METHOD FOR CONTROLLING AN ELECTRICAL POWER SUPPLY TO ACCESSORIES IN AN ELECTRIC VEHICLE

Abstract

The invention relates to a method for controlling the power supply of accessories in an electric vehicle comprising a main battery, a voltage converter, and an auxiliary battery connected to the vehicle's 12-volt network. The method comprises: - activation of a control device by a user, and establishment of an electrical contact state on the 12-volt network, characterized in that the method provides for: - evaluating the amount of energy remaining in the main battery, - if the amount of energy remaining is greater than a predetermined energy threshold, activating the voltage converter for a first time delay (DT1), - if the amount of energy remaining is less than the predetermined energy threshold, initiating a second time delay (DT2), and leaving the voltage converter inactive. Figure 2

Description

Title of the invention: METHOD FOR CONTROLLING AN ELECTRICAL POWER SUPPLY ACCESSORIES IN AN ELECTRIC VEHICLE

[0001] The invention relates to a method for controlling the power supply to accessories in an electric or hybrid vehicle. More specifically, the invention relates to the situation of such a vehicle at rest, not moving but with the electrical connection established, so as to allow the use of certain accessory equipment such as the multimedia system (including the car radio) or the interior lighting of the passenger compartment.

[0002] Accessory equipment such as the multimedia system (including the car radio) or the interior lighting of the passenger compartment are electrically powered from the vehicle's low voltage network, i.e. the 12-volt network to which a 12-volt nominal voltage battery is connected.

[0003] Furthermore, the main electrical energy storage component in this type of vehicle is the traction battery. The traction battery is capable of enabling the vehicle to move in pure electric mode, that is, in zero-emission mode. This traction battery is referred to here as a "high-voltage" battery, as opposed to a 12-volt battery. The term "high voltage" here covers voltages from 48 volts up to more than 400 volts.

[0004] The traction battery can have an electrical energy storage capacity of between 1.5 kWh for hybrid vehicles and several tens of kilowatt-hours for long-range electric vehicles.

[0005] In an electric or hybrid vehicle, a voltage converter is provided to supply the 12-volt battery from the traction battery. Furthermore, in a hybrid vehicle, the traction battery is recharged by an alternator when it is operating.

[0006] The use of certain accessory equipment consumes electrical energy. The 12-volt battery is not sized to provide sufficient power to the accessory equipment for a duration meeting user needs. Less than 50 Ah, therefore less than 600 Wh.

[0007] When the electric motor is not activated for vehicle operation, generally the voltage converter is not functioning, and the 12-volt battery cannot be supported by the traction battery via the voltage converter.

[0008] In the context described above, the inventors sought to propose a solution to provide a satisfactory user experience, particularly for the use of certain accessories, while not risking excessively discharging either of the batteries on board the vehicle.

[0009] To this end, the present invention proposes a method for controlling the power supply of accessories in an electric or hybrid vehicle comprising an electric motor unit, a main battery, a voltage converter and an auxiliary battery connected to a 12 Volt network of the vehicle, the method comprising: - activation of a control device by a user, and establishment of an electrical contact state on the 12 Volt network, characterized in that the method provides for: - assess the amount of energy remaining in the main battery, - if the amount of remaining energy is greater than a predetermined energy threshold, put the voltage converter into service for a first time delay, - if the amount of remaining energy is less than the predetermined energy threshold, start a second time delay, and leave the voltage converter inactive.

[0010] Thanks to the provisions described above, the auxiliary battery is not discharged if it is not being charged by the voltage converter. Excessive discharge of the main battery due to the power supply of accessories is also prevented. Nevertheless, the user can operate the desired accessories and equipment for a substantially long period.

[0011] The term "12 Volt vehicle network" should be interpreted as the nominal voltage 12 volt network, the voltage of which is generally between 11.5 Volt and 14 Volt depending on various operating parameters and in particular the use of a recharge from the main battery via the voltage converter.

[0012] The term "control element" refers on the one hand to the conventional ignition key of the vehicle which the user turns in the ignition switch and on the other hand to a push button ('push button' or 'start-stop engine' button) which is the equivalent of the key in traditional keyless ignition start configurations.

[0013] It is noted that in the configuration with a "start-stop" push button, in order to obtain the established contact state without starting the vehicle's electro-motor unit, the user must press the "start-stop" push button without simultaneously pressing the vehicle's brake pedal.

[0014] According to one embodiment, the first time delay is significantly longer than the second time delay.

[0015] The electrical energy storage capacity of the main battery is much greater than that of the auxiliary battery; therefore, a larger value is chosen. for the first time delay without risking lowering the state of charge of the main battery too much.

[0016] Thanks to a smaller value for the second time delay, it is avoided to discharge the auxiliary battery too much.

[0017] According to one embodiment, the power supply of accessories includes at least one power switch which supplies accessory equipment of interest, the method being characterized in that the power switch is activated in the on state as long as one of the first or second time intervals elapses and has not expired or as long as the electromotor set is started.

[0018] In other words, the power supply to the accessories of interest is cut off as soon as one (or both) of the two timers have reached their end.

[0019] Consequently, multimedia and interior lighting equipment, as well as accessory sockets, e.g., the cigarette lighter socket and USB charging ports, are no longer powered after the timers have expired. It follows that from this point onward, the current drawn from the auxiliary battery becomes negligible.

[0020] According to one embodiment, it is provided that if, while the first time period is running out, the voltage converter happens to be deactivated before the end of the first time period, then the second time period is started at that moment.

[0021] The power supply to the accessories of interest is thus extended for one hour even after the voltage converter is switched off to allow the occupants to continue to use the equipment of interest.

[0022] According to one embodiment, it is provided that if, during the second time period, the voltage converter happens to be activated, then the voltage converter is kept in operation on the basis of the first time period counted from the establishment of the electrical contact state (i.e., the contact being made).

[0023] Thus, the long time delay mode is reactivated if the converter is activated while the second, short time delay is running.

[0024] According to an optional embodiment in addition to the previous one, it is provided that if the first timeout has expired, the second timeout is reset and restarted.

[0025] Thus, after the expiry of the first time period, the logic cleverly switches back to managing the second time period.

[0026] According to one embodiment, the electric vehicle includes an electromotor unit, and the method provides that if the electromotor unit is started, then the first and second time delays are inhibited.

[0027] Starting up the electric motor and, a fortiori, driving the vehicle implies that the electrical contact is continuously established until the user has voluntarily stopped the electric motor.

[0028] According to one embodiment, the action of putting the voltage converter into service is preceded by the energizing of the main battery, with closure of the isolation relays.

[0029] According to one embodiment, the first time delay is configurable or calibrable. In a particular example, a value of approximately 4 hours is chosen for the first time delay.

[0030] The term "calibrable" here means that the calibrable value is deduced from a one-dimensional or multi-dimensional calibration table of parameters.

[0031] According to one embodiment, the second time delay is configurable or calibrable. According to a particular example, a value of the order of Ih is chosen for the second time delay.

[0032] According to one embodiment, the predetermined energy threshold is parameterizable or calibrable.

[0033] The same logic can thus be used with different parameters according to the different technical platforms of vehicles and the respective capacities of the main and auxiliary batteries.

[0034] The invention further relates to an electrical distribution system in an electric or hybrid vehicle, the electrical distribution system comprising an accessory power supply selectively controlled by a general computer, the electrical distribution system comprising a main battery, a voltage converter and an auxiliary battery, the electrical distribution system being characterized in that the general computer is configured to implement the method as described above.

[0035] The invention further relates to an electric or hybrid vehicle comprising at least one electrical distribution system as described above.

[0036] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: [Fig.1] illustrates, in schematic view, an example of an electrical distribution system in a vehicle, in which the present invention is implemented; [Fig.2] shows a chronogram illustrating a first feeding sequence according to a first scenario; [Fig.3] shows a chronogram illustrating a second feeding sequence according to a second scenario; [Fig.4] shows a chronogram illustrating a third feeding sequence according to a third scenario; [Fig.5] shows a chronogram illustrating a fourth feeding sequence according to a fourth scenario; [Fig.6] shows a chronogram illustrating a fifth feeding sequence according to a fifth scenario.

[0037] In the various figures, the same reference numerals designate identical or similar elements. For the sake of clarity, some elements are not necessarily shown to scale.

[0038] Figure [1] illustrates an electrical distribution system in an electric vehicle.

[0039] Herein, the term electric vehicle means a vehicle equipped with an electric drivetrain capable of moving the vehicle in zero-emission mode.

[0040] Thus, in the context of this document, the term electric vehicle encompasses hybrid vehicles comprising an electric drivetrain and an internal combustion engine.

[0041] The vehicle includes a main battery, designated 1. This main battery is also referred to in technical terms as the 'battery pack'. This component is considered to be known in itself and therefore not described in detail here.

[0042] The main battery includes a battery management computer 15, also known in practical terms as a 'BMS' (Battery Management System), which is associated with isolation contacts, namely one isolation contactor on each of the main positive and negative lines. An isolation relay can thus be found on each of the lines (positive and negative) that connect the main battery 1 to the HVN high-voltage on-board network.

[0043] The main battery supplies at least one traction motor via a 4L power inverter. The traction motor is included in a group called the electromotor group, denoted 4, which may optionally contain other components besides the traction motor (e.g., internal combustion engine, reducer, rear axle electric motor).

[0044] In a 100% electric vehicle and in a plug-in hybrid vehicle, the main battery can be recharged from a terminal outside the vehicle via equipment called an on-board charger, assumed to be known per se, and therefore not described in detail here.

[0045] The HVN high voltage network is connected to the main battery 1 and the on-board charger.

[0046] In addition, a voltage converter 2 is provided to supply the 12-volt battery from the traction battery. Such a voltage converter 2 is known per se and is therefore described in detail here. The voltage converter can be integrated into the on-board charger.

[0047] Furthermore, in a hybrid vehicle, the traction battery 1 is recharged by an alternator when the latter is operating. In other cases, the traction battery 1 is recharged by means of equipment external to the vehicle, as is well known.

[0048] Furthermore, the vehicle includes a 12-volt battery, designated 3, and a vehicle low-voltage network, designated LVN. The 12-volt battery 3 is connected to the low-voltage network LVN.

[0049] We are considering here certain equipment available in the vehicle which the occupants can benefit from.

[0050] Among these features of interest are accessory equipment such as the multimedia system (including the car radio that receives broadcast radio programs), which is very useful to the vehicle's occupants and to the driver when the vehicle is parked. Occupants can listen to music or radio broadcasts, or watch videos.

[0051] This equipment also includes interior lighting for the passenger compartment, which the occupants in the vehicle may need.

[0052] This equipment also includes accessory sockets, such as the cigarette lighter socket and USB charging sockets for charging mobile phones or other portable devices of the vehicle's occupants.

[0053] The aforementioned equipment is electrically powered from the 12-volt low-voltage network, which is powered only by the 12-volt battery when the voltage converter is inactive.

[0054] The aforementioned equipment is collectively identified by 8 in the figures.

[0055] One or more power switches 7 are provided, which can be in an ON or OFF state, to power the aforementioned auxiliary equipment. When the power switch(es) 7 are ON, the auxiliary equipment is powered; it may or may not be in actual operation depending on the actions of the vehicle occupants. Conversely, when the power switch(es) 7 are OFF, the auxiliary equipment is not powered and is switched off.

[0056] A mobility computer 5 is provided in charge of managing the electromotor group 4 and the traction battery.

[0057] A general computer 6 is planned, responsible in particular for the passenger compartment functions and especially for managing the power supplies of the accessory equipment of interest in this document.

[0058] The user has a control device to start the vehicle. More specifically, the control device allows either the electrical circuits to be energized in a state called "established electrical contact," or to be switched off. voltage the electromotor unit which then becomes ready to drive the vehicle in motion, in particular in response to an action on the accelerator pedal.

[0059] In a long-known traditional version, the control element is formed by an ignition key which is inserted into an ignition / starter switch, this being represented by reference numeral 9' primes in [Fig. 1]. As illustrated, in this configuration there are at least three positions: the off position marked OFF, the 'ignition' position marked APC and the engine start position marked DEM.

[0060] According to a more modern version, the control unit is formed by a push button 9 (button indicated by an international marking 'start-stop engine') which is the equivalent of the key in traditional keyless ignition start configurations.

[0061] When the driver / user presses the push button without pressing the brake pedal, the electrical distribution system is in the "contact made" configuration, without the electric motor being activated. Conversely, when the driver / user presses the push button while simultaneously pressing the brake pedal, the electric motor is activated and ready to drive the vehicle. It should be noted that this state of movement implies that the electrical contact is established.

[0062] The start stop push button 9 actuates an electrical contactor 91 which delivers information to the main control unit 6.

[0063] The brake pedal 19 actuates an electrical contactor 92 which delivers information to the main computer 6.

[0064] Expressed in general terms, the proposed method first involves an activation of a control element 9,9' by a user / driver, and the establishment of an electrical contact state on the 12 Volt network.

[0065] The proposed method then involves evaluating the amount of energy remaining in the main battery 1. This information is usually managed by the battery management computer 15, which continuously calculates a current state of charge of the battery. The amount of energy remaining can be deduced from the discharge of the current state of charge of the main battery 1.

[0066] If the amount of energy remaining in the main battery 1 is greater than a predetermined energy threshold (case UC1), the voltage converter is put into service for a first time delay DTI.

[0067] The commissioning of the voltage converter 2 can be done according to various configurations, either by the mobility computer 5, or by the general computer 6.

[0068] If the amount of energy remaining in the main battery 1 is less than the aforementioned predetermined energy threshold, then the process starts a second time delay DT2, and the voltage converter is left inactive.

[0069] Optionally, it is provided that the predetermined energy threshold in question is configurable or calibrable.

[0070] The term "calibrable" means in this document that the calibrable value is deduced from a one-dimensional calibration table or a multi-dimensional, i.e., multi-parameter table.

[0071] Moreover, the first DTI time delay is significantly longer than the second DT2 time delay.

[0072] Advantageously, the first DTI time delay is configurable or calibrable. According to a particular example, a value of approximately 4 hours is chosen for the first time delay.

[0073] Advantageously, the second time delay DT2 is configurable or calibrable. According to a particular example, a value of the order of Ih is chosen for the second time delay.

[0074] In Figures 2 to 6, the line labeled S9 represents the user's action on the push button 9. The line labeled DTI represents the status of the first time delay DTI. The line labeled DT2 represents the status of the second time delay DT2. The line labeled S2 represents the activation status of the voltage converter 2. The line labeled S7 represents the status of the power switch(es) 7. The line labeled S19 represents the user's action on the brake pedal 19.

[0075] Fig. 2 illustrates a first identified user case UC1, where the amount of energy remaining in the main battery 1 is greater than the predetermined energy threshold.

[0076] The user presses the push button between times ta and tb, illustrated by signal S9.

[0077] The main computer 6 exchanges information with the mobility computer 5, which provides it with an assessment of the amount of energy remaining in the main battery. In the scenario shown, this assessed amount of remaining energy is greater than a predetermined energy threshold.

[0078] At time tb, the first DTI timer is launched.

[0079] At time tb, the voltage converter 2 is activated and the power switch 7 is activated, and the occupants of the vehicle can freely use the auxiliary equipment of interest discussed above.

[0080] At time tf, the first DTI timeout ends, i.e. expires.

[0081] At time tf, the voltage converter 2 is deactivated and the power switch 7 is cut off, and the power consumption drops drastically.

[0082] It is noted that in the case UC1 of [Fig.2], the second time delay DT2 does not occur.

[0083] Fig. 3 illustrates a second user case identified as UC2, where the amount of energy remaining in the main battery 1 is less than the predetermined energy threshold.

[0084] As in the previous case, the user presses the push button between times ta and tb, illustrated by the signal S9, and the mobility computer 5 transmits to the general computer 6 an evaluation of the amount of energy remaining in the main battery, which in this case turns out to be less than the predetermined energy threshold.

[0085] At time tb, the first DTI timer is started, and the second DT2 timer is started.

[0086] At time tb, the voltage converter 2 is not activated.

[0087] At time tb, the power switch 7 is activated. Thus, the occupants of the vehicles can use the auxiliary equipment of interest discussed above.

[0088] At time te, the second time delay DT2 ends, i.e. comes to an end.

[0089] At time te, the power switch 7 is switched off and the consumption electrical power drops drastically.

[0090] Figure 4 illustrates another use case.

[0091] As in the previous case, the user presses the push button between times ta and tb, illustrated by the signal S9, and the mobility computer 5 transmits to the general computer 6 an evaluation of the amount of energy remaining in the main battery, which in this case turns out to be greater than the predetermined energy threshold.

[0092] At time tb, the first DTI timer is launched.

[0093] Furthermore, at time tb, the voltage converter 2 is activated and the power switch 7 is activated.

[0094] It happens that at time te, the voltage converter 2 happens to be deactivated, for a reason which may be for example the thermal protection of the latter, but which may also be of another nature.

[0095] The method provides that in this case a second timer DT2 is started at time te. The voltage converter 2 remains activated and the power supply switch 7 remains activated.

[0096] At time td, the second time delay DT2 ends, i.e., expires. The voltage converter 2 is then deactivated and the power supply switch 7 is then deactivated.

[0097] In this case, the expiry of the first DTI time delay at time tf produces no effect.

[0098] In another scenario not shown, it may happen that the second time delay DT2 must end after the expiry of the first one time delay. In this case, it is the expiry of the first DTI time delay that causes the power switches 7 to be cut off.

[0099] Fig. 5 illustrates another use case.

[0100] The sequence begins exactly like that of [Fig. 3] with the activation of the second timer DT2 and the voltage converter 2 not activated. The sequence continues at time te with the activation of the voltage converter. This scenario may correspond to the fact that the voltage converter was in thermal protection mode when the contact tb was made and becomes available a few minutes or tens of minutes later.

[0101] When the voltage converter starts up, the mobility control unit 5 and / or the main control unit 6 are informed of this change, and the logic switches to the long delay case; that is, the first DTI delay takes over and keeps the voltage converter in operation and the accessory power switches 7 activated. It should be noted that the first delay begins from the moment the ignition is switched on, and not from the moment the voltage converter is switched on.

[0102] At time tf, the first DTI timer ends, i.e., expires. At time tf, the voltage converter 2 is deactivated and the power switch 7 is switched off, and the power consumption drops drastically.

[0103] In addition, it may be provided that if the voltage converter 2 happens to be deactivated again, then the second timer is restarted to extend the supply for a period of one hour for example.

[0104] It can be provided that, in all cases, at the expiry of the first DTI time delay since the contact was made (instant tb), the voltage converter as well as the accessory supply contactor 7 are cut off.

[0105] According to an alternative logic, the extension generated by the second time delay can exceed that of the first time delay.

[0106] Fig. 6 illustrates another use case.

[0107] The scenario here begins like the previous ones, we have symbolized here the two main cases, by the launch of the first timer DTI and the launch of the second timer DT2 at the moment of the tb contact being put on.

[0108] At time te, the driver presses the push button 9 and simultaneously the brake pedal 19; the impulse on the brake pedal is illustrated by the signal S19 in [Fig. 6]. This causes the electric traction machine to start up, i.e., the electromotor unit 4 ('GEM ON') to start up, which is then ready to impart movement to the vehicle in response to an action on the accelerator pedal by the driver.

[0109] In a conventional ignition key configuration, the equivalent is actuation of the DEM position of the ignition switch. In a hybrid vehicle configuration, this can generate the starting of the internal combustion engine.

[0110] Thus, the method provides that if the electromotor unit is started, then the first and second time delays are inhibited. The time delays may be used again after the motor is switched off and the electrical contact is possibly restored.

[0111] Furthermore, in order to put the voltage converter into service, the main battery must be connected to the high voltage network.

[0112] If the isolation contactors are not already closed, the commissioning of the voltage converter is preceded by the procedure for closing the isolation relays / contactors, this procedure with pre-charge is assumed to be known and therefore not described here.

[0113] It is noted that the proposed logic does not take into account the state of charge of the auxiliary battery.

[0114] Furthermore, a typical use case for these timers corresponds to the configuration where the vehicle driver is parked and waiting for an event such as the arrival of a third party, or some other type of event. This wait can last from a few minutes to several tens of minutes or even a few hours.

[0115] Another case corresponds to a vehicle occupant who remains on board the vehicle while the driver has gone to run an errand.

Claims

Demands

1. A method for controlling an accessory power supply in an electric vehicle comprising an electromotor unit (4), a main battery (1), a voltage converter (2) and an auxiliary battery (3) connected to a 12 Volt network of the vehicle, the method comprising: - activation of a control element (9) by a user, and establishment of an electrical contact state on the 12 Volt network, characterized in that the method provides for: - evaluating the amount of energy remaining in the main battery, - if the amount of energy remaining is greater than a predetermined energy threshold, putting the voltage converter into operation for a first time delay (DTI), - if the amount of energy remaining is less than the predetermined energy threshold, starting a second time delay (DT2), and leaving the voltage converter inactive.

2. A method according to claim 1, wherein the accessory power supply comprises at least one power switch (7) which supplies accessory equipment of interest (8), the method being characterized in that the power switch (7) is activated in the on state as long as one of the first or second time delays (DTI, DT2) elapses and has not expired or as long as the electromotor set is started.

3. A method according to any one of claims 1 to 2, characterized in that if, while the first time delay (DTI) is running out, the voltage converter happens to be deactivated before the end of the first time delay, then the second time delay (DT2) is started at that instant.

4. A method according to any one of claims 1 to 2, characterized in that if, while the second time delay (DT2) is elapsed, the voltage converter happens to be activated, then the voltage converter is kept in operation on the basis of the first time delay (DTI) counted from the establishment of the electrical contact state.

5. Method according to claim 4, characterized in that if the first time delay (DTI) has expired, the second time delay (DT2) is reset and restarted.

6. A method according to any one of claims 1 to 5, the electric vehicle comprising an electric motor unit, the method being characterized in that if the electric motor unit is started, then the first and second timings are inhibited.

7. A method according to any one of claims 1 to 6, characterized in that the action of putting the voltage converter (2) into service is preceded by the energizing of the main battery (1), with closure of the isolation relays.

8. A method according to any one of claims 1 to 7, characterized in that the first time delay (DTI) is parameterizable or calibrable, and / or characterized in that the second time delay (DT2) is parameterizable or calibrable.

9. Electrical distribution system in an electric or hybrid vehicle, the electrical distribution system comprising an accessory power supply (8) selectively controlled by a general control unit (6), the electrical distribution system comprising a main battery (1), a voltage converter (2) and an auxiliary battery (3), the electrical distribution system being characterized in that the general control unit is configured to implement the method according to any one of claims 1 to 8.

10. Electric or hybrid vehicle comprising at least one electrical distribution system according to claim 9.

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