Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
  • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
  • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
  • B60L58/20—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules having different nominal voltages
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
  • B60L53/20—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by converters located in the vehicle
  • B60L53/22—Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
  • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
  • B60L58/12—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries responding to state of charge [SoC]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
  • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
  • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
  • B60L58/21—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules having the same nominal voltage
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
  • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
  • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
  • B60L58/22—Balancing the charge of battery modules
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
  • H02J7/0014—Circuits for equalisation of charge between batteries
  • H02J7/0019—Circuits for equalisation of charge between batteries using switched or multiplexed charge circuits
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
  • H02J7/0048—Detection of remaining charge capacity or state of charge [SOC]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/54—Drive Train control parameters related to batteries
  • B60L2240/547—Voltage
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02T90/10—Technologies relating to charging of electric vehicles
  • Y02T90/14—Plug-in electric vehicles

Definitions

• the present invention relates to an improved power supply system, which can in particular be used in an electric or hybrid vehicle.
• a battery pack supplies a DC voltage which a DC/AC converter is responsible for converting in order to supply control voltages to the electric motor of the vehicle on its two or three phases (depending on the configuration of the motor).
• the battery pack may comprise several batteries, each battery itself comprising several modules and each module generally comprising several electrochemical cells.
• the system can be reversible and the mechanical braking of the motor can also make it possible to recharge the batteries of the battery pack, in energy regeneration mode.
• a standard 12V (or 24V) lead acid battery is often used.
• This additional lead battery is justified by the need to have a voltage of 12V even when the vehicle is not on and by the need to have an independent 12V source which does not discharge the traction battery.
• This auxiliary battery is charged by the battery pack of the vehicle in the case of an electric or hybrid vehicle, through a DC/DC type converter, or by an alternator in the case of a thermal vehicle.
• the installation of the auxiliary battery must in particular be able to adapt to an architecture capable of permanently supplying a constant DC voltage, for example 48 V DC or 400 V DC in an electric vehicle, through a DC power supply bus.
• Patent application EP20798148A2 already describes an architecture used in an electric or hybrid vehicle, capable of supplying different voltage levels, without using DC/DC converters.
• Patent application US2018/043789A1 also describes a power supply system capable of dispensing with DC/DC converters.
• the object of the invention is therefore to propose an electrical power supply system which:
• This system will be adapted in particular to be used in an electric or hybrid vehicle to participate in the traction of the vehicle but also to supply various equipment items of the vehicle.
• an electrical power supply system for electrical equipment which comprises: A continuous supply bus,
• a first battery capable of supplying a first DC voltage on said DC power supply bus, said first battery comprising first cells, each switchable between an active state and an inactive state, An auxiliary battery configured to supply a second DC voltage, distinct from the first DC voltage,
• a second battery capable of supplying said first DC voltage on said DC power supply bus, said second battery being mounted in parallel with said first battery, said second battery comprising second cells, each switchable between an active state and an inactive state,
• First switching means arranged to connect or disconnect the first battery from the DC power supply bus
• Second switching means arranged to connect or disconnect the second battery from the DC power supply bus
• Third switching means configured to connect or disconnect the auxiliary battery in series with the first battery and/or in series with the second battery
• Said control unit being configured to: o select at least one battery from among the first battery and the second battery to fix said voltage on the DC power supply bus by connecting it to the DC power supply bus, o control a connection to the DC bus of the unselected battery, and charging said auxiliary battery by placing it in series with the unselected battery and switching the cells of said unselected battery to drive a charging current of said auxiliary battery.
• the architecture of the invention has the advantage of being completely symmetrical, in the sense that it makes it possible to select one or the other of the two main batteries for the supply of the voltage on the bus, and of use the unselected battery to possibly charge the auxiliary battery.
• the first switching means are arranged to connect or disconnect the first battery to a charge/discharge unit intended to be connected to an AC network.
• the second switching means are arranged to connect or disconnect the second battery to said charge/discharge unit.
• control unit is configured to control a charge of the unselected battery by a connection to said charge/discharge unit.
• control unit is configured to control the supply of a variable voltage to said charge/discharge unit by connecting the first battery or the second battery to said charge/discharge unit.
• control unit is configured to control a connection of the auxiliary battery in series with both the first battery and the second battery to charge the auxiliary battery using a current present on the bus continuous feeding.
• control unit comprises means for monitoring the following quantities: o The voltage at the terminals of the first battery, o The voltage at the terminals of the second battery, o The voltage at the terminals of the auxiliary battery, o The current which circulates in a first branch carrying the first battery, o The current which circulates in the second branch carrying the second battery, o The charging current of the auxiliary battery. o DC power supply bus voltage;
• control unit comprises means for determining and monitoring the state of charge of the first battery, the state of charge of the second battery and the state of charge of the auxiliary battery , from the values of the monitored quantities.
• control unit comprises means for controlling the charging current of the auxiliary battery by applying connection phases and disconnection phases of the auxiliary battery to said non-selected battery.
• the first battery and the second battery each comprise several cells connected in series and parallel, each cell comprising at least one capacitor and switching means.
• the invention also relates to a control method implemented in the control unit of an electrical power supply system as defined above, said method comprising the following steps:
• control unit is configured to control a charge of the battery not selected by a connection to said charge/discharge unit.
• control unit is configured to control a connection of the auxiliary battery in series with both the first battery and the second battery to charge the auxiliary battery using a current (l_R) present on the DC power supply bus.
• control unit is configured to control the supply of a variable voltage to said charge/discharge unit by connecting the first battery or the second battery to said charge/discharge unit.
• the invention finally relates to a use of the system as defined above in an electric or hybrid vehicle to supply one or more electrical equipment items of said vehicle.
• FIG. 1 schematically represents the electrical architecture of the system
• FIG. 2 schematically represents the control architecture of the system
• Figure 3A, Figure 3B and Figure 3C represent the electrical architecture of Figure 1, controlled to apply the three operating modes of the system;
• FIG. 4 illustrates the principle of charging the auxiliary battery when charging on the network
• Figure 5 illustrates the principle of switching between the two batteries of the system, making it possible to maintain the supply of the DC voltage
• Figure 6 shows an embodiment of the transformer that can be used in the system of the invention
• FIG. 7 represents an embodiment of a switched-cell battery
• DC signifies "Direct Current” for direct current
• AC signifies "Alternating Current” for alternating current.
• the invention relates to a power supply system for electrical equipment.
• the system is in particular perfectly adapted to be installed in an electric or hybrid vehicle. It is then embarked on board the vehicle and can take part in the traction of the vehicle or in the supply of various equipment of the vehicle.
• the system comprises a DC supply bus comprising two supply lines L1, L2 between which a first DC voltage U_DC can be applied.
• This voltage can be generated directly by a battery pack of suitable capacity.
• this first voltage can be for example 48V DC or 400V DC.
• a recharging current may appear on the bus.
• the electrical power supply system thus comprises at least one battery pack.
• the battery pack comprises at least a first battery BATT 1 and a second battery BATT2.
• Each battery can comprise several modules, each module comprising several electrical energy storage cells.
• cell is meant an elementary cell or a group of elementary cells placed in series and/or in parallel.
• elementary cell it can be a storage element (battery cell, electrical capacity, micro-battery, etc.), a generator (fuel cell, Zinc-air battery, photovoltaic cell, or a combination of the two (generator associated with a buffer storage element)
• a switchable cell in the case where it consists of a group of elementary cells placed in series and/or in parallel, is switchable between an active state and a globally inactive state (the switching applies to the terminals of this group of elementary cells).
• a battery pack is intended to supply at output a first DC voltage U_DC (for example 48V DC or 400V DC) available on the DC power supply bus.
• U_DC for example 48V DC or 400V DC
• each battery (BATT in FIG. 7) of the pack is produced according to a so-called switched-cell architecture.
• This solution makes it possible to replace the converter (DC/DC or DC/AC) at the output of the battery pack.
• each cell Cell_x can be individually controlled.
• Several cells connected in series and/or parallel can form a module M_y.
• Each cell of the battery pack can in fact be switched between an active state and an inactive state thanks to suitable switching means S_x1, S_x2 connected in series and parallel to its capacitance C_x (battery, capacitor or super-capacitor type).
• a control system is then responsible for controlling the switching means to vary the voltage supplied by each battery in its entirety.
• This type of architecture is well known and described in particular in patent applications No. WO2013/007810A1, WO2012/117111A1,
• the two batteries BATT1, BATT2 of the system are mounted in parallel between the two supply lines L1, L2 of the DC power bus and form two separate branches, called the first branch carrying the first battery BATT 1 and second branch carrying the second battery BATT2.
• the two batteries can thus work in redundancy to supply the DC voltage on the DC power supply bus.
• the other battery can be charged on the AC network or ensure the supply of an AC voltage for components external to the system. In this way, the system may be able to permanently maintain the U_DC voltage on the bus, by selectively connecting one or the other of the two branches.
• the first branch and the second branch each comprise two connection terminals, a first terminal (B1 for the first branch and B3 for the second branch) intended to be connected to the first supply line L1 of the bus and a second terminal (B2 for the first branch and B4 for the second branch) intended to be connected (directly or indirectly) to the second supply line L2 of the bus.
• switching means are arranged to manage the selective connection of each branch to the DC power supply bus.
• auxiliary battery B AUX the system includes a third battery, called auxiliary battery B AUX.
• auxiliary battery B AUX may be a lead-acid battery, or else of the Iron-Phosphate type, capable of supplying a voltage of 12V or 24V. It can be used, for example, to power the vehicle's on-board network, i.e. the headlights, the windows, the ABS when braking, the steering assistance, but also much more basic functions such as than centralized opening/closing by remote control.
• the auxiliary battery B AUX has two terminals B5, B6 to integrate into the system.
• the system can also have a transformer TR, forming a charge/discharge unit and comprising two so-called input terminals B7, B8 and two so-called output terminals B9, B10. Its two output terminals can be connected to the AC network to recharge the system. Furthermore, it is also possible to provide an AC voltage at the output of the transformer, between its two output terminals B9, B10, from a rectified voltage U_AC_r (for example 48V AC rectified) supplied by one or the other of the two batteries between the two input terminals B7, B8 of the transformer. To recharge on the grid, the battery cells (BATT 1 or BATT2) being charged are switched appropriately to synchronize with the AC grid.
• U_AC_r for example 48V AC rectified
• the battery with switched architecture which must be recharged on the AC network, is controlled by the control system so that the AC current of the battery is perfectly in phase with the voltage of the network.
• An algorithm having as input data the voltage of the AC network or its rectified image as well as the exchange current between the network and the battery, regulates the current exchanged with respect to a setpoint current, which is itself substantially in phase with the mains voltage.
• the potential difference at the input (between the terminals B7-B8) is, via the operation of the transformer TR, a reproduction of the potential difference present between the output terminals (B9-B10) attenuated and straightened.
• the current setpoint is then an image of the rectified network voltage, or even a rectified sinusoidal signal substantially in phase with the rectified network voltage.
• the transformer can be of any type and formed from an assembly of several components, allowing the charging of the batteries on the AC network and the supply of an AC voltage.
• An exemplary embodiment is presented in FIG. 7 and will be described below.
• the entire system can operate according to the following different modes:
• First operating mode known as normal: Supply of a constant DC voltage (for example 48V DC or 400V DC) on the DC power supply bus, without the presence of the network.
• a single battery or both batteries can be connected to the bus to fix the DC voltage.
• One of the two batteries can also be configured to drive an auxiliary battery charging current.
• Second operating mode (MOD2) charging on the bus (in regeneration mode or charging via the heat engine):
• the system uses the current generated on the DC power supply bus to charge itself.
• One of the two batteries or both batteries BATT 1 , BATT2 can be charged simultaneously thanks to the current present on the bus.
• the two batteries to contribute in parallel to the charging of the auxiliary battery B AUX, while maintaining a constant DC voltage on the BUS.
• the system synchronizes one of the two batteries (BATT1 or BATT2) on the AC voltage of the network to charge via the transformer TR. Only one of the two batteries is thus charged on the network, the second battery having to maintain the DC voltage of the BUS (eg 48V DC or 400V DC).
• the system can also connect the auxiliary battery B AUX to it in series and drive a charging current from the auxiliary battery B AUX.
• a voltage U_AC outside the system whether to provide power to an electrical network or to supply an external load).
• one of the two batteries is dedicated to supplying the voltage U_AC while the other maintains the supply of a constant DC voltage on the bus.
• the control of the battery supplying the voltage U_AC could be adapted to the type of device connected at the output (network or load).
• the control of the battery advantageously makes it possible to control the phase and the amplitude of the output current in relation to the network voltage.
• the system comprises various switching means.
• these switching means must make it possible to:
• each battery BATT 1 , BATT2 separately to the two lines of the bus or to the two terminals of the transformer;
• the system may include various switching means.
• the system may thus comprise:
• First switching means C1 arranged in series with the first battery BATT1 and intended to connect the first battery to the first supply line of the bus or to the first terminal of the transformer;
• Second switching means C2 arranged in series with the second battery BATT2 and intended to connect the second battery to the first supply line of the bus or to the first terminal of the transformer;
• Third switching means C3 arranged to connect the first branch between the two supply lines of the bus, directly or through the auxiliary battery B AUX; The auxiliary battery is then placed in series with the first battery;
• Fourth switching means C4 arranged to connect the second branch between the two supply lines of the bus, directly or via the auxiliary battery B AUX; The auxiliary battery is then placed in series with the second battery;
• the first switching means C1 may comprise a first switch S1 arranged between the first terminal of the first branch and the first supply line and a second switch S2 arranged between the first terminal of the first branch and the first terminal of the transformer.
• the second switching means C2 may comprise a first switch S3 arranged between the first terminal of the second branch and the first supply line and a second switch S4 arranged between the first terminal of the second branch and the first terminal of the transformer.
• the third switching means C3 may include a first switch S5 arranged between the second terminal of the first branch and the second supply line and a second switch S6 arranged between the second terminal of the first branch and the first terminal of the auxiliary battery, the second terminal of the auxiliary battery being connected directly to the second supply line.
• the fourth switching means C4 may comprise a first switch S8 arranged between the second terminal of the second branch and the second supply line and a second switch S7 arranged between the second terminal of the second branch and the first terminal of the auxiliary battery, the second terminal of the auxiliary battery being connected directly to the second supply line.
• the system comprises:
• the system includes a control and processing unit UC responsible for managing the different operating modes and for controlling the switching means and the cells of each battery to implement the selected operating mode.
• the control unit thus comprises:
• a high charging current can be supplied and at the end of charging a reduction in its intensity will allow deeper charging.
• a maximum charging current must not be exceeded. This maximum charging current can be determined a priori by the manufacturer, for example according to the temperature and on condition that it does not go outside the authorized voltage range.
• this maximum charging current can depend on the state of charge of the auxiliary battery B AUX, its state of health and its internal impedance, so as to extend its life without penalizing its charging time too much. .
• one of the objectives is to keep this auxiliary battery B AUX charged as much as possible so that it remains completely available. It is a question of taking advantage of all the phases where the current is negative on the DC bus and/or in the presence of an AC recharge power from the network to keep it charged. It should be noted that the worst case of operation may be the so-called "normal" mode MOD1 explained above, in which the auxiliary battery B AUX is not necessarily recharged.
• the auxiliary battery is not recharged as long as its state of charge SOC_aux is not critical and below a threshold. If the current requested on the DC bus is not too high, one of the two batteries BATT1 or BATT2 can switch to current regulation mode to recharge the auxiliary battery B AUX.
• the sizing of the relative capacities (in Ah) between the auxiliary battery and the two batteries BATT1 , BATT2 is such that most of the time the two batteries BATT1 , BATT2 need to be recharged before the auxiliary battery is too discharged, so this method of recharging remains relatively rare. It makes it possible to satisfy extreme cases, such as for example the vehicle stationary or at slow speed (low power drawn on BATT 1 and BATT2) while accessories such as the power steering draw a large current on the auxiliary battery.
• control and processing unit UC is able to control the passage from one mode of operation to another, in particular to switch from the first battery BATT1 to the second battery BATT2 , or vice versa, for supplying the voltage on the DC bus, and to do the same for recharging the auxiliary battery B AUX.
• the system may thus have to be permanently reconfigured, in particular to guarantee good balancing (energy, thermal, etc.) of the system; this advantage is obtained with the symmetrical structure proposed here (the two main batteries can be used statistically in the same way, ensuring in particular a homogeneous aging and state of charge).
• FIG. 3A illustrates the architecture of the system for the implementation of this first mode of operation. In this figure 3A, we can see that:
• the second branch is connected to the DC power supply bus, by closing switch S3 and switch S8.
• the first branch is connected to the DC power supply bus via the auxiliary battery, by closing switch S1 and switch S6.
• a variant of this operating mode consists in connecting the two batteries BATT1 and BATT2 to the DC power supply bus to supply the voltage U_DC on the bus, and in disconnecting the B AUX battery from the batteries BATT 1 and BATT2 by opening the switches S6 and S7.
• This operating mode can be interesting if high power is required on the bus.
• a current I_R is generated on the DC power supply bus (in regenerative mode during braking or generated thanks to the heat engine of the vehicle). This current I_R can be used for charging the auxiliary battery.
• the auxiliary battery B AUX is thus connected in series with at least one of the two batteries, for example the first battery BATT 1 and the latter is connected to the bus and controlled by the control unit UC to generate the charging current l_aux suitable for charging the auxiliary battery B AUX.
• the second battery BATT2 can also be connected to the bus to be charged with the current I_R available on the bus.
• Figure 3B illustrates the system architecture for implementing the second mode of operation.
• the second branch is connected to the DC power supply bus, by closing switch S3 and switch S8.
• the first branch is connected to the DC power supply bus via the auxiliary battery, by closing switch S1 and switch S6.
• the second battery BATT2 can also be connected in series with the auxiliary battery B AUX by closing the switches S3 and S7 and by opening the switch S8.
• the auxiliary battery B AUX then sees all of the charging current l_R.
• the charging current l_aux of the auxiliary battery may not be regulated and then corresponds directly to the charging current l_R.
• Third mode of operation - Figure 3C One or the other of the two batteries (BATT 1 ) is charged on the AC network via the transformer TR. If necessary, the other battery, which is not charging, can continue to supply DC voltage.
• the auxiliary battery B AUX can be recharged through the charging branch connected to the AC network. Its charge is controlled according to the network voltage level, the current flowing through the cells of the BATT1 battery and according to its state of charge. As soon as the mains voltage is higher than 12V, it is possible to connect the auxiliary battery B AUX.
• the connection time of the auxiliary battery B AUX depends on its state of charge.
• Figure 3C illustrates the system architecture for implementing the third mode of operation. In this figure, we can see that:
• the second branch is connected to the DC power supply bus, by closing switch S3 and switch S8.
• the first branch is connected to the transformer via the auxiliary battery, by closing switch S2 and switch S6.
• switch S2 In this configuration, it should be noted that it may prove necessary to open switch S6 and close switch S5 when the potential difference between the input terminals B7 and B8 of the transformer falls below the U_aux voltage present at the auxiliary battery terminals.
• FIG. 4 illustrates the principle of operation of the third mode of operation.
• This figure represents a time diagram schematically illustrating the principle of connection and disconnection of the auxiliary battery B AUX during its charging.
• the auxiliary battery B AUX is connected for a duration T1.
• This disconnection period T2 can be of any width between 0 and the temporal distance which separates the start of the period T1 from the end of the period T3.
• the period T2 can be distributed in the form of several disconnection zones.
• the diagram represented in FIG. 5 indicates how to swap the two batteries BATT 1 , BATT2 without however modifying the principle of recharging the auxiliary battery during recharging on the AC network.
• control unit UC To invert the functions performed by each branch of the pack and thus maintain the voltage U_DC, the control unit UC must follow the following steps:
• one of the two batteries (BATT1) provides voltage U_DC and the other battery (BATT2) is connected to the transformer to provide useful AC voltage outside the system or to charge on the AC network;
• V_DC for example 48V DC or 400V DC.
• the transformer TR can be a simple 50/60Hz transformer associated with an active rectifier bridge.
• the 50/60Hz transformer allows the AC network voltage to be lowered before being rectified to generate a voltage compatible with the voltages that the first battery BATT1 and the second battery BATT2 can handle.

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• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

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• 2020
  • 2020-11-02 FR FR2011226A patent/FR3115737A1/fr active Pending
• 2021
  • 2021-11-02 US US18/251,190 patent/US20240278688A1/en active Pending
  • 2021-11-02 EP EP21805889.9A patent/EP4237273A1/de active Pending
  • 2021-11-02 CN CN202180084798.0A patent/CN116601046A/zh active Pending
  • 2021-11-02 WO PCT/EP2021/080311 patent/WO2022090558A1/fr active Application Filing

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