METHOD FOR RECHARGED A DEVICE BATTERY

Abstract

One aspect of the invention relates to a method (100) for recharging a battery comprising the steps of: Determining (101) a first maximum charging current that a charging system can supply; Determining (102) a second maximum charging current for the battery; Determining (103) a third maximum current for supplying the battery and an electrical network; Transmitting (104) a first current setpoint to the electrical charging system equal to the third current; Charging (105) the battery with a current equal to the first charging current setpoint; Determining (106) a fifth charging current at the battery terminals; If the fifth current is less than the second current, transmitting (107a) a second current setpoint greater than the first setpoint; Charging (108) the battery with a current equal to the second setpoint. Figure 2

Description

Title of the invention: METHOD FOR RECHARGED A BATTERY IN A DEVICE

[0001] One aspect of the invention relates to a method for recharging a device's battery. This device may, for example, be a digital tablet or a handheld tool. In another example, the device may be an electric or hybrid vehicle, and the battery may be a high-power battery. Another aspect of the invention relates to an electric or hybrid vehicle, particularly a car, configured to implement such a method.

[0002] These aspects of the invention find particularly interesting applications in the field of charging power batteries of electric or hybrid motor vehicles.

[0003] When recharging a power battery, it is known to determine a maximum charging current that the latter can withstand depending on a state of charge and a temperature of this power battery.

[0004] The maximum charging current that the power battery can support can be determined by a battery control system (better known by the acronym BMS for Battery Management System in English).

[0005] When the power battery is connected to an electric charging station, the battery control system transmits to the charging station a maximum charging current command that it can handle. As described in document CN-B1-109591650, the charging station then supplies a charging current to the power battery according to the received command, the value of this charging current changing as the power battery is being charged.

[0006] However, such an electric charging station usually has a safety margin, for example of 10%. Thus, the current transmitted by the electric charging station corresponds to the current setpoint minus a safety margin.

[0007] The 10% safety margin makes it possible to compensate for any potential discrepancies in current measurements between the electric charging station and the vehicle's battery control system. Since the charging current supplied by the charging station is 10% lower than the maximum charging current that the power battery can handle, the power battery's charging time is also increased by 10%.

[0008] The object of the invention is to overcome the disadvantages of the prior art by proposing a method of recharging a battery of a device allowing to optimize its recharging time.

[0009] In this context, the invention thus relates, in its broadest sense, to a method of recharging a battery of a device.

[0010] The method includes, when the battery is being recharged by an electric charging system, the steps, executed by control means of the device, of: • Determining a first maximum charging current that the electric charging system can provide; • Determine a second maximum battery charging current based on the battery's state of charge and temperature; • Determine a third maximum power supply current for the battery and an electrical network including at least one electrical equipment, the third maximum power supply current being a function of the second maximum battery charging current and a fourth current consumed by at least one electrical equipment; • Transmit a first charging current instruction to the electric charging system, the first charging current instruction being equal to the third maximum supply current determined; • Charge the battery using a current equal to the first charging current setting; • Determine a fifth charging current at the battery terminals; • If the fifth determined charging current at the battery terminals is less than the second maximum charging current of the battery, • transmit to the electric charging system a second charging current instruction that is higher than the first charging current instruction, • Charge the battery using a current equal to the second charging current setting.

[0011] The method according to this aspect of the invention allows, when the electric charging system applies a safety margin to the transmitted current, for the second current setting transmitted to the electric charging system to be increased beyond the second maximum charging current acceptable to the battery. This increase compensates for the safety margin of the electric charging system and thus positions the fifth current, in other words, the charging current actually received by the battery, at the level of the maximum charging current acceptable to the battery. Therefore, the battery charging time is reduced thanks to the method according to this aspect of the invention.

[0012] In addition to the characteristics just mentioned in the preceding paragraph, the process according to this aspect of the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0013] According to a non-limiting aspect of the invention, the second charging current setpoint is equal to the first charging current setpoint plus a current deviation, the current deviation being equal to an integral corrector of the second maximum charging current of the determined battery less the fifth charging current at the terminals of the determined battery.

[0014] According to a non-limiting aspect of the invention, the integral corrector has a predetermined gain value.

[0015] According to a non-limiting aspect of the invention, • The process repeats the steps of: • determine a first maximum charging current that the electric charging system can provide; • Determine a second maximum battery charging current; • Determine a third maximum current for supplying power to the battery and the electrical network; • According to this aspect of the invention, the process comprises the additional steps of: • Transmit a third charging current instruction to the electric charging system, the third charging current instruction being equal to the third determined maximum supply current plus the current deviation; • Charge the battery using a current equal to the third charging current setting; • According to this aspect of the invention, the method then repeats the step of determining the fifth charging current at the battery terminals; • If the fifth charging current at the battery terminals determined is less than the second maximum charging current of the battery determined, the process repeats the step of transmitting to the electric charging system a second charging current setpoint greater than the first charging current setpoint, • If the fifth determined charging current at the battery terminals is higher by a predetermined percentage than the second determined maximum charging current, the method includes an additional step of transmitting, to the electric charging system, a second charging current setting equal to the third maximum current of the battery and the electrical grid supply, • according to this aspect of the invention, the process then repeats the step of charging the battery using a current equal to the second charging current setpoint.

[0016] According to a non-limiting aspect of the invention, the predetermined percentage is equal to 0.5%.

[0017] According to a non-limiting aspect of the invention, the fifth charging current at the battery terminals determined is equal to a maximum current value selected from a plurality of current values ​​measured at the battery terminals in a predetermined time window.

[0018] According to a non-limiting aspect of the invention, the step of determining the fifth charging current at the terminals of the battery is repeated according to a first predetermined period of between 10 and 20 milliseconds.

[0019] According to a non-limiting aspect of the invention, the step of transmitting a third charging current instruction is repeated according to a second predetermined period of between 20 and 100 milliseconds.

[0020] According to a non-limiting aspect of the invention, - The device is an electric or hybrid vehicle; - The electrical network is a power network; - The battery is a power battery; and - The electric charging system is an electric charging station.

[0021] Another aspect of the invention relates to an electric or hybrid vehicle comprising control means arranged to implement the process according to any one of the aforementioned aspects of the invention.

[0022] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures.

[0023] [[Fig.1] illustrates, schematically, a vehicle according to a non-limiting aspect of the invention.

[0024] [Fig.2] represents, schematically, a non-limiting implementation method of the method according to the invention.

[0025] [Fig.3] represents a current map implemented by the method according to the invention.

[0026] For non-limiting examples of implementations of the invention illustrated in Figures 1, 2 and 3, • The device of the invention is formed by an electric vehicle; • The electrical network is formed by a power network for said vehicle electric; • The battery of the invention is formed by a power battery for said electric vehicle; and • The electric charging system, for its part, consists of an electric charging station.

[0027] Figure 1 illustrates an electric vehicle 1 arranged to implement the method according to the invention. The electric vehicle 1 includes, in particular • A power network 2 comprising electrical equipment; in the illustrated example, the electrical equipment consists of an electric air conditioning compressor 3 and a heating system 4. • A power battery 5, for example 400V or 48V, the power battery 5 electrically supplying the electrical equipment 3, 4 of the power network 2, and • Control means 6 arranged to implement a method for recharging the power battery 5 according to one aspect of the invention.

[0028] In a non-limiting example of an embodiment, the control means 6 may include: • A vehicle control unit 7 (better known by its acronym VCU for Vehicle Control Unit), and • A battery management system (better known by the acronym BMS for Battery Management System in English).

[0029] The electric vehicle 1 is further connected to an electric charging station 9 arranged to electrically recharge the power battery 5.

[0030] Figure 2 shows the steps of an implementation of process 100 according to the invention. The steps of process 100 are carried out by control means such as, for example, the control means 6 shown in Figure 1.

[0031] When the power battery 5 is being recharged by the electric charging station 9, the method 100 includes a step of determining 101 a first maximum charging current that the electric charging station 9 can supply to the electric vehicle 1.

[0032] To this end, in a non-limiting embodiment, the electric charging station 9 transmits to the vehicle control unit 7 the charging current level that it is capable of supplying. The vehicle control unit 7 then determines a first maximum charging current that the electric charging station 9 can supply.

[0033] The method 100 further includes a step of determining 102 a second maximum charging current of the power battery 5 as a function of a state of charge and a temperature of the power battery 5.

[0034] The state of charge of the power battery 5 is also known as the SoC (for State of Charge in English).

[0035] In a non-limiting example embodiment, the battery control system 8 determines the state of charge of the power battery 5 as well as the temperature of this power battery 5.

[0036] In a non-limiting example of an embodiment, the temperature of the power battery 5 is determined by the battery control system 8 by means of temperature values ​​measured by temperature sensors (not shown) that comprise the power battery 5 and transmitted to the battery control system 8.

[0037] In a non-limiting implementation, the battery control system 8 is then able, by means of a current mapping, to determine the second maximum charging current of the power battery 5 as a function of the state of charge and the temperature of the power battery 5.

[0038] Figure 3 schematically illustrates an example of a current map showing different charging currents for the power battery 5 as a function of battery charge state and temperature. For example, for a battery temperature of 10°C and a charge state of approximately 30%, the second maximum charging current for the power battery 5 is 290 A. This second maximum charging current for the power battery 5 corresponds to an electrical current that will not damage it.

[0039] The method 100 includes a step of determining 103, for example by means of the vehicle control unit 7, a third maximum electrical supply current for the power battery 5 and the power network 2 comprising, in our example, an electric air conditioning compressor 3 and a heating system 4. In one embodiment, the third maximum supply current is equal to the sum of the second maximum charging current of the power battery 5 determined in step 102 and a fourth current consumed by the electric air conditioning compressor 3 or the heating system 4.

[0040] The method 100 further includes a step of transmitting 104 a first charging current setpoint to the electric charging station 9. The first charging current setpoint is equal to the third maximum supply current determined during step 103.

[0041] The method 100 then includes a step 105 of charging the power battery 5 with a current equal to the first charging current setpoint. To this end, the electric charging station 9 transmits a current equal to the first charging current setpoint to the power battery 5.

[0042] The method 100 then includes a step of determining 106, for example by means of the battery control system 8, a fifth charging current at the terminals of the power battery 5.

[0043] In a non-limiting embodiment, this step 106 is executed periodically by the battery control system 8 according to a first predetermined period of between 10 and 20 milliseconds, typically 20 milliseconds.

[0044] In a non-limiting embodiment, to determine the fifth charging current, a current measurement is taken at the terminals of the power battery 5 and transmitted to the battery control system 8.

[0045] In a different embodiment, several current measurements are taken across the terminals of the power battery 5 within a predetermined time window, for example, between 10 and 30 milliseconds, typically 20 milliseconds. The fifth charging current determined across the terminals of the power battery is then equal to the maximum current value of the time window. In other words, within the 20-millisecond time window, if four current measurements are taken, the highest current value is selected from among these four measurements within said time window.

[0046] The method 100 further includes a step, carried out for example by means of the vehicle control unit 7, of transmitting 107a a second charging current setpoint higher than the first charging current setpoint when the fifth charging current at the terminals of the determined power battery 5 is lower than the second maximum charging current of the power battery 5.

[0047] In a non-limiting embodiment, the second charging current setpoint is equal to the first charging current setpoint plus a current deviation. The added current deviation is equal to the second maximum charging current of the determined power battery 5 minus the fifth charging current at the terminals of the determined power battery 5.

[0048] In a non-limiting embodiment, an integral corrector can be applied to this subtraction.

[0049] The use of an integral corrector for the calculation of the current deviation makes it possible to reduce the risk of exceeding the second maximum charging current of the power battery 5 by the fifth charging current at the terminals of the power battery 5.

[0050] In a complementary embodiment, the integral controller has a predetermined gain value. This gain value makes it possible to determine a convergence rate of the fifth charging current at the terminals of the power battery with the second maximum charging current of the power battery.

[0051] The method 100 then includes a step of charging the power battery 5 with a current equal to the second charging current setpoint. To this end, the electric charging station 9 transmits a current equal to the second charging current setpoint to the power battery 5.

[0052] In a non-limiting implementation, process 100 repeats the steps of: • Determine 101 a first maximum charging current that the electric charging station 9 can provide; • Determine 102 a second maximum charging current for the power battery 5; • Determine 103 a third maximum electrical supply current from the power battery 5 and the electrical network 2.

[0053] The method 100 then includes an additional step, carried out for example by means of the vehicle control unit 7, of transmitting 109 a third charging current setpoint to the electric charging station 9, the third charging current setpoint being equal to the third maximum supply current determined plus the current difference.

[0054] In a non-limiting implementation, this step 109 is executed periodically by the vehicle control unit 7 according to a second predetermined period of between 20 and 100 milliseconds.

[0055] The method 100 then includes an additional step, carried out for example by means of the vehicle control unit 7, of charging the power battery 5 with a current equal to the third charging current setpoint. For this purpose, the electric charging station 9 transmits a current equal to the third charging current setpoint to the power battery 5.

[0056] The process 100 then repeats the step of determining 106 the fifth charging current at the terminals of the power battery 5.

[0057] Next, the method 100 comprises the steps, executed for example by means of the vehicle control unit 7, of: • If the fifth charging current at the terminals of the determined power battery 5 is less than the second maximum charging current of the determined power battery 5, transmit 107a, to the electric charging terminal 9, a second charging current instruction greater than the first charging current instruction, or • if the fifth charging current at the terminals of the determined power battery 5 is higher by a predetermined percentage than the second maximum charging current of the determined power battery 5, transmit 107b, to the electric charging terminal 9, a second charging current command equal to the third maximum electrical supply current of said battery 5 and the electrical network 2. The predetermined percentage may for example be 1%.

[0058] The process 100 then repeats the step of charging the power battery 5 108 by means of a current equal to the second charging current setpoint.

[0059] It should be noted that a person skilled in the art is able to make different variations to the aforementioned aspects of the invention, for example by modifying the values ​​of the current mapping.

[0060] Furthermore, the examples described relate to a vehicle, but it is understood that the method according to the invention can be applied to any other type of device equipped with a battery, for example a digital tablet or a portable tool.

Claims

1.

2. Demands Method (100) for recharging a power battery (5) of an electric or hybrid vehicle (1) comprising an electrical power network (2) including at least one electrical device (3, 4) powered by the power battery (5), said method (100) comprising, when said battery (5) is being recharged by an electric charging station (9), the steps, executed by control means (6) of the vehicle (1), of: - Determine (101) a first maximum charging current that the electric charging station (9) can provide; - Determine (102) a second maximum charging current of said battery (5) as a function of a state of charge and a temperature of said battery (5); - Determine (103) a third maximum electrical supply current of said battery (5) and of the electrical power network (2), said third maximum supply current being a function of said second maximum charging current of said battery (5) and of a fourth current consumed by said at least one electrical equipment (3,4); - Transmit (104) a first charging current instruction to the electric charging station (9), said first charging current instruction being equal to said third maximum supply current determined; - Charge (105) the battery (5) using a current equal to 1 a first charging current setting; - Determine (106) a fifth charging current at terminals of said battery (5); - If the said fifth charging current at the said terminals of the said battery (5) determined is less than the said second maximum charging current of the said battery (5), transmit (107a), to the electric charging terminal (9), a second charging current instruction greater than the said first charging current instruction, - Charge (108) said battery (5) by means of a current equal to said second charging current setting. Method (100) according to the preceding claim, characterized in that the second charging current setpoint is equal to the first charging current setpoint to which is added a current deviation, said current deviation being equal to an integral corrector of the second maximum charging current of the battery (5) determined from which is subtracted the fifth charging current at the terminals of said battery (5) determined.

3. Method (100) according to the preceding claim, characterized in that the integral corrector has a predetermined gain value.

4. A method (100) according to any one of claims 2 or 3, characterized in that it repeats the steps of: - Determine (101) a first maximum charging current that the electric charging station (9) can provide; - Determine (102) a second maximum charging current for the battery (5); - Determine (103) a third maximum electrical supply current of said battery (5) and electrical power network (2); - Said process (100) comprising the additional steps of: • Transmit (109) a third charging current instruction to the electric charging station (9), said third charging current instruction being equal to said third determined maximum supply current plus the current deviation; • Charge (110) the battery (5) using a current equal to the third charging current setting; - Said process (100) then repeats the steps of: • Determine (106) the fifth charging current at the terminals of said battery (5); • If the said fifth charging current at the said terminals of the said battery (5) determined is less than the said second maximum charging current of the said battery (5) determined, transmit (107a), to the electrical charging terminal (9), a second charging current setting greater than the said first charging current setting, - if said fifth charging current at said terminals of said battery (5) determined is greater by a predetermined percentage than said second maximum charging current of the battery (5) determined, said method (100) includes a supplementary step of transmitting (107b), to the electric charging terminal (9), a second charging current setpoint equal to said third maximum electrical supply current of said battery (5) and the electrical power network (2), - said method (100) then repeats the step of charging (108) said battery (5) by means of a current equal to said second charging current setpoint.

5. Method (100) according to the preceding claim, characterized in that the predetermined percentage is equal to 0.5%.

6. Method (100) according to any one of claims 4 or 5, characterized in that the step of transmitting (109) a third charging current instruction is repeated over a second predetermined period of between 20 and 100 milliseconds.

7. A method (100) according to any one of the preceding claims, characterized in that the fifth charging current at the terminals of the battery (5) determined is equal to a maximum current value selected from a plurality of current values ​​measured at the terminals of said battery (5) in a predetermined time window.

8. Method (100) according to any one of the preceding claims, characterized in that the step of determining (106) the fifth charging current at the terminals of the battery (5) is repeated over a first predetermined period of between 10 and 20 milliseconds.

9. Electric or hybrid vehicle (1), characterized in that it comprises control means (6) arranged to carry out the steps of the process (100) according to any one of the preceding claims.

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