WO2015032874A1

WO2015032874A1 - Electrical management system for the packs of a battery based on the power required by the battery and the charge of the packs

Info

Publication number: WO2015032874A1
Application number: PCT/EP2014/068873
Authority: WO
Inventors: Anh-Linh BUI-VAN; Pierre Perichon
Original assignee: Renault S.A.S
Priority date: 2013-09-04
Filing date: 2014-09-04
Publication date: 2015-03-12
Also published as: FR3010250B1; FR3010250A1

Abstract

The invention proposes a method for powering an electric engine (3) of a motor vehicle using a set of battery packs (10, 11, 12, 13) connected in series, at least one of the packs being able, successively, to be excluded from or included in the set powering the engine (3), by means of a switch or a pair of switches (30). While the vehicle is travelling, the switch or pair of switches is controlled in such a way as to limit the output voltage of the battery so that it remains compatible with the vehicle systems or so as to optimise the useful energy of the battery, even if the packs have very different charge states.

Description

Electrical block management system of a battery according to the required power of the battery and the charge of the blocks

The invention is obj and electric propulsion vehicles, or hybrid propulsion vehicles comprising both an electric propulsion means and other propulsion means, for example by heat engine.

The invention relates more particularly to the management of the electrical energy source on board the vehicle.

The electrical energy of the vehicle is conventionally stored in an electrochemical accumulator battery comprising a number of electrochemical cells connected together in series and / or in parallel.

The battery can generally be defined as a set of electrical blocks connected together in series. All blocks are crossed by the same intensity of current.

In order to avoid premature aging or battery degradation, it must be ensured at all times that none of the cells in any of the blocks fall below a critical state of charge or exceed a state of charge. critical. For this purpose, moreover, when recharging the battery, systems exist, which are designed to partially discharge the cells which would be substantially more loaded than others. These systems ensure an almost equivalent state of charge of all cells at the end of a battery recharge.

The patent application CN 10 1 1 573 42 discloses an electric propulsion vehicle capable of accepting a modular system of electric battery blocks. A user can thus be satisfied at first, or for certain paths, a minimum group of electric blocks. It can subsequently acquire additional blocks or modules, in order to improve the autonomy and / or the power of the vehicle. The vehicle has several electric motors, each of which can be associated with a battery blo c. Engines The electric motors can alternatively be coupled / decoupled from the driving wheels of the vehicle, for example by means of an electromagnetic clutch. It is thus possible to increase the driving power of the vehicle by simultaneously operating the two engines, or to increase the range of the vehicle by operating in turn each of the motors as the battery packs associated with this engine are sufficiently loaded. The main drawbacks of this solution are the high cost due in particular to the multiphase of the motors and their electronic converters, the large size and the joule losses in an overly extensive cabling network.

The object of the invention is to propose a battery management system that makes it possible to use a variable number of battery blocks supplying the same electric motor, which can then be the only motor of the vehicle. The invention also aims to allow the use of battery packs having different charge levels.

The invention also makes it possible to increase the number of battery packs that can be used without damaging the electrical network of the vehicle, thus increasing the total autonomy of the vehicle.

To this end, the invention proposes a power supply system for an electric machine, comprising a battery of electric battery packs assembled in a series connection. The battery comprises at least one pair of switches connected to one of the blocks, a first switch being connected in series with the blo c and a second switch being connected in parallel with the set 'blo c + first switch'. The switches of said pair are oppositely controlled so that the first switch is closed when the second switch is open, thereby including the block in the serial connection, and so that the second switch is closed when the first switch is open. , thus excluding the blo c of the serial connection. The system includes a management unit that is able to determine a state of charge of each block. The management unit is configured to exclude from the serial connection at times or to reinsert in the serial connection, one or more blocks provided with switches, according to a power setpoint to be delivered by the battery and the state of charge of each block.

The battery comprises for example a group of several disconnectable blocks equipped with pairs of switches, and the management unit is configured to exclude at times from the serial connection, one or more blocks if the charge state of these blocks goes below a load threshold. Preferably, the load threshold is the same for several blocks, or even the same for all blocks. Advantageously, the load threshold used for each block is constant during the running of the vehicle.

Each block may comprise one or more electricity storage cells connected in series and / or in parallel within the blok. The load threshold can be evaluated from an open-circuit voltage of the block, or can be calculated from a history of the current through the block and the voltage across the block.

According to a preferred embodiment, the battery comprises a group of several disconnectable blocks equipped with pairs of switches. The management unit can be configured, when it delivers an electrical power to an electric machine, to exclude from the connection in priority blo cs of less state of charge. The management unit can also be configured to, when the machine runs as a generator, exclude from the connection the highest state of charge blocks.

According to a preferred embodiment, the management unit receives a variable electrical power instruction to be delivered by the battery to an electric machine, and is configured to exclude at times from the serial connection or reinclude in the serial connection, one or more blocks with switches, depending on the variable power setpoint and the state of charge of each block c. According to another embodiment, the management unit is configured to exclude at times from the serial connection or reinclude in the serial connection, one or more blo cs provided with switches, according to a constant power reference (P). and the state of charge of each block. Advantageously, the management unit is configured to adapt the number of blocks included in the connection so as to reach an objective voltage which is a function of the power to be delivered. The objective voltage can for example be read in a map according to the power of the engine or the combined values of torque and engine speed.

According to one embodiment that can be combined with the previous one, the management unit is configured to limit the number of blo cs included in the connection so as not to exceed a threshold voltage. The sum of the voltages available on all the blo cs belonging to the battery can thus be greater than the allowable voltage on the electrical network supplying the electric machine.

In this embodiment, the management unit may further be configured to, when the total voltage of the available blocks is greater than the voltage required by the electrical machine, rotate on the blocks equipped with pairs of switches, for exclude them in turn from the connection. The voltage required by the electrical machine can be a constant, or can be estimated according to a power demand required from the electric machine.

The power system according to the invention can be used to power an electric vehicle or hybrid electric vehicle. In this vehicle, one or more blocks of the battery are configured to be extracted from the vehicle during a refueling stop and replaced by another blo c or group of blo cs. The extractable blocks may or may not have switches. By supply stop means a stop of moderate duration - for example less than one hour - during which one exchange part of the blocks of the battery to replace them better loaded blocks, without disassembling the vehicle.

According to an alternative embodiment, only part of the blocks is configured to be extracted quickly from the vehicle during a refueling stop. Blocks that are not configured to be extracted quickly have pairs of switches. Other blocks may be provided with or not equipped with switches. According to an alternative embodiment, the total voltage of the battery is imposed by a series assembly of blo cs each provided with a pair of switches. In other words, each cell of the battery belongs to a block which can be excluded from the power supply circuit of the motor while leaving connected to the motor at least one other block of the serial connection of the battery.

According to another aspect, the invention proposes a method for supplying an electric motor of a motor vehicle with a set of battery packs connected in series, at least one of the blocks being able to be successively excluded or included, by means of a switch or a pair of switches, the assembly supplying the motor. During the running of the vehicle, the switch or the pair of switches is piloted in such a way as to adapt the characteristics of the battery according to the power which the driver of the motor vehicle makes of the motor.

According to a preferred embodiment, the exclusion of the series connection supplying the motor, of certain blocks excluded or blocked in reserve, can be made due to a state of charge lower than that of the blocks included in the connection. series.

According to a preferential embodiment, it is possible to monitor the no-load voltages at the terminals of each excluded or reserve block and / or the state of charge of each block excluded or in reserve, it is possible to classify the excluded or excluded blocks. in decreasing or increasing order of these voltages and / or states of charge, it is possible to determine an optimum voltage required as a function of the power required by the driver of the vehicle and, if the total voltage available at the terminals of the battery is less than When the optimum voltage is required, an extra block can be connected as part of the excluded or spare blocks, starting with the one in the no-load voltage, where the highest is the state of charge.

According to a preferred embodiment, it is possible to evaluate the minimum value of the state of charge of the various included blocks currently connected, it is possible to evaluate the highest state of charge of the various blocks currently excluded or in reserve and, if the state of load of one of the blocks currently excluded or in reserve is greater than the state of charge of one of the included blo cs currently connected, one can connect said block in reserve and can disconnect said block currently connected. Other objects, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which:

FIG. 1 represents an electric propulsion vehicle equipped with a power supply system according to the invention,

FIG. 2 is a simplified representation of a power supply system according to the invention, FIGS. 3 and 4 are representations of two different configurations in which one and the same power supply system according to the invention can be found,

FIG. 5 is a simplified algorithm for operating a power supply system according to the invention, and

FIG. 6 is an algorithm simulated from another possible mode of operation for a feed system according to the invention.

As illustrated in FIG. 1, a vehicle 2 comprises an electric motor 3 powered by a power supply system 1, which can also be referred to as a battery pack 1. The power supply system 1 comprises in particular three subgroups 4, 5 and 6 of electric accumulators. The first subgroup of accumulators 4 is placed for example under the hood of the vehicle so as to be relatively accessible for rapid exchange of the subgroup or part of the subgroup. For another example of configuration, it could also be placed under the floor of the vehicle so as to be easily 'quick-dropable'. The other two subgroups 5 and 6 are placed at less accessible places of the vehicle, for example under the seats 7 of the vehicle. The Subgroups 4, 5 and 6 are connected in series with each other so as to power an electric motor 3 of the vehicle 2. Each of the subgroups consists of unit blocks B connected in series with each other. to form subgroup 4, subgroup 5 or subgroup 6.

Figure 2 schematically illustrates the operating principle of the power supply system 1. Battery blocks 1 0, 1 1, 12, 13 are arranged on an electrical network 1 8 so as to be connected in series, and thus supply the electric motor 3. At each blok 10, 1 1, 12, 13 30, 31, 32, 33, and a bypass connection, respectively 40, 41, 42, 43 are associated. The switch 30, 31, 32, 33 may be in a first configuration, where associated block, respectively 10, 1 1, 12, 13, is connected in series with the motor 3. A switch may also be in a second configuration, like the blocks 10 and 11 in FIG. 2. In FIG. 2, these two blocks are in a configuration where they are excluded from the series connection supplying the motor 3. The current delivered by the other blocks then passes through the bypass connections associated with each of the blocks 10 and 11.

The switches have been schematically represented as mechanical switches. Advantageously, these mechanical switches could be replaced by electronic switches.

Each block 10, 1 1, 12, 13 is equipped with a voltage measuring system, respectively 20, 21, 22, 23 which measures the voltage, respectively Vi, V ₂ , V ₃ , V ₄ , at the terminals of the block . Each voltage measuring system is connected to an electronic management unit 7 to which the voltages Vi, V ₂ , V ₃ , V ₄ are sent.

The electronic management unit 7 controls the switches 30,

3 1, 32, 33. It sends to these switches signals, respectively IO i, I0 ₂ , I0 ₃ , I0 ₄ , for example Boolean, indicating whether the switch must be in the first or in the second configuration. The electrical circuit 1 8 is equipped with a current sensor 9, also connected to the electronic management unit 7, to which the current sensor 9 sends an instantaneous value I of current flowing through the circuit 1 8. electronic management 7 receives a P power instruction to the electric motor 3 to respond to a command of the driver of the vehicle. The driver control can for example be transmitted by means of an accelerator pedal 14.

The electronic management unit 7 comprises a calculation unit 15 configured to calculate, from the history of the current delivered by the current sensor 9, and the history of each voltage delivered by the voltage measuring systems 20 , 21, 22, 23, a state of charge of the "SOCi" or "State Of Charge" battery of each block 10, 1 1, 12, 1 3 of the battery assembly 1.

Methods of calculating the state of charge of a battery pack are known. One of these methods is for example described in the patent application FR 2 971 855. The electronic management unit 7 comprises a selector 16 which, depending on the states of charge of the different blocks 10, 1 1, 12, 13, and of the total power P requested by the driver, elaborates the boolean messages IO i, I0 ₂ , I0 ₃ , I0 ₄ for the switches 30, 31, 32, 33.

Figure 3 is a simplified representation of a feed system 1 according to the invention. FIG. 3 shows elements that are common to the preceding figures, the same elements being designated by the same references. The power supply system of FIG. 3 comprises, although they are not represented in the figure, an electronic management unit 7 equivalent to that of FIG. 2, also connected to the different switches of the different blocks, to a control system. voltage measurement dedicated to each block, and to a current sensor measuring the intensity of current flowing through the motor 3.

FIG. 3 essentially shows a power supply system 1 or battery pack 1 consisting of twelve battery packs connected in series and designated by the marks B 1 to B 12. The blocks B 1 to B 4 correspond to a first group 4 blo cs electric, group that is configured to be easily exchangeable by extraction of the vehicle and replaced by another group of blo cs, preferably of the same size. They can be extracted without immobilizing the vehicle for an extended period of time, for example being extracted and replaced in less than half an hour, by opening dedicated covers of the vehicle, and without extracting parts of the vehicle that are not intended to be exchanged with the blocks. , or by extracting at most one or two such organs.

Blocks marked B5 to B12 are blocks not configured for quick exchange of battery packs. They may for example correspond to the second and third groups 5 and 6 of Figure 1.

Each of the blocks B 1 to B 12 is provided with a switch 25 as described in FIG. 1, as well as an associated bypass connection 26. Embodiments may be envisaged in which the switches 25 of blocks B 1 to B 4 remain on board the vehicle during the exchange of the associated battery blocks. Embodiments may also be envisaged in which the switches 25 and / or the bypass connections 26 are integrated in each exchangeable block or not, as shown in FIG.

In FIG. 3, each of the blocks B 1 to B 12 comprises a group of electrochemical cells 24 which may be included or excluded from the serial connection supplying the motor 3 by means of a switch 25.

Although the bypass connection can be part of the blo c, by misnomer, by describing Figures 1 to 6, we say that a block is excluded from the serial connection if its switch 25 is in a position such that the current passing through the blok passes through the bypass connection 26 associated with blo c, instead of crossing the electrochemical cell (s) 24 belonging to blo c.

In FIG. 3, the switches 25 of the blocks B 1 to B 4 are positioned in such a way that the blocks B 1 to B 4 feed the motor 3. On the other hand, the switches associated with the blocks B 5 to B 8 and B9 to B12 are positioned to exclude blocks B5 to B8 and B9 to B12 from the series connection supplying the motor 3.

This configuration may for example be imposed by a selector 16 equivalent to that of FIG. 2, when the blocks of the first group 4 are more charged than the blocks of the second groups 5 and 6, and the voltage across the terminals of the group blo cs B l to B4, ensures sufficient power of the engine 3-compared to a setpoint from the pedal 14 of Figure 2.

For example, the vehicle 2, after a maximum permissible load of all the battery packs B 1 to B 12, has rolled so as to partially discharge all the battery packs B 1 to B 12. Then, following a stop of refueling, the blocks B 1 to B 4 were exchanged for other battery packs with a maximum charge level, or at least a higher charge level than the blocks extracted from the vehicle.

In the configuration of FIG. 3, as long as the motor 3 is so at a low power level P, the selector 16 includes the blocks B 1 to B 4 in the series connection supplying the motor 3. At the same time, the selector 16 excludes the blocks B5 to B12 of the serial connection.

If the power required at the motor 3 increases, the selector 16 may toggle some of the connectors 25 of the blocks into reserves B5 to B12, so as to include all or part of these blocks in the serial connection.

This last case is illustrated in Figure 4. Figure 4 shows elements of Figure 3, identified by the same references.

Thus, in FIG. 4, blocks B 1 to B 4 continue to be included in the serial connection. Blocks B5, B6, B7, as well as blocks B9, B10, B11 are also, at least temporarily, included in the serial connection. Blocks B8 and B12 remain in Figure 4 excluded from the serial connection. These blocks B 8 and B 12 may subsequently be solicited if the power requested to the motor 3 increases. On the other hand, when the power demanded by the motor 3 decreases, the selector 16 can again actuate a part of the switches 25, so as to exclude some of the blocks B5, B6, B7, or B9, B10, B11 of the serial connection. Preferably, the blocks with the lowest state of charge will be excluded first. In this way, a critical state of charge threshold of the least charged blocks is reached as late as possible, which leads to excluding these blocks from the serial connection even when high powers are demanded from the motor 3.

In order to select the blocks to include or exclude from the serial connection, the selector 16 can monitor either the voltages at the terminals of each block or, preferably, both the voltages at the terminals of each block and at the same time state of charge calculated integrally by the calculation unit 15 for each block c.

In a simplified variant of the invention, the estimation of the state of charge of a block temporarily excluded from the serial connection can be done by means of the no - load voltage measured by the voltage measurement system associated with this blo c.

FIG. 5 illustrates an example of an operating algorithm of the selector 16 in a power supply system 1 according to the invention. In the example illustrated in FIG. 5, it is considered that there are no unused blocks in the serial connection, plus a number, here unspecified, of blocks already supplying the motor 3. The number n "as the additional number of already connected blocks subsequently evolve during the algorithm, especially in steps 55 and 58.

At a step 50, the selector 16 reads the empty voltages V ₁ , V ₂ , V _n delivered by the voltmeters or voltage measurement systems of the n blocks in reserve, that is to say nblo cs mounted on the vehicle 2 but temporarily excluded, because of the position of their respective connectors, the serial connection.

At a step 5 1, the selector 16 classifies these voltages, for example in decreasing order, then, at a step 53, it reads in the map 17 an optimum voltage V _opt i as a function of the power P delivered by the pedal 14. At a step 54, the selector 1 6 checks whether the total voltage currently available at the terminals of the battery is greater than or equal to the required optimum voltage. If this is not the case, at a step 55 the breeder 16 connects a block starting with the one with the highest empty voltage.

If the voltage already available at the terminals of the battery is sufficient, then in a step 57 the selector 1 6 evaluates the minimum value "min (SO Cj) bioc connected" corresponding to the lowest state of charge among the blocks currently connected in the serial connection, and also evaluates the highest state of charge "max (SO Ci) bioc reserve" corresponding to the best state of charge among the blocks currently in reserve.

If the minimum state of charge of the blocks currently connected remains higher than the highest charge state of the blocks in reserve, then the selector 16 repeats step 50.

If, in step 57, the selector 1 6 finds that one of the reserve blocks has a state of charge greater than the state of charge of one of the blocks currently in operation, then, in a step 58, the selector 16 switches the switches of these two blocks.

The coach 16 then repeats step 50.

By following this process, it is ensured both to always have sufficient voltage across the motor 3, and it is ensured to delay the maximum expiry where one of the blocks will present a state of charge beyond which it will no longer be possible to be under pain of degradation.

FIG. 6 illustrates an alternative algorithm that can be used for the operation of the selector 16. FIG. 6 shows some steps that are common to FIG. 5, the same steps being designated by the same references. In this variant embodiment, the selector 1 6 classifies (step 52) all the blocks of the supply system - here at the number of twelve -, in order of increasing state of charge or in descending order (in descending order in the example shown in Figure 6). Then, in a step 53, it reads in the map 17 an optimal voltage V _opt i according to the power P delivered by the pedal 14. In a step 54, the selector 1 6 checks whether the total voltage currently available across the the battery is greater than or equal to the required optimum voltage. When, in step 54, the selector 16 finds that the voltage at the terminals of the motor 3 is insufficient, then, in a step 56, it connects the reserve block whose classification in step 52 indicates that it has the state the highest load among the blocks in reserve.

It then returns to step 54. The monitoring of step 57 concerning the state of charge of the connected loops with respect to the state of charge of the unconnected blocks remains the same as on the algorithm of FIG. .

It could also include in these algorithms a monitoring step where, before connecting an additional block, it would be verified that the total voltage across the motor 3 will not exceed, after connection of this block, a maximum voltage allowed by the drivers and the components of circuit 1 8. By adding such a step, one can afford to have a higher number of blocks available on the vehicle than the number of blocks that can be connected in their maximum state of charge. without damage to circuit 1 8.

In order to avoid excessive cycling of some blocks compared to other blocks, it is also possible to replace the permutation steps 57 and 58 by periodic swapping. Periodic permutation may regularly exclude a number of blocks from the serial connection, ensuring that all blocks are excluded in turn, either individually or in groups - for example, in groups of two or three blocks.

A permutation of the blocks connected either according to the steps 57, 58 of FIGS. 5 and 6, or by permutation, can be carried out even if none of the blocks is configured to be extracted from the vehicle during the refueling steps.

The use of the network of switches and bypass connections to swap the blocks in operation and to exclude some blocks periodically, makes it possible to avoid premature aging of certain blocks, makes it possible to have a battery with a number of blocks. higher, and therefore provides greater autonomy to the vehicle. As all blocks are unloaded, the number of blocks excluded from the serial connection can be reduced. First of all, the load level of active blocks is offset by the increase in the number of active blocks.

In this configuration with a large number of blocks, it is possible, in a first embodiment, to maintain the voltage across the motor at the maximum value allowed by the circuit as long as the state of charge of all the blocks allows it.

It is also possible, according to another embodiment, to manage the number of blocks connected as a function of the power demanded from the vehicle, as illustrated for example in steps 53, 54 and 55 or 53, 54 and 56 of FIG. 6. The vehicle range is then increased, both by the increased number of available blocks and by the selective use of the heaviest blocks.

Finally, in another embodiment, blo cs which are easily refillable, for example those which are 'quick-dropable', may be discharged preferably.

The invention is not limited to the embodiments described and can be declined in many variants.

Each of the two-position switches 30, 31, 32, 33 can be replaced by two switches, one in series with the corresponding block, the other mounted on the bypass connection associated with the block. that is, parallel to the block. The two switches are then oppositely controlled so that the first switch is closed when the second switch is open, thereby including the block in the serial connection, and so that the second switch is closed when the first switch is open, thereby excluding the block of the serial connection. Configuration with a two-position switch and configuration with two switches operating in opposition are equivalent. The state of charge delivered at the state of charge calculation unit 15 can be calculated in many ways, generally involving a current through the series connection, the voltage across the block concerned, and a capacity of the blo c which itself can be estimated in various ways known in the literature.

The blocks can have substantially the same capacity and the same voltage when they are all built with the same technology. However, it is conceivable to use blocks in the series connection supplying the motor with different numbers of chemical cells, or even cells of a different chemical nature, in which case the capacitances and the voltages at vacuum can differ from one block to the next. other. Capacities and no-load voltages can also vary significantly from one block to the next if blocks with chemical aging states (due to the number of different charge and discharge cycles) are used. The invention makes possible the use of different state of charge blo cs while optimizing the exploitation of the electric energy available in each blo c.

All power system blocks can be equipped with switches. It is also possible to envisage a power supply system comprising a fixed block or a group of fixed blocks which remain permanently connected to the motor, and a second subgroup of blocks provided with switches.

One could also not use current intensity to estimate the state of charge of blocks, and evaluate this state of charge from the empty voltage of each block, performing a periodic rotation of the blocks in activity so to have at all times a recent estimate of no-load voltage for each block.

It is possible to perform permutations on the block connections without adapting the total voltage of the blocks to a motor power setpoint. However, this total voltage is maintained above a constant minimum value and, if necessary, below a maximum value which is also constant.

The preferential connection of certain blocks may also be used during regenerative braking phases of the vehicle. During these braking phases, the kinetic energy of the vehicle is converted by the electric motor 3 into electrical energy which is returned to the power system 1 to be stored. For example, it is possible to use the switches to send the electrical energy of the braking system to a small number of blocks with the lowest charge state, and preferably to non-exchangeable system blocks quickly.

The power supply system according to the invention makes it possible at the same time to increase the autonomy of the vehicle equipped with such a system and to increase the lifetime of the various exchangeable or non - exchangeable blocks constituting the energy reserve of the vehicle. this system.

Claims

1. Power supply system (1) for an electric machine, comprising a battery of blocks (10, 1 1, 12, 13, B01, B02 ... B 12) of electric accumulators assembled in a series connection, the battery comprising minus one switch (30) with two connection positions for shorting one of the blocks, or having an equivalent pair of switches connected to said block (10), a first switch being connected in series with the blok and a second switch being connected in parallel with the block, the switches of said pair being oppositely controlled so that the first switch is closed when the second switch is open, thereby including the block (10) in the serial connection, and so that the second switch is closed when the first switch is open, thereby excluding the block (10) from the serial connection, the system comprising a management unit (7) which is able to determine a state of charge (SO Ci) of each block, characterized in that the management unit (7) is configured to exclude at times from the serial connection or reinclude in the serial connection, one or more blocks (10, 1 1) provided with switches, in function of a power setpoint (P) to be delivered by the battery and the state of charge of each block.

2. System according to claim 1, wherein the battery comprises a group of several blo cs (10, 1 1, 12, 1 3) disconnectable equipped with pairs of switches, and wherein the management unit (7) is configured to exclude at times from the serial connection, one or more blocks (10, 1 1) if the state of charge (SOCi) of these blo cs falls below a load threshold.

3. System according to any one of the preceding claims, wherein the management unit (7) receives a setpoint (P) of variable electrical power to be delivered by the battery to an electric machine (3), and is configured to exclude at times of the serial connection or reinclusion in the serial connection, one or several blocks (10, 11) provided with switches, according to the variable power setpoint (P) and the state of charge of each block.

4. System according to any one of the preceding claims, wherein the management unit (7) is configured to adapt the number of blocks included in the connection so as to reach an objective voltage (V _op t i) which is a function of the power to be delivered (P).

5. System according to any one of the preceding claims, wherein the management unit (7) is configured to limit the number of blocks included in the connection so as not to exceed a threshold voltage.

6. System according to any one of claims 2 to 5, wherein the management unit (7) is configured, when the total voltage of the available blocks and operating above their respective load thresholds, is greater than the voltage required by the electric machine (3), to rotate on the blocks (10, 11, 12, 13) equipped with pairs of switches (30, 31, 32, 33) to be excluded in turn from the connection.

7. Power system (1) according to any one of the preceding claims, for powering an electric motor (3) of vehicle (2) electric or hybrid, wherein one or more blocks (Bl, B2, B3, B4 ) of the battery are configured to be extracted from the vehicle (2) during a refueling stop and replaced by another block or group of blocks.

8. Fuel system according to claim 7, of which only part of the blocks (B1, B2, B3, B4) is configured to be quickly extracted from the vehicle (2) during a refueling stop, at least the blocks ( B5, B6, B7, B8, B9, B10, B11, B12) not configured to be quickly extracted being provided with pairs of switches (25).

9. Power supply system according to any one of the preceding claims, wherein the total voltage of the battery is imposed by a series assembly of blocks (B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12) each having a pair of switches (25).

10. A method of supplying an electric motor (3) of a motor vehicle (2) with a series of battery packs (1 0, 1 1, 12, 13) connected in series, at least one of the blocks being able successively to be excluded or included, by means of a switch or a pair of switches (30), of the assembly supplying the motor (3), characterized in that during driving of the vehicle (2) the driver is switch or the pair of switches so as to adapt the characteristics of the battery according to the power that the driver of the vehicle is requesting from the engine.

1 1. A method according to claim 10, in which: the exclusion of the series connection supplying the motor of certain blocks excluded or blocked in reserve (B5-B 12) is made due to a state of charge lower than that of the blocks included in the serial connection (B 1 -B 14).

12. Method according to one of claims 10 or 1 1 wherein:

the no-load voltages at the terminals of each block excluded or in reserve and / or the state of charge of each block excluded or in reserve are monitored;

the excluded or stored blo cs are classified in descending or increasing order of these voltages and / or states of charge;

a desired optimum voltage (V _op t i (P) is determined as a function of the power demanded by the driver of the vehicle;

- if the total voltage available at the battery terminals is lower than the required optimum voltage, an additional block is connected as part of the excluded or spare blocks, starting with the one in the no-load voltage is the highest or the state of charge is the highest.

13. The method of claim 12 wherein:

- the minimum value of the state of charge of the various included blo cs currently connected is evaluated;

- the highest load status of the different blo cs currently excluded or in reserve is evaluated; if the state of charge of one of the blocks currently excluded or in reserve is greater than the state of charge of one of the included currently connected blocks, said block is connected in reserve and said currently connected block is disconnected.