DEHEATING OF A BATTERY ARRANGEMENT

Abstract

According to an embodiment, it is a battery arrangement comprising plurality of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string, and third string configured to connect to an electric machine as one respective phase; and plurality of battery cell controllers, each connected to a terminal of at least one of the battery cells within one string, each of the battery cell controllers comprising at least a power electronics arrangement, and each of the battery cell controllers forming a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of a respective battery cell, and wherein the battery arrangement is configured for connecting to the electric machine and/or a power supply.

Description

TECHNICAL FIELD

The present disclosure relates to electric and/or hybrid electric vehicle drive technologies. In particular, the present invention relates to a battery arrangement, a method for deheating at least a part of such a battery arrangement, and a vehicle comprising such a battery arrangement.

BACKGROUND ART

Electro mobility is an increasingly respected part of today's and tomorrow's mobility. For example, in view of regional and/or global climate targets, there is a need for practical and efficient electric drive technologies.

It is known from practical experience that electric drive technology is limited, for example, by the battery arrangements available today. This concerns, for example, limitations given by the complex requirements, e.g., a large number of charging cycles, performance requirements in terms of electrical power output, available capacity, operating conditions, etc.

For example, heat dissipation of such battery arrangements is a field of Research and Development (R&D) that is receiving special attention because heat dissipation, such as efficient heat dissipation, is also a limiting factor for electro mobility.

SUMMARY

There may, therefore, be a need to provide a structurally simple way to deheat a battery arrangement or at least a part thereof.

The object of the present disclosure solved by the subject-matter of the appended independent claims, wherein further embodiments are incorporated in the dependent claims.

According to a first aspect, there is provided a battery arrangement for connecting to an electric machine and/or a power supply, comprising:

• • a number of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string and third string being connectable to the electric machine as one respective phase; and
  • a number of battery cell controllers, each being connected to a terminal of at least one of the number of battery cells within one string, each battery cell controller comprising at least a power electronics arrangement, and each battery cell controller comprising or forming a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of the respective battery cell.

In this way, at least part of the control of the battery cells is transferred to the battery cell controllers, which in principle provide a kind of distributed control. Here, the individual battery cell controllers take on the additional function, i.e., provide at least a dual function including the control function, of serving to dissipate heat or thermal energy from the battery cells. That is, deheating or cooling a battery arrangement or at least a part thereof is improved while reducing the overall structural complexity. Thereby, the battery cell itself may act as thermal mass, allowing to re-use the battery cell for deheating and/or cooling the battery cell controllers. In normal operation, the battery cell may have a maximum operating temperature, such as about e.g., 65° C., that is lower than a maximum operating temperature of the power electronics arrangement, which may be about e.g., 120° C., providing a significant heat sink potential towards the battery cell.

As used herein, batteries or battery cells, which may be arranged in a battery arrangement or assembly as described herein, in electric vehicles and hybrid vehicles supply the electric motor(s), i.e., the electric machine, with electrical energy, which is converted into mechanical kinetic energy for propulsion.

Further, each one of the number of battery cells, which may also be referred to as battery segments and which may be e.g., of Li-ion technology, is a power source in itself. For example, these may also power the battery cell controller.

For example, each of the number of battery cells board may contain four terminals or output points. Two of these may be AC terminals or power points and two may be isolated DC terminals or power points. The battery cell connection to the outside world may be done through these points.

When a battery cell is connected to one or more other battery cells, here, the number of battery cell controllers may be made between the two cells AC points, and not between cell terminals as in conventional technologies. Since the battery cell itself can internally, i.e., by the battery cell controller connected thereto, control if and how it should be connected to the AC-terminals, this allows for the battery cell to disconnect itself from the main battery without affecting the complete battery arrangement or pack performance significantly. This mode may also be referred to as bypass mode and may be default. The battery cell controller may be designed to be one per battery cell or even one per two or more battery cells.

In electric and hybrid vehicles, the battery cell controller and/or the power electronics, among other things, control the electric drive and establish a connection between the electric motor and the, e.g., high-voltage, battery and/or individual battery cells.

Further, as used herein, a master node may be configured to connect to each one of the number of battery cell controllers, which may also be referred to as a number of slave nodes. The master node may be configured to broadcast information or data, e.g., transmitted as a message, which may be of a predefined format, to each one of the slave nodes. Likewise, the each slave node, or one slave node of each string, may be configured to transmit information or data, e.g., in a message of a predefined format, to the master node and/or to one or more of the other slave nodes. Further, the one or more, or even each of the slave nodes may be configured to broadcast information or data within the system of the battery arrangement. For example, the master node may be configured, e.g., by a communication interface, to connect to the one or more slave nodes by wireless communication or another galvanic isolated communication.

Further, the master node may be configured to generate a virtual sine wave as control information to be used by the slave nodes for controlling the battery cells, e.g., to be switched on and off, etc. The virtual sine wave is used by the slave nodes to generate a corresponding signal by switching the batteries on and off.

Further, for example, there may be a master node/slave node work split, providing distributed feedback control. The master node may be configured to request one or more of e.g., modulator phase current, phase angle, present cycle time and resolver angle every millisecond (ms). The slave nodes may run with a closed loop phase current control of about 10 kHz and may comprise an on-board current sensor to achieve desired phase current, and may detect or determine cycle time, current set point and resolver angle updated every millisecond (ms). As an option, in order to increase control performance, the slave node may further measure a phase between current and voltage to adjust its own phase. The slave node may further comprise an internal slave current control.

Optionally, at least a part of the number of battery cell controllers may comprise or may be formed as a busbar spanning over one or more of the number of battery cells. In other words, the battery cell controller may also form a busbar, i.e., a connector, configured to connect two terminals of at least two battery cells with each other. In this way, the battery cell controller may integrate several functions in itself, e.g., control functions and connector functions.

Optionally, the power electronics arrangement may contact the respective terminal via a conductive material integrated in the number of battery cell controllers. In other words, the number of battery cell controllers may be mounted directly onto the respective one or more battery cells, not requiring additional connectors, cables, or the like, to connect to the battery cell. In this way, complexity of the overall structure may be reduced. In this way, the power electronics arrangement may be located next or adjacent to the one or more terminals, allowing good heat transfer.

Optionally, the conductive material may be made of copper or a copper alloy or of aluminum or an aluminum alloy. These materials are each good conductors, with the slightly lower conductivity of aluminum complemented by a lower weight.

Optionally, the conductive material may be a metal core or a metal back of a printed circuit board, pcb, in which the power electronics arrangement is embedded. For example, such a pcb may have a metal core or back, onto which a thin electrically insulated film is bonded. For example, on top of this film, there may be an etched copper layer comprising electrical traces. The insulated layer may be as thin as to allow good thermal conductivity towards the metal core or metal back. Further, by way of example, the film may comprise one or more through holes, optionally filed with a conducting material, such as copper, aluminum or the like, which allows electric conduction from the power electronics arrangement towards the metal core or metal back.

Optionally, the metal core or metal back may be made of copper or a copper alloy or of aluminum or an aluminum alloy. These materials are each good conductors, with the slightly lower conductivity of aluminum complemented by a lower weight.

Optionally, the number of battery cell controllers may comprise or may be formed as a metal core or a metal backed printed circuit board, pcb, in which the power electronics arrangement is embedded, the metal core or metal back of the pcb contacting the power electronics arrangement and the respective terminal of the number of battery cells. This allows for an integrated unit that is easy to install and enables short thermal or heat conduction paths.

Optionally, the pcb may be formed in multiple layers, a base or first layer may comprise at least a section made of the metal core or metal back and may be configured to engage the respective terminal, thereby forming at least a part of a busbar, an intermediate layer comprising a number of through holes in which the power electronics arrangement is held in place, and a top or second layer comprising at least a section made of the metal core or metal back and being configured to engage the respective terminal, thereby forming at least a part of a busbar. In this way, the thermal conduction path may have short distances due to an integrated design. In other words, the power may be embedded in the PCB. For example, the first layer may be formed as a pcb layer where e.g., two busbar parts may be made out of metal backed pcb. The intermediate layer may be formed from e.g., a standard PCB comprising one or more through holes in place to locate the embedded power electronics arrangement. By way of example, the power electronics arrangement may comprise a number of power switches, such as FET, MOSFET, or the like. The second layer may be formed from a standard PCB as well as two metal backed pcb. On top of the layer, a controller chip and/or a transformer core may be arranged.

Optionally, the power electronics arrangement may be arranged between the base or first layer and the top or second layer, thereby contacting the conductive material of at least one of the layers. This allows a large area for heat transfer.

Optionally, the number of battery cell controllers may further comprise or form a second thermal conduction path extending from the power electronics arrangement via the terminal and/or the body to a casing of the respective battery cell and/or the battery arrangement. In other words, a further, second thermal conduction path, i.e., deheating and/or cooling path, may be formed by establishing direct or indirect contact between the battery cell controller, e.g., with a busbar section of the same, with the casing. This allows heat dissipation to be made even more efficient.

Optionally, the casing may cover the number of battery cell controllers and may contact a top side of the at least a part of the number of battery cell controllers. For example, the casing may contact a busbar section of the respective battery cell controller. This allows a large area for heat transfer, making the heat dissipation more efficient.

Optionally, the casing may contact the number of battery cell controllers via a thermal interface material, arranged between at least a part of the number of battery cell controllers and the casing, the thermal interface material being further in contact with the battery cell controller. In this way, integrating the number of battery cell controllers may be facilitated, thereby allowing heat dissipation to be made even more efficient.

Optionally, the thermal interface material may be formed as a pad contacting each of the number of battery cell controllers and the casing two-dimensionally. This allows a large area for heat transfer.

Optionally, the casing may have an outer surface exposed to ambient air of the battery arrangement. This allows a large area for heat transfer by convection.

Optionally, the casing may be made of aluminum or an aluminum alloy. These materials are each good conductors, with the slightly lower conductivity of aluminum complemented by a lower weight.

Optionally, the battery arrangement may further comprise a third thermal conduction path arranged and/or formed between the number of battery cells by a heat conducting blade contacting the body of at least a part of the number of battery cells and/or the number of battery cell controllers and may be exposed to ambient air with respect to the battery arrangement. This allows heat dissipation to be made even more efficient.

Optionally, the heat conducting blade being coupled to the body of the number of battery cells and/or the number of battery cell controllers by interconnecting a thermal interface material, TIM, there between. This allows a large area for heat transfer.

Optionally, the battery arrangement may further comprise a fourth thermal conduction path formed by a number of rails running along of at least a part of the number of battery cell controllers. This allows heat dissipation to be made even more efficient.

Optionally, each of the number of battery cell controllers may be materially bonded to the terminal. This allows a direct and/or short-distance thermal conduction path.

Optionally, the material bonding may be formed by a welded bond. This allows the connection between the battery cell, e.g., its terminal, and the battery cell controller to be robust.

Optionally, the material bonding may be formed by laser welding. This manufacturing process can be used particularly cost-effectively and/or efficiently.

Optionally, the number of battery cells may be connected to at least one refrigerant and/or coolant circuit through which thermal energy given off from the power electronics arrangement to the body of the number of battery cells can be dissipated. In other words, the battery cell and/or its body may be actively cooled by at least one refrigerant and/or coolant circuit, which may be part of a vehicle in which the battery arrangement is included. In this way, the thermal mass and/or the thermal heat sink potential of the battery cells may be further increased, allowing the heat dissipation to be more efficient.

Optionally, the power electronics arrangement may comprise a number of power switches. For example, FET, MOSFET or the like may be included in or may form the power electronics arrangement. By way of example, the number of power switches may be arranged in a H-bridge or another suitable circuit allowing connecting and disconnecting of individual battery cells and/or individual battery cell terminals.

According to a second aspect, there is provided a vehicle, comprising:

• • an electrical machine; and
  • a battery arrangement according to the first aspect, connected to the electrical machine.

As described above, the battery arrangement of the first aspect allows the electrical machine to be powered in an efficient way, since the battery arrangement provides improved heat dissipation capabilities.

Optionally, the battery or hybrid vehicle further comprises a power supply interface, the battery arrangement being further connected to the power supply interface. For example, the power supply interface, which may be connected to a power supply, e.g., a mains or a power grid, to charge the battery arrangement of the vehicle or to feed electrical energy towards or into the power supply. For example, the power supply interface and/or the battery arrangement may be configured to determine, e.g. measure etc., parameters, e.g. an amplitude, phase, time, etc., of the power supply to align the battery arrangement, e.g. the number of battery cell controllers, to the parameters, in order to connect the battery arrangement to it. Then, the phase may be adjusted to achieve desired charge/discharge current. In this way, the battery arrangement may be part of an overall system extending beyond the individual vehicle.

According to a second aspect, there is provided a method for deheating a battery cell controller of a battery arrangement for connecting to an electric machine and/or a power supply, the method comprising:

• • providing a number of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string and third string being connectable to the electric machine as one respective phase;
  • providing a number of battery cell controllers, each battery cell controller comprising at least a power electronics arrangement; and
  • connecting each of the number of battery cell controllers to a terminal of at least one of the number of battery cells within one string, each battery cell controller comprising or forming a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of the respective battery cell.

As described above, the battery arrangement of the first aspect and the system, i.e., vehicle, of the second aspect allow the electrical machine to be powered in an efficient way, since the battery arrangement provides improved heat dissipation capabilities.

The method may be at least partly computer-implemented, and may be implemented in software or in hardware, or in software and hardware. Further, the method may be carried out by computer program instructions running on means that provide data processing functions. The data processing means may be a suitable computing means, such as an electronic control module etc., which may also be a distributed computer system. The data processing means or the computer, respectively, may comprise one or more of a processor, a memory, a data interface, or the like.

It should be noted that the above examples and/or options may be combined with each other irrespective of the aspect involved. Accordingly, the method may be combined with structural features and, likewise, the apparatus, i.e., battery arrangement, and/or the system, i.e., vehicle, may be combined with features described above with regard to the method.

These and other aspects of the present invention will become apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary embodiments of the invention will be described in the following with reference to the following drawings.

FIG. 1 shows in a schematic top view a battery arrangement for connecting to an electric machine and/or a power supply, according to an embodiment.

FIG. 2A shows in a perspective view a battery cell controller designed to be one per battery cell, according to an embodiment.

FIG. 2B shows in a perspective view a battery cell controller designed to be one per two or more battery cells, according to an embodiment.

FIG. 3 shows in an exploded view a structure of a battery cell controller according to an embodiment.

FIG. 4 shows in a cross-sectional view a part of the battery arrangement and particularly of the battery cell controller, according to an embodiment.

FIG. 5 shows in a cross-sectional view a part of the battery arrangement and particularly of the battery cell controller, according to an embodiment.

FIG. 6 shows in a flow chart a method for deheating a battery cell controller of a battery arrangement for connecting to an electric machine and/or a power supply, according to an embodiment.

FIG. 7 shows in a schematic top view a battery arrangement for connecting to an electric machine and/or a power supply, according to an embodiment.

FIG. 8 shows in a timeline the scheduling of multi-directional broadcasting, according to an embodiment.

FIG. 9 shows in a timeline tasks of a master node and one or more slave nodes, triggered and/or synchronized by an update event.

The figures are merely schematic representations and serve only to illustrate embodiments of the invention. Identical or equivalent elements are in principle provided with the same reference signs.

DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a battery arrangement 100 for connecting to an electric machine 200 and/or a power supply 300. In FIG. 1, the connection(s) between the battery arrangement 100 and the electric machine 200 is (are) indicated by solid lines. The electric machine 200 is a e.g., three-phase electric motor, which is, for example, part of a vehicle 1 or the vehicle's powertrain or drive. The battery arrangement 100 is configured to provide electric energy to the electric machine 200 and/or the power supply and/or to be charged via the power supply.

The battery arrangement 100 comprises a number of battery cells 110, which are connected in series in three strings, providing three phases to run the electric machine 200, i.e., each string forms one phase if connected to the electric machine 200. The three strings are indicated in FIG. 1 by the addition of the reference sign 110 with −1, −2 and −3. In other words, as shown in FIG. 1, a first sub-number of the battery cells 110 connected in series form a first string, a second sub-number of the battery cells 110 connected in series form a second string, and a third sub-number of the battery cells 110 connected in series form a third string, the first string, second string and third string being connectable to the electric machine 200 as one respective phase. As indicated in FIG. 1, the number, and/or total number, of battery cells 110 may vary from a single, to multiple, to a plurality, to dozens, wherein 96 are given here only by way of example, and fewer or more battery cells 110 are also possible.

Further, if the battery cells 110 are connected in a suitable number to reach a desired voltage, the battery arrangement 100 may also be connected to the power supply, e.g. a mains with 50 Hz or the like, and the battery cells 110 may be charged by the power supply or may supply the net with energy from the battery cells 110.

The battery arrangement 100 further comprises a number of battery cell controllers 120, each being connectable or connected to a terminal of at least one of the number of battery cells 110 within one string. The number of battery cell controllers 120 may also be referred to as a number of nodes, i.e., a number of slave nodes, as will be explained in more detail further below.

Thereby, the battery cell controller 120 may be designed to be one per battery cell 110 as shown in FIG. 2A, or one per two or more battery cells 110 as shown in FIG. 2B. Each of the number of battery cells 110 comprises four terminals or output points. Two of these may be AC terminals or power points and two may be isolated DC terminals or power points, as indicated in FIG. 2A for one electric pole by AC and DC.

Now referring to FIG. 3, which shows in an exploded view a structure of the battery cell controller 120. Each battery cell controller 120 comprises a power electronics arrangement 121, which is embedded in a multi-layer structure, which may also be referred to as at least a kind of printed circuit board (pcb) or a composition of several pcb or parts of it.

As shown in FIG. 3, the pcb of the battery cell controller 120 may be formed in multiple layers, a base or first layer 122 may comprise at least a section made of a metal core or metal back and may be configured, in FIG. 3 by respective through holes, to engage the respective terminal of the battery cell 110, thereby forming at least a part of a busbar. Further, an intermediate layer 123 comprises a number of through holes 123A, forming a frame structure, in which the power electronics arrangement 121 is held in place. Furthermore, a top or second layer 124 comprises at least a section made of the metal core or metal back and is configured, in FIG. 3 by respective through holes, to engage the respective terminal, thereby forming at least a part of a busbar. For example, the first layer 122 may be formed as a pcb layer where e.g., two busbar parts may be made out of metal backed pcb. The intermediate layer may be formed from e.g., a standard PCB comprising one or more through holes in place to locate the embedded power electronics arrangement 121. On top of the layer, a controller unit or chip 125 and/or a transformer core may be arranged.

The power electronics arrangement 121 comprises a number of power switches, such as FET, MOSFET, or the like. The second layer may be formed from a standard pcb as well as two metal backed pcb.

Still referring to FIG. 3, the power electronics arrangement 121 may be arranged between the base or first layer 122 and the top or second layer 124, thereby contacting the conductive material of at least one of the layers.

FIG. 4 shows in a cross-sectional view a part of the battery arrangement 100 and particularly of the battery cell controller 120. As indicated in FIG. 4 by arrows A and B, each battery cell controller 120 comprises or forms a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of the respective battery cell 110. Thereby, the power electronics arrangement 121 contacts the respective terminal via a conductive material, i.e., the above metal core or metal back, integrated in the number of battery cell controllers 120, as explained above.

FIG. 5 shows in a cross-section view a part of the battery arrangement 100 and particularly of the battery cell controller 120. As indicated in FIG. 5 by arrows C and D, the number of battery cell controllers 120 further comprises or forms a second thermal conduction path extending from the power electronics arrangement 121 via the terminal and/or the body of the battery cell 110 to a casing 130 of the respective battery cell 110 and/or the battery arrangement 100. As shown, the casing 130 covers the number of battery cell controllers 120 and contacts a top side of the at least a part of the number of battery cell controllers 120. Further, the casing 130 contacts the number of battery cell controllers 120 via a thermal interface material (TIM) 126, being arranged between at least a part of the number of battery cell controllers and the casing, the thermal interface material being further in contact with the battery cell controller. For example, the thermal interface material 126 may be formed as a pad contacting each of the number of battery cell controllers 120 and the casing 130 two-dimensionally. Further, by way of example, the casing 130 may have an outer surface exposed to ambient air of the battery arrangement 100. Further, the casing 130 may be made of aluminum or an aluminum alloy.

Alternatively or additionally, as indicated in FIG. 5 by a dashed line, the battery arrangement 100 may further comprise a third thermal conduction path arranged and/or formed between the number of battery cells 100 by a heat conducting blade 140 that contacts the body of at least a part of the number of battery cells 100 and/or the number of battery cell controllers 120, and that is exposed to ambient air with respect to the battery arrangement 100, the heat conducting blade being coupled to the body of the number of battery cells and/or the number of battery cell controllers by interconnecting a thermal interface material 126 there between.

In a non-illustrated example, the battery arrangement further comprises a fourth thermal conduction path formed by a number of rails running along of at least a part of the number of battery cell controllers.

Optionally, each of the number of battery cell controllers 120 may be materially bonded to the terminal of the battery cell 110. Alternatively, the connection may be made of a screw connection. For example, the material bonding being formed by a welded bond. Further, the material bonding being formed by laser welding.

Further optionally, the number of battery cells 110 may be connected to at least one refrigerant and/or coolant circuit (indicated in FIG. 5 by dashed lines for only one battery cell 100) through which thermal energy given off from the power electronics arrangement 121 to the body of the number of battery cells 110 can be dissipated.

Referring to FIG. 6, which shows a flow chart, a method for deheating a battery cell controller 120 of a battery arrangement 100 (such as described above) for connecting to an electric machine 200 and/or a power supply 300, may be performed as described below.

In a step S100, there is provided a number of battery cells 100, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string and third string being connectable to the electric machine as one respective phase.

In a step S200, there is provided a number of battery cell controllers 120, each battery cell controller 120 comprising at least a power electronics arrangement 121.

In a step S300, each of the number of battery cell controllers is connected to a terminal of at least one of the number of battery cells 110 within one string, each battery cell controller 120 comprising or forming a first thermal conduction path extending from the power electronics arrangement 121 via the terminal to a body of the respective battery cell 110.

Now referring to FIG. 7, which shows the battery arrangement 100 similarly to FIG. 1, the battery arrangement 100 comprises the number of battery cells 110 forming three strings, i.e., three phases, to be connected to the electric machine 200 and/or the power supply 300. Further, the battery arrangement 100 comprises the number of battery cell controllers 120, wherein these further form a number of slave nodes. Thereby, each battery cell controller 120 connects at least one terminal of the number of battery cells within one of the strings, each battery cell controller 120 comprises the power electronics arrangement 121 and a sensor 127 (see e.g., FIG. 3) configured to acquire at least one battery cell parameter. Further, the battery arrangement 100 comprises a master node 150, configured to connect to each of the first string, second string and third string and/or to each of the slave nodes, i.e., the number of battery cell controllers 120. Further, the master node is configured to acquire a total parameter of a respective one of the first string, second string and third string. Thereby, the battery arrangement 100 is configured to verify the at least one battery cell parameter acquired and the total parameter acquired against each other. The total parameter may be, for example, the total voltage of the respective string, a current, a

In other words, the master node 150 is configured to measure and/or determine the total parameter, e.g., total voltage, its phase etc., total current, State of Charge (SOC), temperature, etc., of each string. This total parameter can be verified with the cell parameter, e.g., voltage, measurement by turning on one slave node, which measures the cell parameter, e.g., total voltage, its phase etc., total current, SOC, temperature, etc., at a time and compare values from slave node with the total value measured by the master node. For example, this could be performed during start up, e.g., startup of the battery arrangement 100 and/or the vehicle 1. Further, for example, in DC operation, the values from the slave nodes may be summed up and compared with the master's measured value. In AC operation, a stable condition may be controlled for a time interval, e.g., about 100 milliseconds, to collect data from the slave nodes.

Further, the battery arrangement 100 may be further configured to verify the at least one battery cell parameter acquired, and the total parameter acquired against each other by controlling only one single slave node to be activated at one time and acquiring the at least one battery cell parameter of the correspondingly activated slave node and/or battery cell.

Furthermore, the battery arrangement may be further configured to activate each of the number of slave nodes one by one, acquire the respective at least one battery cell parameter and sum them up and then verify with the total parameter acquired.

Still referring to FIG. 7, which shows the battery arrangement 100 similarly to FIG. 1, the battery arrangement 100 comprises the number of battery cells 110 forming three strings, i.e., three phases, to be connected to the electric machine 200 and/or the power supply 300. Further, the battery arrangement 100 comprises the number of battery cell controllers 120, wherein these further form a number of slave nodes. Thereby, each battery cell controller 120 connects at least one terminal of the number of battery cells within one of the strings, each battery cell controller 120 comprises the power electronics arrangement. Further, the battery arrangement 100 comprises a master node 150, configured to broadcast a control information message to each of the number of slave nodes, the control information message allows each slave node to control its power electronics arrangement 121.

In other words, the battery arrangement 100 comprises the master node 150 that is configured to dictate a behavior of the system, i.e., the battery arrangement 100, and the number of slave nodes, i.e., the battery cell controllers 120, which are mounted directly on the battery cells 110. The slaves know their position in the battery arrangement. They receive the broadcasted control information message at the same time or within an agreed time limit. They may be configured to connect and disconnect themselves depending on the control information message, e.g., a modulator angle or the like, included therein. The slaves are connected in the three strings and together they can create three sine shaped voltages, which are controlled to achieve desired phase currents, e.g., a torque. The master node 150 may be configured to generate a virtual sine wave, which may also be referred to as modulator. This is done by broadcasting a propulsion request info with a predetermined pace, for example every millisecond. Broadcasting may be done over radio or other galvanic isolated communication method. Since broadcasted transmission delay is well defined and the absolute time is transmitted in the broadcasted message, the complete system will have the same absolute time with an accuracy better than 1 microsecond. The slave nodes may have time slots scheduled to distribute information to the system. The slave nodes broadcast a message in the same manner as the master node 150. In this way, all nodes in the system will get all the information that is flowing in the network. The scheduled slave node response can be made so that three slaves (one from each string) have time to respond between every master transmission. For example, current from each string with the same time stamp is available on the network, enabling to analyze the AC current every millisecond based on an internal current sensors in the slave nodes.

FIG. 8 shows in a timeline the scheduling of the multi-directional broadcasting as described above. The time interval T may be in the millisecond or microsecond range, e.g., about 1 ms. M may indicate the master node's 150 transmission, and 1:1, 2:1, 3:1, etc. may indicate the respective time slot of the respective battery cell controller 120, i.e., the slave node, between each broadcasting of the master node 150. As described above, the designation 1:1, 1:2, 1:3 refer to the respective strings of battery cells 110.

In other words, the master node 150 may be configured to generate a virtual sine wave, which is also referred to as the modulator. This may be done by broadcasting propulsion request info with a predetermined pace, for example every millisecond. Broadcasting can be done over radio or other galvanic isolated communication method. Since broadcasted transmission delay is well defined and the absolute time is transmitted in the broadcasted message, the complete system, i.e. the battery arrangement 100, will have the same absolute time, e.g. with an accuracy better than 1 microsecond. The slave nodes have time slots scheduled to distribute information to the system. The slave nodes broadcast a message in the same manner as the master node. For example, even all nodes in the system may get all the information that is flowing in the network. The scheduled slave node response can be made so that three slaves (one from each string) have time to respond between every master transmission. For example, a current from each string with the same time stamp is available on the network and it is possible to analyze the AC current every millisecond based on the internal current sensors in the slave nodes.

Now referring to FIG. 9, which shows in a timeline tasks of a master node and one or more slave nodes, triggered and/or synchronized by an update event. The update event may occur with the above time interval T. The update event is the base for all time synchronized changes in the modulator. The Master node message transmission is scheduled just after update. Then three slave node transmissions are scheduled before next master node's transmission. For example, after the update event, some or all nodes in the battery arrangement may measure a respective current at the same time. The master node may measure resolver angle and may get or determine current modulator angle.

Still referring now to FIG. 9, modulator, i.e., the virtual sine wave generated by the master node 150, is explained in more detail. At every update event the master node 150 may transmit a current modulator angle. The slave nodes, i.e., the battery cell controllers 120, may receive this angle, compare with their own modulator angle and, if deviating, calculate a correction. This is indicated in FIG. 9 by rectangles representing switch-on times of a slave node or a battery cell, respectively, and fit into the virtual modulator voltage (angle) by changing the switching times. The offset of the respective slave node may be applied once to modulator timing at the next switch on event, thereby the modulator is kept in synchronization as absolute timing is synchronized. It is noted that FIG. 9 Figure shows a system with only two slave nodes generating a rather low resolution sine wave. It also shows the virtual sine voltage that the system generates. With a large number of slave nodes, the generated voltage will be very close to true sine shape.

As described above, the virtual sine wave generated by the master node may also be referred to as the modulator. The update event may be regarded as the base for all time synchronized changes in the modulator. The master's node message transmission is scheduled just after the update event. Then, as explained above with reference to FIG. 8, the three slave node transmissions are scheduled before the next master's node transmission.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from the study of the drawings, the disclosure, and the appended claims. In the claims the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items or steps recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A battery arrangement comprising: plurality of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string, and third string configured to connect to an electric machine as one respective phase; andplurality of battery cell controllers, each connected to a terminal of at least one of the battery cells within one string, each of the battery cell controllers comprising at least a power electronics arrangement, and each of the battery cell controllers forming a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of a respective battery cell; andwherein the battery arrangement is configured for connecting to at least one of the electric machine and a power supply.

2. The battery arrangement according to claim 1, wherein at least a part of the battery cell controllers comprising a busbar spanning over one or more of the battery cells.

3. The battery arrangement of claim 1, wherein the power electronics arrangement contacting the terminal via a conductive material integrated in the battery cell controllers, and wherein the conductive material is made of at least one of a copper, a copper alloy, aluminum, and an aluminum alloy.

4. (canceled)

5. The battery arrangement of claim 3, wherein the conductive material comprises one of a metal core and a metal back of a printed circuit board in which the power electronics arrangement is embedded.

6. The battery arrangement of claim 5, wherein the metal core is made of at least one of copper, a copper alloy, aluminum, and an aluminum alloy; and wherein the metal back is made of at least one of copper, a copper alloy, aluminum, and an aluminum alloy.

7. The battery arrangement according to claim 1, the battery cell controllers comprising one of a metal core and a metal back printed circuit board in which the power electronics arrangement is embedded, wherein one of the metal core and metal back printed circuit board contacts the power electronics arrangement and a respective terminal of the battery cells.

8. The battery arrangement according to claim 6, wherein the printed circuit board is formed in multiple layers, a first layer comprising at least a section made of one of the metal core and metal back and configured to engage the respective terminal, thereby forming at least a part of a busbar, an intermediate layer comprising plurality of through holes in which the power electronics arrangement is held in place, and a second layer comprising at least a section made of one of the metal core and metal back and configured to engage the respective terminal, thereby forming at least a part of the busbar, and wherein the power electronics arrangement is arranged between the first layer, and the second layer, thereby contacting the conductive material of at least one of the layers.

9. (canceled)

10. The battery arrangement of claim 1, wherein the battery cell controllers further comprising a second thermal conduction path extending from the power electronics arrangement via at least one of the terminal and the body to a casing of at least one of a respective battery cell and the battery arrangement.

11. The battery arrangement of claim 10, wherein the casing covers the battery cell controllers and contacting a top side of the at least a part of the battery cell controllers.

12. The battery arrangement of claim 10, wherein the casing contacting the battery cell controllers via a thermal interface material, is arranged between at least a part of the battery cell controllers and the casing, wherein the thermal interface material is further in contact with the battery cell controllers; and wherein the thermal interface material forms a pad contacting each of the battery cell controllers and the casing, two-dimensionally.

13. (canceled)

14. The battery arrangement of claim 10, wherein the casing having an outer surface exposed to ambient air of the battery arrangement.

15. The battery arrangement of claim 10, wherein the casing is made of one of an aluminum and an aluminum alloy.

16. The battery arrangement of claim 1, wherein the battery arrangement further comprising a third thermal conduction path formed between the battery cells by a heat conducting blade contacting the body of at least one of at least a part of the battery cells and at least a part of the battery cell controllers, and is exposed to ambient air with respect to the battery arrangement.

17. The battery arrangement according to claim 16, wherein the heat conducting blade is coupled to the body of at least one of the battery cells and the battery cell controllers by interconnecting a thermal interface material there between.

18. The battery arrangement of claim 1, wherein the battery arrangement further comprising a fourth thermal conduction path formed by plurality of rails running along of at least a part of the battery cell controllers.

19. The battery arrangement of claim 1, wherein each of the battery cell controllers are materially bonded to the terminal via a material bonding; and wherein the material bonding is formed by at least one of a welded bond and a laser bond.

20-21. (canceled)

22. The battery arrangement of claim 1, wherein the battery cells are connected to at least one refrigerant and a coolant circuit through which thermal energy is given off from the power electronics arrangement to the body of battery cells is dissipated.

23. The battery arrangement of claim 1, wherein the power electronics arrangement comprising plurality of power switches.

24. A vehicle, comprising: an electrical machine; anda battery arrangement; and wherein the battery arrangement comprises,plurality of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string, and third string configured to connect to an electric machine as one respective phase; andplurality of battery cell controllers, each connected to a terminal of at least one of the battery cells within one string, each of the battery cell controllers comprising at least a power electronics arrangement, and each of the battery cell controllers forming a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of a respective battery cell; andwherein the battery arrangement is configured for connecting to at least one of the electric machine and a power supply.

25. (canceled)

26. A method comprising: providing plurality of battery cells, of which a first sub-number connected in series form a first string, a second sub-number connected in series form a second string, and a third sub-number connected in series form a third string, the first string, second string, and third string connectable to an electric machine as one respective phase;providing plurality of battery cell controllers, each of the battery cell controllers comprising at least a power electronics arrangement; andconnecting each of the battery cell controllers to a terminal of at least one of the battery cells within one string, each of the battery cell controllers comprising a first thermal conduction path extending from the power electronics arrangement via the terminal to a body of a respective battery cell; andwherein the method is configured for deheating the battery cell controllers of a battery arrangement for connecting to at least one of the electric machine and a power supply.