Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/14—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
  • H02J7/1423—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle with multiple batteries
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
  • H02J7/342—The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Definitions

• the invention relates to a method for controlling a DC-DC converter of a system for storing and restoring electrical energy.
• the invention finds its application more particularly, but not exclusively, in the field of vehicles, especially automobiles.
• the invention relates to a method for controlling a DC-DC converter of a storage and electric energy recovery system comprising a first battery connected to a second battery via the DC-DC converter. continuous, the first battery and the converter being connected to at least one electrical energy consuming element and at least one element generating electrical energy.
• Such control is for example described in document FR 2 933 356, in which the control of the DC-DC converter depends on a state of charge of each of the batteries, so as to maintain each of said batteries in their optimum operating range.
• An object of the present invention is to provide control of the DC-DC converter to minimize energy losses in the system.
• an object of the present invention is a method for controlling a DC-DC converter of a storage and electric energy recovery system comprising a first battery connected to a second battery via the continuous converter. -continued, the first battery and the converter being connected to at least one electrical energy consuming element and to at least one electric energy generating element, said method comprising a step of determining a total power P to t resulting from the sum of a power P c consumed by the at least one consumer element and a power P p produced by the at least one generating element, said total power P to t being of negative sign when the power P c consumed is less than power P p produced; then if P tot ⁇ 0, a step of determining a power P 2 * set to be applied across the converter side of the second battery, so that j
• Such a method makes it possible to manage a use of the second battery via the converter, so as to minimize the energy losses in the system for storing and returning electrical energy.
• Such a method therefore has the advantage of increasing the autonomy of the system, and of saving energy.
• such a method has the advantage of using a calculation method for determining the target power output of the simple converter to implement, and requiring only a limited number of information.
• the determination of the total power P to t comprises a step of measuring a voltage U i across the first battery; a step of measuring a voltage U 2 i across the converter terminals on the side of the first battery; then a step of determining an average voltage from the voltages at the terminals of the first battery and the converter; a step of measuring an intensity ⁇ - ⁇ entering or leaving the first battery; a measurement step of an intensity ⁇ 2 - ⁇ entering or leaving the converter on the side of the first battery; then a step of calculating the sum of the intensities of the first battery and the converter.
• the method comprises, prior to the step of determining the desired power, a step of determining a charge state SOC of the first and / or second battery; then a step of measuring a temperature T of the first and / or second battery; and finally a step of determining the no-load voltage of the first and / or second battery from the state of charge SOC and the temperature T of said battery.
• the method comprises, prior to the step of determining the desired power, a step of determining a charge state SOC of the first and / or second battery; then a step of measuring a temperature T of the first and / or second battery; and finally a step of determining the internal resistance R of the first and / or the second battery from the state of charge SOC and the temperature T of said battery.
• the method further comprises, prior to the step of determining the internal resistance R of the first and / or the second battery, a step of measuring an intensity I entering or leaving the first and / or the second battery, so that the internal resistance R of said battery is also determined from said intensity I.
• the method comprises, prior to the step of determining the desired power, a step of measuring a TDCDC temperature of the converter; then a step of determining the efficiency ⁇ of the converter from the TDCDC temperature of said converter.
• the invention also relates to a system for storing and restoring electrical energy comprising a first battery connected to a second battery via a DC-DC converter, the first battery and the converter being able to be connected. at least one element that consumes electrical energy and at least one element that generates electrical energy, said system further comprising means for implementing the method, as previously described.
• the invention also relates to a vehicle comprising a system for storing and restoring electrical energy, as previously described.
• FIG. 1 a schematic view of a system for storing and restoring electrical energy, according to one embodiment of the invention
• FIG. 2 a schematic view of a control device of the system for storing and restoring electrical energy, according to the embodiment shown in Figure 1;
• FIG. 3 a graph representing the power losses of the electrical energy storage and delivery system, according to one embodiment of the invention, as a function of a power of setpoint applied across a DC-DC converter of said system;
• FIG. 4 a logic diagram of a control method of the DC-DC converter for minimizing losses in the energy storage and delivery system, according to the embodiment presented in FIG.
• FIG. 1 shows a schematic view of a system 10 for storing and restoring electrical energy according to one embodiment of the invention.
• a system 10 for storing and restoring electrical energy is for example used in a vehicle of the automotive type.
• the system 10 comprises a first battery 1 1 connected to a second battery 12 via a bidirectional DC-DC converter 13.
• the first battery 1 1 serves as the main battery, while the second battery 12 serves as a reserve.
• powers (Pi, P 2 ) at the terminals of the first and second batteries (1 1, 12), respectively, are considered positive during the discharge of said battery.
• the powers (Pi, P 2 ) across the first and second batteries (1 1, 12) are considered negative when charging said battery.
• variables relating to the main battery 1 1 will have index 1
• variables relating to the battery 12 reserve will have index 2.
• the converter 13 is said to be a voltage converter, that is to say a voltage delivered at the output of said converter is less than a voltage applied at the input of said converter.
• the converter 13 is a booster, that is to say that a voltage output of said converter is greater than a voltage applied at the input of said converter.
• the converter 13 is able to work as a deflator and booster.
• the system 1 0 is able to be supplied with electrical energy by means of at least one element 14 producing electrical energy connected to said system between the first battery 1 1 and the converter 1 3, so that said element 14 producer allows to directly recharge the main battery 1 1 and recharge the reserve battery 12 via the converter 1 3.
• the at least one generating element 14 is for example an electric machine in generator mode or mains charger or terminal. In the following description, a power P p supplied by the producing element 14 is considered negative.
• the system 1 0 is able to supply electrical energy to at least one electrical energy consuming element connected to said system between the first battery 1 1 and the converter 1 3.
• a power P c to be delivered to the consumer element is considered positive.
• the system 1 0 also comprises a device 1 6 control of which Figure 2 is a schematic representation.
• the control device 1 6 comprises a microprocessor 1 7, a memory 1 8 of data, a memory 1 9 of programs and at least one bus 20 communication.
• control device 1 6 is connected by an input interface 21 to a first means 22 for measuring a temperature T-, the main battery 1 1, a second means 23 for measuring a temperature T 2 of the reserve battery 12, and a third means 24 for measuring a temperature T D CDC of the converter.
• the control device 16 is also connected by the input interface 21 to a fourth means 25 for measuring a voltage Ui across the main battery 1 1, a fifth means 26 for measuring a voltage U 2 i at the terminals of the converter 1 3 on the side of the main battery 1 1, a sixth means 27 for measuring an intensity entering or leaving the main battery 1 1, a seventh means 28 for measuring an intensity l 2 i entering or leaving the converter 1 3 on the side of the main battery 1 1, and a eighth means 29 for measuring an intensity l 2 entering or leaving the battery 12 reserve.
• the control device 16 is connected by an output interface 30 to the converter 13, so as to transmit operating instructions to said converter 13.
• the control device 16 controls the converter 13 by means of a setpoint output power P * said converter.
• the reference power P * of the converter 13 is applied to the terminals of said converter on the side of the reserve battery 12.
• the reference power P * corresponds to the power P 2 at the terminals of the reserve battery 12, and makes it possible to control the charge of said reserve battery.
• the reference power P * will be noted in the following description P 2 * and will be considered negative. This case corresponds to a first driving mode of the converter 13.
• the reference power P * of the converter 13 is applied to the terminals of said converter vis-à-vis the main battery 1 1.
• the reference power P * corresponds to a power P 2 i across said converter on the side of the main battery 1 1, and can control the discharge of the battery 12 reserve.
• the power P * setpoint will be noted in the following description P 2 * and will be considered positive. This case corresponds to a second driving mode of the converter 13.
• the powers (P 2 * , P 2 i) setpoint are determined as follows.
• 0SS of system 10 power are mainly related to losses by Joule effect of batteries (1 1, 12) and to a yield ⁇ of the converter 13, we obtain, for each of the drive modes of the converter 13, the losses P
• the first efficiency ⁇ - ⁇ 2 corresponds to a direction of operation of the converter 13 towards the reserve battery 12
• the second efficiency ⁇ 2 ⁇ corresponds to a direction of operation of the converter 13 towards the main battery 1 1 and / or the at least one producer element 14 and / or the at least one consumer element.
• Figure 3 shows a graph showing the evolution of losses P
• FIG. 3 shows that for a given total power P to t, the power Pioss losses have an overall arithmetic minimum at a given reference power P * .
• the overall arithmetic minimum of each curve is marked with an asterisk in Figure 3.
• FIG. 3 also reveals that for small absolute values of the total power P to t supplied or consumed by the set formed by the at least one generating element 14 and the at least one consumer element, the overall arithmetic minimum changes of sign, that is to say that the sign of the global arithmetic minimum becomes the opposite of the sign of the power P * dictated by the driving mode of the converter 13.
• This solution being nonphysical, it is considered that in this case, the reference power of the converter 13 is zero, that is to say that the power losses are minimized, when the main battery 1 1 works alone.
• 0SS of power are defined as follows.
• FIG. 4 shows a logic diagram of a driving method of the DC-DC converter 13, so as to minimize the losses P
• the total power P to t supplied or consumed by the assembly formed by the at least one generating element 14 and the at least one consumer element is determined.
• the determination 40 of the total power P to t comprises a step 401 for measuring the voltage U i across the main battery 1 1 and a step 402 measuring the voltage U 2 i across the converter terminals on the side of said main battery through the fourth and fifth measurement means (25, 26), respectively. Then, it is calculated at one stage
• the determination 40 of the total power P to t furthermore comprises a step 404 for measuring the intensity entering or leaving the main battery 1 1, and a measurement step 405 of the intensity l 2 i entering or leaving the converter 13 on the side of the main battery 1 1 via the sixth and seventh measurement means (27, 28), respectively.
• the intensities ⁇ 1 and l 2 i thus measured are summed in a step 406.
• the total power P to t is then calculated during a step 407, starting from the average voltage calculated at step 403 and the sum of the intensities. and i 2 calculated in step 406.
• the total power P tot is stored in the data memory 18 of the control device 16 in a step 41.
• the sign of the total power P to t is then determined during a step 42.
• Such control comprises a step 43 for determining the open-circuit voltage OCV at the terminals of each of the batteries (1 1, 12), the internal resistance R of each of the batteries (1 1, 12) and the first efficiency ⁇ 2 of the converter 13.
• a state of charge SOC of each of the batteries (1 1, 12) is determined during a step 431 and the temperature T of each of said batteries is measured by via the first and second measurement means (22, 23) in a step 432.
• the open-circuit voltage OCV across each of the batteries (1 1, 12) is determined from the state of charge SOC and the temperature T of each of said batteries in a step 433.
• the open-circuit voltage OCV across each of said batteries is measured.
• the steps (431, 432) for determining the state of charge SOC of the batteries (1 1, 12) and for measuring the temperature T of said batteries are followed.
• the internal resistance R of each of the batteries (1 1, 12) is determined from the charge state SOC, the temperature T, and the intensity I of each of said batteries during a step 435.
• said internal resistance is determined solely from the state of charge SOC and the temperature T of each of said batteries.
• said internal resistance is considered constant and is previously stored in the data memory 18 of the control device 16 via an interface panel.
• a temperature T D converter 13 CDC is measured in a step 436 through the third means 24 for measuring.
• the first efficiency ⁇ - ⁇ 2 of the converter 13 is determined from the temperature TDCDC of said converter in a step 437.
• the first efficiency ⁇ 2 of the converter 13 is considered constant and is previously stored in the data memory 18 of the control device 16 via the interface panel.
• the determinations 43 of the open-circuit voltage OCV at the terminals of each of the batteries (1 1, 12), the internal resistance R of each of the batteries (1 1, 12) and the first efficiency ⁇ - ⁇ 2 of the converter 13 are made simultaneously.
• the reference power P 2 * of the converter 13 is determined from the total power P to t, the open-circuit voltage OCV at the terminals of each of the batteries (1 1, 12), the internal resistance R of each said batteries and the first efficiency ⁇ - ⁇ 2 of the converter 13 at a step 44, so that:
• the target power P 2 * of the converter 13 thus obtained is then stored in the data memory 18 of the control device 16 in a step 45, then applied to the terminals of the converter 13 on the side of the reserve battery 12 at a step 46 .
• the method continues after the application 46 of the reference power P 2 * by a new determination step 40 of the total power P to t, so that forming a loop that repeats until the system 10 stops at a step 47.
• step 42 If it is revealed in step 42 that the total power P to t is positive, then the system 10 is driven according to the second mode.
• Such control includes a step 48 for determining the open-circuit voltage OCV at the terminals of each of the batteries (1 1, 12), the internal resistance R of each of the batteries (1 1, 12) and the second efficiency ⁇ 2 ⁇ of the converter 13.
• the progress of step 48 is equivalent to the progress of step 43, and includes the same alternatives.
• the reference power P 2 i * of the converter 13 is determined from the total power P to t, the open-circuit voltage OCV at the terminals of each of the batteries (1 1, 12), the internal resistance R of each of said batteries and the second efficiency ⁇ 2 ⁇ of the converter 13 at a step 49, so that:
• the target power P 2 i * of the converter 13 thus obtained is then stored in the data memory 18 of the control device 16 in a step 50, and applied across the converter 13 on the side of the main battery 1 1 at a step 51.
• the method continues after the application 51 of the reference power P 2 i * by a new determination step 40 of the total power P to t, so forming a loop which repeats until the system 10 is stopped at step 47.
• Such a drive method of the converter 13 to minimize Pioss power losses in the system 10 has the advantage of increasing the autonomy of said system, and thus to allow a user to achieve energy savings.
• the control method of the converter 13 also has the advantage of using a method for determining the setpoint power P * of said simple converter to be implemented, and which does not require, especially in the automobile, the addition of means (22). , 23, 24, 25, 26, 27, 28, 29) are complex and expensive.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Dc-Dc Converters (AREA)

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Applications Claiming Priority (2)

Publications (2)

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Cited By (2)

Citations (1)

Family Cites Families (4)

• 2012
  • 2012-06-07 FR FR1255329A patent/FR2991824B1/fr active Active
• 2013
  • 2013-05-31 EP EP13731382.1A patent/EP2859640A2/de not_active Withdrawn
  • 2013-05-31 WO PCT/FR2013/051228 patent/WO2013182784A2/fr active Application Filing

Patent Citations (1)

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