Activation of batteries connected in parallel
Patent Information
- Application Number
- FR2022010919
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-10-21
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2042-10-21
Smart Images
Figure 00000016_0000
Abstract
Description
Title of the invention: Activation of batteries connected in parallel Technical field
[0001] The invention relates to the field of hybrid or electric vehicles, in particular 2-wheel vehicles, and more precisely to an electrical power supply system, a method of supplying a vehicle electrical network by the power supply system and a method of recharging the power supply system. Prior art
[0002] In a known manner, an electric or hybrid vehicle comprises a set of electrical power supply batteries, for example lithium-ion batteries, for supplying power to the vehicle's electrical network. The electrical network thus makes it possible to supply power to the vehicle's electrical equipment.
[0003] According to the example presented here, all batteries are independently connected to the electrical network. The batteries are connected in parallel.
[0004] It may happen that the batteries are not at the same state of charge, some batteries having been removed from the system to be charged and / or to be replaced by a battery having a different charge level. A problem thus persists in the case where several batteries are connected in parallel to the electrical network and their state of charge is different. This can create energy transfers from a more charged battery to a less charged battery, which can damage the batteries and the electrical circuits and components of the electrical equipment connected to the power network, such as for example the input capacitors or the connectors of the electrical equipment, which must then be replaced.
[0005] In order to remedy this problem, a switching device, commonly called a "switching box" by those skilled in the art, is added, connected on the one hand to each battery and on the other hand to the vehicle's electrical network. The switching box analyzes the charge states of each of the batteries to only connect batteries with compatible voltages and charge states.
[0006] More specifically, the switching device comprises a set of contactors, each contactor being connected between a battery and the vehicle's electrical network. Closing a contactor therefore makes it possible to connect the corresponding battery to the electrical network. Thus, the battery is connected to the network and supplies the electrical supply network. The expression used "activation of a battery" corresponds to the fact of connecting a battery to the electrical network, by closing the contactor. The switching device is therefore configured to activate or deactivate each battery so as to avoid connecting in parallel batteries whose state of charge is significantly different, and thus avoid energy transfers between batteries.
[0007] However, this type of switching device adds constraints regarding integration into the vehicle. In addition, this device must be powered by electrical energy. This also requires adding a power source for the switching device, as well as connectors and electrical power wires to connect the power source and the switching device.
[0008] There is therefore a need for a solution that can overcome, at least in part, the drawbacks described above. Statement of the invention
[0009] To this end, the invention relates to an electrical power supply system for a motor vehicle, the vehicle comprising an electrical power supply network, the power supply system comprising a plurality of batteries, each battery comprising: a. an electrical energy storage unit, b. a control unit, c. a switching device, connected on the one hand to the energy storage unit and intended to be connected on the other hand to the electrical power supply network of the vehicle, said switching device comprising: i. A first switch called a "load" switch, configured to: 1. In a so-called “closed” state, allow the energy storage unit to charge from the electrical energy supplied by the power supply network, 2. In a so-called “open” state, prevent current from moving from the supply network to the energy storage unit, ii. A second switch called a “discharge switch”, connected in series with the first switch and configured to: 1. In a so-called “closed” state, allow the energy storage unit to discharge and supply electrical energy to the electrical network, 2. In a so-called “open” state, prevent current from moving from the energy storage unit to the power supply network, the control unit being configured to control the charge switch and the discharge switch, each battery being configured to operate according to: a. an “activated” mode in which the charge and discharge switches are in the closed state, b. an “off” mode in which the charge and discharge switches are in the open state, i.e. a charging mode in which the charging switch is in the closed state and the discharging switch is in the open state, d. a discharge mode in which the charge switch is in the open state and the discharge switch is in the closed state.
[0010] Thus, the batteries are therefore connected in parallel with respect to the electrical supply network. Furthermore, when a battery operates in charge mode, it charges exclusively, and when a battery operates in discharge mode, it discharges exclusively. Thus, when several batteries operate simultaneously in charge mode, respectively in discharge mode, no transfer of current or energy can take place from one battery to another, thus preventing the batteries from being damaged and from wearing out prematurely. The charge mode and the discharge mode are used in particular in the so-called "transition" phase, that is to say: when determining which battery to connect to the vehicle's power supply network.
[0011] More preferably, to respond to the detection of the need to supply the electrical supply network from the power supply system as presented previously, the control unit of each battery is configured to activate the discharge mode of all the batteries. The need to supply the supply network occurs for example at the time the vehicle is switched on by the driver; it is then necessary to supply the network in order to supply the vehicle equipment.
[0012] Thus, the battery is therefore "intelligent", independent and autonomous, it is not necessary to add a global connection module to control all the batteries. It is thanks to this that the battery which has the highest state of charge will automatically supply the electrical supply network without risk of current leakage between the batteries.
[0013] More preferably, to respond to the detection of the need to supply electrical energy to the batteries, the control unit of each battery is configured to activate the charging mode of all the batteries.
[0014] Thus, since each battery is said to be “intelligent”, it is also thanks to this that the battery which has the lowest state of charge will automatically be supplied by the electrical supply network without risk of current leakage between the batteries.
[0015] According to a first embodiment, for each battery of the power supply system as presented previously: a. The charge switch includes a MOSFET transistor, b. The discharge switch includes a MOSFET transistor, c. The load switch and the discharge switch are connected so that: i. The source of the load switch is connected to that of the discharge switch, ii. The drain of the load switch is connected to the supply network, iii. The drain of the discharge switch is connected to the energy storage unit.
[0016] According to a second embodiment, for each battery of the power supply system as presented previously: a. The charge switch comprises a MOSFET transistor, b. The discharge switch comprises a MOSFET transistor, c. The charge switch and the discharge switch are connected so that: i. The source of the load switch is connected to that of the discharge switch, ii. The drain of the load switch is connected to the energy storage unit, iii. The drain of the discharge switch is connected to the supply network.
[0017] The type of switching module as presented above according to the first embodiment or according to the second embodiment is simple in itself and simple to integrate into a vehicle.
[0018] The invention also relates to a motor vehicle comprising an electrical power supply system as presented previously.
[0019] The invention also relates to a method for supplying a motor vehicle power supply network by an electrical power supply system as presented previously, said method comprising a step consisting of activating the discharge mode of all the batteries.
[0020] When several batteries are connected in parallel, the power supply method thus advantageously makes it possible to determine, among the batteries connected in parallel, the battery which has the highest state of charge and therefore becomes the battery which will automatically supply the electrical power supply network without risk of current leakage between the batteries connected in parallel.
[0021] More preferably, the power supply method presented above comprises, for each battery and to follow the activation of the discharge mode of all the batteries, the steps of: a. Measuring: i. the value of the discharge current, designating the current flowing from the battery to the supply network, ii. and / or the voltage of the supply network, iii. and / or the value of the internal voltage of the battery energy storage unit, b. Obtain: i. the value of the measured discharge current, ii. and / or the voltage of the supply network, iii. and / or the value of the internal voltage of the battery energy storage unit, c. Enable battery active mode if: i. the discharge current value is greater than a predefined discharge threshold, ii. or if the supply network voltage is lower than the internal voltage of the battery.
[0022] More preferably, the invention relates to a method for recharging a power supply system as presented previously, from the energy supplied by a motor vehicle power supply network, said method comprising a step consisting of activating the charging mode of all the batteries.
[0023] Thus, when several batteries are connected in parallel, the recharging method makes it possible to determine, among the batteries connected in parallel, the battery which has the lowest state of charge and which will therefore automatically be supplied by the electrical supply network without risk of current leakage between the batteries.
[0024] Advantageously, the recharging method as described above comprises, for each battery and to follow the activation of the charging mode of all the batteries, the steps consisting of: a. Measuring: i. the value of the charging current, designating the current flowing from the battery to the supply network, ii. and / or the voltage of the supply network, iii. and / or the value of the internal voltage of the battery energy storage unit, b. Obtain: i. the value of the measured charging current, ii. and / or the voltage of the supply network, iii. and / or the value of the internal voltage of the battery energy storage unit, c. Enable battery active mode if: i. the charging current value is greater than a predefined charging threshold, ii. or if the supply network voltage is higher than the internal voltage of the battery. Brief description of the drawings
[0025] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which:
[0026] [Fig-1] [Fig.l] is a schematic representation of a power supply system according to the invention. Description of the embodiments
[0027] With reference to [Fig.l], an embodiment of the power supply system according to the invention will now be presented, mounted in a vehicle, and in particular a two-wheeled vehicle. The power supply system here makes it possible to implement functions which can be used in the context of BMS, for “Battery Monitoring System” or “Battery Management System” in English.
[0028] The vehicle comprises an electrical power supply network 10, in particular making it possible to power the electrical equipment mounted in the vehicle.
[0029] Power supply system 1
[0030] The power supply system comprises N batteries B1, B2, ..., Bn, N being a positive integer greater than or equal to 2.
[0031] More precisely, each battery Bl, B2, Bn comprises: a. an electrical energy storage unit SI, S2, Sn, b. a switching device Cl, C2, Cn, connected on the one hand to the energy storage unit SI, S2, Sn and intended to be connected on the other hand to the electrical supply network of the vehicle, c. A precharge circuit Cprec connected in parallel with the switching device Cl, C2, Cn, d. a control unit U1, U2, UN.
[0032] switching device Cl, C2, Cn
[0033] Each switching device C1, C2, Cn comprises a first switch called “charge” switch I1 and a second switch called “discharge” switch I2, connected in series.
[0034] The charge switch II and the discharge switch each comprise a MOSFET transistor.
[0035] According to a first embodiment, the charge switch II and the discharge switch 12 are connected so that: a. The source of the load switch II is connected to that of the discharge switch 12, b. The drain of load switch II is connected to the supply network 10, c. The drain of the discharge switch 12 is connected to the energy storage unit SI, S2, Sn.
[0036] As a reminder, each MOSFET transistor comprises an intrinsic diode.
[0037] According to a second embodiment, the charge switch II and the discharge switch 12 are connected so that: a. The source of the load switch II is connected to that of the discharge switch 12, b. The drain of the load switch II is connected to the energy storage unit SI, S2, Sn, c. The drain of the discharge switch 12 is connected to the supply network 10.
[0038] More precisely, the first load switch II is configured to: a. According to a so-called “closed” state, allowing the energy storage unit SI, S2, Sn to charge from the electrical energy supplied by the power supply network 10, b. According to a so-called “open” state, prevent the current from moving from the power supply network 10 to the energy storage unit SI, S2, Sn.
[0039] Similarly, the second discharge switch 12 is configured to: a. In a so-called “closed” state, allowing the energy storage unit SI, S2, Sn to discharge and supply the electrical network 10 with electrical energy, b. In a so-called “open” state, preventing current from moving from the energy storage unit SI, S2, Sn to the power supply network 10.
[0040] Operating modes
[0041] Each battery Bl, B2, Bn is configured to operate according to at least the following 4 operating modes: a. an “activated” mode in which the load switch II and the discharge switch 12 are in the closed state, b. an “off” mode in which the charge switch II and the discharge switch 12 are in the open state, c. a charging mode in which the charging switch II is in the closed state and the discharging switch 12 is in the open state, d. a discharge mode in which the charge switch II is in the open state and the discharge switch 12 is in the closed state.
[0042] Measuring device
[0043] In addition, each battery B1, B2, BN comprises a device (not shown in the figures) for measuring the current i flowing between said battery B1, B2, Bn and the power supply network 10. For this purpose, the measuring device is in particular configured to measure the value of the current between said battery B1, B2, Bn and the power supply network 10 and / or between the switching device C1, C2, Cn and the energy storage unit S1, S2, Sn.
[0044] In the case where at least one battery Bl, B2, Bn supplies the power supply network 10, this means that the current flows from the at least one battery Bl, B2, Bn to the power supply network 10 in order to precharge the power supply network 10. In this case, the current measured by the measuring device corresponds to a discharge current Idecharge.
[0045] Conversely, in the case where at least one battery B1, B2, BN is powered by the power supply network 10, this means that the current flows from the power supply network 10 to the at least one battery B1, B2, BN. The current measured by the measuring device corresponds to a charging current Icharge.
[0046] Each battery B1, B2, BN, may also include a device for measuring the voltage in the energy storage unit SI, S2, SN.
[0047] Control unit Ul, U2, UN
[0048] The control unit Ul, U2, UN is configured to control the load switch II and the discharge switch 12.
[0049] In addition, the control unit Ul, U2, UN of each battery Bl, B2, Bn is configured to: a. detect the need to supply the power supply network 10 from the energy supplied by the at least one battery Bl, B2, BN, for example when the driver turns on the vehicle, b. when this detection is made, activate the discharge mode of all batteries Bl, B2, Bn, c. Obtain: i. the value of the measured discharge current, ii. and / or the voltage of the supply network, iii. and / or the value of the internal voltage of the energy storage unit SI, S2, SN of the battery, d. If: i. the value of the discharge current Idecharge is greater than a predefined discharge threshold, ii. or if the network voltage 10 is lower than the internal voltage of the battery Bl, B2, Bn, this means that battery Bl, B2, Bn can power the vehicle, the control unit Ul, U2, UN is therefore configured to control the closing of the charging switch II. In this way, the battery in turn supplies the power supply network 10. In other words, here, the control unit Ul, U2, UN activates the activated mode of the battery.
[0050] If the value of the discharge current is lower than the predefined discharge threshold, the battery remains in discharge mode to avoid recirculation, in other words a transfer, of energy from another battery connected to the power supply network 10.
[0051] In the case of a charger being connected to the electrical network 10, the control unit Ul, U2, UN of each battery Bl, B2, Bn is configured to: a. detect the need to connect the charger to at least one battery, so that it is recharged using the electrical energy supplied by the charger, b. when this detection is made, activate the charging mode of all the batteries Bl, B2, Bn, c. Obtain the: i. the value of the measured charging current Icharge, ii. and / or the voltage of the supply network 10, iii. and / or the value of the internal voltage of the energy storage unit SI, S2, Sn of the battery Bl, B2, Bn, d. If: i. the value of the charging current Icharge is greater than a predefined charging threshold, ii. or if the voltage of the supply network 10 is higher than the internal voltage of the battery Bl, B2, Bn, this means that the battery Bl, B2, Bn is the least charged, the control unit Ul, U2, UN is configured to control the closure of the discharge switch 12 so that the battery Bl, B2, Bn is charged. In other words, here, the control unit Ul, U2, UN activates the activated mode of the battery Bl, B2, Bn.
[0052] If the value of the charging current Icharge is lower than the predefined charging threshold, the battery Bl, B2, Bn remains in charging mode to avoid recirculation of energy to another battery Bl, B2, Bn. The control unit Ul, U2, UN does not send any command to the discharge switch.
[0053] The invention also relates to a method for recharging the batteries B1, B2, Bn from the power supply network 10, the method being implemented by the control unit U1, U2, UN.
[0054] The power supply system 1, the power supply method and the recharging method each make it possible to prevent and prevent energy transfers between different batteries B1, B2, Bn connected in parallel to a vehicle electrical power supply network 10.
Claims
Claims
1. Method for supplying an electrical power supply system (1) for a motor vehicle, the vehicle comprising an electrical power supply network (10), the power supply system (1) comprising a plurality of batteries (Bl, B2), each battery (Bl, B2) comprising: a. an electrical energy storage unit (SI, S2, Sn), b. a switching device (Cl, C2, Cn), connected on the one hand to the energy storage unit (SI, S2, Sn) and intended to be connected on the other hand to the electrical supply network (10) of the vehicle, said switching device (Cl, C2, Cn) comprising: i. A first switch (II) called “load”, configured to:
1. According to a so-called “closed” state, allowing the energy storage unit (SI, S2, Sn) to charge from the electrical energy supplied by the power supply network (10), 2. According to a so-called "open" state, prevent the current from moving from the supply network (10) to the energy storage unit (SI, S2), ii. A second switch called a “discharge” switch (12), connected in series with the first switch (II) and configured to:
1. According to a so-called “closed” state, allow the energy storage unit (SI, S2, Sn) to discharge and supply the electrical network (10) with electrical energy, 2. According to a so-called “open” state, prevent the current from moving from the energy storage unit (SI, S2) to the supply network (10), c. a control unit (U1, U2, UN), configured to control the load switch (II) and the discharge switch (12), Each battery (Bl, B2) being configured to operate according to: - an “activated” mode in which the charge (II) and discharge (12) switches are in the closed state, - a “deactivated” mode in which the charge (II) and discharge (12) switches are in the open state, - a charging mode in which the charging switch (II) is in the closed state and the discharging switch (12) is in the open state, - a discharging mode in which the charging switch (II) is in the open state and the discharging switch (12) is in the closed state, the method comprising the following steps: - activate the discharge mode of all batteries (Bl, B2, Bn), - following activation of the discharge mode of all batteries (B1, B2, Bn): a. measure: i. the value of the discharge current (Idecharge), designating the current flowing from the battery (Bl, B2, Bn) to the supply network (10), ii. and / or the voltage of the supply network (10), iii. and / or the value of the internal voltage of the energy storage unit (SI, S2, Sn) of the battery (Bl, B2, Bn), b. obtain: i. the value of the discharge current (Idecharge) measured, ii. and / or the voltage of the supply network (10), iii. and / or the value of the internal voltage of the energy storage unit (SI, S2, Sn) of the battery (Bl, B2, Bn), c. activate the battery activated mode (B 1, B2, Bn) if: i. the discharge current value (Idecharge) is higher than a predefined discharge threshold, ii. or if the voltage of the supply network (10) is lower than the internal voltage of the battery (Bl, B2, Bn).
2. Recharging method according to the preceding claim, comprising, for each battery (Bl, B2, Bn) and following activation of the charging mode of all the batteries (Bl, B2, Bn), the steps consisting of: a. activate the discharge mode of all batteries (Bl, B2, Bn), - following activation of the charging mode of all batteries (Bl, B2, Bn): - Measure:
1. the value of the charging current (Icharge), designating the current flowing from the supply network (10) to the battery (Bl, B2, Bn), 2. and / or the voltage of the supply network (10), 3. and / or the value of the internal voltage of the energy storage unit (SI, S2, Sn) of the battery (Bl, B2, Bn), - Get :
1. the value of the measured charging current (Icharge), 2. and / or the voltage of the supply network (10), 3. and / or the value of the internal voltage of the energy storage unit (SI, S2, Sn) of the battery (Bl, B2, Bn), - Activate battery active mode (B 1, B2, Bn) if:
1. the charging current value (Icharge) is greater than a predefined charging threshold, 2. or if the supply network voltage (10) is higher than the internal battery voltage (Bl, B2, Bn).
3. An electrical power supply system (1) for a motor vehicle, the vehicle comprising an electrical power supply network (10), the power supply system (1) comprising a plurality of batteries (B1, B2), each battery (Bl, B2) comprising: a. an electrical energy storage unit (SI, S2, Sn), b. a switching device (Cl, C2, Cn), connected on the one hand to the energy storage unit (SI, S2, Sn) and intended to be connected on the other hand to the electrical supply network (10) of the vehicle, said switching device (Cl, C2, Cn) comprising: i. A first switch (II) called “load”, configured to:
1. According to a so-called “closed” state, allowing the energy storage unit (SI, S2, Sn) to charge from the electrical energy supplied by the power supply network (10), 2. According to a so-called "open" state, prevent the current from moving from the supply network (10) to the energy storage unit (SI, S2), ii. A second switch called a “discharge” switch (12), connected in series with the first switch (II) and configured to:
1. According to a so-called “closed” state, allow the energy storage unit (SI, S2, Sn) to discharge and supply the electrical network (10) with electrical energy, 2. According to a so-called “open” state, prevent the current from moving from the energy storage unit (SI, S2) to the supply network (10), c. a control unit (U1, U2, UN), configured to control the load switch (II) and the discharge switch (12), Each battery (Bl, B2) being configured to operate according to: - an “activated” mode in which the charge (II) and discharge (12) switches are in the closed state, - a “deactivated” mode in which the charge (II) and discharge (12) switches are in the open state, - a charging mode in which the charging switch (II) is in the closed state and the discharging switch (12) is in the open state, - a discharging mode in which the charging switch (II) is in the open state and the discharging switch (12) is in the closed state, The control unit (U1, U2, UN) is configured to implement the method according to any one of claims 1 to 2.
4. Power supply system (1) according to any one of the preceding claims, wherein, for each battery (Bl, B2, Bn): a. The load switch (II) comprises a MOSFET transistor, b. The discharge switch (12) comprises a MOSFET transistor, c. The charge switch (II) and the discharge switch (12) are connected so that: i. The source of the charge switch (II) is connected to that of the discharge switch (12), ii. The drain of the load switch (II) is connected to the supply network (10), iii. The drain of the discharge switch (12) is connected to the energy storage unit (SI, S2, Sn).
5. Power supply system (1) according to any one of claims 1 to 3, wherein, for each battery (Bl, B2, Bn): a. The load switch (II) comprises a MOSFET transistor, b. The discharge switch (12) comprises a MOSFET transistor, c. The charge switch (II) and the discharge switch (12) are connected so that: i. The source of the charge switch (II) is connected to that of the discharge switch (12), ii. The drain of the load switch (II) is connected to the energy storage unit (SI, S2, Sn), iii. The drain of the discharge switch (12) is connected to the supply network (10).
6. Motor vehicle comprising an electrical power supply system (1) according to any one of claims 3 to 5.