A dynamic system for balancing the charging voltage of battery modules.

Abstract

The invention relates to a battery (1) for storing electrical energy, comprising: a plurality of battery modules (1A, 1B) electrically connected by an electric circuit (10); and a switch unit (3) comprising a plurality of switches (31, 32, 33, 34, 35, 36) arranged in the electric circuit and designed to connect the battery modules in series in the electric circuit (10) during a charging phase of the battery by a charger (2). According to the invention, the switch unit (3) further comprises a system (40) for balancing the charge of the battery modules, arranged in the electric circuit and designed to vary the electric circuit in a mixing phase in which the battery is charged by the charger and simultaneously discharged into a demand circuit (4) that it supplies, in order to shunt part of the current delivered to one of the overcharged battery modules to another of the undercharged battery modules.

Description

Technical Field

[0001] The present invention generally relates to batteries for storing electrical energy.

[0002] More particularly, the present invention relates to a battery for storing electrical energy, the battery comprising: - a plurality of battery modules each adapted to store electrical energy and electrically connected by an electrical circuit; - a switch unit comprising a plurality of switches adapted to connect the battery modules in series in the electrical circuit during battery charging by a charger and arranged on the electrical circuit. The battery also includes a switch unit.

[0003] The present invention finds advantageous applications in batteries for land, river or air transport vehicles, particularly in batteries for electric vehicles. This battery is particularly suitable for rapid recharge at a voltage higher than the nominal voltage delivered from the battery to supply electrical energy to the vehicle components.

[0004] The present invention also relates to a method for controlling such a battery in order to control the switches of the switch unit to open and close, particularly depending on the charging or discharging stage of the battery.

Background Art

[0005] In order to shorten the time required for charging a battery to store electrical energy, the charging power of the battery should be increased. For this purpose, rather than increasing the charging current of the battery, it is preferable to increase the charging voltage across the terminals of the battery.

[0006] However, increasing the battery charging voltage makes it incompatible with the operating voltage of vehicle components such as air conditioning and heating systems, radios, fans, i.e., actually inverters, which require electrical energy supply from the battery.

[0007] The first known solution involves converting the vehicle's components so that their operating voltage equals the charging voltage, which is extremely expensive.

[0008] A second solution disclosed in U.S. Patent Application Publication No. 20180062402 involves charging the battery by setting the battery charging voltage higher than the operating voltage of the vehicle's components. For this purpose, the battery is divided into battery modules, which are electrically connected in series with each other through a high-voltage battery charging phase. Through the battery discharge phase, only one battery module supplies electrical energy to the vehicle's components, and the voltage delivered by this battery module is compatible with the operating voltage of the said components of the vehicle. Once this battery module reaches a selected charge level, it is taken over by another battery module to supply power to the components.

[0009] However, with this second solution, it is not possible to supply power to the vehicle's components while the battery is charging. [Overview of the project]

[0010] Presentation of the invention To mitigate the aforementioned shortcomings of the prior art, the electrical energy storage battery proposed by the present invention can supply power to a vehicle circuit that consumes electrical energy at a first voltage, and at the same time, can be recharged at a second voltage higher than the first voltage.

[0011] More specifically, according to the present invention, a battery as defined in the opening section is proposed, and the switch unit further comprises a system on the electrical circuit for balancing the charging of battery modules, the system being adapted to change the electrical circuit so that some of the current sent to the overcharged battery module is diverted to another undercharged battery module through a mixing stage in which the battery is being charged by a charger while simultaneously discharging to a demand circuit that supplies electrical energy.

[0012] Therefore, the present invention enables simultaneous battery utilization and rapid charging without damaging the battery or the vehicle components supplied with power from the battery via a demand circuit.

[0013] More specifically, a system for balancing the batteries allows for the dynamic balancing of the charge levels of each battery module. This balancing system controls the voltage of each battery module within a specific margin, ensuring that the charge level remains the same until the battery is fully charged. Even if one of the battery modules is required to supply electrical energy to a demand circuit while the batteries are charging, each battery module remains balanced. When two battery modules are supplying the same voltage (controlled within the margin), the terminals between them are at the "same charge level."

[0014] The battery according to the present invention has other advantageous and non-limiting functions, which may be employed individually or in any technically possible combination. - The switch unit's switch is adapted to connect the battery modules in series in the electrical circuit throughout the mixing stage, and at the same time connect the demand circuit to the terminals of at least one battery module, preferably just one battery module. - The switches in the switch unit are further adapted to connect the battery modules in parallel in the electrical circuit through the discharge phase of the battery to the demand circuit, and the balance system is adapted to change the electrical circuit during the transient phase between the charging and discharging phases of the battery so that some of the current sent to the overcharged battery module is diverted to another undercharged battery module. - The balance system comprises at least one main balance unit, positioned as a branch from a portion of an electrical circuit branch connecting the two positive terminals of two separate battery modules, the main balance unit comprising a switch connected in series with a coil and in parallel with a diode to prevent overvoltage from being applied to the switch. - The closing period of the switch of the main balance unit is controlled by pulse width modulation, depending on the voltage across the terminals of the battery module to be balanced and the charging current from the charger. - The balance system is positioned as a branch from a portion of the branch of the electrical circuit connecting the two negative terminals of the two separate battery modules, and comprises at least one sub-balance unit which includes a switch connected in series with a coil and in parallel with a diode to prevent overvoltage from being applied to the switch. - The switches for each main balance unit and sub-balance unit are power transistors. - A first battery module is provided, the negative terminal of which is connected to the positive terminal of the second battery module by a first diode and a second diode connected in series with each other, the current input terminal of the first diode is connected to the negative terminal of the first battery module, and the current output terminal of the second diode is connected to the positive terminal of the second battery module. - A switch unit is provided, comprising: a first switch having a first contact point configured to connect to the positive terminal of the charger and a second contact point connected to the positive terminal of the first battery module; a second switch having a first contact point configured to connect to the negative terminal of the charger and a second contact point connected to the negative terminal of the second battery module; a third switch having a first contact point connected to the positive terminal of the second battery module and a second contact point connected to one terminal of the demand circuit; a fourth switch having a first contact point connected to the negative terminal of the second battery module and a second contact point connected to the other terminal of the demand circuit; a fifth switch having a first contact point connected to the positive terminal of the first battery module and a second contact point connected to the current output terminal of the second diode; and a sixth switch having a first contact point connected to the negative terminal of the second battery module and a second contact point connected to the current input terminal of the first diode. - A main balance unit of the balance system is provided, positioned on an electrical branch connecting the positive terminal of the first battery module and the current input terminal of the second diode, and the current input terminal of the diode of the main balance unit is connected to the current output terminal of the first diode. - The sub-balance unit of the balance system is positioned on an electrical branch connecting the negative terminal of the second battery module and the current input terminal of the second diode, and the current output terminal of the diode of the sub-balance unit is connected to the current output terminal of the first diode.

[0015] The present invention also proposes a method for controlling a battery comprising a plurality of battery modules electrically connected by a switch unit in an electrical circuit, wherein the switch unit comprises a plurality of switches and a system for balancing the charging of the battery modules, and accordingly, - To control the switches of the switch unit to connect the battery modules in series with each other throughout the charging stage of the battery by the charger, and - A control unit is provided for controlling a balance system of a switch unit to shunt some of the current sent to the overcharged battery module in the battery module to another undercharged battery module in the battery module through a mixing stage in which the battery is charged by a charger while simultaneously discharging to a demand circuit. A control unit is provided.

[0016] The method according to the present invention has the following advantageous and non-limiting other functions, which are employed individually or in any technically possible combination. - The control unit controls the switches of the switch unit to connect the demand circuit to at least one terminal of the battery module while keeping the battery modules connected in series through the mixing stage. - The control unit controls the switches of the switch unit to connect the battery modules in parallel with each other through a discharging stage in which the battery supplies electrical energy to the demand circuit.

[0017] Of course, various features, modifications and embodiments of the present invention can be combined with each other in various ways if they are not incompatible or mutually exclusive with each other.

[0018] The configuration of the present invention and the method of implementing the present invention will be easily understood from the following description accompanied by references to the attached drawings shown as non-limiting examples.

Brief Description of the Drawings

[0019] [Figure 1] It is an electrical circuit diagram of a battery according to the present invention. [Figure 2] It is a diagram showing the main steps of the control method according to the present invention.

Embodiments for Implementing the Invention

[0020] FIG. 1 shows a circuit diagram of an example of a battery 1 according to the present invention.

[0021] The battery 1 is installed in a vehicle (not shown), such as an electric vehicle or a hybrid vehicle.

[0022] The battery 1 is adapted to store electrical energy and, when required, return it by sending all or part of the stored electrical energy to the demand circuit 4, which is inside the vehicle and is connected to various components of the vehicle, such as an air conditioning and heating system, a radio, a fan, or actually an inverter. The battery 1 can send a nominal supply voltage Va, which is about 400 volts here, to the demand circuit 4.

[0023] The battery 1 is adapted to be charged (recharged in everyday language) by an external charger 2 that sends a charging current Ic and a charging voltage Vc to store electrical energy. The charger 2 itself is known. The charger 2 is, for example, a public or private charging stand provided on a street, at a gas station, in a parking lot, etc.

[0024] To quickly charge the battery, the charging voltage Vc sent by the charger 2 to the battery is much higher than the supply voltage Va that the battery 1 supplies to the demand circuit 4. For example, the charging voltage Vc is twice the supply voltage Va. Here, the charging voltage Vc is about 800 volts.

[0025] The battery 1 comprises a plurality of battery modules 1A, 1B that are electrically connected to each other by an electrical circuit 10 that can incorporate various configurations so that the battery 1 can be charged with a charging voltage Vc higher than the supply voltage Va to the demand circuit 4.

[0026] Each battery module 1A, 1B is adapted to store electrical energy as long as it comprises a plurality of electrochemical cells (not shown) in which the electrical energy is stored. The battery modules 1A, 1B are, for example, lithium-ion batteries.

[0027] Here, all battery modules 1A and 1B are sized to deliver the same nominal supply voltage Va between their respective positive and negative terminals. For this purpose, all battery modules 1A and 1B are equipped with the same number of electrochemical cells of the same storage capacity, connected in series with each other within the same battery module 1A or 1B.

[0028] In the example shown in Figure 1, battery 1 comprises a first battery module 1A and a second battery module 1B, each sized to deliver a nominal supply voltage Va of approximately 400 volts.

[0029] In this example, in the electrical circuit 10, the negative terminal of the first battery module 1A is connected to the positive terminal of the second battery module 1B through the first diode DA and the second diode DB. The first diode DA and the second diode DB are connected in series with each other, and as a result, the current input terminal of the first diode DA is connected to the negative terminal of the first battery module 1A, and the current output terminal of the second diode DB is connected to the positive terminal of the second battery module 1B.

[0030] Typically, a diode allows current to flow in only one direction through the connected electrical branch. Therefore, by convention, the "current input terminal of a diode" refers to the terminal through which current flows into the diode, and the "current output terminal of a diode" refers to the terminal through which the current flows out after passing through the diode.

[0031] In order to enable the electrical connection of battery modules 1A and 1B in the electrical circuit 10 according to various configurations, the battery 1 is equipped with a switch unit 3 that includes multiple switches 31, 32, 33, 34, 35, and 36 arranged on the electrical circuit 10.

[0032] In the example in Figure 1, the switch unit 3 is - A first switch 31 having a first contact point configured to connect to the positive terminal of charger 2 and a second contact point connected to the positive terminal of the first battery module 1A, - A second switch 32 having a first contact point configured to connect to the negative terminal of charger 2 and a second contact point connected to the negative terminal of second battery module 1B, - A third switch 33 having a first contact point connected to the positive terminal of the second battery module 1B and a second contact point connected to one terminal (in this case, the negative terminal) of the demand circuit 4, - A fourth switch 34 having a first contact point connected to the negative terminal of the second battery module 1B and a second contact point connected to the other terminal (in this case, the positive terminal) of the demand circuit 4, - A fifth switch 35 having a first contact point connected to the positive terminal of the first battery module 1A and a second contact point connected to the current output terminal of the second diode DB, - A sixth switch 36 having a first contact point connected to the negative terminal of the second battery module 1B and a second contact point connected to the current input terminal of the first diode DA. It is equipped with.

[0033] The electrical circuit 10 can be adjusted to employ separate configurations corresponding to each operating stage of the battery 1 by opening and / or closing each of the switches 31, 32, 33, 34, 35, and 36 of the switch unit 3. A configuration of the electrical circuit 10 for the charging stage of the battery 1 by the charger 2, and another configuration of the electrical circuit 10 for the discharge stage of the battery 1 to the demand circuit 4 are specifically provided.

[0034] In practice, the switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 are controlled by the control unit 5 to open and close depending on the operating stage of the battery 1. In other words, the control unit 5 is adapted to control the switch unit 3 to change the electrical circuit 10 according to various possible configurations.

[0035] The control unit 5 may be integrated into the battery 1 or may be remote from the battery 1. The control unit 5 comprises, for example, an electronic circuit having a microprocessor including a central processing unit (CPU), a random access memory and / or read-only memory for storing information, and an interface for communicating with the battery 1. The random access memory and / or read-only memory stores, in particular, information about the electrical circuit 10, information about the supply voltage Va detected across the respective terminals of the battery modules 1A and 1B, and information about the charging current Ic and charging voltage Vc delivered by the charger 2.

[0036] Throughout the charging phase of battery 1 by charger 2, switches 31, 32, 33, 34, 35, and 36 of switch unit 3 are controlled to connect the positive terminal of battery 1 to the positive terminal of charger 2 and the negative terminal of battery 1 to the negative terminal of charger 2. Throughout the charging phase of battery 1, switches 31, 32, 33, 34, 35, and 36 are further controlled to connect battery modules 1A and 1B in series in the electrical circuit 10.

[0037] Therefore, in the example shown in Figure 1, the first switch 31 and the second switch 32 are closed and the third switch 34, the fourth switch 35, the fifth switch 36, and the sixth switch 37 are opened during the charging phase of battery 1.

[0038] In contrast, during the discharge phase of battery 1 to the vehicle's demand circuit 4, switches 31, 32, 33, 34, 35, and 36 are controlled to connect the positive terminal of battery 1 to the negative terminal of demand circuit 4 and the negative terminal of battery 1 to the positive terminal of demand circuit 4. During the discharge phase of battery 1, switches 31, 32, 33, 34, 35, and 36 are also controlled to connect battery modules 1A and 1B in parallel in the electrical circuit 10.

[0039] Therefore, in the example shown in Figure 1, the third switch 33, the fourth switch 34, the fifth switch 35, and the sixth switch 36 are closed and the first switch 31 and the second switch 32 are opened during the discharge phase of battery 1.

[0040] The battery 1 according to the present invention is further adapted to operate in a mixed phase, being charged by a charger 2 at a charging voltage Vc and simultaneously discharging by supplying power to a demand circuit 4 at a supply voltage Va.

[0041] Therefore, during such a mixed operation phase of battery 1, the vehicle user can use one of the vehicle's components, such as the air conditioning system or the radio, at the same time as recharging battery 1.

[0042] Throughout the mixed operation phase, switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 are controlled to connect the positive terminal of battery 1 to the positive terminal of charger 2 and the negative terminal of battery to the negative terminal of charger 2. Throughout the mixed operation phase, switches 31, 32, 33, 34, 35, and 36 are further controlled to connect the demand circuit 4 to at least one terminal of battery modules 1A and 1B while keeping battery modules 1A and 1B connected in series in the electrical circuit 10 (connecting the positive terminal of one of battery modules 1A and 1B to the positive terminal of demand circuit 4, and connecting the negative terminal of the at least one battery module 1A or 1B to the negative terminal of demand circuit 4).

[0043] Therefore, in the example shown in Figure 1, through the mixed operation phase of battery 1, the first switch 31, the second switch 32, the third switch 33, and the fourth switch 34 are closed, and the fifth switch 35 and the sixth switch 36 are opened. Then, the demand circuit 4 is electrically connected only to the terminals of the second battery module 1B.

[0044] Notably, the switch unit 3 further includes a balance system 40 that dynamically balances the charging of battery modules 1A and 1B, especially when charging and discharging of the battery modules 1A and 1B are performed simultaneously. The balance system 40 makes it particularly possible to maintain the balance between the components of the electrical circuit 10 and the components of the vehicle connected to the demand circuit 4 throughout the mixed operation phase of the battery 1.

[0045] The balancing system 40 is positioned on the electrical circuit 10 and adapted to modify the electrical circuit 10 so as to divert some of the current sent to the overcharged battery module 1A, 1B to the other undercharged battery module 1A, 1B. Thus, when balancing is not performed, some of the current intended to power one of the battery modules 1A, 1B is diverted by the balancing system 40 as needed through the mixing stage. More specifically, when the balancing system 40 is activated, the undercharged battery module 1A, 1B is simultaneously discharged, particularly to the demand circuit 4, so some of the current intended to power the overcharged battery module 1A, 1B is diverted to supply more power to the undercharged battery module 1A, 1B. Balancing is considered "dynamic" as long as charging and discharging of the battery modules 1A, 1B are occurring on the one hand and not interfering with the charging and discharging of the battery modules 1A, 1B on the other hand.

[0046] The balance system 40 includes at least one main balance unit 41, which is positioned as a branch from a portion of the branch of the electrical circuit 10 that connects the two positive terminals of two separate battery modules 1A and 1B.

[0047] As shown in Figure 1, the main balance unit 41 here comprises a switch 410 connected in series with a coil L1 and in parallel with a diode D1. The diode D1 protects the switch 410 from potential overvoltages. Here, the switch 410 of the main balance unit 41 is a power transistor.

[0048] In the example shown in Figure 1, the main balance unit 41 of the balance system 40 is located on an electrical branch connecting the positive terminal of the first battery module 1A and the current input terminal of the second diode DB. The current input terminal of diode D1 of the main balance unit 41 is connected to the current output terminal of the first diode DA.

[0049] In the example shown in Figure 1, the main balance unit 41, when the switch 410 is closed, allows some of the charging current Ic from the charger 2, which is normally intended to recharge the first battery module 1A, to be transferred to the second battery module 1B, which is undercharged to the first battery module 1A because it is discharging to the demand circuit 4.

[0050] When switch 410 is closed, a current lamp appears in the branch of the electrical circuit 10 that carries coil L1. The longer the switch 410 is closed, the greater the current transmitted to the second battery module 1B through the main balance unit 41. To achieve accurate and precise balancing, the opening and closing of switch 410 should be controlled at a frequency of approximately 50 kHz.

[0051] The diode D1 of the main balance unit 41 can protect the switch 410 when it is opened. When the switch 410 is opened, the current flowing through the main balance unit 41 continues to flow for the coil L1. The so-called "freewheel" diode D1 allows some of this current to flow to the positive terminal of the first battery module 1A when the switch 410 is opened, thus preventing the switch 410 from tripping.

[0052] The closing period of the switch 410 of the main balance unit 41 is controlled by pulse width modulation. The width of the control pulse is adjusted, on the one hand, based on the supply voltage Va detected across the terminals of the battery modules 1A and 1B to be balanced, and on the other hand, based on the charging current Ic from the charger 2.

[0053] Here, the control unit 5 controls the opening and closing pulses of the switch 410 of the main balance unit 41 of the balance system 40.

[0054] To enable balancing of battery modules 1A and 1B in both directions, that is, from the overcharged first battery module of battery modules 1A and 1B to the undercharged second battery module of battery modules 1A and 1B on the one hand, and from the second battery module that became overcharged during operation to the undercharged first battery module of battery modules 1A and 1B on the other hand, the balance system 40 also includes a sub-balance unit 42, which is positioned as a branch from a part of the branch of the electrical circuit 10 that connects the two negative terminals of the two separate battery modules 1A and 1B.

[0055] As shown in Figure 1, the sub-balance unit 42 is similar to the main balance unit 41. The sub-balance unit 42 is equipped with a switch 420 connected in series with a coil L2 and in parallel with a diode D2. The diode D2 protects the switch 420 from potential overvoltages. Here, the switch 420 of the sub-balance unit 42 is a power transistor.

[0056] In the example shown in Figure 1, the sub-balance unit 42 of the balance system 40 is located on an electrical branch of the electrical circuit 10 that connects the negative terminal of the second battery module 1B to the current input terminal of the second diode DB. The current output terminal of diode D2 of the sub-balance unit 42 is connected to the current output terminal of the first diode DA.

[0057] In the example shown in Figure 1, the sub-balance unit 42 operates in the same manner as described with respect to the main balance unit 41, so that when the switch 420 is closed, it can transfer some of the current intended to recharge the overcharged second battery module 1B to the undercharged first battery module 1A relative to the second battery module 1B.

[0058] The control unit 5 also controls the switching pulses for the switch 420 of the sub-balance unit 42 of the balance system 40. The pulse width is adjusted on the one hand, depending on the voltage between the respective terminals of the battery modules 1A and 1B to be balanced, and on the other hand, depending on the charging current Ic from the charger 2.

[0059] The inductance of coil L1 and the characteristics of diode D1, like the inductance of coil L2 and the characteristics of diode D2, are finally fixed depending on the power of battery 1 and the maximum allowable imbalance between the terminal supply voltages Va of battery modules 1A and 1B, respectively. Just as the characteristics of diodes D1 and D2 are not necessarily identical, the inductance of coil L2 is not necessarily identical to the inductance of coil L1.

[0060] When the balance system 40 is operating, the control unit 5 does not control the switch 410 of the main balance unit 41 and the switch 420 of the sub-balance unit 42 to close simultaneously. Symmetrically, the control unit 5 controls the switches 410 and 420 to close alternately. When the balance system 40 stops operating, the switch 410 of the main balance unit 41 and the switch 420 of the sub-balance unit 42 are opened simultaneously.

[0061] Advantageously, the aforementioned balancing system 40 is also adapted to modify the electrical circuit 10 so that, during the transient phase between the charging and discharging phases of battery 1, some of the current sent to the overcharged battery module 1A, 1B is diverted to the undercharged battery module 1A, 1B.

[0062] The transient operation phase is the phase that occurs between the end of charging of battery 1 and the configuration of the electrical circuit 10 for the discharge phase of battery 1.

[0063] Throughout the transient phase of battery 1, switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 are controlled to disconnect the positive terminal of battery 1 from the positive terminal of charger 2 on the one hand, and to disconnect the negative terminal of battery 1 from the negative terminal of charger 2 on the other hand. Throughout the transient phase, battery modules 1A and 1B are not yet connected in parallel in the electrical circuit 10.

[0064] Therefore, in the example in Figure 1, throughout the transient phase of battery 1, the first switch 31 and the second switch 32 are open, as are the fifth switch 35 and the sixth switch 36. The third switch 33 and the fourth switch 34 are also open.

[0065] In the case of two battery modules 1A and 1B, the first switch 31 and the second switch 32 are open at the end of the charging stage of battery 1 or at the end of the mixing stage of battery 1, and are dynamically balanced by the balance system 40, but they are not at exactly the same charge level and therefore cannot deliver the same nominal supply voltage Va between the terminals of each module. The balance system 40 can correct this imbalance, and the control unit 5 controls the alternation of closed and open pulses and the switch 410 of the main balance unit 41 and the switch 420 of the sub-balance unit 42 until the balance is restored.

[0066] Figure 2 shows the main steps of an example of a method for controlling battery 1, as previously described.

[0067] According to the control method of the present invention, - In order to control switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 so as to connect the battery modules 1A and 1B in series with each other during the charging stage of the battery 1 by the charger 2, - To control the balance system 40 of the switch unit 3 so that, through a mixed phase in which battery 1 is being charged by charger 2 and simultaneously discharged to demand circuit 4, some of the current sent to the overcharged battery module 1A, 1B is diverted to the undercharged battery module 1A, 1B. A control unit 5 is provided.

[0068] Throughout the mixing stage, the control unit 5 further controls switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 to connect battery modules 1A and 1B in series and simultaneously connect the demand circuit to at least one terminal of battery modules 1A and 1B. More specifically, as shown in Figure 2, during step E1, the control unit 5 determines whether the charger 2 is connected to the electrical circuit 10. If the charger is not connected to the circuit, the control unit 5 repeats step E1 until the charger 2 is connected to the electrical circuit 10.

[0069] When the charger 2 is connected to the electrical circuit 20, the control unit 5 controls the switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 to connect the battery modules 1A and 1B in series with each other through step E2. The electrical circuit 10 then adopts the configuration associated with the aforementioned charging stage of the battery 1.

[0070] Next, during step E3, the control unit 5 determines whether the vehicle components connected to the demand circuit 4 are operational or activated by the vehicle user.

[0071] If no vehicle components are in operation, battery 1 is charged by a conventional known method as indicated in step E4a of Figure 2. According to this known method, each electrochemical cell is monitored by a cell voltage sensor (CVS), and if one of the electrochemical cells reaches a higher voltage than the other electrochemical cells in the same battery module, it is immediately discharged into a resistor.

[0072] On the other hand, if at least one component of the vehicle is operating, or as soon as the operation of a component of the vehicle is detected by the control unit 5, the demand circuit 4 is connected to the battery 1 (step E4 in Figure 2). Through this step E4, the control unit 5 controls switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 to connect the demand circuit 4 to at least one terminal of the battery modules 1A and 1B. The electrical circuit 10 then adopts the configuration associated with the aforementioned mixed operation stage of the battery 1.

[0073] Next, through step E5, the control unit 5 determines whether there is a charge imbalance between battery modules 1A and 1B. For this purpose, the control unit 5 uses a voltage sensing unit (not shown) to determine the terminal supply voltage Va of battery modules 1A and 1B, respectively.

[0074] If no imbalance is detected, the control unit 5 repeats step E5 until an imbalance is detected.

[0075] When the control unit 5 detects an imbalance, it controls the balance system 40 of the switch unit 3 during step E6 to divert some of the current that would normally be intended to power the overcharged battery module 1A or 1B to the other undercharged battery module 1A or 1B. In step E6, the control unit 5 controls the open and closed periods of switches 410 and 420 of the balance system 40 by pulse width modulation to activate the balance system 40, thereby controlling the switches 410 and 420 to close alternately.

[0076] Through step E7, the control unit 5 determines whether the rebalancing of the charge of battery modules 1A and 1B is complete. If it is not complete, that is, if the control unit 5 determines that the terminal supply voltages Va of battery modules 1A and 1B are different, it repeats step E6 described above.

[0077] In contrast, once the control unit 5 determines that rebalancing is complete, i.e., that the terminal supply voltages Va of battery modules 1A and 1B are approximately equal, it controls switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 to disconnect the charger 2 during step E8. In practice, the control unit 5 controls the opening of the first switch 31 and the second switch 32 during step E8. The electrical circuit 10 then adopts the configuration associated with the aforementioned transient phase of battery 1.

[0078] Next, through step E9, the control unit 5 determines again whether there is an imbalance in the battery modules 1A and 1B due to opening the first switch 31 and the second switch 32.

[0079] When the control unit 5 detects an imbalance, it controls the balance system 40 again through step E10 to operate in a manner similar to that described with respect to step E6.

[0080] Once the terminal supply voltages Va of battery modules 1A and 1B become equal, the control unit 5 controls switches 31, 32, 33, 34, 35, and 36 of the switch unit 3 to connect battery modules 1A and 1B in parallel during step E11.

[0081] Next, the electrical circuit 10 adopts a configuration related to the aforementioned discharge stage of the battery 1. Then, the balance system 40 stops operating, i.e., switches 410 and 420 remain open.

[0082] If no imbalance is detected in step E9, the control unit 5 directly performs step E11.

[0083] Thus, the battery 1 and its control method according to the present invention make it possible to recharge the battery 1 while it is in use. For example, in a situation with two identical battery modules 1A and 1B, each with a capacity of 40 kilowatt-hours (kWh) and capable of supplying a nominal voltage of 400 volts when fully charged, and two coils L1 and L2 with a capacity of 200 microhenries (μH), if a 30-volt imbalance occurs between the battery modules 1A and 1B, the balance system 40 according to the present invention can distribute up to 10 amperes (A) of current to the undercharged module to compensate for this imbalance. In practice, since the battery modules 1A and 1B are dynamically rebalanced, i.e., drift, such an imbalance between the two battery modules 1A and 1B does not reach 30V. Therefore, generally, the current that the balance system 40 distributes from one of the battery modules 1A and 1B to the other is much smaller.

[0084] The present invention is not limited to the embodiments described and shown, and those skilled in the art will be able to see how to add any variations of the present invention to these embodiments.

[0085] In particular, a battery can contain more than two battery modules. Each battery module may have a different storage capacity, in which case the electrical circuit and the various configurations that the electrical circuit can employ are adapted accordingly.

Claims

1. A battery (1) for storing electrical energy, Multiple battery modules (1A, 1B), each adapted to store electrical energy and electrically connected by an electrical circuit (10), A switch unit (3) comprising a plurality of switches (31, 32, 33, 34, 35, 36), wherein the plurality of switches (31, 32, 33, 34, 35, 36) are arranged on the electrical circuit (10) and are adapted to connect the battery modules (1A, 1B) in series in the electrical circuit (10) through the charging stage of the battery (1) by the charger (2), wherein the battery (1) is The switch unit (3) further comprises a balancing system (40) for balancing the charging of the battery modules (1A, 1B), the balancing system (40) being positioned on the electrical circuit (10) and adapted to change the electrical circuit (10) so that, through a mixing stage in which the battery (1) is charged by the charger (2) while simultaneously discharging to the demand circuit (4), some of the current sent to the overcharged battery module (1A, 1B) is diverted to the undercharged battery module (1A, 1B), The balance system (40) includes at least one main balance unit (41) which is arranged as a branch from a part of the branch of the electrical circuit (10) that connects the two positive terminals of the two battery modules (1A, 1B). A battery (1) characterized by the following.

2. The battery (1) according to claim 1, wherein the switches (31, 32, 33, 34, 35, 36) of the switch unit (3) are adapted to connect the battery modules (1A, 1B) in series in the electrical circuit (10) throughout the mixing stage, and at the same time connect the demand circuit (4) to at least one terminal of the battery modules (1A, 1B), preferably to only one terminal of the battery modules (1A, 1B).

3. The battery (1) according to claim 1 or 2, wherein the switches (31, 32, 33, 34, 35, 36) of the switch unit (3) are further adapted to connect the battery modules (1A, 1B) in parallel in the electrical circuit (10) through the discharge phase of the battery (1) to the demand circuit (4), and the balance system (40) is adapted to change the electrical circuit (10) during a transient phase between the charging phase and the discharge phase of the battery (1) to transfer some of the current supplying power to the overcharged battery module (1A, 1B) to the other undercharged battery module (1A, 1B).

4. The battery (1) according to any one of claims 1 to 3, wherein the main balance unit (41) comprises a switch (410) connected in series with a coil (L1) and in parallel with a diode (D1).

5. The battery (1) according to any one of claims 1 to 4, wherein the closing period of the switch (410) of the main balance unit (41) is controlled by pulse width modulation based on the terminal supply voltage (Va) of the battery modules (1A, 1B) to be balanced and the charging current (Ic) from the charger (2).

6. Battery (1) according to claim 4 or 5, wherein the balance system (40) comprises at least one sub-balance unit (42), the at least one sub-balance unit (42) comprising a switch (420) connected in series with a coil (L2) and in parallel with a diode (D2), and is arranged as a branch from a portion of the branch of the electrical circuit (10) that connects the two negative terminals of the two battery modules (1A, 1B).

7. The battery (1) according to any one of claims 4 to 6, wherein the switches (410, 420) of each balance unit (41, 42) are power transistors.

8. A first battery module (1A) is provided in the battery (1), and the negative terminal of the first battery module (1A) is connected to the positive terminal of the second battery module (1B) by a first diode (DA) and a second diode (DB) connected in series with each other, the current input terminal of the first diode (DA) is connected to the negative terminal of the first battery module (1A), and the current output terminal of the second diode (DB) is connected to the positive terminal of the second battery module (1B). The switch unit (3) A first switch (31) having a first contact point configured to be connected to the positive terminal of the charger (2) and a second contact point connected to the positive terminal of the first battery module (1A), A second switch (32) having a first contact point configured to be connected to the negative terminal of the charger (2) and a second contact point connected to the negative terminal of the second battery module (1B), A third switch (33) having a first contact point connected to the positive terminal of the second battery module (1B) and a second contact point connected to one terminal of the demand circuit (4), A fourth switch (34) having a first contact point connected to the negative terminal of the second battery module (1B) and a second contact point connected to the other terminal of the demand circuit (4), A fifth switch (35) having a first contact point connected to the positive terminal of the first battery module (1A) and a second contact point connected to the current output terminal of the second diode (DB), The system includes a sixth switch (36) having a first contact point connected to the negative terminal of the second battery module (1B) and a second contact point connected to the current input terminal of the first diode (DA), The battery (1) according to any one of claims 4 to 7, wherein the main balance unit (41) of the balance system (40) is positioned on an electrical branch connecting the positive terminal of the first battery module (1A) and the current input terminal of the second diode (DB), and the current input terminal of the diode (D1) of the main balance unit (41) is connected to the current output terminal of the first diode (DA).

9. The battery according to claim 8, combined with claim 6, wherein the sub-balance unit (42) of the balance system (40) is positioned on an electrical branch connecting the negative terminal of the second battery module (1B) and the current input terminal of the second diode (DB), and the current output terminal of the diode (D2) of the sub-balance unit (42) is connected to the current output terminal of the first diode (DA).

10. A battery (1) comprising a plurality of battery modules (1A, 1B) electrically connected by a switch unit (3) having a plurality of switches (31, 32, 33, 34, 35, 36) in an electrical circuit (10), and a method for controlling a balance system (40) for balancing the charging of the battery modules (1A, 1B), wherein according to the method, In order to control the switches (31, 32, 33, 34, 35, 36) of the switch unit (3) so as to connect the battery modules (1A, 1B) in series with each other during the charging stage of the battery (1) by the charger (2), and also, Through a mixing phase in which the battery (1) is being charged by the charger (2) while simultaneously discharging to the demand circuit (4), the balance system (40) of the switch unit (3) is controlled such that some of the current sent to the overcharged battery module (1A, 1B) is diverted to the undercharged battery module (1A, 1B). A control unit (5) is provided, The switch unit (3) includes at least one main balance unit (41) which is arranged as a branch from a part of the branch of the electrical circuit (10) that connects the two positive terminals of the two battery modules (1A, 1B). method.

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