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
  • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
  • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
  • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
  • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
  • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
  • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
  • H02M3/1588—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load comprising at least one synchronous rectifier element
• • 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
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• • 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
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
  • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

• the present invention relates to a converter-regulator ⁇ continuous voltage DC voltage, or converter-DC-DC regulator, used for charging a battery, for example a mobile phone battery, via a fuel cell.
• a converter-regulator ⁇ continuous voltage DC voltage, or converter-DC-DC regulator used for charging a battery, for example a mobile phone battery, via a fuel cell.
• battery means a set of accumulators coupled so as to act simultaneously, an accumulator being an electrolytic element which is charged by passing a direct current and which can then be discharged, c ' that is to say, to restore, in the form of a direct current in the opposite direction, a part of the energy accumulated in chemical form.
• batteries including nickel-cadmium batteries, nickel-metal-hydride batteries, lead-acid batteries and lithium batteries.
• the electronic components of a mobile phone are usually powered by a battery adapted to be charged repeatedly.
• the charging of the battery of a mobile phone can be carried out at a constant current with a minimum charge voltage or at a constant voltage with a limited current according to the Battery Type.
• the battery is typically connected to a generator supplying a ten ⁇ load sion and a suitable charging current.
• the generator may comprise a DC voltage converter that receives the AC voltage from the mains. It may also include a DC voltage converter powered by batteries.
• a fuel cell is a system of supplying electric power in which electricity is obtained by oxidation of an electrode stack of a fuel reduction ⁇ tor coupled to the reduction on the other electrode of an oxidant, such as the oxygen of the air.
• the fuel may be hydrogen or methanol which is converted to hydrogen for the oxidation reaction.
• a fuel cell has the advantage of not being polluting since it discharges only water.
• the fuel of the fuel cell can be stored in a tank supplying the fuel cell. The performance and dimensions of the currently available fuel cells make it possible to use them for charging a battery, in particular a mobile phone battery.
• FIG 1 shows an example of 5 Evolu ⁇ curve of the voltage V F ç across a fuel cell according to the current Ip Q provided by the fuel cell.
• the VPC voltage decreases from a maximum voltage V F C max in the absence of load connected to the fuel cell to zero voltage at which the fuel cell provides a maximum current iFCmax-
• the maximum voltage V F C max may be from 1 about 8 V and the maximum current Ipcmax C an be of the order of 400 at 500 mA.
• FIG. 1 also shows a curve 6 for the evolution of the power Pp Q supplied by the fuel cell. Curve 6 has a bell shape which has a maximum for a given voltage Vp Q and current Ip Q.
• the power supplied by the fuel cell must be high enough for the charge the battery does not have an excessive duration; and the efficiency of the fuel cell must be high enough to avoid excessive fuel consumption of the fuel cell, which would result in the impossibility of carrying out several successive charging operations without refueling the fuel cell of the fuel cell. combustible.
• the present invention is directed to a dc voltage converter / regulator allowing the use of a fuel cell to charge a battery, for example a mobile phone battery.
• the converter-regulator has a high efficiency during the tota ⁇ lity of a charging operation.
• the converter-regulator has a simple structure.
• the present invention also provides a method of converting the voltage supplied by a fuel cell for charging a battery.
• the present invention provides a continuous voltage DC voltage converter / converter for connecting a fuel cell to a filter adapted to be connected to an electrochemical storage means for electrical energy during a control operation. load of the storage medium.
• the regulator converter comprises means adapted to maintain, during the charging operation, the voltage at the terminals of the fuel cell at a given operating voltage.
• the converter-regulator comprises means for providing an error signal representative of the difference between the voltage at the terminals of the fuel cell and the given operating voltage; and a step-down or step-up circuit that drives the filter with an average voltage corresponding to the voltage across the multiplied fuel cell by a factor that depends on the error signal, whereby, when the voltage at the fuel cell terminals is greater than the given operating voltage, the current supplied to the battery is increased, and that when the voltage across the fuel cell is below the given operating voltage, the current supplied to the the battery is decreased.
• the converter-regulator comprises means for adjusting the given operating voltage.
• the converter-regulator comprises a capacitor connected to the terminals of the fuel cell.
• the step-down or step-up circuit is a chopper circuit controlled by a cyclic rectangular signal having a duty cycle that depends on the error signal.
• the present invention also provides a power supply system, intended to be connected to an electrochemical storage means of electrical energy during an operation of load of the storage medium.
• the power system includes a fuel cell; a filter intended to be connected to the storage means during the charging operation; and a converter-regulator as previously defined connecting the fuel cell to the filter.
• the filter comprises an inductance intended to be connected in series with the storage means.
• the present invention also provides an electronic system, in particular a mobile phone, comprising an electrochemical storage means for electrical energy and a supply system for said storage means as defined above.
• the present invention also provides a voltage conversion method to the terminals of a fuel cell in a power supply voltage of a filter connected to an electrochemical storage means of electric energy, at a ⁇ of opera charging the storage means, consisting in maintaining, during the charging operation, the voltage at the terminals of the fuel cell at a given operating voltage.
• the method comprises the steps of providing an error signal representative of the difference between the voltage at the terminals of the fuel cell and the given operating voltage; and providing the filter with an average voltage corresponding to the voltage across the fuel cell multiplied by a factor that depends on the error signal, whereby when the voltage across the fuel cell is higher than at the given operating voltage, the current supplied to the battery is increased, and when the voltage across the fuel cell is lower than the given operating voltage, the current supplied to the battery is decreased.
• FIG. previously described, represents the evolution ⁇ tion of the voltage at the terminals of a fuel cell and the power delivered by the fuel cell according to the current supplied by the fuel cell;
• FIG. 2 diagrammatically represents a mobile telephone connected to a fuel cell via a converter-regulator according to the invention;
• FIG. 3 diagrammatically represents an exemplary embodiment of a converter-regulator according to the invention;
• FIG. 4 represents a more detailed exemplary embodiment of the converter-regulator of FIG. 3;
• Figure 5 illustrates changes in voltages charac teristics ⁇ regulator-converter of Figure 4 in operation;
• FIG. 6 represents the evolution of the voltage at the terminals of the fuel cell, the voltage at the terminals of the battery and the current supplied to the battery during a charging operation of the battery; and
• FIG. 7 represents the evolution of the efficiency of the converter / regulator according to the invention as a function of the current supplied by the fuel cell.
• FIG. 2 schematically shows a mobile phone 10 comprising a battery 11 connected to a charge control module 12.
• the battery 11 is, for example, a lithium-ion type battery.
• the charge of the battery 11 is realized by means of an electric power source 13 comprising a fuel cell 14 using, for the supply of electrical energy, a fuel stored in a tank 15. This is, for example, a battery fueled with hydrogen or methanol.
• the fuel cell 14 is connected to the mobile phone 13 via a converter-regulator 16 and a filter 17.
• the charge control module 12 is adapted to detect a connection between the telephone 10 and the source of the battery. Energy 13 for triggering a charge operation of the battery 11, for example, by detecting that a current greater than a given current is supplied to the battery 11.
• the charge control module 12 is also adapted to detect whether the battery 11 is sufficiently charged to interrupt the charging operation.
• the present invention consists, during a charging operation, of operating the fuel cell at a determined operating point, that is to say at a pair of determined values (VpQop ⁇ , 1 FCoPt) ⁇ e ⁇ a voltage Vpc and current Ip Q.
• a determined operating point is called the optimum operating point and allows to obtain a rapid charge of the battery while avoiding an excessive fuel consumption by the fuel cell.
• the present invention consists in maintaining the voltage V E Q at the terminals of the fuel cell 14 at the voltage of the optimum operating point V F ç O p-
• the fuel cell 14 provides a substantially constant iFCopt current enabling constant current charging.
• FIG. 3 schematically represents an exemplary embodiment of the converter-regulator 16 according to the invention.
• the converter-regulator 16 comprises an error amplifier 22 which compares the voltage Vpc across the fuel cell 14 and compares it with a reference voltage V REF supplied by a reference voltage generator 26.
• the amplifier of FIG. error 22 provides an error voltage V ERROR 'representative of the difference between the voltages Vpc and V REF' to a modulator 28 pulse width or modulator PWM (English Pulse Width Modulation).
• the modulator 28 provides a square wave voltage Vp ⁇ j y j modulated pulse width to a control module 30, which may correspond to a voltage step-down circuit or a step-up circuit.
• the module 30 supplies a voltage V L to the filter 17 which drives the battery 11 with a charge current IBAT.
• the charge control module 12 is not represented in FIG. 3.
• FIG. 4 represents a more detailed exemplary embodiment of the converter-regulator 16 of FIG. 3.
• the fuel cell 14 is represented by a constant voltage generator 34 connected in series with a resistor 36, representing the internal resistance of the battery.
• fuel 14 is connected between a source of a reference potential 38, generally ground, and a node F.
• the converter-regulator 16 comprises a capacitor 40 connected between the node F and the ground.
• the error amplifier 22 includes an operational amplifier 42 whose inverting (-) input is connected to the output of a generator 43 of a constant voltage V ⁇ QMP P ar via a resistor 44. Further, the inverting input (-) is connected to the output of the amplifier 42 via a capacitor 46. The non-inverting input (+) of the amplifier 42 is connected to the node F via A resistor 48. A variable resistor 49 is provided between the non-inverting input (+) and the ground.
• the pulse width modulator 28 comprises an oscillator 50 supplying a triangular voltage VQSC ⁇ e constant frequency and an operational amplifier 51 whose non-inverting input (+) receives the error voltage V ERR QR and whose inverting input (-) receives the triangular voltage VQSC-
• the amplifier 51 is mounted as a comparator and provides a rectangular voltage Vp ⁇ .
• the optimum operating point of the fuel cell 14 is of the order of 5 V, which corresponds to the supply of a current Ipcopt ⁇ e the order of 200 to 300 mA, and the battery 11 is a battery lithium-ion whose capacity is of the order of 600 to 800 mA.h (2160 coulombs to 2880 coulombs).
• the regulation module 30 then corresponds to a voltage-reducing circuit which comprises a control module 52 receiving the voltage V PW] y [ and which provides two control voltages S ] _ and S2.
• the regulation module 30 comprises a MOS transistor.
• the filter 17 includes an inductor 58 connected between the node O and an output OUT terminal of the power source 13 and a capacitor 59 connected between the output terminal OUT and the ground.
• the battery is represented by a capacitor 11 connected between the output terminal OUT and the ground, the masses of the mobile phone 10 and the power source 13 being put in common when the mobile phone 10 is connected to the source of power. energy 13.
• the supply of the components of the error amplifier 22 and the pulse width modulator 28 is performed via a stabilized voltage source, not shown, receiving, for example, the voltage Vpc.
• FIG. 5 represents the evolution of characteristic voltages of the converter / regulator 16 according to the invention in operation.
• the error amplifier 22 performs an amplification operation of the difference between the voltage Vpc and a reference voltage and a filtering operation.
• the reference voltage can be adjusted by modifying the value of the variable resistor 49.
• the error amplifier 22 corresponds to an assembly of the type subtractor-integrator.
• the voltage V ERR QR is equal to the sum of a constant voltage V ERR QR0 / - OR bias voltage, and a variable voltage v error .
• the voltage V PW] y [ is obtained from the comparison between the voltages V ERR Q R and VQSC shown superimposed in FIG. 5.
• the voltage V PW] y [ is a cyclic rectangular voltage having a duty ratio ⁇ equal to the ratio between the duration T ] _ during which the voltage V PW] y [ is in a high state during a cycle and the duration T2 of a cycle.
• the cyclic ratio ⁇ depends on the value of the voltage V ERR QR- S control voltages] _ and S2 are rectangular voltages obtained from the voltage Vp ⁇ .
• the transistor 56 When the voltage S2 is at the high state, the transistor 56 is on and when the voltage S2 is low, the transistor 56 is blocked.
• the control voltages S] _ and S2 are set so that the rising and falling edges of the voltages S] _ and S2 are not simultaneous to prevent the transistors 54 and 56 are partially conducting simultaneously.
• the voltage S] _ corresponds substantially to the inverse of the voltage Vp ⁇
• the voltage S] _ is however, for each cycle, to the low state on a slightly smaller length T] _
• the voltage S2 corresponds substantially to the reciprocal of the voltage Vp ⁇ , the voltage S2 being however, for each cycle, in the low state over a time slightly greater than T ] _.
• transistor 54 When voltages S] _ and S2 are in the low state, transistor 54 is on and the transistor 56 is blocked. The node 0 is then connected directly to the node F and the voltage V L is equal to the voltage V F ç less the source-drain voltage of the transistor 54. The intensity of the current flowing through the inductor 58 then tends to increase.
• transistor 54 When voltages S] _ and S2 are in the high state, transistor 54 is off and transistor 56 is conducting. Node 0 is then connected to ground.
• the voltage V L is substantially equal to the drain-source voltage of the transistor 56 and the intensity of the current flowing through the inductor 58 tends to decrease.
• the average of the voltage V L is substantially equal to ⁇ Vpç and the average current traver ⁇ sant the inductor 58 depends on the cyclic ratio and ⁇ is the provision of a I ⁇ ç current by the fuel cell 14 which also depends the cyclic ratio ⁇ .
• the current Ip Q required by the inductor 58 imposes the voltage across the fuel cell 14, that is to say the voltage Vpc at the node F.
• the voltage Vpc is equal to the voltage V F ç O p-
• a ⁇ - a voltage V ERRR QR0 corresponds to a voltage V PW] y [ steady state with a ratio cyclic ⁇ g determined.
• the voltage V ERR QR0 can be chosen so that the duty ratio ⁇ g is equal to 0.5.
• the bias voltage V ERRR Q R O is equal to the sum of the maximum and minimum voltages provided by the oscillator 50.
• V E ç If the voltage V E ç is greater than Vpcopt ', a voltage V ERR Q R greater than V ERRR Q R O is obtained. •
• the voltage V PW ] y [then has a duty cycle ⁇ greater than ⁇ g. Is then obtained an increase of the average time that the transistor 54 is on and thus an increase of the average current traver ⁇ sant the inductor 58, that is to say an increase in current CPI supplied by the fuel cell 14 This results in a decrease of the voltage V E ç.
• FIG. 6 illustrates the steps of a complete charging process of the battery 11 by the battery 14 combus ⁇ tible.
• step I the mobile phone 10 is not connected to the output terminal OUT of the energy source 13.
• the current I ⁇ AT supplied to the output terminal OUT is therefore zero.
• the battery 11 is discharged and the voltage V BAT is equal to a minimum voltage V BATm -j_ n .
• the fuel cell 14 is deactivated, the fuel tank 15 being, for example, disconnected from the fuel cell 14.
• the voltage V E ç is therefore zero.
• step II the fuel cell 14 is activated, the battery 11 still not being connected to the output terminal OUT. This is achieved, for example, by feeding the battery to fuel 14 to fuel. The fuel cell 14 then reaches a stabilized operating conditions, which results in an elevation of the voltage VPC to the voltage V F C max of no load.
• step III the battery 11 is connected to the OUT terminal.
• the regulator-converter 16 then operates to maintain the voltage V Q at the terminals of the fuel cell 14 to V E C O p
• step IV the battery 11 is considered to be charged.
• the charge control module 12 Such a detection of the state of charge of the battery 11 can be carried out by the charge control module 12.
• the battery 11 is then electrically disconnected from the terminal OUT by the charge control module 12, the mobile phone 10 remaining mechanically connected to the electric power source 13.
• the regulator-converter 16 does realizes more regulating the VPC voltage that rises again until the voltage V f c max, while the I ⁇ AT current becomes zero.
• the voltage V BAT decreases as the battery 11 supplies the loads of the mobile phone 10 to which it is connected.
• step V the mobile phone 10 is disconnected from the OUT terminal.
• step VI the fuel cell 14 is deactivated, for example by cutting off the fuel supply of the fuel cell 14.
• FIG. 7 represents two curves 60, 62 of variation of the efficiency of the converter / regulator 16 according to the invention as a function of the current I ⁇ c supplied by the fuel cell 14.
• the curve 60 corresponds to a battery voltage V BAT of 3, 6 V which corresponds to an example of average voltage across the battery 11 being charged and curve 62 corresponds to a battery voltage V BAT of 2.7 V which corresponds to an example of voltage across the battery 11 at the beginning of charge.
• the output is the ratio of the power supplied to the battery 11 and the power provided by the fuel cell 14 (that is to say, the sum of the power supplied to the battery 11 and losses).
• the current supplied to the battery being substantially constant and within a well-defined range, for example from 150 mA to 290 mA, the efficiency of the converter / regulator 16 is greater than 85% throughout the load.
• a regulation module 30 corresponding to a voltage-reducing circuit has been considered. However, if the optimum operating voltage V F ç O p-
• the electric power source 13 can be provided directly at the mobile phone 10 and permanently mechanically connected to the battery 11. A charging operation of the battery 11 is then performed as has been done. previously described by the activation of the fuel cell 14 of the electric power source 13.
• the present invention is susceptible of various variations and modifications which will be apparent to those skilled in the art.
• the filtering operation performed by the error amplifier 22 may be more complex than previously described.

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• 2005
  • 2005-07-18 FR FR0552226A patent/FR2888685A1/fr not_active Withdrawn
• 2006
  • 2006-07-18 WO PCT/FR2006/050726 patent/WO2007010167A2/fr active Application Filing
  • 2006-07-18 EP EP06794481A patent/EP1905222A2/de not_active Withdrawn
  • 2006-07-18 US US11/989,121 patent/US20090102430A1/en not_active Abandoned

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