Hybrid management of batteries using different technologies

Abstract

An electronic circuit (8), arranged to be connected to batteries (5, 6) of different technologies, comprising: a bidirectional charger (9); for each battery, a link (10, 11) connecting the charger to the battery, each link comprising a primary link (12) and a secondary link (14), the primary link comprising a primary disconnect device (15), the secondary link comprising a secondary disconnect device (16) and a current limiting device (17); voltage sensors (25); a processing unit (22) arranged to, based on voltage measurements, control the disconnect devices to charge and discharge the batteries using first the secondary link and then the primary link. (Figure from the summary: Fig. 1)

Description

Title of the invention: Hybrid management of batteries of different technologies

[0001] The invention relates to the field of power supply systems comprising batteries.

[0002] BACKGROUND

[0003] In rural areas, telecommunications towers play a very important role in connecting millions of people to civil infrastructure and in providing access to digital services, including health and education services.

[0004] Typically, these telecommunications towers are powered by one or more diesel generators (DGs). However, DGs present a number of environmental drawbacks. They produce carbon dioxide, nitrogen oxides, particulate matter, and other hazardous exhaust gases that are released into the atmosphere.

[0005] The consumption of 1 L of diesel fuel emits on average 2.7 kg of CO2. Compared to other energy sources, diesel generators are therefore a very significant source of pollution. Furthermore, maintenance and fuel costs can considerably increase the operating costs of diesel generators.

[0006] A power supply system based on the use of solar energy as the primary energy source and a battery bank as a secondary energy source has therefore been designed to power telecommunication towers. Such a power supply system, particularly suited to countries with high levels of sunshine, can significantly improve the environmental impact of the energy system and reduce its operating costs.

[0007] Batteries used as a secondary energy source are typically lead-acid batteries. The batteries are used at night and during periods of bad weather.

[0008] Lead-acid batteries have a number of qualities: reliability, high power density, etc.

[0009] But lead-acid batteries also have a number of disadvantages, including: - Depth of discharge: the DOD (for Depth Of Discharge) of lead-acid batteries should not exceed 50%. Beyond this point, the battery life can be affected; - the life cycle: lead-acid batteries have a short life cycle which varies between 100 and 300 charge / discharge cycles; - efficiency: lead-acid batteries have a reduced efficiency of 80 to 85%; - Energy density: lead-acid batteries have a low energy density energy.

[0010] This power supply system is therefore not perfectly satisfactory.

[0011] We therefore plan to introduce lithium batteries into this power supply system.

[0012] Replacing lead-acid batteries with lithium batteries is a relatively common operation, frequently performed to modernize existing power systems. However, replacing lead-acid batteries generally requires replacing the entire power system, which represents a significant cost. Furthermore, replacing (and therefore disposing of) still-functional batteries with new ones has a considerable environmental impact, even if the new batteries are more efficient and environmentally friendly. Moreover, as we have seen, lead-acid batteries, although generally less efficient than lithium batteries, still possess technical qualities that may be worth preserving.

[0013] OBJECT

[0014] The invention aims to modernize a pre-existing power supply system equipped with a pre-existing battery, by integrating a new battery of different technology, without removing the pre-existing battery and by optimizing the combined operation of the two batteries.

[0015] SUMMARY

[0016] To achieve this goal, an electronic circuit is proposed, arranged to be connected to at least two batteries of different technologies, comprising: • a bidirectional charger including an output; • for each battery, a link connecting the output of the bidirectional charger to said battery, each link comprising a primary link and a secondary link connected in parallel. • the main link comprising a main switching device arranged to selectively cut or make pass said main link; • the secondary link comprising a secondary switching device arranged to selectively switch on or off said secondary link, and a current limiting device mounted in series with the secondary switching device; • voltage sensors arranged to measure, for each battery, the voltage across the terminals of said battery, as well as the voltage on the output of the bidirectional charger; • a processing unit arranged to, based on voltage measurements produced by the voltage sensors, control the primary and secondary switching devices to charge and discharge the batteries via the bidirectional charger, using, for each battery, first the secondary link for a predetermined time, then the primary link of the connection associated with said battery.

[0017] The electronic circuit processing unit therefore controls the switching devices, based on voltage measurements and the individual characteristics of the batteries, in order to optimize the charging and discharging of the batteries via the bidirectional charger. Secondary links ensure a gradual start to the charging and discharging of each battery to prevent excessive inrush currents. The electronic circuit thus makes it possible to upgrade a pre-existing power system that already includes a pre-existing battery, by integrating a new battery of a different technology into the power system, without removing the pre-existing battery.

[0018] An electronic circuit as previously described is further proposed, in which each current limiting device includes a thermistor.

[0019] An electronic circuit as previously described is further proposed, in which each main switching device and secondary switching device comprises two MOSFET-type transistors mounted in series.

[0020] An electronic circuit as previously described is further proposed, in which the processing unit is arranged to implement: • a first phase, designed to ensure that a voltage difference between the voltages across the battery terminals is less than a predetermined threshold; • then a second phase, designed to optimize the charging and / or discharging of the batteries.

[0021] An electronic circuit as previously described is further proposed, in which, during the first phase, the processing unit is arranged to:

[0022] - determine a maximum voltage among the voltages across the battery terminals;

[0023] - check if the maximum voltage is higher than the voltage at the charger output bidirectional;

[0024] - if so, and if the voltage across the battery terminals which has the voltage If the maximum voltage is greater than its minimum discharge voltage, discharge said battery;

[0025] - if this is not the case, charge each other battery whose voltage is lower than its maximum charging voltage.

[0026] An electronic circuit as previously described is further proposed, in which, during the second phase, the processing unit is arranged to: • for each battery, compare the voltage across the terminals of said battery with the voltage at the output of the bidirectional charger; • for each battery, if the voltage across the terminals of said battery is less than the voltage on the output of the bidirectional charger, and if the voltage across the terminals of said battery is less than its maximum charging voltage, charge said battery; • for each battery, if the voltage across the terminals of said battery is greater than the voltage at the output terminals of the charger, and if the voltage across the terminals of said battery is greater than its minimum discharge voltage, discharge said battery.

[0027] A power supply system is also proposed comprising at least two batteries of different technologies and an electronic circuit as previously described.

[0028] A hybrid battery management method is further proposed, implemented in the electronic circuit processing unit as previously described, and comprising the steps of:

[0029] - acquire the voltage measurements produced by the voltage sensors;

[0030] - control the main switching devices and the switching devices secondary links to charge and discharge the batteries via the bidirectional charger, using, for each battery, first the secondary link for a predetermined time, then the primary link of the connection associated with said battery.

[0031] A hybrid battery management method as previously described is also proposed, comprising: • a first phase, designed to ensure that a voltage difference between the voltages across the battery terminals is less than a predetermined threshold; • then a second phase, designed to optimize the charging and / or discharging of the batteries.

[0032] A hybrid battery management method as previously described is further proposed, comprising the steps, during the first phase, of:

[0033] - determine a maximum voltage among the voltages across the battery terminals;

[0034] - check if the maximum voltage is higher than the voltage at the charger output bidirectional;

[0035] - if so, and if the voltage across the battery terminals which presents the voltage If the maximum voltage is greater than its minimum discharge voltage, discharge said battery;

[0036] - if this is not the case, charge each other battery whose voltage is lower than its maximum charging voltage.

[0037] A hybrid battery management method as previously described is further proposed, comprising the steps, during the second phase, of: • for each battery, compare the voltage across the terminals of said battery with the voltage at the output of the bidirectional charger; • for each battery, if the voltage across the terminals of said battery is less than the voltage on the output of the bidirectional charger, and if the voltage across the terminals of said battery is less than its maximum charging voltage, charge said battery; • for each battery, if the voltage across the terminals of said battery is greater than the voltage at the output terminals of the charger, and if the voltage across the terminals of said battery is greater than its minimum discharge voltage, discharge said battery.

[0038] A computer program is also proposed comprising instructions which lead the processing unit of the electronic circuit as previously described to execute the steps of the hybrid battery management process as previously described.

[0039] A computer-readable recording medium is also proposed, on which the computer program as previously described is recorded.

[0040] The invention will be better understood in the light of the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0041] Reference will be made to the attached drawings, among which:

[0042] [Fig. 1] [Fig. 1] represents an electronic circuit connected to a first battery and a second battery;

[0043] [Fig.2] [Fig.2] is a diagram representing the steps of the hybrid battery management process;

[0044] [Fig.3] [Fig.3] is a diagram representing the steps of the second phase of the process. DETAILED DESCRIPTION

[0045] With reference to [Fig. 1], a load, here a telecommunications tower 1, is powered by a power supply system 2 comprising a primary energy source, which here includes photovoltaic panels 3, and a secondary energy source, which includes a battery bank. The telecommunications tower 1 can also be powered via a "traditional" electrical grid 4.

[0046] The battery bank here comprises at least two batteries of different technologies, here a first battery 5 of a first technology, which is here a lithium battery (here lithium-ion), and a second battery 6 of a second technology, which is here a lead-acid battery (here lead-acid). Two batteries are considered to use different technologies when they exhibit different structures or when they use different materials (for the electrodes, the electrolyte, etc.).

[0047] The second battery 6 was present at the time of the initial installation and commissioning of the power supply system 2.

[0048] Later, to modernize the power supply system, this first battery 5, which is more modern and overall more efficient, was therefore added to the power supply system 2.

[0049] At the time of installation of the first battery 5, an electronic circuit 8 is also integrated into the power supply system 2 which allows the use of the two types of battery to be optimized.

[0050] The electronic circuit 8 is connected to the first battery 5, to the second battery 6, to the telecommunications tower 1, to the photovoltaic panels 3 and to the network 4.

[0051] The electronic circuit 8 includes a bidirectional charger 9 which includes an input El connected to the photovoltaic panels 3, an input E2 connected to the network 4, an output SI connected to the telecommunications tower 1, and an output S2 connected to both the first battery 5 and the second battery 6.

[0052] For each battery 5, 6, the electronic circuit 8 includes a link connecting the output S2 of the bidirectional charger 9 to said battery.

[0053] The output S2 of the bidirectional charger 9 is therefore connected to the first battery 5 via the first link 10, and to the second battery 6 via the second link 11.

[0054] Each link comprises a primary link 12 and a secondary link 14 connected in parallel, • the main link 12 comprising a main switching device 15 arranged to selectively switch off or switch on said main link 12; • the secondary link 14 comprising a secondary switching device 16 arranged to selectively switch off or switch on said secondary link 14, and a current limiting device 17 mounted in series with the secondary switching device 16.

[0055] Each main switching device 15 and each secondary switching device 16 comprises two MOSFET-type transistors 18 mounted in series.

[0056] Each current limiting device 17 includes a thermistor 19, here of type NTC (for Negative Temperature Coefficient, or NTC, in French, for Negative Temperature Coefficient).

[0057] The main link 12 of the first link 10 therefore comprises transistors 18a, 18b. The drain of transistor 18a is connected to the output S2 of the charger 9. The source of transistor 18a is connected to the source of transistor 18b. The drain of transistor 18b is connected to the positive terminal of the first battery 5.

[0058] The secondary link 14 of the first link 10 therefore comprises transistors 18c, 18d and the thermistor 19. The drain of transistor 18c is connected to the output S2 of the charger 9. The source of transistor 18c is connected to the source of transistor 18d. The drain of transistor 18d is connected to one terminal of the thermistor 19, the second terminal of the thermistor 19 being connected to the positive terminal of the first battery 5.

[0059] The main link 12 of the second link 11 therefore includes transistors 18e, 18f, which are connected as for the main link 12 of the first link 10, but with the second battery 6.

[0060] The secondary link 14 of the second link 11 therefore includes transistors 18g, 18h and the thermistor 19, which are connected as for the secondary link 14 of the first link 10, but with the second battery 6.

[0061] The electronic circuit 8 further includes a control module 20a having outputs connected to the gates of transistors 18a, 18b, a control module 20b having outputs connected to the gates of transistors 18c, 18d, a control module 20c having outputs connected to the gates of transistors 18e, 18f, and a control module 20d having outputs connected to the gates of transistors 18g, 18h.

[0062] The electronic circuit 8 further includes a processing unit 22. The processing unit 22 is an electronic and software unit. The processing unit 22 includes at least one processing component 23, which is, for example, a "general-purpose" processor, a processor specializing in signal processing (or DSP, for Digital Signal Processor), a processor specializing in artificial intelligence algorithms (of the NPU type, for Neural Processing Unit), a microcontroller, or a programmable logic circuit such as an FPGA (for Field Programmable Gate Arrays) or an ASIC (for Application Specified Integrated Circuit).

[0063] The processing unit 22 also includes one or more memories 24, connected to or integrated into the processing component(s) 23. At least one of these memories 24 forms a computer-readable recording medium, on which is recorded at least one computer program comprising instructions which lead the processing unit 22 to execute the steps of the hybrid battery management process which will be described.

[0064] The processing unit 22 is connected to the control modules 20a, 20b, 20c, 20d of the transistors 18 and drives the transistors 18, via the control modules 20a, 20b, 20c, 20d, to open or close the links 12, 14 of the connections 10, 11. All the links can be controlled independently. Note that the control modules 20a, 20b, 20c, 20d can be integrated into the processing unit 22 (and even into the processing component(s) 23).

[0065] The electronic circuit 8 also includes sensors which produce voltage measurements at the terminals of the batteries 5, 6 and on the output S2 of the bidirectional charger 9.

[0066] The voltage sensors 25 measure a first voltage V1 across the terminals of the first battery 5, a second voltage V2 across the terminals of the second battery 6, and a third voltage V3 on the output S2 of the charger 9. Here, the voltage sensors 25 are integrated into the processing unit 22, that is to say, the processing unit 22 is connected to the points where these voltages are applied, and it measures said voltages.

[0067] The electronic circuit 8 further includes a current sensor 26 which measures the current II flowing between the charger 9 and the first battery 5 (charging or discharging current), and a current sensor 27 which measures the current 12 flowing between the charger and the second battery 6 (charging or discharging current).

[0068] The secondary links 14 ensure a gradual start-up of the system to avoid excessive inrush currents. The thermistors 19 decrease their resistance when heated. The secondary links 14 therefore each mimic the behavior of an active current limiter for better regulation of magnetic flux and voltage.

[0069] The various MOSFET transistors 18 function as switches by controlling the current flow in different operating regions. When the transistors 18 are switched on (closed), they operate in the triode (ohmic) region, allowing current to flow through their channel and closing the switch. In the OFF or disabled (open) mode, the transistors operate in the cutoff region, blocking the current flow and opening the switch.

[0070] The main links 12 allow the charging and discharging of the first battery 5 and the second battery 6 to be controlled. Their operation depends on the electrical configuration of the system and is controlled by the processing unit 22.

[0071] The bidirectional charger 9 allows the batteries 5, 6 to be charged (using energy produced by the photovoltaic panels 3 and / or the grid 4) or the batteries to be discharged (to the telecommunications tower 1) as needed. The bidirectional charger 9 offers increased flexibility in energy management depending on the availability of sources. It has the ability to adapt to different energy sources such as solar energy (or another form of renewable energy, such as wind power), the electrical grid, or diesel generators. Such a charger 9 can intelligently select the most appropriate power source based on the availability and reliability of energy at any given time. This dynamic energy management optimizes the overall efficiency of the system and reduces energy costs.

[0072] The processing unit 22 continuously monitors the system currents and voltages. The processing unit 22 controls the various transistors 18 to ensure optimal and safe operation.

[0073] The measurement of currents II and 12 makes it possible to protect the batteries 5, 6 and the rest of the circuit 8. When a current peak occurs, the processing unit 22 controls the cutting devices 15, 16 of the link 10, 11 concerned to cut off the current.

[0074] The processing unit 22 is arranged to, according to voltage measurements VI, V2, V3, drive the switching devices 15, 16 to charge and discharge the batteries 5, 6 via the bidirectional charger 9, using, for each battery 5, 6, first the secondary link 14 for a predetermined time, then the main link 12 of the link 10, 11 associated with said battery 5, 6.

[0075] Thus, in general, the processing unit 22 controls a gradual start of the charging and discharging of the batteries 5, 6.

[0076] When a battery 5, 6 is started to charge or discharge, the transistors 18 of the secondary link 14 of the associated link 10, 11 are activated. The thermistor 19 of the secondary link 14 limits the inrush current and allows for a gradual power increase. The temperature of the thermistor 19 increases and its resistance decreases. Once the gradual start-up is complete, the processing unit 22 controls the charging or discharging of said battery 5, 6 using the main link 12.

[0077] The processing unit 22 selects the appropriate transistors 18 according to the electrical configuration and power requirements. The bidirectional charger 9 charges or discharges the batteries as needed.

[0078] The hybrid battery management process, implemented in the processing unit 22, is now described.

[0079] The method is therefore designed to simultaneously manage several different types of batteries, for example a lithium-ion battery and a lead-acid battery, which are connected in parallel. This configuration makes it possible to exploit the specific advantages of each type of battery while combining their capacities to meet the energy needs of the system as a whole.

[0080] Processing unit 22 implements: • a first phase, intended to ensure that a voltage difference, between the voltages VI, V2 at the terminals of batteries 5, 6, is less than a predetermined threshold; • then a second phase, intended to optimize the charging and / or discharging of batteries 5, 6.

[0081] During the first phase, the processing unit 22 is arranged to: • determine a maximum voltage among the voltages across the battery terminals; • check if the maximum voltage is higher than the voltage on the output of the bidirectional charger; • if this is the case, and if the voltage across the terminals of the battery which has the maximum voltage is greater than its minimum discharge voltage, discharge said battery; • if this is not the case, charge each other battery whose voltage is lower than its maximum charging voltage.

[0082] The first phase of the algorithm therefore consists of equalizing the voltages of the two batteries 5 and 6. Since lithium-ion and lead-acid batteries can have different initial voltages, this equalization is crucial to avoid deep discharge or overcharging problems, which could damage the batteries and compromise their lifespan. Once the voltages of batteries 5 and 6 are equalized, the process proceeds to a second phase, which aims to determine an operating range within which the two batteries can be charged or discharged together safely and efficiently.

[0083] To achieve this, a variety of factors can be taken into account, such as the charging and discharging characteristics specific to each type of battery, environmental conditions (such as temperature or humidity, which can influence battery performance), and the requirements of the power supply system (such as the need to provide a stable power supply during a period of rapid charging or discharging). The objective is to find an optimal balance that maximizes the use of available energy while preserving battery integrity.

[0084] With reference to [Fig.2], the hybrid battery management process begins with a start-up step E0.

[0085] The processing unit 22 acquires the measurements of the first voltage VI, the second voltage V2 and the third voltage V3 (step El).

[0086] Then, the processing unit 22 implements the first PI phase which ensures that the voltage difference between the first voltage VI across the terminals of the first battery 5 and the second voltage V2 across the terminals of the second battery 6 is less than a predetermined threshold.

[0087] To do this, the processing unit 22 calculates the voltage difference AV between the first voltage VI across the terminals of the first battery 5 and the second voltage V2 across the terminals of the second battery 6:

[0088] AV = VI - V2 (step E2).

[0089] Then, the processing unit 22 compares the voltage difference with the predetermined threshold (max_difference_voltage). The processing unit 22 checks, for example, whether:

[0090] Av > max_difference_voltage (step E3).

[0091] If the voltage difference is less than (here strictly) the predetermined threshold (i.e. if Av < max_difference_voltage), the second phase P2 is launched.

[0092] We assume that Av > max_difference_voltage.

[0093] The processing unit 22 determines the battery with the maximum voltage.

[0094] The processing unit 22 compares VI and V2.

[0095] The processing unit 22 checks, for example, whether:

[0096] VI > V2 (step E4).

[0097] If the first voltage VI of the first battery 5 is greater than the second voltage V2 of the second battery 6, the first battery 5 is the battery with the maximum voltage.

[0098] If the second voltage V2 of the second battery 6 is greater than the first voltage VI of the first battery 5, the second battery 6 is the battery with the maximum voltage.

[0099] The processing unit 22 then performs the voltage equalization.

[0100] At step E4, if the first voltage VI of the first battery 5 is greater than the second voltage V2 of the second battery 6, the processing unit 22 compares the first voltage VI with the third voltage V3 on the output S2 of the charger 9 (step E5).

[0101] Processing unit 22 checks, for example, whether:

[0102] V3>V1.

[0103] If VI > V3, the processing unit 22 checks if the first voltage V1 is less than (here less than or equal to) the minimum discharge voltage threshold (Bl_discharge_min) of the first battery 5 (step E6).

[0104] If so, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b, 18c, 18d of the main link 12 and of the secondary link 14 of the first link 10 are in the blocked (open) state: step E7.

[0105] The first battery 5 does not discharge.

[0106] If this is not the case, the processing unit 22 drives the control module 20b so that the transistors 18c, 18d of the secondary link 14 of the first link 10 are in the conducting (closed) state: step E8.

[0107] The first battery 5 enters discharge mode.

[0108] The discharge is first ensured by the transistors 18c, 18d with the thermistor 19 connected in series to limit the discharge current.

[0109] Time t is incremented:

[0110] t = t+l.

[0111] Processing unit 22 checks if:

[0112] t > Td,

[0113] Td being the predetermined delay (step E9). Td is for example between 1s and 5s.

[0114] As long as this is not the case, the process returns to step E8. When this is the case, the The process proceeds to step E10.

[0115] After the predetermined delay Td, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b are in the conducting state and the transistors 18c, 18d are in the blocked state (step E10).

[0116] The discharge of the first battery 5 is therefore ensured via the main link 12 of the first link 10, and the process returns to step EL

[0117] At step E5, if V3 > VI, the processing unit 22 checks if the second voltage V2 is less than (here strictly) the maximum charge voltage threshold (B2_charge_max) of the second battery 6 (step Eli).

[0118] If this is not the case, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f, 18g, 18h of the main link 12 and the secondary link 14 of the second link 11 are in the blocked state (step El2). The second battery 6 does not charge and the process returns to step EL

[0119] If so, the processing unit 22 drives the control module 20d so that the transistors 18g, 18h of the secondary link 14 of the second link 11 are in the conducting state (step El3).

[0120] The second battery 6 switches to charging mode.

[0121] The charge is first provided by the transistors 18g, 18h with the thermistor 19 connected in series to limit the discharge current.

[0122] Time t is incremented:

[0123] t = t+l.

[0124] Processing unit 22 checks if:

[0125] t > Td (step E14).

[0126] As long as this is not the case, the process returns to step E13. When this is the case, the process proceeds to step E15.

[0127] After the predetermined delay Td, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f of the main link 12 of the second link 11 are in the conducting state and the transistors 18g, 18h of the secondary link 14 are in the blocked state (step E15).

[0128] The second battery 6 is therefore charged via the main link 12 of the second link 11, and the process returns to step EL

[0129] At step E4, if the second voltage V2 is greater (here greater than or equal to) the first voltage VI of the first battery 5, the processing unit 22 compares the second voltage V2 with the third voltage V3.

[0130] Processing unit 22 checks, for example, whether:

[0131] V3 > V2 (step E16).

[0132] If V2 > V3, the processing unit 22 checks whether the second voltage V2 is less than (here less than or equal to) the minimum discharge voltage threshold (B2_discharge_min) of the second battery 6 (step E17).

[0133] If so, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f, 18g, 18h of the main link 12 and of the secondary link 14 of the second link 11 are in the blocked state (step E18). The second battery 6 does not discharge and the process returns to step E1.

[0134] If this is not the case, the processing unit 22 drives the control module 20d so that the transistors 18g, 18h of the secondary link 14 of the second link 11 are in the conducting state (step E19).

[0135] The second battery 6 goes into discharge mode.

[0136] The discharge is ensured by the transistors 18g, 18h with the thermistor 19 connected in series to limit the discharge current.

[0137] Time t is incremented:

[0138] t = t+l.

[0139] Processing unit 22 checks if:

[0140] t > Td (step E20).

[0141] As long as this is not the case, the process returns to step E19. When this is the case, the process proceeds to step E21.

[0142] After the predetermined delay Td, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f of the main link 12 of the second link 11 are in the conducting state and the transistors 18g, 18h of the secondary link 14 are in the blocked state (step E21).

[0143] The discharge of the second battery 6 is therefore ensured via the main link 12 of the second link 11, and the process returns to step EL

[0144] At step E16, if V3 > V2, the processing unit 22 checks if the first voltage V1 is less than (here strictly) the maximum charge voltage threshold (Bl_charge_max) of the first battery 5 (step E22).

[0145] If this is not the case, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b, 18c, 18d of the main link 12 and the secondary link 14 of the first link 10 are in the blocked state (step E23). The first battery 5 does not charge, and the process returns to step EL

[0146] If so, the processing unit 22 drives the control module 20b so that the transistors 18c, 18d of the secondary link 14 of the first link 10 are in the conducting state (step E24).

[0147] The first battery 5 enters charging mode.

[0148] The load is first supplied by transistors 18c, 18d with thermistor 19 connected in series to limit the discharge current.

[0149] Time t is incremented:

[0150] t = t+l.

[0151] Processing unit 22 checks if:

[0152] t > Td (step E25).

[0153] As long as this is not the case, the process returns to step E24. When this is the case, the process proceeds to step E26.

[0154] After the predetermined delay Td, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b of the main link 12 of the first link 10 are in the conducting state and the transistors 18c, 18d are in the blocked state (step E26).

[0155] The charging of the first battery 5 is therefore ensured via the main link 12 of the first link 10, and the process returns to step EL

[0156] With reference to [Fig.3], we are now interested in the second phase P2, which takes place following the realization of the first phase PI, and therefore when the first voltage V1 across the terminals of the first battery 5 and the second voltage V2 across the terminals of the second battery 6 have been equalized.

[0157] The objective of this second phase P2 is to charge and discharge the batteries in an optimized manner when the first voltage VI of the first battery (Li-ion) and the second voltage V2 of the second battery (lead) are equal.

[0158] During the second phase, the processing unit 22: • for each battery 5, 6, compare the voltage VI, V2 across the terminals of said battery with the voltage V3 on the output S2 of the bidirectional charger 9; • for each battery, if the voltage across the terminals of said battery is less than the voltage on output S2 of the bidirectional charger, and if the voltage across the terminals of said battery is less than its maximum charging voltage, charge said battery; • for each battery, if the voltage across the terminals of said battery is greater than the voltage on output S2 at the terminals of the charger, and if the voltage across the terminals of said battery is greater than its minimum discharge voltage, discharge said battery.

[0159] The second phase P2 begins at step E30.

[0160] The processing unit 22 checks if the third voltage V3 is greater (here strictly) than the first voltage VI and the second voltage V2 (step E31).

[0161] If so, the second voltage V2 is compared with the maximum charging voltage of the second battery 6. The processing unit 22 checks if:

[0162] V2 <B2_charge_max (step E32).

[0163] If so, the first voltage V1 is compared with the maximum charging voltage of the first battery 5. The processing unit 22 checks if:

[0164] VI < Bl_charge_max (step E33).

[0165] If the voltage of the two batteries 5, 6 is less than their maximum charging voltage, the two batteries 5, 6 are connected in parallel and charging begins.

[0166] The charging of batteries 5, 6 is carried out in the following manner.

[0167] The processing unit 22 first drives the control modules 20b, 20d so that the transistors of the secondary links 14 of the links 10, 11 are in the conducting state, all the transistors of all the other links being in the blocked state (step E34).

[0168] Time t is incremented:

[0169] t = t+l.

[0170] Processing unit 22 checks if:

[0171] t > Td (step E35).

[0172] As long as this is not the case, the process returns to step E34. When this is the case, the process proceeds to step E36.

[0173] After the predetermined delay Td, the processing unit 22 controls all the control modules so that the transistors 18a, 18b, 18e, 18f of the main links 12 are in the conducting state and the transistors 18c, 18d, 18g, 18h of the secondary links 14 are in the blocking state (step E36). The batteries are thus charged via the main links, and the process returns to step E30.

[0174] At step E32, if:

[0175] V2 > B2_charge_max,

[0176] The processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f, 18g, 18h of the second link 11 are in the blocked state (E37).

[0177] Processing unit 22 checks if:

[0178] VI < Bl_charge_max (step E38).

[0179] If this is not the case, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b, 18c, 18d of the first link 10 are in the blocked state (step E39). Neither battery is recharged and the process returns to step E30.

[0180] If so, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18c, 18d are in the conducting state and the transistors 18a, 18b are in the blocked state.

[0181] The first battery 5 discharges firstly via the secondary link 14 of the first link 10.

[0182] Then, after the delay Td, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18c, 18d of the secondary link 14 are in the blocked state and the transistors 18a, 18b of the main link 12 of the first link 10 are in the conducting state (step E40.

[0183] The first battery 5 is charged via the main link 12 of the first link 10.

[0184] Similarly, at step E33, if:

[0185] VI > Bl_charge_max,

[0186] The processing unit 22 drives the control modules so that the transistors 18a, 18b, 18c, 18d of the first link 10 are in the blocked state, and that the transistors 18g, 18h of the secondary link 14 of the second link 11 are in the conducting state.

[0187] The second battery 6 discharges firstly via the secondary link 14 of the second link 11.

[0188] Then, after the delay Td, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f are in the conducting state, and the transistors 18g, 18h are in the blocked state (step E41).

[0189] The second battery 6 discharges via the main link 12 of the second link 11, and the process returns to step E30.

[0190] Thus, if the voltage of one battery is lower than the maximum charging voltage and the voltage of the other battery is higher, the algorithm will allow the battery that has not reached its maximum charging voltage to be charged.

[0191] At step E31,

[0192] siV3 <V2etVl,

[0193] The first voltage V1 is compared with the minimum discharge voltage of the first battery 5. The processing unit 22 checks if:

[0194] VI > Bl_discharge_min (step E42).

[0195] If so, the second voltage V2 is compared with the minimum discharge voltage of the second battery 6. The processing unit 22 checks if:

[0196] V2 > B2_discharge_min (step E43).

[0197] If the voltage of the two batteries is greater than the minimum discharge voltage, the two batteries are connected in parallel and the discharge begins.

[0198] The batteries are discharged in the following manner.

[0199] The processing unit 22 first drives the control modules so that the transistors 18c, 18d, 18g, 18h of the secondary links 14 of the two links 10, 11 are in the conducting state, the transistors of the other links being in the blocked state.

[0200] Time t is incremented:

[0201] t = t + 1 (step E44).

[0202] Processing unit 22 checks if:

[0203] t > Td (step E45).

[0204] As long as this is not the case, the process returns to step E44. When this is the case, the process proceeds to step E46.

[0205] After the delay Td, the processing unit 22 drives the control modules so that the transistors 18a, 18b, 18e, 18f of the main links 12 are in the conducting state and the transistors 18c, 18d, 18g, 18h of the secondary links 14 are in the blocked state.

[0206] The discharge of the batteries is therefore ensured via the main links 12, and the process returns to step E30.

[0207] At step E42, if:

[0208] VI < Bl_discharge_min,

[0209] The processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b, 18c, 18d are in the blocked state (step E47).

[0210] Then, processing unit 22 checks if:

[0211] V2 > B2_discharge_min (step E48).

[0212] If this is not the case, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18e, 18f, 18g, 18h are in the blocked state (step E49). None of the batteries discharge and the process returns to step E30.

[0213] If so, the processing unit 22 drives the control module 20d so that the transistors 18g, 18h of the secondary link 14 of the second link 11 are in the conducting state (step E50).

[0214] The second battery 6 is first discharged via the secondary link 14 of the second IL link

[0215] Then, after the delay Td, the processing unit 22 drives the control modules 20c, 20d so that the transistors 18g, 18h of the secondary link 14 are in the blocked state and the transistors 18e, 18f of the main link 12 of the second link 11 are in the conducting state.

[0216] The second battery 6 discharges via the main link 12 of the second link 11, and the process returns to step E30.

[0217] Similarly, at step E43, if:

[0218] V2 < B2_discharge_min,

[0219] The processing unit 22 drives the control modules 20a, 20b, 20c, 20d so that the transistors 18e, 18f, 18g, 18h of the second link 11 are in the blocked state, and so that the transistors 18c, 18d of the first link 10 are in the conducting state.

[0220] The first battery 5 discharges firstly via the secondary link 14 of the first link 10.

[0221] Then, after the delay Td, the processing unit 22 drives the control modules 20a, 20b so that the transistors 18a, 18b are in the conducting state and the transistors 18c, 18d are in the open state (step E51).

[0222] The first battery 5 discharges via the main link 12 of the first link 10, and the process returns to step E30.

[0223] Thus, if the voltage of one battery is lower than the minimum discharge voltage and the voltage of the other battery is higher, the algorithm will allow the discharge of the battery that has not reached its minimum discharge voltage.

[0224] It should be noted that the electronic circuit 8 is designed to ensure the safety and reliability of the system. It allows for monitoring the batteries and detecting anomalies, thereby preventing accidents and breakdowns.

[0225] It is also noted that the circuit 8 can be designed in a modular fashion, which allows it to be easily adapted to the specific needs of each application. This reduces costs and improves the flexibility of the system.

[0226] For example, each link can be designed as a modular link block comprising a primary link 12 and a secondary link 14. A third battery of a third technology, different from the first and second technologies, could then be easily added to the power supply system by providing an additional link block. The additional link block would then simply need to be connected to the charger 9, the third battery, and the processing unit 22.

[0227] The solution that has been described therefore makes it possible to facilitate the paralleling and simultaneous management of batteries of different technologies, which makes it possible, for example, to modernize old installations equipped with lead-acid batteries, by integrating lithium-ion batteries without requiring the complete replacement of the entire installation.

[0228] The usefulness of this invention is multifaceted. First, it enables a significant economic, technical, and environmental transition. By modernizing existing installations with newer batteries, such as lithium-ion batteries, this solution offers economic advantages by avoiding the full cost of infrastructure replacement. From a technical standpoint, it provides optimized energy management by intelligently combining the characteristics of new and existing batteries. Furthermore, the invention allows users to benefit from the technical characteristics of a two-battery combination, thus offering greater flexibility in the use of stored energy. From an environmental perspective, the invention promotes a sustainable approach by extending the lifespan of existing installations and integrating more environmentally friendly technologies.

[0229] Thus, the invention meets the need to modernize existing energy systems, by offering an innovative and efficient solution that reconciles technical performance, economic advantages, energy flexibility and environmental responsibility.

[0230] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0231] The battery-powered load is not necessarily a telecommunications tower. The charger is not necessarily connected to photovoltaic panels; another primary energy source can be considered (wind power, for example).

[0232] The invention can be implemented with a different number of batteries, designed according to a different number of different technologies. The technologies used are not necessarily lead-acid and lithium-ion technologies.

[0233] The current limiter used in the secondary links is not necessarily a thermistor. It could be a different device, for example a device that uses PWM (Pulse Width Modulation) and modifies the duty cycle of the current to limit it.

Claims

Demands

1. An electronic circuit (8), arranged to be connected to at least two batteries (5, 6) of different technologies, comprising: • a bidirectional charger (9) including an output (S2); • for each battery, a link (10, 11) connecting the output (S2) of the bidirectional charger to said battery, each link comprising a primary link (12) and a secondary link (14) connected in parallel, • the primary link comprising a primary switching device (15) arranged to selectively switch said primary link on or off; • the secondary link comprising a secondary switching device (16) arranged to selectively switch said secondary link on or off, and a current limiting device (17) mounted in series with the secondary switching device;• Voltage sensors (25) arranged to measure, for each battery, the voltage (VI, V2) across the terminals of said battery, as well as the voltage (V3) at the output of the bidirectional charger; • A processing unit (22) arranged to, based on voltage measurements produced by the voltage sensors, control the primary and secondary switching devices to charge and discharge the batteries via the bidirectional charger, using, for each battery, first the secondary link for a predetermined time, then the primary link of the connection associated with said battery.

2. Electronic circuit according to claim 1, wherein each current limiting device comprises a thermistor (19).

3. Electronic circuit according to any one of the preceding claims, wherein each primary switching device and secondary switching device comprises two MOSFET-type transistors (18) mounted in series.

4. An electronic circuit according to any one of the preceding claims, wherein the processing unit (22) is arranged to implement: • a first phase (PI), designed to ensure that the voltage difference between the voltages across the battery terminals is less than a predetermined threshold; • then a second phase (P2), designed to optimize the charging and / or discharging of the batteries.

5. Electronic circuit according to claim 4, wherein, during the first phase (PI), the processing unit (22) is arranged to: - determine a maximum voltage among the voltages (VI, V2) across the battery terminals; - check if the maximum voltage is greater than the voltage (V3) on the output of the bidirectional charger (9); - if so, and if the voltage across the battery that has the maximum voltage is greater than its minimum discharge voltage, discharge said battery; - if not, charge each other battery whose voltage is less than its maximum charge voltage.

6. An electronic circuit according to any one of claims 4 or 5, wherein, during the second phase (P2), the processing unit (22) is arranged to: • for each battery (5, 6), compare the voltage across said battery with the voltage (V3) at the output of the bidirectional charger (9); • for each battery, if the voltage across said battery is less than the voltage (V3) at the output of the bidirectional charger, and if the voltage across said battery is less than its maximum charging voltage, charge said battery; • for each battery, if the voltage across said battery is greater than the voltage (V3) at the output of the charger, and if the voltage across said battery is greater than its minimum discharge voltage, discharge said battery.

7. Power supply system (2) comprising at least two batteries (5, 6) of different technologies and an electronic circuit (8) according to any one of the preceding claims.

8. Hybrid battery management method, implemented in the processing unit (22) of the electronic circuit (8) according to any one of the preceding claims, and comprising the steps of: - acquiring the voltage measurements produced by the voltage sensors (25); - driving the main disconnect devices (15) and the secondary disconnect devices (16) to charge and discharge the batteries (5, 6) via the bidirectional charger (9), using, for each battery, first the secondary link for a predetermined time, then the main link of the connection associated with said battery.

9. Hybrid battery management method according to claim 8, comprising: • a first phase (PI), intended to ensure that a voltage difference, between the voltages (VI, V2) at the terminals of the batteries, is less than a predetermined threshold; • then a second phase (P2), intended to optimize a charge and / or discharge of the batteries.

10. Hybrid battery management method according to claim 9, comprising the steps, during the first phase (PI), of: - determining a maximum voltage among the voltages (VI, V2) across the battery terminals; - checking if the maximum voltage is greater than the voltage at the output of the bidirectional charger; - if so, and if the voltage across the battery that has the maximum voltage is greater than its minimum discharge voltage, discharging said battery; - if not, charging each other battery whose voltage is less than its maximum charge voltage.

11. A hybrid battery management method according to claim 9 or 10, comprising the steps, during the second phase (P2), of: • for each battery (5, 6), comparing the voltage across said battery with the voltage at the output of the bidirectional charger; • for each battery, whether the voltage across said battery is less than the voltage at the output of the bidirectional charger, and whether the voltage across said battery is lower than its maximum charging voltage, charge said battery; • for each battery, if the voltage across said battery is greater than the voltage at the output across the charger terminals, and if the voltage across said battery is greater than its minimum discharge voltage, discharge said battery.

12. Computer program comprising instructions that drive the processing unit (22) of the electronic circuit (8) according to any one of claims 1 to 6 to perform the steps of the hybrid battery management method according to any one of claims 8 to 11.

13. Computer-readable recording medium on which the computer program according to claim 12 is recorded.

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