• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a device for balancing (3) charging a storage device including several elements connected in series, comprising: a DC / AC converter (320) including: an inverter; a series resonant circuit connected to the output of the inverter; a plurality of AC / DC converters (301, 302, 303) each having an input, and an output connected to one of said respective storage elements and selectively supplying its output; a transformer (310) whose primary (311) is connected to the series resonant circuit (340) and whose secondary (312) has outputs connected to an input of a respective AC / DC converter; a control circuit (5) configured to control the DC / AC converter (320) as a current source when the number of powered outputs is less than or equal to a threshold, and configured to control the DC / AC converter (320) at constant power when the number of powered outputs is greater than said threshold.
    公开号:FR3014253A1
    申请号:FR1361819
    申请日:2013-11-29
    公开日:2015-06-05
    发明作者:Laurent Garnier；Daniel Chatroux；Marc Lucea；Pierre-Emmanuel Ory
    申请人:Commissariat a lEnergie Atomique CEA；Renault SAS；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；
    IPC主号:
    专利说明:

    [0001] The invention relates to a load balancing device for a power battery with electrochemical accumulators. High voltage direct current electrical systems are developing significantly. Indeed, many transport systems include a DC voltage supply. Hybrid combustion / electric or electric vehicles include, in particular, high power batteries. Such batteries are used to drive an AC electric motor through an inverter. The voltage levels required for such engines reach several hundred volts, typically of the order of 400 volts. Such batteries also have a high capacity to promote the autonomy of the vehicle in electric mode. To obtain high powers and capacities, several groups of accumulators are placed in series. The number of stages (number of accumulator groups) and the number of accumulators in parallel in each stage vary according to the desired voltage, current and capacity for the battery. The combination of several accumulators is called a storage battery. The electrochemical accumulators used for such vehicles are generally of the lithium ion type for their ability to store a large amount of energy with a weight and volume contained. Lithium ion iron phosphate LiFePO4 battery technologies are undergoing significant development due to a high intrinsic safety level, to the detriment of a somewhat lower energy storage density. An electrochemical accumulator usually has a nominal voltage of the following order of magnitude: 3.3 V for a Lithium Iron Phosphate LiFePO4 technology, 4.2 V for a lithium-ion technology based on cobalt oxide. The invention can also be applied to supercapacitors. The charging or discharging of an accumulator results respectively in a growth or a decrease in the voltage at its terminals. A charged or discharged accumulator is considered when it has reached a voltage level defined by its electrochemical process. In a circuit using multiple accumulator stages, the current flowing through the stages is the same. The level of charge or discharge of the stages therefore depends on the intrinsic characteristics of the accumulators. Voltage differences between the stages appear during charging or discharging because of manufacturing, aging, assembly and operating temperature differences between the different accumulators. For a battery of Li-ion technology, a voltage too high or too low, called threshold voltage, can damage or destroy it. For example, the overloading of a cobalt oxide Li-ion battery can lead to thermal runaway and start of fire. For a Li-ion battery based on iron phosphate, an overload results in a decomposition of the electrolyte which decreases its life or deteriorates. Too deep a discharge which leads to a voltage below 2 V, for example, mainly leads to an oxidation of the current collector of the negative electrode when it is made of copper and therefore deterioration of the accumulator. Consequently, the monitoring of the voltages at the terminals of each accumulator stage (s) is obligatory during charging and discharging for a question of safety and reliability. A monitoring device is thus generally arranged in parallel with each stage and ensures this function. The purpose of the monitoring device is to monitor the state of charge (or the residual charge) and discharge of each accumulator stage (s) and to transmit the information to the control circuit in order to stop charging or discharging of the battery when a stage has reached its threshold voltage. However, on a battery with several accumulator stages (s) arranged in series, if the charge is stopped when the most charged stage reaches its threshold voltage, the other stages may not be fully charged. Conversely, if the discharge is stopped when the most discharged stage reaches its threshold voltage, the other stages may not be fully discharged. The capacity of each accumulator stage (s) is therefore not exploited, which represents a major problem in transport-type applications, with on-board batteries having high autonomy constraints. The useful capacity of the battery is indeed reduced by the interruption of the discharge of the battery, while stages are not yet completely discharged. Indirectly, the cost of the useful kWh increases, as well as the mass and the volume of the pack. To overcome this problem, the monitoring device is generally associated with a load balancing device. The balancing device has the function of optimizing the charge of the battery and thus its autonomy by bringing the accumulator stages (s) in series to an identical state of charge and / or discharge. There are two categories of balancing devices, so-called energy dissipation balancing devices, or so-called energy transfer devices. ICG10875 EN Depot Text VLG.doc With energy dissipation balancing systems, the voltage across the stages is standardized by diverting all or part of the load current from one or more stages that have reached the threshold voltage and dissipating the energy in a resistance. In a variant, the voltage across the stages is standardized by discharging one or more stages having reached the high threshold voltage. However, such energy dissipation balancing systems have the major disadvantage of consuming more energy than necessary to charge the battery. Indeed, it is necessary to discharge several accumulators or to divert the charge current of several accumulators so that the last accumulator or batteries a little less charged finish their load. The energy dissipated can therefore be much greater than the energy of the charge or charges remaining to be realized. In addition, they dissipate excess energy in heat, which is not compatible with the integration constraints in transport and on-board applications, and this leads to a sharp drop in the life of the accumulators when the temperature rises. Energy transfer balancing systems exchange energy between them between accumulator stages, or with an auxiliary energy network. Balancing time is a major factor in the efficiency of balancing. Therefore, a relatively large charging power can be sought. The energy transfer can be either unidirectional, from the battery to the stages or floors to the battery, or bidirectionally from the battery to the floors and floors to the battery or from adjacent floor to stage. . Document WO2011095608 describes an example of a load balancing device for a battery. In this example, the load balancing device 30 has a one-way converter with several outputs. The converter has a dedicated charging device for each of its outputs. Each stage can thus be loaded independently during balancing. The converter further comprises a voltage generator receiving an auxiliary battery voltage on its input and applying its output voltage to each dedicated charging device. The voltage generator comprises in particular a complete bridge with four switches, whose voltage is applied to the primary of a transformer. The secondary of the transformer is connected to apply its voltage to the input of each charging device. The balancing current of a stage is mainly limited by the dimensioning of the components of its load device. ICG10875 EN Depot Text VLG.doc However, such a load balancing device has disadvantages. This device has in particular a relatively limited power load and is therefore unsuitable when a significant imbalance exists between the stages. Indeed, the electrical power applied to the primary of the transformer is distributed over several charging devices. Moreover, obtaining the state of charge of each stage requires an accurate measurement of the charge energy supplied by each charging device and requires measurements of current and voltage at the secondary of the transformer. Such measurements induce an additional cost for the balancing device, which is difficult to reconcile with most applications. Document US20010115436 describes another example of a load balancing device for a battery. The charges or discharges of the different stages are here carried out sequentially. The load balancer includes an isolated bidirectional converter. The bidirectional converter comprises a matrix of transistors, so that the voltage and the charging current are applied selectively only on a single stage simultaneously. The converter further comprises a transformer whose primary is powered by an auxiliary battery and whose secondary is connected to the input of the matrix of the transistors.
    [0002] Such a load balancing device also has drawbacks. For a relatively uniform imbalance, the balancing time is quite long, due to the relatively low load power and the number of stages to be balanced. If the converter is sized to provide a higher load current, Joule losses will become too large. This device has a significant cost and a relatively low electrical efficiency especially when the voltage of the stages is relatively low (or so requires even more expensive components). The invention aims to solve one or more of these disadvantages. The invention thus relates to a device for balancing the charge of a power electrical energy storage device including several electrical energy storage elements connected in series, comprising: a DC / AC converter including: an inverter having an input for connecting a DC voltage source; a series resonant circuit connected to the output of the inverter; a plurality of AC / DC converters each having an input, and an output connected to one of said respective energy storage elements, each AC / DC converter selectively supplying its output; ICG10875 EN Depot Text VLG.doc - a transformer whose primary is connected to the series resonant circuit and whose secondary has outputs, each of these outputs being connected to an input of a respective AC / DC converter; a control circuit configured to control each AC / DC converter for selectively supplying its output, and configured to control the DC / AC converter as a current source when the number of outputs fed by their AC / DC converter is lower or equal to a threshold, and configured to control the DC / AC constant power converter when the number of outputs fed by their AC / DC converter is greater than said threshold. According to one variant, said series resonant circuit comprises a capacitor and an inductance connected in series. According to another variant, each of said AC / DC converters comprises a rectifier circuit and an inductor connected between the input of this AC / DC converter and its rectifier circuit. According to another variant, the control circuit is configured to determine which energy storage element has the lowest voltage, and configured to control the supply of an output by its AC / DC converter only when it has been determined that the energy storage element connected to this output has the lowest voltage. According to yet another variant, the control circuit determines the state of charge of each of said storage elements from the supply time of the output connected to each storage element on the one hand when the DC / AC converter is controlled at constant power and secondly when this DC / AC converter is controlled current source. Alternatively, each of said AC / DC converters comprises four rectifiers and a secondary output of said transformer is bridged between the four rectifiers. According to a further variant, the secondary of the transformer comprises a secondary midpoint winding for each of said AC / DC converters, and each of said AC / DC converters comprises first and second rectifying elements connected on the one hand to a terminal of their storage element and secondly to a respective terminal of their secondary winding, the midpoint of the secondary winding being connected to the other terminal of their storage element. According to another variant, each of said AC / DC converters 40 comprises a switch controlled by said control circuit so as to selectively connect an output of this AC / DC converter to its respective storage element. According to yet another variant, each of the AC / DC converters comprises a rectifying element and a relay controlled by said control circuit, said relay selectively connecting the secondary of the transformer to said rectifier element. According to a variant, each of said AC / DC converters is connected to a respective output of the secondary of the transformer via first and second conductive links having respective inductances Lai and Lri for an AC / DC converter of index i, l secondary leakage inductance of the transformer for its output connected to the index converter i having a value Lti, the values of Lti, Lai and Lri verifying the following relation for each value of the index i: Lti + Lai + Lri = K, with K a constant.
    [0003] According to a variant, said inverter is sized for an input voltage lower than the voltage at the terminals of the electrical power storage device. Other features and advantages of the invention will become clear from the description which is given below, by way of indication and in no way limiting, with reference to the accompanying drawings, in which: FIG. 1 is a diagrammatic representation of an example of a power supply system including a load balancing device embodying the invention; FIG. 2 illustrates an exemplary accumulator stage of a load-balancing power supply system; FIG. 3 is a schematic representation of a load balancing device; FIG. 4 is a circuit diagram of an example of a DC / AC converter of the load balancing device; FIG. 5 is a circuit diagram of an example of an AC / DC converter of the load balancing device; FIG. 6 is a diagram comparing the power provided by different load balancing devices as a function of the number of simultaneously loaded storage elements; FIG. 7 is a circuit diagram of a variant of a rectifying rectifier circuit of the AC / DC converter; FIG 8 is an electrical diagram of a first variant of a rectifier circuit connected to a secondary mid-point; Figure 9 is a circuit diagram of a second variant of a rectifier circuit connected to a mid-point secondary; FIG. 10 is a circuit diagram of a third variant of a rectifier circuit connected to a mid-point secondary; FIG. 11 is an electrical diagram of another variant of a relay selection rectifier circuit; FIG 12 is an electrical diagram detailing the inductors on the side of an AC / DC converter.
    [0004] Figure 1 is a schematic representation of an exemplary power supply system 1. The power supply system 1 comprises firstly a system for storing electrical energy in the form of power batteries 2 connected in series. Each battery 2 comprises several stages connected in series between its terminals. A battery 2 illustrated in Figure 1 comprises in particular stages 201, 202 and 203 connected in series. The voltage between the positive terminal and the negative terminal of the electrical energy storage system (at the terminals of all the batteries 2 connected in series) is typically between 100 V and 750 V, for example of the order of 400 V. The electrical energy storage system is for example intended to supply an electrical load (not shown) such as the engine of a hybrid or electric vehicle being connected to the terminals of an inverter, and is advantageously isolated from the chassis metal of such a vehicle. As illustrated in FIG. 2, each battery 2 can include a plurality of electrochemical accumulators 211 connected in parallel in several branches and / or connected in series in several stages. On the other hand, the power supply system 1 comprises a load balancing device 3 for each battery 2, of energy transfer type. The detailed load balancer 3 comprises a connection interface configured to be connected to the terminals of each of the stages of the battery 2. The load balancer 3 also includes a connection interface 390 configured to be connected to a terminal. DC voltage source, for example via an auxiliary network 4, for example an on-board electrical network of a vehicle, whose voltage is generally regulated to a value close to 12 V. This regulated voltage may for example vary in a range between 10.5 V and 14 V, generally using an auxiliary battery, a supercapacitor or a capacitor connected to this on-board network 4. This regulated voltage of the network 4 is lower than the voltage across the battery 2 (for example at least five times lower). Auxiliary charges are usually connected to the auxiliary network 4. The balancing device 3 comprises several AC / DC converters, the output of each of these converters being connected to a respective stage. In this case, the converters 301 to 303 have their respective output connected to the respective terminals of the stages 201 to 203. The converters 301 to 303 are advantageously intended to balance the stages 201 to 203 of the battery 2 (and thus optimize the charge of this power battery 2) More precisely, in the example illustrated with reference to FIG. 3, the load balancing device 3 comprises: a transformer 310; a DC / AC converter 320 whose input is connected to the on-board network 4, and the output of which is connected to the primary 311 of the transformer 310; AC / DC converters 301 to 303 whose outputs are intended to be respectively connected to the stages 201 to 203, and whose inputs are connected to respective outputs 312 of the secondary of the transformer 310; A detailed control circuit later. Due to the use of a transformer 310, the converters 301 to 303 are isolated with respect to the edge network 4 and with respect to the DC / AC converter 320. The secondary of the transformer 310 advantageously comprises independent secondary windings dedicated to respective converters 301 to 303. Thus, the converters 301 to 303 are isolated from each other. The transformer 310 also allows, in a manner known per se, to adapt the level of voltage applied to the input of each of the converters 301 to 303. FIG. 4 is a circuit diagram of an example of a DC / AC converter 320 of the device. The auxiliary network 4 is connected to the input of the DC / AC converter 320 to apply a voltage to it and supply it with a current. The converter 320 includes an inverter 330. The inverter 330 here has a known in-bridge bridge structure. The inverter 330 comprises transistor type switching components. The transistors are controlled by a control circuit 350 in order to transform the DC voltage supplied by the network 4 into an AC voltage applied to the output of the inverter 330. The control circuit 350 is itself controlled by a control circuit. A resonant circuit 340 is connected to the output of the inverter 330, that is to say at the output of the bridge arm of this inverter 330. The resonant circuit 340 series here comprises a capacitor 341, an inductor 342 and an inductor 343. The series resonant circuit 340 is connected in series with the primary 311 of the transformer 310. An example of the dimensioning of the resonant circuit 340 may be the following: it is defined in advance a power value to transmit to the secondary of the transformer 310, for example a value Pout = 48W; a minimum input voltage Emin is determined for the AC / DC converter 320, for example Emin = 11V for a 12V-type network 4 and whose voltage is regulated between 11 and 13 V; a performance of the DC / AC converter 320 of 85 ° / o is assumed to be fixed at a minimum operating frequency of 220 kHz related to the technology of the control circuits and the type of semiconductors used; the operation of the converter 320 is chosen at a frequency greater than a resonance frequency f 0, with f 0 chosen to be worth, for example, 200 kHz; an overvoltage factor applicable to the capacitor 341 is determined. This criterion varies according to the technology of this capacitor 341 and the operating frequency. With a COG type ceramic capacitor, this overvoltage factor has a value of approximately 1, for example 1.075; a maximum output voltage Voutmax = 4V is fixed at the terminals of the primary 311. A total inductance of 2879 nH calculated for the combination of the inductances 342 and 343, and a capacitance value of 220nF for the capacitor 341 then makes it possible, for example to obtain the desired resonance frequency f0. A simple transformation ratio m such that m * Emin> Voutmax can be chosen between the primary 311 and each output of the secondary 312. However, the further away the relation m * Emin = Voutmax, the lower the conversion efficiency. . A compromise may lead to choosing m = 0.5. The combination of the inverter 330 with the series resonant circuit 340 and the control circuit 5 makes it possible to selectively operate the DC / AC converter 320 in a mode of operation of AC current. Furthermore, the control circuit 5 can also selectively control another mode of operation of the converter 320, so that it operates at constant power. In the current source operating mode, it is easy to control the current applied to the primary of the transformer 310 and thus the power transmitted to the stages. The control circuit 5 switches between the current source operation and the constant power operation according to the following criteria: if the act number of AC / DC converters 300 to simultaneously supply their respective output is less than or equal to a threshold nt, the control circuit 5 operates the converter 320 so as to regulate its current Icc. The current setpoint Icc of the converter 320 is then Icc = act * lun (assuming a conversion ratio of 1 and a 100% efficiency for the converters 300) with the current that the converter 320 must output to a single converter 300 applies the nominal load current to a stage 200; if the act number of AC / DC converters 300 to supply simultaneously their respective output is greater than the threshold nt, the control circuit 5 operates the converter 320 with a constant power type control. The charge current of the stages 200 recharged simultaneously is then lower than their nominal load current. The threshold nt can for example be determined in the following manner. Let Ppr be the maximum power that the converter 320 can supply to the secondary of the transformer 310, and Psec the maximum power that each converter 300 can apply on its output (it is assumed for simplicity a 100% efficiency for the converters 300). The operating modes are then determined according to the following rules: if act * Psec Ppr, then the control circuit 5 operates the converter 320 in current source mode current current Icc = actlun so as to provide the secondary of the transformer a power equal to act * Psec, -if act * Psec> Ppr, then the control circuit 5 operates the converter 320 in constant power mode. The threshold nt is therefore the largest value of act for which the relation act * Psec Ppr is verified. Thus, according to the invention, the cooling of the converter 320 can remain dimensioned for a relatively reduced power, while benefiting from an optimized load balancing time for the battery 2. Likewise, it is possible to use an optimized load balancing time for the battery 2. Similarly, the VLG text depot is used. doc can adapt the size of the transformer 310 to this relatively low power. By using a converter 320 of a relatively low power, it is possible to avoid the Joule losses that would result from a converter of greater power. The operation of the converter 320 has optimum energy efficiency, since it operates at its nominal power for a preponderant duration corresponding to the constant power operating mode. At every moment, the transmitted energy is optimized, which has the effect of considerably reducing the balancing times.
    [0005] FIG. 5 is a circuit diagram of an exemplary AC / DC converter 300 of the load balancing device 3. The converter 300 has an input connected to a respective output or winding of the secondary 312 of the transformer 310. the converter 300 is here connected in bridge between four rectifying elements 374 of a rectifying circuit 360. The rectifying elements 374 are here diodes. A switch 373 is connected between the rectifier circuit 360 and the output of the converter 300. The switch 373 here comprises a transistor of the Mosfet type. This transistor 373 is controlled by the control circuit 5, via a non-detailed control circuit. The switch 373 selectively interrupts the power supply to the output of the converter 300. The switch 373 thus makes it possible to selectively control the load of the stage 200 connected to this output.
    [0006] The diagram of FIG. 6 makes it possible to highlight the load-balancing performance of a balancing device 3 according to the invention with respect to other load-balancing devices designed according to the state of the art. The dashed line curve corresponds to a load balancing device corresponding to the teaching of WO2011095608. The dashed line corresponds to the teaching of document US20010115436. The curve in solid line corresponds to a load balancing device 3 according to an implementation of the invention. In this diagram, the abscissa corresponds to the act number of AC / DC converters during load balancing. The ordinate 35 is the total charge power or a multiple of the total charge current supplied by each charge balancer. For the various load balancing devices, it has been assumed that each of them is capable of providing a 48W power output. ICG10875 EN Depot Text VLG.doc For the load balancing device represented by the dashed line, each output converter is sized to provide a maximum load current of 1A at 4V. The charging power is then proportional to the number of stages Act being charged.
    [0007] For the load balancing device represented by the dashed line, it can be seen that the average load power (because the load of the different stages is sequential) is high for a reduced number of stages whose load is to be balanced. The average load power is then essentially limited by the sizing of the output converters.
    [0008] As soon as the number of stages whose load is to be balanced increases, the average load power drops rapidly. For the balancing device 3 according to the invention, it has been assumed that AC / DC converters sized to each provide a load current of their stage up to 4A. The load power is proportional to the number of stages being simultaneously charged for the left part of the diagram, which corresponds to the mode of operation of the DC / AC converter in current source. The stage or stages being simultaneously charged then benefit from a relatively high charge current in order to proceed to a fast balancing phase (this mode of operation corresponds more to a start of load balancing). The load power is constant and optimal for the right part of the diagram, which corresponds to the mode of operation of the DC / AC converter in power regulation (this mode of operation corresponds more to a load balancing end). This phase of load balancing is also fast since all the power made available by the DC / AC converter is exploited. Advantageously, each AC / DC converter 300 comprises an inductance connected between its input and its rectifier circuit 360. In the example illustrated in FIG. 5, the converter 300 comprises two inductive elements 371 and 372 connected between the input of the converter 300 and the rectifier circuit 360. This inductor is used to present a preponderant value compared to spurious inductances connectivity. When several converters 300 simultaneously feed their respective stages 200, the current flowing in the primary of the transformer 311 is distributed in the windings of the secondary prorata line impedances of these converters. By means of said inductors, it is possible to homogenize the currents delivered by different AC / DC converters 300 simultaneously.
    [0009] Figure 7 is an electrical schematic of an AC / DC converter variant 300 of the load balancer 3. The converter 300 has an input connected to a respective winding of the secondary 312 of the transformer 310. The input of the converter 300 is here bridged between four rectifying elements 375 of a rectifier circuit 360. The rectifiers 375 here are switches based on Mosfet type transistors. The rectifier circuit 360 is synchronously rectified, the switching of said rectifying transistors being controlled by the control circuit 5 and by a control circuit not illustrated. A switch 373 is connected between the rectifier circuit 360 and the output of the converter 300. The switch 373 is controlled by the control circuit 5 in order to selectively interrupt the supply of the output of the converter 300. The switch 373 thus allows selectively controlling the load of a stage 200 connected to this output. FIG. 8 is a circuit diagram of another variant of a rectifier circuit 360. The rectifier circuit 360 is connected to a secondary winding 313 at the mid-point of the transformer 310. The rectifying elements 376 of the rectifier circuit 360 are here diodes. Each diode is connected between on the one hand a respective terminal of the secondary winding 313, and on the other hand an output terminal of the AC / DC converter 300. The other output terminal of the AC / DC converter 300 is connected to the intermediate point of the winding 313 via the switch 373. FIG. 9 is a circuit diagram of another variant of a rectifier circuit 360 of an AC / DC converter 300. The rectifier circuit 360 is connected to a secondary winding 313 mid-point of the transformer 310. The rectifier circuit 360 is here of synchronous type. The rectifying elements 377 of the rectifier circuit 360 here include bidirectional switches for example based on series-type Mosfet transistors. Each switch 377 is connected between on the one hand a respective terminal of the secondary winding 313, and on the other hand an output terminal 35 of the AC / DC converter 300. The other output terminal of the AC / DC converter 300 is connected to the midpoint of the winding 313. The openings of the switches 377 can be controlled to selectively interrupt the supply of the output of the AC / DC converter 300, and thus dispense with a dedicated switch 40 for this function. FIG. 10 is a circuit diagram of a variant of the AC / DC converter 300 of FIG. 8. This converter differs from that of FIG. 8 by the use of Mosfet type switches 379. replacement of the 5 diodes 376. FIG. 11 is a circuit diagram of another AC / DC converter variant 300. In this case, the power supply of the output of the converter 300 is selectively interrupted by the intermediate 10 of FIG. a relay 378 controlled by the control circuit 5. The relay 378 is thus configured to selectively open a connection with the input of the converter 300, upstream of the rectifying circuit 360. Moreover, to avoid disparities in charging currents between the different stages 200 loaded simultaneously, it is desirable that these stages 200 have the same voltage. Therefore, the control circuit 5 can control the charging of the stages as follows. The control circuit 5 is configured to determine at regular intervals which stage (s) have the lowest voltage. The control circuit 5 then controls the load of only the one or more stages that have been determined to have the lowest voltage. This strategy makes it possible, in the context of the invention, to apply a high load current on stages that are significantly more discharged than the others. The balancing thus starts with the optimal charging of the most limiting accumulators for the overall capacity of the battery 2. Thus, even if the load balancing time is limited, this operating mode makes it possible to benefit from an efficiency of optimal balancing. In addition, only stages having the same voltage level are then simultaneously charged. It is thus possible to benefit from a uniform distribution of the current between the stages being charged. The control circuit 5 determines at regular intervals the state of charge of each of the stages 200. This state of charge can be determined by voltage measurement or extrapolated from the knowledge of the quantity of energy stored in each stage 200 during load balancing. The control circuit 5 can for example determine the charging energy by knowing the number of stages (and therefore the operating mode) loaded simultaneously for given durations. Such a determination of the state of charge is facilitated by the control strategy described above, since the stages being charged have the same voltage and receive the same charge energy simultaneously. As previously detailed, it is advantageous to have the same line impedances for the different AC / DC converters 300. Such a homogenization of the line impedance is relatively difficult to obtain for the battery. 2. Indeed, it turns out in practice impossible to obtain an identical connection distance between the different stages and the transformer 310. Therefore, these differences in distance induce dispersions between the line impedances. Similarly, the different outputs of secondary 312 may have leakage inductances with dispersions.
    [0010] FIG. 12 is an electrical diagram detailing inductance values on the side of an AC / DC converter 300. Lt represents the leakage inductance of the secondary output 312 for this transformer. Represents the inductance induced by a first connection of the rectifier circuit 360 to a first secondary output terminal 312 for this transformer, and Lr represents the inductance induced by a second connection of the rectifier circuit 360 to the second output terminal of the secondary 312 for this transformer. By designating, by Lti, the leakage inductance in the secondary winding for an AC / DC converter of index i, Lai and Lri, the connection inductances induced by the conductive elements between the rectifier circuit 360i and this output, these elements will be dimensioned. drivers for each AC / DC converter to verify the following relationship: Lti + Lai + Lri = K, with K a constant. This relationship can be met by pre-measuring the different Lt values and adapting the Lai and Lr values by appropriate inductive connections or components. For example, it is conceivable to group on the same printed circuit the connections between the different AC / DC converters and the outputs of the secondary 312. During the design, the width of the link tracks 30 of the printed circuit is then adapted as a function of their length, in order to obtain Lai and Lri values verifying the mentioned relation. Load balancing per charge of different stages can be implemented either during a global charging phase or during a global discharge phase. Although not illustrated, the power supply system 1 advantageously comprises a device for measuring and monitoring the voltage across the accumulator stages. ICG10875 EN Depot Text VLG.doc
    权利要求:
    Claims (11)
    [0001]
    REVENDICATIONS1. Load balancing device (3) for a power electrical energy storage device (2) including a plurality of series connected electrical energy storage elements (201, 202, 203), characterized in that comprises: a DC / AC converter (320) including: an inverter (330) having an input for connecting a DC voltage source (4); a series resonant circuit (340) connected to the output of the inverter; a plurality of AC / DC converters (301, 302, 303) each having an input, and an output connected to one of said respective energy storage elements (201, 202, 203), each AC / DC converter selectively supplying its output; a transformer (310) whose primary (311) is connected to the series resonant circuit (340) and whose secondary (312) has outputs, each of these outputs being connected to an input of a respective AC / DC converter; a control circuit (5) configured to control each AC / DC converter (301, 302, 303) for the selective supply of its output, and configured to control the DC / AC converter (320) as a current source when the number of outputs fed by their AC / DC converter is less than or equal to a threshold, and configured to control the DC / AC converter (320) constant power when the number of outputs fed by their AC / DC converter is greater than said threshold.
    [0002]
    The charge balancing device (3) according to claim 1, wherein said series resonant circuit (340) comprises a capacitor (341) and an inductor (342) connected in series.
    [0003]
    The charge balancing device (3) according to claim 1 or 2, wherein each of said AC / DC converters (300) comprises a rectifier circuit (360) and an inductor connected between the input of this AC / DC converter. and its rectifier circuit.
    [0004]
    A charge balancing device (3) according to any one of the preceding claims, wherein the control circuit (5) is configured to determine which energy storage element (200) has the lowest voltage, and configured to control the power supply of a VLG Text Generator.doc output by its AC / DC converter (360) only when it has been determined that the energy storage element (200) connected to that output the lowest voltage.
    [0005]
    Load balancing device (3) according to claims 3 and 4, wherein the control circuit (5) determines the state of charge of each of said storage elements (200) from the feed time of the output connected to each storage element on the one hand when the DC / AC converter (320) is controlled at constant power and on the other hand when the DC / AC converter (320) is controlled as a current source.
    [0006]
    A charge balancing device (3) according to any one of the preceding claims, wherein each of said AC / DC converters comprises four rectifying elements and wherein an output of the secondary (312) of said transformer (310) is connected. in bridge between the four straightening elements.
    [0007]
    The charge balancing device (3) according to any one of claims 1 to 5, wherein the secondary (312) of the transformer comprises a secondary mid-point winding for each of said AC / DC converters (300), and wherein each of said AC / DC converters comprises first and second rectifying elements (376) connected on the one hand to a terminal of their storage element and, on the other hand, to a respective terminal of their secondary winding, the midpoint of the secondary winding being connected to the other terminal of their storage element.
    [0008]
    A charge balancing device (3) according to any one of the preceding claims, wherein each of said AC / DC converters (300) comprises a switch (373) controlled by said control circuit (5) so as to connect selectively an output of this AC / DC converter (300) to its respective storage element.
    [0009]
    The charge balancing device (3) according to any one of claims 1 to 7, wherein each of the AC / DC converters (300) comprises a rectifying element and a relay controlled by said control circuit, said relay selectively connecting the secondary (312) of the transformer to said rectifying element. ICG10875 EN Depot Text VLG.doc
    [0010]
    A load balancing device (3) according to any one of the preceding claims, wherein each of said AC / DC converters (300) is connected to a respective output of the secondary of the transformer via first and second links. conductive having respective inductances Lai and Lri for an AC / DC converter of index i, the secondary leakage inductance (312) of the transformer for its output connected to the index converter i having a value Lti, the values of Lti , Lai and Lri verifying the following relation for each value of the index i: Lti + Lai + Lri = K, with K a constant.
    [0011]
    A load balancing device according to any one of the preceding claims, wherein said inverter (330) is sized for an input voltage lower than the voltage across the power storage device. ICG10875 EN Depot Text VLG.doc
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    同族专利:
    公开号 | 公开日
    KR102280311B1|2021-07-21|
    CN105814769B|2019-02-05|
    JP6480935B2|2019-03-13|
    FR3014253B1|2017-05-19|
    US10003202B2|2018-06-19|
    EP3075058B1|2020-03-11|
    US20170264109A1|2017-09-14|
    KR20160091369A|2016-08-02|
    JP2016538812A|2016-12-08|
    WO2015079188A1|2015-06-04|
    CN105814769A|2016-07-27|
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    引用文献:
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    JP5332031B2|2008-03-31|2013-11-06|株式会社小松製作所|Switching control method for transformer coupled booster|
    WO2011034957A2|2009-09-16|2011-03-24|National Semiconductor Corporation|Active cell and module balancing for batteries or other power supplies|
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    JP5567684B2|2009-12-14|2014-08-06|リーチインターナショナルコーポレイション|Battery balancing circuit and method for balancing energy stored in a plurality of cells of a battery having a first terminal and a second terminal|
    FR2956260B1|2010-02-05|2012-04-13|Commissariat Energie Atomique|CHARGE BALANCING SYSTEM FOR BATTERIES|
    FR2959885B1|2010-05-05|2014-12-05|Commissariat Energie Atomique|POWER BATTERY BALANCING SYSTEM, LOAD BALANCING METHOD, AND CORRESPONDING CHARGE AND FEED BALANCING COMBINATION METHOD|
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    CN102522790B|2011-12-05|2015-07-08|中电普瑞科技有限公司|Equalization device for series battery packs|US10581253B2|2016-01-15|2020-03-03|Enedym Inc.|Energy storage balancing system|
    FR3063850B1|2017-03-09|2019-04-19|Commissariat A L'energie Atomique Et Aux Energies Alternatives|DOUBLE BRIDGE CONVERTER|
    US10530270B2|2017-12-01|2020-01-07|Qatar University|Modular isolated half-bridge based capacitor-tapped multi-module converter with inherent DC fault segregation capability|
    CN108382230A|2018-02-07|2018-08-10|成都信息工程大学|The active equalization control method of power battery|
    CN111204259A|2020-02-26|2020-05-29|潍柴动力股份有限公司|Battery equalization circuit and battery management method|
    法律状态:
    2015-11-30| PLFP| Fee payment|Year of fee payment: 3 |
    2016-11-30| PLFP| Fee payment|Year of fee payment: 4 |
    2017-11-30| PLFP| Fee payment|Year of fee payment: 5 |
    2018-11-29| PLFP| Fee payment|Year of fee payment: 6 |
    2019-11-29| PLFP| Fee payment|Year of fee payment: 7 |
    2020-11-30| PLFP| Fee payment|Year of fee payment: 8 |
    优先权:
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    FR1361819A|FR3014253B1|2013-11-29|2013-11-29|CHARGE BALANCING DEVICE FOR ELEMENTS OF A POWER BATTERY|FR1361819A| FR3014253B1|2013-11-29|2013-11-29|CHARGE BALANCING DEVICE FOR ELEMENTS OF A POWER BATTERY|
    CN201480065125.0A| CN105814769B|2013-11-29|2014-11-28|For balancing the device of capacity cell set of pieces load|
    JP2016534151A| JP6480935B2|2013-11-29|2014-11-28|Charge balance device|
    US15/100,190| US10003202B2|2013-11-29|2014-11-28|Device for balancing a power battery element load|
    PCT/FR2014/053087| WO2015079188A1|2013-11-29|2014-11-28|Device for balancing a power battery element load|
    KR1020167016828A| KR102280311B1|2013-11-29|2014-11-28|Device for balancing a power battery element load|
    EP14821755.7A| EP3075058B1|2013-11-29|2014-11-28|Device for balancing a power battery element load|
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