with separated power links and method thereof - Google Patents

Abstract

The present disclosure relates to techniques in the context of vehicles, and to a power supply arrangement for use in a vehicle. According to a first aspect, the disclosure relates to a power supply arrangement (400) for use in a vehicle (1). The power supply arrangement (400) comprises at least one energy storage device (70), a first power link (101) and a second power link (102). The at least one energy storage device (70) comprising an energy storage (76) being electrically connectable to a first power connector (71) and a second power connector (72), wherein the second power connector (72) is electrically disconnectable from the first power connector (71). The first power link (101) is arranged to connect the first power connector and at least one propulsion system of the vehicle and the second power link (102) is arranged to connect the second power connector and at least one braking system of the vehicle (1). The second power link (102) is electrically separated from the first power link (101) upon disconnection of the second power connector (72) from the first power connector (71). The disclosure also relates to a vehicle (1) comprising the power supply arrangement and to a corresponding method.

Description

Power supply arrangement for a vehicle with separated power links and methodthereof.

Technical field The present disclosure relates to techniques in the context of vehicles, and to apower supply arrangement for use in a vehicle. The disclosure also relates to avehicle comprising the power supply arrangement, to a corresponding method, a computer program and a computer-readable medium.

Backgroundvehicles of today are typicaiiy manufactured for a specific purpose, eg. a hus is inanufactured for transporting peopie and a truck is manufactured for transportinggoods. Such vehicies are commoniy rnanufactured and compieteiy assemhied in afactory, or they may he partiy assernhied in a factory and compieted at a hodymanufacturer. Cšnce the vehicie is assemhied, the vehicie may he used for thespecific purpose. Tims, a hus may he used as a hus and a garhage truck may heused as a garhage truck. Üifferent vehicles are thus needed for different purposes,which may reouire a iarge fteet of vehicies for a hauier, and therehy oecome verycostiy.

There are, for exampie, known soiutions yyhere a truck can he rehuiit hy changinga concrete mixer to a ioading piatform. This increases the fiexihiiity and ttvo differentfunctions can he achieved hy means of one singie vehicie. Aiso, document tiS~âiliid/'Ûtâââšå Af discioses a moduiar eiectric vehicie using interchaifgeahievehicie assernhiy moduies. The user can therehy disassemhie and reassemhie thevehicie for use in different appiications. i-iotvever, in the future, further developmenttowards even more flexible vehicle solutions might be needed to meet customers'different vehicle needs in a cost-efficient way.

Energy for propelling electrical vehicles may be stored in special batteriesconfigured to provide a high system voltage, eg. dot) voit. The batteries need to hesecure due to the high ertergy content. The vehicies' hraking systems have simiiar requirements for povver suppiy. in moduiar vehicie soiutions, it may he adt/antageous to iet set/erat or aii ot the rnoouies ot a vehicie share one energysource. Conseouentiy, the propuision and the braking systems of a vehicie mayhave to share one common eitergyf source. t-iowever, to iet a propuision system and a braking system ota vehicie share one energy source may intpiy security risks.

Summarylt is an object of the disclosure to provide a solution that enables sharing ot one energy source between one or more braking eno propuision systems in e vehicie,virhiie assuring high securityf. For exampie, it is an object to assure that a singieerror, such as e short circuit, cannot propagate between the systems. it is afurther object to provicie a soiution that is suitabie tor use in mociuiai' vehicie soiutions.

According to a first aspect, the disclosure relates to a power supply arrangementfor use in a vehicle. The power supply arrangement comprises at least one energystorage device, a first power link and a second power link. The at least oneenergy storage device comprising an energy storage being electricallyconnectable to a first power connector and a second power connector, whereinthe second power connector is electrically disconnectable from the first powerconnector. The first power link is arranged to connect the first power connectorand at least one propulsion system of the vehicle and the second power link isarranged to connect the second power connector and at least one braking systemof the vehicle. The second power link is electrically separated from the first powerlink upon disconnection of the second power connector from the first powerconnector. Thereby, vehicie design can he simbiitied by ietting the brakingsystems and oroouision systems share one singie energy storege device vvhiiesecurity is stiii ensureoi due to the separated power iinks as a singie error in one otthe systems wiii not propegete to the other systern. iviore speciticeiiy, theproposed power supply arrangement makes it possible to, e.g. in case of an error,completely isolate one of the power links from the other power link and therebymaintain full functionality on the other power link. ln addition, es the propuisionsyfstem may typicaiiyf operate as an auxiiiary braking system, this impiies that itthe main braking systems taiis, then the auxiiiary braking system vviti he abie to continue to oberate, anoi vice versa. ln some embodiments, the at least one energy storage device comprises at leastone switch configured to be controlled to disconnect the first power connectorfrom the second power connector. Thereby, the power links can easily beseparated. ln some embodiments, the at least one energy storage device comprises a controlunit configured to evaluate a predefined error criterion and to control the at leastone switch to disconnect the first power connector from the second powerconnector upon the predefined error criterion being fulfilled. Thereby, differenterror criteria can be used to trigger the electrical separation of the first and second power connectors. ln some embodiments, the control unit is configured to obtain data indicative of acurrent flowing through the first and/or second power links and the predefinederror criterion comprises that the obtained current meets one or more predefined thresholds. Thereby, a current peak cannot propagate between the systems. ln some embodiments, the power supply arrangement comprises at least twoenergy storages, and wherein the first and second power links are arranged toparallel connect the at least two energy storages. Thereby, stacked batteries canbe used to power several propulsion and braking systems, which makes systemdesign less complex as the power links can then connect more than one power SOUFCG. ln some embodiments, the vehicle is assembled by a set of modules. The set ofmodules comprises at least one drive module comprising a pair of wheels, apropulsion system and the at least one brake system; wherein the at least onedrive module is configured to be autonomously operated, and at least onefunctional module. Each module in the set of modules comprises at least oneinterface releasably connectable to a corresponding interface of another module.ln these embodiments, the first and second power links are arranged to connectthe at least one energy storage device, being arranged in one of the at least onemodules, and at least one propulsion system and one brake system beingarranged in one of the other modules. By providing each energy storage devicewith two independent power links, it is ensured titat regardless of whether the drive modules are starid-aione or connected to a functšonai module, the brakefunction is always separated from the propulsion function. ln some embodiments, the first power link is arranged to connect the at least oneenergy storage device and a plurality of propulsion systems of the vehicle andwherein the second power link is arranged to connect the at least one powersource and a plurality of brake systems of the vehicle. Hence, all the power links in the vehicle are connected, which facilitates power supply and charging.

According to a second aspect, the disclosure relates to a vehicle comprising atleast one propulsion system, at least one brake system and the power supplyarrangement of the first aspect. The power supply arrangement is arranged toconnect the at least one energy storage device and the at least one propulsionsystem and the at least one brake system. ln some embodiments, the vehicle comprises a set of modules. The set ofmodules comprises at least one drive module comprising a pair of wheels, apropulsion system and the at least one brake system. Each module in the set ofmodules comprises at least one interface releasably connectable to acorresponding interface on another module. The first and second power links arearranged to connect an energy storage device being arranged in one of the atleast one modules and at least one propulsion system and brake system beingarranged in one of the other modules in the set of modules. ln some embodiments, the first and second power links are arranged to connectan energy storage device being arranged in one of the functional modules and atleast one propulsion system and brake system being arranged in one of the drive modules.

According to a third aspect, the disclosure relates to a method for use in a controlunit of an energy storage device comprising an energy storage being electricallyconnected to a first power connector connectable to a propulsion system of avehicle and a second power connector connectable to a braking system of avehicle. The method comprises evaluating a predefined error criterion and disconnecting the first power connector from the second power connector uponthe predefined error criterion being fulfilled. ln some embodiments, the method comprises obtaining data indicative of acurrent flowing through the first and/or second power links and the predefinederror criterion comprises that the current meets one or more predefined thresholds.

According to a fourth aspect, the disclosure relates to a computer programcomprising instructions which, when the program is executed by a computer,cause the computer to carry out the method according to the third aspect.

According to a fifth aspect, the disclosure relates to a computer-readable mediumcomprising instructions which, when executed by a computer, cause the computerto carry out the method according to the third aspect.

Brief description of the drawinqs Fig. 1 i||ustrates a set of modules, a vehicle assembled from the set of modules,and an offboard system.

Fig. Ea - Fig. 2c schematically i||ustrate a drive module in a side view, a front viewand in a view from above.

Fig. 3 schematically i||ustrates a drive module in further detail in a side view.

Fig. 4 schematically i||ustrates a side view of a functional module comprising apower control arrangement.

Fig. 5 illustrates the power storage device in further detail.

Fig. ß i||ustrates an example implementation of a power supply arrangement.

Fig. 7 i||ustrates a control unit of a power supply arrangement.

Fig. 8 i||ustrates a corresponding method for use in a control unit of an energystorage device.

Detailed descriptionOne way of meeting customers' different vehicle needs in a flexible and cost- efficient way is to use a modularised vehicle assembled from a set of modules.Such a modularised vehicle is typically assembled at the customer's premises andthe customer may thus buy a set of modules from a manufacturer. The modular vehicle can easily be assembled and re-assembled e.g. to perform a certainmission. Even though a vehicle is modular, i.e. assembled by independent units, itmay be desirable to power all the modules using one single power supply, e.g. abattery pack. This means that one battery pack is used for both propelling andbraking the vehicle. ln order to enable the same battery pack to be used for both propelling and abraking without risking security, this disclosure proposes a power supplyarrangement, for use in a vehicle, where the propulsion system(s) and the brakingsystem(s) have separate feed circuits. More specifically, a solution is proposedwhere one or more propulsion systems and one or more braking systems areconnected to separate connectors of a battery pack, herein referred to as batterystorage device, via separate power links. Furthermore, switches or similar arearranged in the power storage device(s) to ensure that the power links of theindividual (propulsion and braking) systems can be separated, so that a single errorin one of the systems does not propagate to the other system. Thereby, the powerlinks between the energy storage and the different systems in the vehicle arecompletely separated. Because each battery pack has two independent powerconnectors that are connected to two separate power links, one for each system, itis ensured that regardless of whether the drive modules are stand-alone or pairedwith a functional module to form a complete vehicle, the brake function is alwaysseparated from the propulsion function.

The term “power link” refers herein to an electrical connection which is typically anelectrical conductor that allows the flow of an electrical current in one or moredirections. The electrical conductor is e.g. a cable or wire. A power link may beassembled by several electrically connected sub links (or parts).

For better understanding of the proposed technique the concept of assembling avehicle from modules will now be explains with reference to the example embodiment of Fig. 1.

Fig. t iiiustrates an example set of moduies 2% for assembling a vehicle t. Anoffboard syfstein, herein referred to as a first control device 190, and an example of an assemoied vehicie 'i are aiso iiiustrated. The set of moduies 20 comprises apiuraiity of drive moduies 30 and a piuraiityf of functionai moduies 40, The drive modules' 30 main function is typically to drive (e.g. propel, steer andbrake) a vehicle 1. The drive modules 30 comprise a pair of wheels 37 and areconfigured to be autonomously operated. The functional modules are configured toperform a certain function such as to carry a load, e.g. goods or people. Eachmodule 30, 40 in the set of modules 20 comprises at least one interface 50releasably connectable to a corresponding interface 50 of another module 30, 40, By combining drive rnoduies 30 and functional moduies 40 different types ofvehicies 1 can be achieved. Ešorne vehicies 'i require tvvo or more drive moduies 30and some vehicies 1 oniy require one drive moduie 30, depending on the structuraiconfiguration of the functionai rnoduie 40. Each drive moduie 30 coinprises a controidevice, iierein referred to as a second controi device 200, and may thuscommunicate with a controi center or off-board system, i.e. the first controi device100. Since the drive modules 30 may be configured to be operated asindependently driven units by means of the second control devices 200, the drivemodules 30 may be connected to, or disconnected from, the functional module(s) 40 without manual work.

The principle of assernpiing a tfeiticie “i from moduies 30, 40 vviii now be described.An operator may receive a mission from a ciient to transport goods from oneiocation to another, The operator enters the iriforrnatiori about the mission into thefirst control device 100 via a user interface, such as a touch screen or sirniiar. tt ispcinted out that this is rnereiy an exampie, and the received mission mayautomaticaiiyf he transiated and/or inputted to the first controi device 100, The firstcontroi device 100 then determines vvhich function to be performed and thus whichtype of vehicie 1 is reduired to compiete the mission. in this exarnpie, the reduiredvehicie 1 may be a truck. The first controi device 100 seiects vtfhich rnoduies 30, 40to use for the required truck. The type of vehicie 'i and the rnoduies 30, 40 requiredto cornpiete the mission rnay for exarnpie be seiected based on information aboutthe goods, the distance to travet andior the geographicai iocation. The first controidevice 100 then converts the mission into a comrnand for one or two seiected drive ntoduies 3G te ehysicaiiy and eiectricaiiy connect vvith the seiected tunctienaiineduie 4G. in this exampie, the vehicie “i comprises two drive moduies. The secondcentret devices ZGG ot the drive moduies 3G each receives the cernrnand andconverts the coinmand to centret signais 'tor the respective drive rnoduie 3G, Thedrive nteduies 3G are therehy contreiied te ehysicaiiy and eiectricaiiy cennect vviththe iunctienai rnoduie 4G. Centroiiing the drive nieduie 3G te cennect with atunctionai ntoduie 4G may cernprise contreiiiitg the drive rnoduie 3G to identity theposition et the seiected tunctienai nteduie 4G and move te that peeitien. The positionot the seiected tunctienai rnoduie 4G may he deterrnined hased en informationreceived in the cernrnand to connect the drive nteduie 3G with the tunctienai ntoduie4G. Aiternativeiy, the coinniand to eenneet the drive meduie 3G and the 'itinctienainteduie 4G is transmitted te hoth the drive rnoduie 3G and the tunctienai nfiodtiie 4G,whereey the 'itinctionai ineduie 4G prepares ter the cennection and startstransmitting a signai. The drive moduie 3G may then determine the eesitien et thetunctienai rneduie based en this transmitted signai. The drive rneduies 3G are thusautenenteusiy eeerated te iind the seiected tunctienai rnoduie 4G and connect withthat tunctienai rneduie 4G. At ieast ene senser device GG arranged at the driverneduies 3G andior the tunctionai meduie 4G may he centigured to sense when theehysicai and/er eiectricai cennectien has been performed. The at ieast ene sensordevice 6G rnay send a signai to the secend centret device 2GG indicatirig that theconnectionts) have heen performed. Based en the signai front the at ieast enesensor device GG, the second controi device 2GG inay send a verification signai tothe tirst centroi device "iGG for verification ef the cennectionis). The first centretdevice 'iGG may then generate a unique vehicie identity ter the assenthied vehicieTA vehicie i is thus assemhied and the vehicie t is ready to eertonn the rnissien.The generated unique vehicie identity may then he stered in a database er recordassociated with the ottbeard-systerrt, i.e. the first contrei device 'iGG The generatedunique vehicie identity may aise he transmitted te the rnoduies BGAG et the vehiciei. The tinieee vehicie identity rnay eptienaiiy he diseiayed isy one er inere ot thentoduies 3G, 4G ot the vehicie t.

Fig. .fia - Fig. 2c schematically illustrate a drive module 30 in a side view, a front view and in a view from above, according to an embodiment. The drive module 30 comprises a body 38. The wheels 37 are arranged on two opposite sides of thedrive module 30. The body 38 may have a first and a second side 31, 32, which arefacing in opposite directions. The body 38 may have a third and a fourth side 33,34, which are facing in opposite directions, wherein the third side 33 and the fourthside 34 may extend perpendicular to the first and the second sides 31, 32. The body38 may also have a fifth and a sixth side 35, 36, which are facing in oppositedirections. The fifth and the sixth sides 35, 36 may extend perpendicularly to thefirst and the second sides 31, 32 and the third and fourth sides 33, 34. The first andthe second sides 31, 32 may be referred to as side surfaces. The third and thefourth sides 33, 34 may be referred to as front and rear surfaces respectively. Thefifth side 35 may be referred to as a top surface and the sixth side 36 may bereferred to as a bottom surface. The sides 31, 32, 33, 34, 35, 36 may each have ashape that is flat or curved and may be shaped with indentations and/or protrusions.lnstead of the perpendicularly extension of the sides 31, 32, 33, 34, 35, 36described above, the sides 31 , 32, 33, 34, 35, 36 may extend at any angle in relationto each other.

Fig. 3 schematically illustrates a drive module 30 in further detail in a side view. Thedrive module 30 comprises at least one (only one illustrated) propulsion system 91,at least one (only one illustrated) braking system 92, an interface 50 and a controldevice, i.e. a second control device 200. The propulsion system(s) 91 comprisesfor example an electric machine(s) connected to the wheels 37. ln some embodiments, each wheel 37 is individually driven by its own electric machine The hrakihg system(s) 92 comprises, ter exampte, standard disc brakes andeieetromechanieal aetuaters that require reišabie power suppiy. The braking system92 is typicaiiy the primary braking system ef the vehieie t.

Hevvever, because the braking system 92 :rtay ih some situatiens be ihsufficient erfait for some reasert, a secondary braking system is geheraišy required. Also discbrakes may be worn out if used too frequently. Therefore, the electric machine(s)of the propulsion system(s) 91 in some embodiments operate as generators thatgenerate electric energy while braking the wheels 37. Thus, the propulsion lO system(s) is in some embodiments operates as a secondary or auxiliary brakingsystem of the vehicle 1. ln some embodiments the drive module 30 comprises at least one energy storageunit (not shown) for providing the propulsion system 91 with energy. The energystorage unit is for example an electric battery that may be recharged with electricenergy. Alternatively, when the electric battery is discharged, the electric batterymay be replaced by another charged electric battery. The energy storage unit maybe of limited size and insufficient to supply power to the propulsion system 91 andthe braking system 92 while operating the vehicle 1. ln some embodiments theenergy storage in the drive module 30 is mainly used while assembling the vehicle 1 and/or transporting the drive module 30 without load.

The second control device 200 is configured to operate the drive module 30 as anindependently driven unit. The drive module 30 may transport itself without anyexternally driven unit such as a towing vehicle. The drive module 30 may transportitself by means of the at least one propulsion system 91. The drive module 30 maybe configured to be autonomously operated. Thus, the second control device 200may be configured to control the operation of the drive module 30. The secondcontrol device 200 may be configured to transmit control signals to the varioussystems and components of the drive module 30 for controlling for example thesteering and the propulsion of the drive module 30. The second control device 200may be configured to operate the drive module 30 autonomously based on receivedcommands. The second control device 200 may thus be configured to receivecommands from a remotely located off-board system, i.e. the first control device100, and to convert the commands into control signals for controlling the varioussystems and components of the drive module 30. The second control device 200may also be configured to receive data about the surroundings from at least onesensor (not shown) and based on this data control the drive module 30. The secondcontrol device 200 may be implemented as a separate entity or distributed in twoor more physical entities. The second control device 200 may comprise one or morecomputers. The second control device 200 may thus be implemented or realised by 8 DFOCGSSOF and 8 memOry. ll The drive module 30 may be configured to be releasably connected to either asecond drive module 30 and/or a functional module 40 for forming an assembledvehicle 1. At least one of the sides 31, 32, 33, 34, 35, 36 of the drive module 30may thus have a shape that allows the drive module 30 to be releasably connectedto the second drive module 30 and/or the functional module 40.

The at least one interface 50 of the drive module 30 is configured to physicallyconnect the drive module 30 with a second drive module 30 and/or a functionalmodule 40. The interface(s) 50 of the drive module 30 may be releasablyconnectable to a corresponding interface 50 of a second drive module 30 and/or afunctional module 40. in Fig. t and Fig. 3, the drive itiociuies 30 ere iiiuetreteo with oniy one interface 50,on one side ot the drive rnoduie 30. iiovvever, it is to be tinderstood that each drivemodiiie 30 may corrtpriee e piureiity of interfaces 50 for reieesebie connection withother rnoouies 30, 40. The interface(s) 50 of the drive rnoduies 30 mey be arrangedon different sides of the drive rnociuie 30 and thtie enebie connection with otherrnodiiies 30, 40 on rniiitipie sides of the drive inoduie 30. The intertacee 50 on thedrive rriodtiies 30 end the ftinctionei niodtiies 40 respectiveiy, ere arranged oncorresponding positions to eriahie connection between the inoduies 30, 40. ln some embodiments, the at least two interfaces 50 comprises electric interfaces,arranged for transferring electric power and/or transmitting electric signals betweenthe drive module 30 and another module e.g. to a functional module 40 to whichthe drive module is connected. The electrical interface 50 may be a wired interface50 or a wireless interface e.g. a conductive interface 50. ln other words, byconnecting the drive module 30 and the functional module 40 electrically themodules 30, 40 may transfer power between each other and share information. Thedrive module 30 may, for example, control parts of the functional module 40, such as opening and closing of doors, heating and cooling.

Fig. 4 schematically illustrates a side view of a functional module 40, where theproposed solution may be implemented. The functional module 40 may be providedwith wheels, but generally a functional module 40 cannot move on its own. lnstead,the functional module 40 needs to be connected to at least one drive module 30 to 12 be able to move. The functional module 40 may comprise a space 41 foraccommodating or supporting a load. The at least one functional module 40 maybe configured for transporting goods and may thus function as a truck when beingassembled with at least one drive module 30. ln some embodiments, the functionalmodule 40 coniprises a control device, which hereinafter will be referred to as athird control device 300. The third control device 300 of the functional module 40may be configured to corrirntinlcate vvith the off~board system mentloned inconnection to Fig. i. The third control device 300 may also be configured tocornrntiiiicate vvitlt the second control device 200 of the drive module 30.

The functional module 40 of Fig. 4 also cornprises a power supply arrangement 400comprising one or more power storage devices ït) and power circuitry (illustratedby the clashecl lines). ln the example ot Fig. 4 the power supply arrangement 400comprises three power storage devices ït). Even though a connected drive module30 might also comprise an energy storage it rnay not comprise ertougli energy topropel and hrake the entire vehicle i to accornplish missions. l-lence, whenoperating the vehicle, the energy storage devices ït) of the functional module 40typically supplies power to the drive rnodules 30 via the interface 50. ln other words,the power storage devices 70 are configured to supply power to one or more of thedrive modules 30 of the vehicle t. ih this example, the power storage devices ïtiare configured to supply power to the propulsion systemifis) tät and the brakingsystemts) 92 of two connected drive modules 30. ln sorne ernloodirnents thepropulsion system rnay also, as described above, operete as an auxiliaryf brakingsystem of the vehicle l. The power circuity, which is only schematically illustratedby dashed lines in Fig. 4, vvill he described in turther detail in Fig. 5 and Fig. 6. ln a modular vehicle, such as the modular vehicle of Fig. 1, construction and weightmay be simplified if independent propulsion and braking systems distributed amongindependent modules 30, 40 share one common energy storage. Thus, the effectsof the proposed power supply arrangement 400 are particularly noticeahle vvhenimplemented in such a vehicle, Theretore, the proposed power supply arrangement400 will herein be described in the context of the modular vehicle 1 of Fig. i, Fig. 2and Fig. 3. However, it must be appreciated that the proposed power supply arrangement 400 may in general be used in any vehicle, where one or more power 13 storege devises Tttjotntty soppišes power to hoth e propuisšon system end e hrektrigsystem ot the vehtoie.

The rrtodtiier vehicie t ot Fig. t, which is herein used to deserihe the proposedtechnique, is essernhied hy two drive moduies 30 and s furiotiortei modote 40. ihother words, the drive modtties 30 and the tuhotionei mocitite 40 cohstttute thevehteie t. Consequentty, the components ot those moduies 30, 40 togetheroonstitute the vehieie 1. in other words, the eontponehts ot the drive ntodutes 30and the tuhcttohai rnodute 40 may he considered to he the components ot thevehioie 1 ehd ere therefore, tor sintptšošty, hereih reterred to ss sirnpiy “thecomponents ot the vehäeie 1”. For exampie, the propoision system 91 or hrekesyfstem ot ohe ot the drive rnoduies 30 ot the vehtote t is herein reterred to as thepropuisioh system åt or hreke system 92 ot the vehicie t.

The proposed power suppiy errehgerneht 400 wiii now he desorihed in withreference to Fig. 4, Fig. 5 end Fig. 6.

The proposed technique is applicable on all sorts of road and off-road vehicles.However, the disclosure may relate to heavy vehicles, such as buses, trucks etc.Specifically, the present disclosure may relate to vehicles for use on public roads.

Fig. lö illustrates an example implementation of a power supply arrangement 400.The power supply arrangement 400 comprises three energy storage devices 70(here denoted 70a, 70b and 70c), a first power link 101 and a second power link102. ln this example, the power supply arrangement 400 comprises three energystorage devices 70. However, it must be appreciated that the proposed techniquecould be used for any number of energy storage devices 70, including one singlepower storage device 70. "the power supply arrangement 400 is e.g. arranged in afunctional module 40 of a vehicle 1, as illustrated in Fig. 4. Parts of the power supplyarrangement 400 (e.g. the power links) may also extend to the drive modules 30, e.g. via the interfaces 50.

Fig. 5 ttiostretes e power storage device 70 ih further cieteti. The energy storagedevice 70 is e.g. arranged in a functional module 40 of a modular vehicle 1. Theenergy storage device 70 is e.g. a “battery pack”. The term “battery pack” is often 14 used in conjunction with electric vehicles. A battery pack is a set of any number ofenergy storages e.g. (preferably) identical batteries or individual battery cells. Theenergy storages may be configured in a series, parallel or a mixture of both todeliver the desired voltage, capacity, or power density. The energy storage device70 or “battery pack” is typically rechargeable. For simplicity, the energy storagedevice 70 illustrated in Fig. 4 only comprises one energy storage 76, here illustratedas a battery. ln addition to the energy storage 76, the at least one energy storagedevice 70 comprises a first power connector 71 and a second power connector 72.

The energy storage 76 is arranged to supply power to the first and second powerconnectors 71, 72. ln other words, energy storage 76 is electrically connectable to the first power connector 71 and a second power connector 72.

The power connectors 71, 72 are the electrical contacts used to connect a load orcharger to the energy storage device 70. These contacts may have a wide varietyof designs and sizes. More specifically, the first power connector 71 is configuredto connect one or more propulsion systems 91 of the vehicle 1 to the batterystorage device 70 and the second power connector 72 is configured to beconnected to one or more braking systems 92 to the battery storage device 70.The power connectors 71, 72 typically have one positive terminal (denoted “+” in Fig. 4) and one negative terminal (denoted in Fig. 4).

The energy storage device 70 may also comprise further circuitry. ln this exampleembodiment, the circuitry comprises, switches 73a, 73b, 75a, 75b, two fuses 74a,74b, sensor 78, a pre-charge resistor circuit 79, a control unit 80 and electrical lines 77.

The switches 73a, 73b, 75a, 75b are controllable. ln other words, they areconfigured to receive control signals and open and close in response to thecontrol signals. Two of the controllable switches 73a, 73b are arranged betweenthe positive terminal of the energy storage 76 and the positive terminals of the firstpower connector 71 and second power connector 72 respectively. These switchesare typically used to connect the energy storage 76 to the respective systems e.g.at power up when starting the vehicle 1. The pre-charge resistor circuit 79 is used to limit the inrush current during the power up procedure.

However, when two different devices (such as a braking system and a propulsionsystem) are simultaneously connected to the same energy storage (or powersupply) this typically means that the devices are also interconnected. This is apossible security problem as errors, such as current peaks, may propagatebetween the devices. Therefore, energy storage device 70 is configured such thatthe second power connector 72 is electrically disconnectable from the first powerconnector 71. ln the disconnected state no current may flow between the first andsecond power connectors 71, 72. To achieve this, it is generally not enough thatonly the positive terminals are disconnected, but also the negative terminals needto be disconnected. More specifically, in the example embodiment of Fig. 5, twofurther controllable switches 75a and 75b are arranged between the negativeterminal of the energy storage 76 and the negative terminal of the first powerconnector 71 and second power connector 72 respectively. ln this way, when anerror occurs on one of the power connectors 71, 72 (or in a device connectedthereto), then that power connector, may be completely disconnected from boththe energy storage device 70 and the other connector, by opening both the switchat the positive terminal and the switch at the negative terminal of the powerconnector where the error was detected. For example, if an error occurs in thepropulsion system 91, then the first power connector 71 is disconnected byopening the switch 73a at the positive terminal of the first power connector 71 andthe switch 75a at the negative terminal of the first power connector 71. Thereby,the error cannot propagate to the braking system 92 and the braking system 92may continue to operate and to receive power from the energy storage devices70. Once the error is fixed, the first power connector 71 can be reconnected. lnother words, the switches 73a, 73b, 75a, 75b are configured to be controlled to(completely) disconnect the first power connector 71 from the second powerconnector 72. The switches 73a, 73b, 75a, 75b are e.g. contactors. A contactor isan e|ectrica||y-controlled switch used for switching an electrical power circuit. Acontactor is typically controlled by another circuit, e.g. the control unit 80.

The fuses 74a, 74b are e.g. used as a complement to the switches 75a, 75b atthe negative terminals when the current is too large to be interrupted by e.g. contactors. The fuses 74a, 74b may be passive fuses or controllable fuses, also 16 called pyro fuses. Hence, it must be appreciated that there are many differentways to arrange components to obtain a disconnection of the power connectors 71, 72 e.g. by different combinations of fuses and contactors.

The control unit 80 which may be referred to as an lnternal Battery Unit, IBU, is e.g.an Electrical Control Unit, ECU. Fig. 7 illustrates the control unit 80 in more detail.ln some embodiments, the control unit 80 is a “unit” in a functional sense. Thehardware basically comprises various electronic components on a Printed CircuitBoard, PCB. The most important of those components is typically a processor 81e.g. a microprocessor, along with a memory 82 e.g. EPROM or a Flash memorychip. The software (also called firmware) is typically lower-level software code thatruns in the microcontroller. The control unit 80 is configured to control thefunctionality of the energy storage device 70. ln particular, it is configured to controlthe connection and disconnection of the first and second power connectors 71,72. ln some embodiments, the control unit 80 is configured to control the switches73a, 73b, 75a, 75b when an error condition occurs e.g. the error is indicated bysensors or blown fuses in battery cells of the energy storage device 70, in aconnected propulsion system 91 or anywhere in the vehicle 1. An error conditionis e.g. an abnormal current flow at one of the first and second power connectors71, 72 or in the corresponding systems connected to thereto. ln someembodiments, the control unit 80 obtains sensor data from one or several sensors78 in the energy storage device 70 to detect the error. For example, the one orseveral sensors 78 are configured to measure a current flowing through the first and second power connectors 71, 72. ln some embodiments, the control unit 80 is configured to evaluate a predefinederror criterion and to control the at least one switch 73a, 73b, 75a, 75b todisconnect the first power connector 71 from the second power connector 72upon the predefined error criterion being fulfilled. For example, the control unit 80is configured to obtain data indicative of a current flowing through the first and/orsecond power links 101, 102. The data is e.g. sensor data provided by thesensors 78 Then the predefined error criterion might be that the obtained currentmeets one or more predefined thresholds. More specifically, this means that a 17 metric or other quantity representing the current meets the threshold. Forexample, the condition may be that the current does not go beyond a predefinedthreshold value e.g. 150 A.

Now turning back to Fig. 6, the other parts of the power supply arrangement 400will be described. The first power link 101 is a power circuit that electricallyconnects the first power connectors 71 of the energy storage devices 70a, 70b,70c and one or more propulsion systems 91 of the vehicle 1. The second powerlink 102 is typically a connector that electrically connects the second powerconnectors 72 of the energy storage devices 70a, 70b, 70c and one or morebraking systems 92 of the vehicle 1. Thus, the first and second power links 101,102 are arranged in the functional module 40 and may extend to the drive module30 via the interface 50. ln other words, the interface 50 and the drive module 30also comprises two separated power links for the propulsion system(s) and thebraking system(s). ln other words, the first power link 101 is arranged toelectrically connect the first power connectors 71 and at least one propulsionsystem 91 of the vehicle 1 and the second power link 102 is arranged toelectrically connect the second power connectors 72 and at least one brakingsystem 92 of the vehicle 1. The first power link 101 and the second power link 102are e.g. cables or lines. The first power link 101 and the second power link 102may be implemented as one physical cable package. However, in any case, nocurrent can flow between the power links when one of the power links 71, 72 isdisconnected from the power storage 76 _ ln other words, the power links 101,102 are only electrically connected via the power storage 76. Stated differently,when the second power connector 72 is disconnected from the first powerconnector 71 then the second power link 102 is electrically separated from thefirst power link 101.

For example, if the power the vehicle 1 is assembled by a set of modules 20 asillustrated in Fig. 1-3 then, in some embodiments, the first and second power links101, 102 are arranged to connect the at least one energy storage device 70, beingarranged in one of the at least one modules 30, 40 and at least one propulsionsystem 91 and one brake system 92 being arranged in one of the other modules , 40. ln other words, the first and second power links may be arranged to connect 18 energy storage devices 70 and systems ofa plurality of modules 30, 40 of a modularvehicle.

When the power supply arrangement 400 comprises more than one energy storagedevice 70, which is the case in the example of Fig. 5, then the first and secondpower links 101, 102 are in some embodiments arranged to connect all the energystorage devices 70 to the propulsion system(s) and the braking system(s) of thevehicle. For example, the first and second power links 101, 102 are arranged toparallel connect the at least two energy storages 70a, 70b, 70c. Hence, even in thecase where the vehicle comprises several energy storages 70a, 70b, 70c, theenergy storages 70a, 70b, 70c it is possible to completely isolate one of the powerlinks 101, 102 from the other if one of the power links is short-circuited and keepfull functionality on the other power link. lt is appreciated that modular vehicles as described in Fig. 1 may typicallycomprise several drive modules 30 having independent propulsion and brakingsystems 91, 92. For simplicity it is generally desirable to use one common energystorage device 70 for all the systems. This is achieved by connecting the powerlinks in the entire vehicle 1 i.e. in several or all the drive modules 30 of a modularvehicle. More specifically, if the vehicle 1 comprises a plurality of propulsionsystems 91, the first power link 101 is arranged to connect the first powerconnector 71 and two or more or all of the plurality of propulsion systems 91. Also,if the vehicle 1 comprises a plurality of brake systems 92 then the second powerlink 102 is arranged to connect the second power connector 72 and two or more or all of the plurality of brake systems 92.

Fig. 8 illustrates a corresponding method for use in a control unit 80 of an energystorage device 70 comprising an energy storage 76 being electrically connectedto a first power connector 71 connectable to a propulsion system 91 of a vehicle 1and a second power connector 72 connectable to a braking system 92 of avehicle 1. The method is e.g. implemented by a software program, comprised inmemory 82, executed by the processor 81 of the control unit 80 illustrated in Fig. 19 ln some embodiments the method comprises obtaining S0 data indicative of acurrent flowing through the first and/or second power links 101, 102. The data ise.g. sensor data read from sensors 78. The data may also be received from otherparts of the vehicle. For example, the data may indicate a or other error in the propulsion system.

The data is then evaluated to decide whether one of the systems needs to bedisconnected from the energy storage device 70. ln other words, the methodcomprises evaluating S1 a predefined error criterion. For example, the errorcriterion comprises that the current meets one or more predefined thresholds.This basically means that if the current flowing through one of the powerconnectors is alarming (e.g. above a certain current level), then the error criterionis considered fulfilled. Further examples of the evaluation principle have alreadybeen described in connection with Fig. 5.

The method further comprises disconnecting S2 the first power connector 71 fromthe second power connector 72 upon the predefined error criterion being fulfilled.ln other words, when an alarming condition is detected at the power connectors(or in loads or chargers connected thereto), then the malfunctioning powerconnector is disconnected to avoid that the error propagates to the otherconnector. lf the error occurs in the braking system 92, then the propulsionsystem may then be controlled to operate as an emergency brake to brake thevehicle 1. The proposed technique could of course also be implemented for three or more power connectors, if needed.

The terminology used in the description of the embodiments as illustrated in theaccompanying drawings is not intended to be limiting of the described method;control arrangement or computer program. Various changes, substitutions and/oralterations may be made, without departing from invention embodiments as defined by the appended claims.

The term “or” as used herein, is to be interpreted as a mathematical OR, i.e., asan inclusive disjunction; not as a mathematical exclusive OR (XOR), unlessexpressly stated otherwise. ln addition, the singular forms "a", "an" and "the" areto be interpreted as “at least one”, thus also possibly comprising a plurality of entities of the same kind, unless expressly stated otherwise. lt will be furtherunderstood that the terms "includes", "comprises", "including" and/ or"comprising", specifies the presence of stated features, actions, integers, steps,operations, elements, and/ or components, but do not preclude the presence oraddition of one or more other features, actions, integers, steps, operations,elements, components, and/ or groups thereof. A single unit such as e.g. a processor may fulfil the functions of several items recited in the claims.

Claims (15)

21 Claims

1. _ A power supply arrangement (400) for use in a vehicle (1), the power supply arrangement (400) comprising: - at least one energy storage device (70) comprising an energy storage (76) being electrically connectabie to a first power connector (71) and a second power connector (72), wherein the second power connector(72) is electrically disconnectable from the first power connector (71),- a first power link (101) arranged to connect the first power connector(71) and at least one propulsion system (91) of the vehicle, and- a second power link (102) arranged to connect the second powerconnector (72) and at least one braking system (92) of the vehicle (1),wherein the second power link (102) is electrically separated from the first power link (101) upon disconnection of the second power connector (72) from the first power connector (71 )_

2. _ The power supply arrangement (400) according to claim 1, wherein the at least one energy storage device (70) comprises at least one switch (73a,73b, 75a, 75b) configured to be controlled to disconnect the first power connector (71) from the second power connector (72).

3. _ The power supply arrangement (400) according to any of the preceding claims, wherein the at least one energy storage device (70) comprises acontrol unit (80) configured to evaluate a predefined error criterion and tocontrol the at least one switch (73a, 73b, 75a, 75b) to disconnect the firstpower connector (71) from the second power connector (72) upon thepredefined error criterion being fulfilled.

4. _ The power supply arrangement (400) according to claim 3, wherein the control unit (80) is configured to obtain data indicative of a current flowingthrough the first and/or second power links (101, 102) and wherein the predefined error criterion comprises that the obtained currentmeets one or more predefined thresholds. 22

5. The power supply arrangement (400) according to any of the preceding claims, wherein the power supply arrangement (400) comprises at leasttwo energy storages (70a, 70b, 70c), and wherein the first and secondpower links (101, 102) are arranged to parallel connect the at least twoenergy storages (70a, 70b, 70c).

6. _ The power supply arrangement (400) according to any of the preceding claims, wherein the at least one energy storage device (70) comprises abattery package.

7. _ The power supply arrangement (400) according to any of the preceding claims, wherein the vehicle (1) is assembled by a set of modules (20), theset of modules (20) comprising: at least one drive module (30) comprising a pair of wheels (37), a propulsion system and the at least one brake system (92); wherein the at least one drive module (30) is configured to be autonomously operated, and at least one functional module (40),wherein each module (30; 40) in the set of modules (20) comprises at leastone interface (50) releasably connectable to a corresponding interface (50)of another module, and wherein the first and second power links (101, 102)are arranged to connect the at least one energy storage device (70), beingarranged in one of the at least one modules (30, 40), and at least onepropulsion system (91) and one brake system (92) being arranged in one ofthe other modules (30, 40).

8. _ The power supply arrangement according to any of the preceding claims, wherein the first power link (101) is arranged to connect the at least oneenergy storage device (70) and a plurality of propulsion systems (91) of thevehicle (1) and wherein the second power link (102) is arranged to connectthe at least one power source (70) and a plurality of brake systems of thevehicle (1 )_

9. A vehicle (1) comprising: 23 - at least one propulsion system (91), - at least one brake system (92) and - the power supply arrangement (400) according to any one ofclaims 1-8, wherein the power supply arrangement (400) isarranged to connect the at least one energy storage device (70)and the at least one propulsion system (91) and the at least onebrake system (92).

10.The vehicle of claim 9, wherein the vehicle (1) comprises a set of modules

11. (20), the set of modules (20) comprising:at least one drive module (30) comprising a pair of wheels (37), apropulsion system and the at least one brake system (92); wherein the atleast one drive module (30) is configured to be autonomously operated,andat least one functional module (40), wherein each module (30; 40) in the set of modules (20) comprises at leastone interface (50) releasably connectable to a corresponding interface (50)on another module, and wherein the first and second power links are arranged to connect anenergy storage device (70) being arranged in one of the at least onemodule (30, 40) and at least one propulsion system and brake systembeing arranged in one of the other modules (30, 40) in the set of modules. The vehicle of claim 10, wherein the first and second power links arearranged to connect an energy storage device (70) being arranged in oneof the functional modules (30) and at least one propulsion system and brake system being arranged in one of the drive modules (40).

12.A method for use in a control unit (80) of an energy storage device (70) comprising an energy storage (76) being electrically connected to a firstpower connector (71) connectable to a propulsion system of a vehicle (1)and a second power connector (72) connectable to a braking system of avehicle (1 ), the method comprising: 24 - evaluating (S1) a predefined error criterion and - disconnecting (S2) the first power connector (71) from the secondpower connector (72) upon the predefined error criterion beingfu|fi||ed.

13.The method according to claim 12 comprising:- obtaining (S0) data indicative of a current flowing through the firstand/or second power links (101, 102) andwherein the predefined error criterion comprises that the current meets one or more predefined thresholds.

14.A computer program comprising instructions which, when the program isexecuted by a computer, cause the computer to carry out the method of any one of the claims 12 to 13.

15.A computer-readable storage medium comprising instructions which, whenexecuted by a computer, cause the computer to carry out the method of any one of the claims 12 to 13.