Controlling the speed of an electric machine coupled to an input shaft of a vehicle gearbox

Abstract

The invention relates to a control method implemented in a vehicle comprising a thermal prime mover capable of rotating the primary shaft of a multi-speed gearbox, and an electric machine coupled to the primary shaft and capable of generating electrical power when it is driven by the primary shaft at a rotational speed. This method comprises a step (10-40) in which it is determined at a time t what the future internal temperature of the electric machine will be for a chosen duration starting at this time t in the presence of the current rotational speed and internal temperature of the electric machine, then electrical power can be generated by the electric machine in the presence of this future internal temperature, and if this determined electrical power is below a chosen threshold, the current speed is required to be changed to a higher speed.

Description

DESCRIPTION TITLE: CONTROLLING THE SPEED OF AN ELECTRIC MOTOR COUPLED TO A PRIMARY SHAFT OF A VEHICLE'S GEARBOX The present invention claims priority from French application No. 2411541 filed on October 23, 2024, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field of the invention

[0001] The invention relates to vehicles comprising a thermal engine and an electric machine coupled to the primary shaft of an automated gearbox, and more specifically to the control of the rotational speed of such an electric machine. State of the art

[0002] Some vehicles, possibly of the automobile type, include, on the one hand, a powertrain (or PMT) comprising at least one thermal engine capable of supplying motive power (or engine torque) to the primary shaft of an automated gearbox, and, on the other hand, an electric machine coupled to this primary shaft and capable of generating electrical power when driven by the latter according to a rotational regime.

[0003] It should be noted that this electric motor can potentially be part of the powertrain, and in this case, it is also capable of driving the gearbox's input shaft when powered by the vehicle's main (or traction) battery. The powertrain is then referred to as "hybrid".

[0004] When the vehicle is in a purely thermal driving phase, the electrical power generated by the electric motor is generally used to power an electrical power supply network (known as the "on-board network") installed in the vehicle, to which electrical equipment consuming energy is connected. electrical at a very low predefined voltage (typically 12 V or 24 V).

[0005] As those skilled in the art know, the electrical power generated by an electric machine depends on its rotational speed but also on the remanent magnetic field of its rotor magnets. The intensity of this remanent magnetic field decreases as the internal temperature of the magnets increases, for example, due to the rising temperature of the oil in the gearbox located in close proximity to, or within, the electric machine. For instance, the intensity of the remanent magnetic field of a NeFeBo type magnet can be reduced by 80% at 130°C.

[0006] Therefore, the continuous electrical power generation capacity of an electric machine varies with its internal temperature, generally in a roughly inverse parabolic manner. Consequently, the electrical power generated by the electric machine is frequently insufficient to supply the vehicle's electrical system, necessitating the use of the vehicle's auxiliary battery (when present).

[0007] To prevent the electrical power generated by the electric machine from becoming insufficient to supply the onboard network, it is possible to significantly increase the intensity of the remanent magnetic field of the rotor magnets. This can be achieved, for example, by doping each magnet with a mass of dysprosium (Dy) equal to approximately 10% of its total mass. However, such a solution considerably increases the cost of the magnets due to the very high cost of dysprosium (a rare earth element).

[0008] The invention is therefore intended, in particular, to improve the situation. Presentation of the invention

[0009] In particular, it proposes a control method for this purpose, intended to be implemented in a vehicle comprising a a thermal motive machine suitable for driving in rotation a primary shaft of a gearbox having several ratios, and an electric machine coupled to this primary shaft and suitable for generating electrical power when driven by the latter according to a rotational regime.

[0010] This control process is characterized by the fact that it includes a step in which:

[0011] - we determine at a given time t what the future internal temperature of the electrical machine will be for a chosen duration starting at that time t in the presence of the current rotation regime and a current internal temperature of the electrical machine, then an electrical power that can be generated by the latter in the presence of this determined future internal temperature, and

[0012] - if this determined electrical power is less than a chosen threshold, a change of a current ratio to a ratio greater than the latter is required.

[0013] Thanks to the invention, the introduction of a ratio n+1, higher than that n in progress, induces a notable decrease in the current rotation rate of the primary shaft and therefore also of the electric machine, which makes it possible to significantly limit the increase in the internal temperature in progress and therefore to significantly limit the loss of electrical power generation capacity of the electric machine without having to dope each magnet of the rotor of this electric machine.

[0014] The control method according to the invention may include other features which may be taken separately or in combination, and in particular:

[0015] - in its stage, the chosen duration can be between five seconds and fifteen seconds;

[0016] - in the presence of the first option, in its step, the chosen duration can be equal to ten seconds;

[0017] - in its stage, we can determine the future internal temperature in a first table which establishes a correspondence between pairs of rotation regime and current internal temperature and future internal temperatures;

[0018] - in its stage, we can determine the electrical power that can be generated in a second table which establishes a correspondence between internal temperatures and electrical powers;

[0019] - in its stage, in the presence of an electrical supply network equipping the vehicle and to which are coupled electrical equipment of the latter consuming electrical energy at a predefined very low voltage, the chosen threshold may be an electrical power capable of providing a chosen voltage greater than or equal to this predefined very low voltage;

[0020] - in the presence of the last option, in its step, the voltage chosen can be between 100% of the predefined very low voltage and 120% of the predefined very low voltage.

[0021] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing the control method of the type presented above in a vehicle comprising a thermal engine suitable for rotating a primary shaft of a gearbox having several ratios, and an electric machine coupled to this primary shaft and suitable for generating electrical power when driven by the latter according to a rotational regime, to control the rotational regime of the electric machine.

[0022] The invention also proposes a control device for equipping a vehicle comprising a thermal engine suitable for rotating a primary shaft of a multi-speed gearbox, and a coupled electric machine to this primary shaft and capable of generating electrical power when driven by the latter according to a rotation regime.

[0023] This control device is characterized by the fact that it includes at least one processor and memory arranged to perform the following operations:

[0024] - to determine at a given time t what the future internal temperature of the electrical machine will be for a chosen duration starting at said time t, in the presence of the current rotational regime and a current internal temperature of the electrical machine, and then an electrical power that can be generated by the latter in the presence of this determined future internal temperature, and

[0025] - if this determined electrical power is less than a chosen threshold, to require a change of a current ratio to a ratio greater than the latter.

[0026] The invention also proposes a vehicle, possibly of the automobile type, comprising, on the one hand, a thermal engine suitable for driving in rotation a primary shaft of a gearbox having several ratios, and an electric machine coupled to this primary shaft and suitable for generating electrical power when driven by the latter according to a rotation regime, and, on the other hand, a control device of the type of that presented above.

[0027] For example, the electric machine can be just as suitable for rotating the primary shaft of the gearbox when it is powered by electrical energy from a vehicle's power battery. Brief description of the figures

[0028] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and the accompanying drawings, in which:

[0029] [Fig. 1] schematically and functionally illustrates an example of an embodiment of a vehicle comprising a control device according to the invention, and a hybrid powertrain supervised by a supervisory computer,

[0030] [Fig. 2] schematically and functionally illustrates an example of an embodiment of a supervisory computer comprising a control device according to the invention, and

[0031] [Fig. 3] schematically illustrates an example of an algorithm implementing a control method according to the invention. Detailed description of the invention

[0032] The invention aims in particular to propose a control method, and an associated DC3 control device, intended to allow control of the rotational speed rr(t) of an electric machine ME coupled to the primary shaft AP of an automated gearbox BV and to which can also be coupled a thermal drive machine MMT of a powertrain (or GMP) of a vehicle V.

[0033] In what follows, vehicle V is considered, by way of non-limiting example, to be an automobile. For instance, it could be a car, as illustrated in Figure 1. However, the invention is not limited to this type of vehicle. It relates to any type of vehicle (land, sea (or river), or air) comprising a thermal engine and an electric motor coupled to the input shaft of an automated gearbox.

[0034] Figure 1 schematically represents, as an illustrative example, a vehicle V comprising a hybrid powertrain (and therefore comprising at least one electric motor ME and at least one internal combustion engine MMT associated with an automated gearbox BV), a supervisory control unit CS, a service battery BS, and a power (or main or traction) battery BP (rechargeable), a CV converter, and a DC3 control device according to the invention.

[0035] It should be noted that the invention also relates to vehicles comprising, on the one hand, a purely thermal powertrain, that is to say comprising at least one thermal engine suitable for being coupled to the primary shaft of an automated gearbox to supply it with engine torque, and, on the other hand, an electric machine coupled to this primary shaft and which can only generate electrical power when driven by the latter according to a rotation regime.

[0036] Furthermore, the transmission chain could also allow for a four-wheel drive (or 4x4) or 4x2 mode.

[0037] The auxiliary battery (BS) is responsible for supplying electrical power to the vehicle's electrical power supply network (known as the on-board network) (RB), supplementing the power supplied by the inverter (CV), which is powered by the main battery (BP) via a primary electrical circuit, and sometimes replacing the inverter. For example, this auxiliary battery (BS) can be configured as a very low voltage (VLV) battery (typically 12 V or 24 V). It is (in this case) rechargeable, at least by the inverter (CV), which uses electrical energy stored in the main battery (BP) for this purpose. For the purposes of this example, the auxiliary battery (BS) is assumed to be a 12 V lead-acid battery.

[0038] The RB on-board network is an electrical power supply network to which electrical (or electronic) equipment (or components) are coupled, which consume electrical energy having a predefined very low voltage (VLV).

[0039] The main electrical circuit (or "high voltage" or "power" circuit) is connected, on one side, to the power battery BP via an interface device, and, on the other side, to electronic equipment, such as the CV converter and the ME electric machine. It may also optionally allow for the recharging of the BP power battery by an external power source and temporarily coupled to vehicle V.

[0040] As illustrated in Figure 1, the transmission chain also includes, here, a drive shaft AM, a first coupling device DC1, a second coupling device DC2, and a transmission shaft AT.

[0041] The operation of the transmission chain (and therefore the powertrain) is supervised by a CS supervisory computer.

[0042] The MMT (thermal drive machine) includes a crankshaft (not shown) which is fixedly attached to the drive shaft AM in order to drive the latter (AM) in rotation or to be driven in rotation by this drive shaft AM. This MMT is designed to provide, in this case for the drive wheels of vehicle V, a thermal engine torque which is defined by a thermal torque setpoint, for example determined by the CS (supervisory control unit).

[0043] The operation of the MMT thermal engine is controlled by a CMT thermal engine computer and supervised by the CS supervisory computer. It should be noted that the CMT thermal engine computer and the CS supervisory computer could be part of the same "supercomputer".

[0044] Furthermore, the MMT internal combustion engine is designed to be coupled to the primary shaft AP of the gearbox BV, via at least the first coupling device DC1, to drive it in rotation (and thus supply it with internal combustion engine torque). This latter device (DC1) is designed to deliver torque derived from the internal combustion engine torque, specifically (here) for at least one set T1 of driving wheels, when it is at least partially closed (or open) and therefore when it couples the MMT internal combustion engine to the gearbox BV (and more precisely to a clutch of the latter (BV)).

[0045] For example, the first coupling device DC1 could be a hydraulic circuit clutch. But it could be of another type.

[0046] For example, axle T1 can also be located in the front PW section of vehicle V. Preferably, as illustrated, it is coupled to the AT driveshaft via a differential (here, the front one) DV. However, in a variant, this axle T1 could be the one referenced as T2, which is located in the rear PRV section of vehicle V. The engine torque, which is produced by the powertrain to drive the drive wheels (here, the front axle T1), is therefore supplied to these wheels at the output of the differential DV.

[0047] It should be noted that in the example illustrated (though not exhaustively) in Figure 1, the crankshaft of the MMT internal combustion engine is also coupled to a belt, which is itself coupled to an AD starter-alternator that is powered by the auxiliary battery BS (and which can also (here) recharge the latter (BS)). Thus, the AD starter-alternator can supply torque to the belt, which can then supply this torque to the crankshaft to start the MMT internal combustion engine. The MMT internal combustion engine can also be started by the ME electric motor when the first coupling device DC1 is at least partially closed and the ME electric motor supplies torque to the input shaft (as in the hybrid powertrain). It should be noted that in a variant, the AD starter-alternator could be powered by the BP power battery.

[0048] The electric machine ME is coupled to the primary shaft AP of the gearbox BV so that it can generate electrical power pe when driven by this primary shaft AP at a rotational speed rr(t). The rotational speed rr(t) at any given time t can be measured, for example periodically, by a dedicated sensor (not shown) coupled to the primary shaft AP.

[0049] For example, this coupling between the electric machine ME and the primary shaft AP can be done downstream of the first coupling device DC1, by means of the second coupling device DC2.

[0050] This second DC2 coupling device can, for example, include a cascade of gears connecting the electric machine ME to the input of the gearbox BV (downstream of the first DC1 coupling device).

[0051] It should be noted that, given that the powertrain in the illustrated and described example is hybrid, the electric motor ME, when powered by the BP battery, is also capable of operating at a rotational speed rr(t) to supply the primary shaft AP with an electric motor torque defined by an electrical torque setpoint (for example, determined by the CS supervisory control unit), here for the drive wheels of vehicle V. The electric motor ME therefore provides the electric motor torque it produces for the T1 train and / or for the MMT internal combustion engine. However, in one variant, this first train T1 could be the second train T2, located in the rear PRV section of vehicle V, and in another four-wheel-drive variant, the electric motor torque could be transmitted to both the first T1 and second T2 trains.

[0052] It should also be noted that the electric machine ME can also be configured here to recover a setpoint torque from the vehicle V, for example during regenerative braking. In this case, the recovered torque can be used to recharge the power battery BP associated with the electric machine ME. However, recovery can also be performed on a portion of the internal combustion engine torque supplied by the internal combustion engine MMT.

[0053] The operation of the ME electric machine is controlled by an electrical machine computer CME, and supervised by the CS supervisory computer.

[0054] As illustrated in Figure 1, the ME electric machine is equipped with a temperature sensor CT arranged to measure its internal temperature at time t ti(t), for example, periodically. This makes it possible to determine the internal temperature ti(t) of the rotor magnets of the ME electric machine.

[0055] Note that in the example illustrated (but not limited to) in Figure 1, the differential DV is not part of the gearbox BV. However, in an alternative embodiment, it could be part of this gearbox BV.

[0056] For example, the power battery (or main or traction battery) can be of the cellular type. In this case, it comprises electrical energy storage cells, possibly electrochemical (such as lithium-ion (Li-ion), Ni-MH, or Ni-Cd cells). This power battery can also be, for example, a 48V type. However, this is not mandatory. It could also be a 450V, 600V, or 800V type, for example.

[0057] As mentioned above, the gearbox is automated. For example, it can be a dual-clutch transmission (or DCT). But it could also have only one clutch connected to a single input shaft. This gearbox has several (at least two) gear ratios, designated n, with n = 1 to N (ratio 1 being the lowest and ratio N being the highest). For example, N could be between 5 and 9.

[0058] The operation of the BV gearbox is controlled by a CB gearbox computer, and supervised by the CS supervision computer.

[0059] As illustrated, but not limited to, in Figure 1, vehicle V also includes an accelerator pedal PA that can be operated (here) by the driver's foot, and has a percentage of depressment from which a torque setpoint is defined. global, which is then representative of the driver's intention regarding the acceleration of the vehicle V. This global torque command can, for example, be determined by the CS supervision computer, and the GMP must provide the drive wheels (here of the front axle T1) with an engine torque which must correspond (with a certain tolerance) to this global torque command.

[0060] As mentioned above, the invention notably proposes a control method intended to allow control of the rotational speed rr(t) of the electric machine ME of the vehicle V.

[0061] This control method can be implemented at least partially by the DC3 control device (illustrated at least partially in Figures 1 and 2), which comprises at least one PR1 processor, for example, a microprocessor, and at least one first MD1 memory. This DC3 control device can therefore be implemented as a combination of electrical or electronic circuits or components (or "hardware") and software modules. For example, it could be a microcontroller.

[0062] The MD1 memory is RAM-based in order to store instructions for the PR1 processor to implement at least part of the control process. The PR1 processor may include integrated circuits (or printed circuit boards), or several integrated circuits (or printed circuit boards) connected by wired or wireless connections. An integrated circuit (or printed circuit board) is defined as any type of device capable of performing at least one electrical or electronic operation.

[0063] In the example illustrated (but not limited to) in Figures 1 and 2, the DC3 control unit is part of the CS supervisory control unit. However, this is not mandatory. The DC3 control unit could have its own dedicated control unit, which could then be coupled to the CS supervisory control unit, or it could be part of another control unit embedded in the vehicle (V and) ensuring at least one other function, such as for example the CME electrical machine calculator.

[0064] As illustrated non-limitingly in Figure 3, the (control) method according to the invention includes a step 10-40 which is implemented each time the thermal engine MMT provides thermal engine torque to the primary shaft AP by means of placing the first coupling device DC1 in a state at least partially closed and the electric machine ME generates electrical power pe, for example to supply the on-board network RB and / or recharge the power battery BP.

[0065] Step 10-40 of the process includes a substep 10 in which one (for example, the control device DC3) begins by determining, at time t, the future internal temperature fti(t+dc) of the electrical machine ME for a chosen duration starting at that time t, given the current rotational speed rr(t) and the current internal temperature ti(t) of the electrical machine ME. It should be noted that the current internal temperature ti(t) is measured by the temperature sensor CT and the current rotational speed rr(t) is measured by a dedicated sensor.

[0066] Step 10-40 of the process also includes a substep 20 in which the electrical power pepg that can be generated by the electrical machine ME in the presence of the future internal temperature fti(t+dc) is determined (for example the control device DC3).

[0067] Step 10-40 of the process also includes a substep 40 in which, when the determined electrical power pepg is less than a chosen threshold sc, and therefore on (for example, the control device DC3), a change of the current ratio n in the gearbox BV is required to be made to a ratio (n+1) greater than the current ratio (n). This is because there is considered a risk of a problem with the generation of electrical power by the electric machine ME. This request can be addressed to the CS supervisory computer or the CB gearbox computer.

[0068] It will be understood that by establishing a ratio n+1 higher than the current ratio n, this induces a significant decrease in the current rotational speed rr(t) of the primary shaft AP and therefore also of the electric machine ME. This significantly limits the increase in the current internal temperature ti(t) and thus significantly limits the loss of electrical power generation capacity of the electric machine ME. Consequently, the probability that the electrical power generated by the electric machine ME will be insufficient to supply the onboard network RB is very low, or even zero. The invention is therefore particularly advantageous because it avoids the need to dope each magnet of the electric machine ME's rotor with a mass of dysprosium, which is particularly economical.

[0069] For example, and as illustrated (non-limitingly) in Figure 3, step 10-40 of the process can also include a substep 30 in which the electrical power pepg, determined in substep 20, can be compared to the chosen threshold sc. If the determined electrical power pepg is less than the chosen threshold sc (i.e., pepg < sc), there is a risk of insufficient electrical power generation by the electric machine ME, and substep 40 is performed. Conversely, if the determined electrical power pepg is greater than or equal to the chosen threshold sc (i.e., pepg > sc), there is no risk of insufficient electrical power generation by the electric machine ME, and substep 10 is performed again with the following rotational speed rr(t+1) and the following internal temperature ti(t+1) of the electric machine ME.

[0070] Also, for example, in substep 10 of step 10-40, one (for example, the DC3 control device) can use a chosen duration of which is between five seconds and fifteen seconds.

[0071] As an illustrative example, this chosen duration could be ten seconds. However, other values ​​for the chosen duration could be used. For example, this duration could be chosen during the development or testing phase of a vehicle similar to vehicle V.

[0072] For example, in substep 10 of step 10-40, one (for example, the DC3 control device) can determine the future internal temperature fti(t+dc) in a first lookup table that establishes a correspondence between pairs of current rotation speed and internal temperature and future internal temperatures. It is understood that it suffices to determine in this first lookup table the future internal temperature fti(t+dc) which is stored corresponding to the pair comprising the current rotation speed rr(t) and the current internal temperature ti(t).

[0073] But in one variant (for example the DC3 control device) the future internal temperature fti(t+dc) could be determined by means of at least one mathematical formula having as parameters the current rotation regime rr(t) and the current internal temperature ti(t).

[0074] For example, in substep 10 of step 10-40, one (for example, the DC3 control device) can determine the electrical power that can be generated pepg in a second lookup table that establishes a correspondence between internal temperatures and electrical powers. It will be understood that it suffices to determine in this second lookup table the electrical power that can be generated pepg, which is stored in relation to the future internal temperature fti(t+dc).

[0075] But in one variant (for example the DC3 control device) the electrical power that can be generated pepg could be determined by means of at least one mathematical formula having as a parameter the future internal temperature fti(t+dc).

[0076] For example, when the onboard network RB (to which electrical equipment consuming power at the predefined extra-low voltage tbt is coupled) is connected, in substep 30 of step 10-40, a chosen threshold sc (for example, the control device DC3) can be used. This threshold represents the electrical power required to supply a chosen voltage te that is greater than or equal to this predefined extra-low voltage tbt. Thus, it can be guaranteed that the electrical power generated by the electric machine ME will be sufficient to supply at least the onboard network RB.

[0077] For example, in substep 30 of step 10-40, the selected voltage te, which is used to set the selected threshold sc, can be between 100% of the predefined extra-low voltage tbt and 120% of the predefined extra-low voltage tbt. It is understood that the higher the selected voltage te is compared to the predefined extra-low voltage tbt, the more guaranteed it is that the electrical power generated by the electric machine ME will be sufficient to supply at least the onboard network RB.

[0078] As an illustrative example, the chosen voltage (te) can be equal to 105% of the predefined extra-low voltage (tbt). However, other values ​​for the chosen voltage (te) can be used. For example, this voltage (te) can be chosen during the development or testing phase of a vehicle similar to vehicle V.

[0079] It should also be noted, as illustrated (but not limited to) in Figure 2, that the CS supervisory computer (or the dedicated computer of the DC3 control device) may also include a MEM mass storage device, notably to store each current rotation speed rr(t) and each current internal temperature ti(t), as well as any intermediate data involved in all its calculations and processing. Furthermore, this CS supervisory computer (or the dedicated computer of the DC3 control device) may also include an IE input interface for receiving at least each current rotation speed rr(t) and each current internal temperature ti(t), for use in calculations or processing. possibly after having shaped and / or demodulated and / or amplified them, in a way known per se, by means of a PR2 digital signal processor. In addition, this CS supervisory computer (or the dedicated computer of the DC3 control device) may also include an IS output interface, in particular to deliver each (n — n+1) ratio change message (or command).

[0080] It should also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the type electronic circuits (or hardware), such as for example the PR1 processor, is suitable for implementing the control method described above to control the rotation rate rr(t) of the electric machine ME of the vehicle V.

Claims

1. CLAIMS 2.

1. A control method for a vehicle (V) comprising a thermal engine (MHE) adapted to drive in rotation a primary shaft (P) of a gearbox (GV) having several ratios, and an electric machine (EM) coupled to said primary shaft (PHE) and adapted to generate electrical power when driven by the latter (PHE) according to a rotational regime, characterized in that it comprises a step (10-40) in which a future internal temperature of said electric machine (EM) is determined at a time t for a chosen duration starting at said time t in the presence of the current rotational regime and a current internal temperature of said electric machine (EM), and then an electrical power that can be generated by the latter (EM) in the presence of this determined future internal temperature,and if this determined electrical power is less than a chosen threshold, a change from the current ratio to a ratio greater than that threshold is required.

3.

2. Method according to claim 1, characterized in that in said step (10-40) said chosen duration is between five seconds and fifteen seconds.

4.

3. Method according to claim 1 or 2, characterized in that in said step (10-40) said future internal temperature is determined in a first table establishing a correspondence between pairs of rotation regime and current internal temperature and future internal temperatures.

5.

4. A method according to any one of claims 1 to 3, characterized in that in said step (10-40) said electrical power that can be generated is determined in a second table establishing a correspondence between internal temperatures and electrical powers.

6.

5. A method according to any one of claims 1 to 4, characterized in that in said step (10-40), in the presence of an electrical supply network (RB) equipping said vehicle (V) and to which are coupled electrical equipment of the latter (V) consuming electrical energy at a predefined very low voltage, said chosen threshold is an electrical power capable of supplying a chosen voltage greater than or equal to said predefined very low voltage.

7.

6. Method according to claim 5, characterized in that in said step (10-40) said selected voltage is between 100% of said predefined very low voltage and 120% of said predefined very low voltage.

8.

7. Product computer program comprising a set of instructions which, when executed by processing means, is suitable for implementing the control method according to any one of claims 1 to 6, in a vehicle (V) comprising a thermal engine (MHE) suitable for rotating a primary shaft (P) of a gearbox (GV) having several ratios, and an electric machine (EM) coupled to said primary shaft (P) and suitable for generating electrical power when driven by the latter (P) according to a rotational regime, for controlling said rotational regime of the electric machine (EM).

9.

8. Control device (DC3) suitable for equipping a vehicle (V) comprising a thermal engine (MMT) suitable for rotating a primary shaft (AP) of a gearbox (BV) having several ratios, and an electric machine (ME) coupled to said primary shaft (AP) and suitable for generating electrical power when driven by the latter (AP) according to a rotational regime, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to perform the operations of determining at a time t what will be a future internal temperature of said electric machine (ME) for a chosen duration starting at said time t in the presence of the current rotational regime and a current internal temperature of said electric machine (ME), then an electrical power that can be generated by the latter (ME) in the presence of this determined future internal temperature,and if this determined electrical power is less than a chosen threshold, requiring a change from the current ratio to a ratio higher than that threshold.

10.

9. Vehicle (V) comprising a thermal motive machine (MMT) adapted to drive in rotation a primary shaft (AP) of a gearbox (BV) having several ratios, and an electric machine (ME) coupled to said primary shaft (AP) and adapted to generate electrical power when driven by the latter (AP) according to a rotation regime, characterized in that it further comprises a control device (DC3) according to claim 8.

11.

10. Vehicle according to claim 9, characterized in that said electric machine (ME) is capable of driving said primary shaft (AP) of the gearbox (BV) in rotation when it is supplied with electrical energy by a power battery (BP) of said vehicle (V).

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