System and method for charging the energy storage cells of an energy storage device
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2011-12-20
- Publication Date
- 2026-07-16
AI Technical Summary
Existing battery systems face inefficiencies and increased costs due to the need for multiple-stage charging devices to accommodate varying states of charge among energy storage cells, which also prolong charging times and require complex components.
A method and system that selectively switches and controls energy storage cell modules into energy supply branches during charging, ensuring the charging voltage remains within a predefined range by monitoring and adjusting the state of charge, allowing for the use of less complex and cheaper charging devices.
Reduces the voltage range required for charging, leading to cost savings, improved efficiency, and reduced power losses, while enabling faster charging and compensating for different states of charge without additional cell balancing methods.
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Abstract
Description
[0001] The invention relates to a system and a method for charging the energy storage cells of an energy storage device, in particular in a battery direct converter circuit for supplying power to electrical machines. State of the art
[0002] It is becoming clear that in the future, both in stationary applications, such as wind turbines or solar power plants, and in vehicles, such as hybrid or electric vehicles, electronic systems will increasingly be used that combine new energy storage technologies with electric drive technology.
[0003] The injection of multiphase current into an electric machine is typically accomplished by a converter in the form of a pulse-width modulation (PWM) inverter. For this purpose, a direct current (DC) voltage supplied by a DC link can be converted into a multiphase alternating current (AC) voltage, for example, a three-phase AC voltage. The DC link is supplied by a string of battery modules connected in series. To meet the power and energy requirements of a given application, several battery modules are often connected in series to form a traction battery.
[0004] Document US 5,642,275 A1 describes a battery system with an integrated inverter function. Systems of this type are known as multilevel cascaded inverters or battery direct inverters (BDIs). Such systems comprise DC power sources in multiple energy storage module strings, which can be directly connected to an electric machine or an electrical grid. Single-phase or multi-phase supply voltages can be generated.The energy storage module strings comprise multiple energy storage modules connected in series, each containing at least one battery cell and an associated controllable coupling unit. This coupling unit allows, depending on control signals, the respective energy storage module string to be interrupted, the associated battery cell to be bridged, or the associated battery cell to be connected to the respective energy storage module string. By appropriately controlling the coupling units, for example, using pulse-width modulation, suitable phase signals can also be provided to control the phase output voltage, thus eliminating the need for a separate pulse inverter. The pulse inverter required for controlling the phase output voltage is therefore, in effect, integrated into the BDI (Battery Data Interchange).
[0005] BDIs typically exhibit higher efficiency and greater reliability compared to conventional systems. Reliability is ensured, among other things, by the ability to disconnect defective, failed, or underperforming battery cells from the power supply strings through appropriate bypass control of the coupling units. The phase output voltage of an energy storage module string can be varied and, in particular, adjusted in steps by appropriately controlling the coupling units. The stepping of the output voltage is determined by the voltage of a single energy storage module, with the maximum possible phase output voltage being the sum of the voltages of all energy storage modules in an energy storage module string. Disclosure of the invention
[0006] According to one aspect of the present invention, a method for charging energy storage cells of an energy storage device is provided, comprising: n first output terminals, wherein n ≥ 1, for outputting a supply voltage at each of the output terminals, a second output terminal, wherein a charger can be connected between the first output terminals and the second output terminal, and n parallel-connected power supply branches, each of which is coupled between a first output terminal and the second output terminal, wherein each of the power supply branches comprises a plurality of series-connected energy storage modules, each of which comprises an energy storage cell module comprising at least one energy storage cell, and a coupling device with coupling elements designed to selectively switch or bridge the energy storage cell module in the respective power supply branch.The procedure comprises the following steps: determining a maximum possible charging voltage of a charger that provides a charging voltage for the energy storage device, determining the maximum number of energy storage cell modules of a power supply branch where the sum of the output voltages of the energy storage cell modules, which depend on the current charge states of all energy storage cell modules of a power supply branch, is even lower than the maximum possible charging voltage, and selecting and controlling the coupling elements of energy storage modules of the power supply branch so that only the maximum number of energy storage cell modules is coupled into the power supply branch at any given time.
[0007] According to a further aspect, the present invention provides a system with an energy storage device comprising n first output terminals, wherein n ≥ 1, for outputting a supply voltage at each of the output terminals, a second output terminal, wherein a charger can be connected between the first output terminals and the second output terminal, and n parallel-connected power supply branches, each of which is coupled between a first output terminal and the second output terminal, wherein each of the power supply branches comprises a plurality of series-connected energy storage modules, each of which comprises an energy storage cell module having at least one energy storage cell, and a coupling device with coupling elements designed to selectively switch or bridge the energy storage cell module in the respective power supply branch.The system further comprises a control device which is coupled to the coupling devices and which is designed to carry out a method according to the invention for charging the energy storage cells of the energy storage cell modules. Advantages of the invention
[0008] The idea of the present invention is to selectively switch the energy storage cell modules of a controllable energy storage device into the power supply branches during a charging process, so that the required charging voltage remains within a predefined voltage range throughout the entire charging process. For this purpose, the state of charge of the respective energy storage cells can be determined in order to calculate the required charging voltage per energy storage module and, consequently, to switch those energy storage modules into the power supply branch whose accumulated required charging voltages correspond to the predefined voltage range. With energy storage cells having different states of charge, a cyclical exchange of the energy storage cells to be charged can be carried out.
[0009] A significant advantage of this arrangement is that the voltage range required throughout the charging process of an energy storage device can be reduced. This allows the chargers used to charge the energy storage cells to have a narrower output voltage range, resulting in savings in volume and manufacturing costs on the one hand, and improved efficiency on the other. The chargers can use smaller transformers, no longer need to be multi-stage, and can therefore be implemented with less expensive and less demanding components. Efficiency is indirectly improved through reduced power losses. Furthermore, chargers with alternative topologies, such as resonant converters, can be used, which, by design, only permit a small voltage spread.
[0010] Another advantage is that a charger can be used for different applications by selecting the appropriate voltage range, for example for electric vehicles and hybrid vehicles alike.
[0011] Furthermore, a significant advantage is that differing charge states of energy storage cells, which can occur due to operational or aging factors, for example, can be balanced during the charging process without the need for additional cell balancing procedures. This reduces the overall charging time until all energy storage cells are fully charged.
[0012] According to one embodiment of the method according to the invention, the energy storage cell modules coupled to the energy supply branch can be cyclically exchanged by selecting and controlling the coupling elements of other energy storage modules in the energy supply branch at predetermined time cycles. This allows all energy storage modules to be charged evenly without increasing the charging time.
[0013] According to a further embodiment of the method according to the invention, the coupling elements of another of the unselected energy storage modules of the power supply branch can also be controlled with a variable duty cycle. The variable duty cycle adapts the average voltage required for this energy storage module to a current charging voltage. In an advantageous embodiment, if the variable duty cycle is determined as a function of the difference between the maximum possible charging voltage and the sum of the output voltages of the energy storage cell modules, or the difference between the minimum possible charging voltage and the sum of the output voltages of the energy storage cell modules, the charging voltage that must be provided by a charger can advantageously be kept constant.
[0014] According to a further embodiment of the method according to the invention, the output voltages of the selected energy storage modules of the power supply branch can be monitored during the charging process, and the specified maximum number of energy storage cell modules of a power supply branch can be reduced if the sum of the output voltages of the selected energy storage cell modules exceeds a desired charging voltage, for example, the maximum possible charging voltage. This advantageously makes it possible to remain within a predefined voltage range of the charger throughout the entire charging process.In particular, if, according to an advantageous embodiment, reducing the specified maximum number of energy storage cell modules involves reducing the number by one energy storage cell module at a time, it may be possible not only to remain below the maximum possible charging voltage at every point during the charging process, but also to maintain a charging voltage above a minimum possible charging voltage at all times. This serves to reduce the necessary spread of the output voltage range of a charger.
[0015] According to a further embodiment of the method according to the invention, monitoring the output voltages of the selected energy storage modules of the power supply branch during the charging process, and controlling the coupling elements of energy storage modules whose output voltages exceed a desired final voltage, allows for the permanent decoupling of the energy storage modules from the power supply branch during the remainder of the charging process. In this way, the advantage can be achieved that energy storage cell modules of different energy storage modules can be brought to different final voltages without affecting the charging process for the remaining energy storage cell modules of other energy storage modules of the same power supply branch.
[0016] According to one embodiment of the system according to the invention, a charger can be provided which is coupled to the n first output terminals and the second output terminal, and which is designed to provide a charging voltage for the energy storage device in the voltage range between a minimum possible charging voltage and the maximum possible charging voltage.
[0017] According to a further embodiment of the system according to the invention, a switching device can be provided which is coupled between the charger and the first n output terminals and which is designed to selectively disconnect the charger from the energy storage device. This advantageously enables the charger to be separated from the energy storage device during operation of the energy storage device, for example, after the charging process has finished. In addition, the switching device allows for the targeted charging of individual power supply branches.
[0018] According to a further embodiment of the system according to the invention, the coupling devices can comprise coupling elements in a full bridge circuit.
[0019] According to a further embodiment of the system according to the invention, the coupling devices can comprise coupling elements in a half-bridge configuration.
[0020] Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings. Brief description of the drawings
[0021] They show:
[0022] Fig. 1 a schematic representation of a system with an energy storage device according to an embodiment of the present invention;
[0023] Fig. 2 a schematic representation of an energy storage module of an energy storage device according to a further embodiment of the invention;
[0024] Fig. 3 a schematic representation of an energy storage module of an energy storage device according to a further embodiment of the invention;
[0025] Fig. 4 a schematic representation of a system with an energy storage device according to a further embodiment of the invention;
[0026] Fig. 5 a schematic representation of a system with an energy storage device according to a further embodiment of the invention;
[0027] Fig. 6 a schematic representation of a control strategy of an energy storage device for charging energy storage cells of the energy storage device according to a further embodiment of the invention;
[0028] Fig. 7 a schematic representation of a control strategy of an energy storage device for charging energy storage cells of the energy storage device according to a further embodiment of the invention; and
[0029] Fig. 8 a schematic representation of a method for charging energy storage cells of an energy storage device according to a further embodiment of the present invention.
[0030] Fig. 1 shows a system 100 for voltage conversion by energy storage modules 3The system converts the supplied DC voltage into an n-phase AC voltage. 100 includes an energy storage device 1 with energy storage modules 3 , which are connected in series in energy supply branches. Examples include in Fig. 1 Three energy supply branches are shown, which are used to generate a three-phase alternating voltage, for example for a three-phase machine. 2 , are suitable. However, it is clear that any other number of energy supply branches is equally possible. The energy storage device 1 Each branch of the energy supply system has a first output connection 1a , 1b , 1c , which are each connected to phase lines 2a , 2b or 2c are connected. The system serves as an example. 100 in Fig. 1 for supplying a three-phase electric machine 2However, it may also be provided that the energy storage device 1 for the generation of electricity for an energy supply network 2 is used.
[0031] The system 100 can still be a control device 9 include those connected to the energy storage device 1 is connected, and with the help of which the energy storage device 1 It can be controlled to set the desired output voltages at the respective first output terminals. 1a , 1b , 1c to provide. In addition, the control unit can 9 be designed to be used when charging the energy storage cells of the energy storage device 1 the respective active switching elements of the energy storage device 1 to head for.
[0032] The energy supply branches can be connected to a reference potential at their end. 4(reference rail) are connected, which in the illustrated embodiment with respect to the phase lines 2a , 2b , 2c the electric machine 2 a medium potential. The reference potential 4 This could, for example, be a ground potential. Each of the energy supply branches has at least two energy storage modules connected in series. 3 For example, the number of energy storage modules is... 3 per energy supply branch in Fig. 1 three, however any other number of energy storage modules 3 This is also possible. Preferably, each of the energy supply branches comprises the same number of energy storage modules. 3 , however, it is also possible to use a different number of energy storage modules for each energy supply branch. 3 to provide.
[0033] The energy storage modules 3Each has two output connections 3a and 3b on, via which an output voltage of the energy storage modules 3 can be provided. Since the energy storage modules 3 Since the primary components are connected in series, the output voltages of the energy storage modules add up. 3 to a total output voltage, which is at each of the first output terminals 1a , 1b , 1c the energy storage device 1 can be provided.
[0034] Examples of energy storage module designs 3 are in the Fig. 2 and Fig. 3 shown in greater detail. The energy storage modules 3 Each includes a coupling device 7 with multiple coupling elements 7a , 7c and, if applicable, 7b and 7d The energy storage modules 3Each also includes one energy storage cell module. 5 with one or more energy storage cells connected in series 5a until 5k .
[0035] The energy storage cell module 5 This could include, for example, batteries connected in series. 5a until 5k , for example, lithium-ion batteries. The number of energy storage cells is 5a until 5k in the Fig. 2 and Fig. 3 energy storage modules shown 3 Two examples, but any other number of energy storage cells 5a until 5k is also possible.
[0036] The energy storage cell modules 5 are connected via connecting lines to input terminals of the associated coupling device 7 connected. The coupling device 7 is in Fig. 2. Example of a full bridge circuit with two coupling elements each7a , 7c and two coupling elements 7b , 7d trained. The coupling elements 7a , 7b , 7c , 7d Each of these components can include an active switching element, for example a semiconductor switch, and a freewheeling diode connected in parallel. It may be provided that the coupling elements 7a , 7b , 7c , 7d are designed as MOSFET switches, which already have an intrinsic diode. Alternatively, it is possible to use only two coupling elements each. 7a , 7c to train so that – as in Fig. Figure 3 is shown as an example – a half-bridge circuit is implemented.
[0037] The coupling elements 7a , 7b , 7c , 7d can be controlled in this way, for example using the in Fig. 1 control unit shown 9that the respective energy storage cell module 5 selectively between the output terminals 3a and 3b is switched on or that the energy storage cell module 5 is bridged. With reference to Fig. 2. The energy storage cell module 5 for example in the forward direction between the output terminals 3a and 3b They can be switched by activating the active switching element of the coupling element. 7d and the active switching element of the coupling element 7a are put into a closed state, while the two remaining active switching elements of the coupling elements 7b and 7c to be put into an open state. A bridging state can be set, for example, by connecting the two active switching elements of the coupling elements. 7a and 7bare put into a closed state while the two active switching elements of the coupling elements 7c and 7d held in the open state. Analogous considerations can be applied to the half-bridge circuit in the Fig. 3 will be hired.
[0038] By appropriately controlling the coupling devices 7 Therefore, individual energy storage cell modules can be used. 5 the energy storage modules 3 can be specifically integrated into the series connection of a power supply branch. This is particularly useful for the targeted control of the coupling devices. 7 for selective switching of the energy storage cell modules 5 the energy storage modules 3 into the energy supply branches during a charging process of the energy storage cells 5 the energy storage modules 3 be.
[0039] For a charging process of the energy storage cells 5a until 5keach of the energy storage cell modules 5 the energy storage modules 3 can a charger 6 provided for, which in the exemplary embodiment in Fig. 1 via an initial charging connection 2d with a star point of the electric machine 2 on the one hand, and via a second output port 1d the energy storage device 1 on the other hand, a supply voltage for charging the energy storage cells 5a until 5k is connected. The charger 6 Alternatively, it could also be an external electrical energy source such as an electrical power grid or the like.
[0040] Fig. Figure 4 shows a schematic representation of another system. 200 for voltage conversion by energy storage modules 3 The system converts the supplied DC voltage into an n-phase AC voltage. 200differs from the one in Fig. 1 system shown 100 essentially in that the charging connection 2d of the charger 2d directly to the first output connections 1a , 1b , 1c the individual energy supply branches of the energy storage facility 1 is connected. For this purpose, the charging connection can be established, for example, via a first switching device. 6a with the first output connections 1a , 1b 1c be coupled. The first switching device 6a For example, it may have semiconductor switches that can be closed when the energy storage cell modules 5 the energy storage device 1 to be charged. Furthermore, a second switching device can be used. 6b between the first output terminals 1a , 1b , 1c the energy storage device 1and the phase connections of the electrical machine 2 be trained, which is designed to be used during a charging process of the energy storage device 1 the electric machine 2 from the energy storage device 1 to disconnect in order to prevent the occurrence of unwanted currents and thus potentially unwanted torques in the electric machine. The second switching device also 6b For example, it may have semiconductor switches that can be opened for a charging process.
[0041] Fig. Figure 5 shows a schematic representation of another system 400 The system 400 This includes an energy storage device 10 on, which has a first output port 10a and a second output port 10b with input connections of an inverter 13 They can be coupled. The energy storage device 10can supply one or more power supply branches of energy storage modules connected in series 3 exhibit, as in Fig. 2 and Fig. 3 shown as an example. Between the energy storage device 10 and the inverter 13 For example, an LC filter can be combined with an intermediate circuit capacitor. 12 and an energy storage choke 11 be coupled. The inverter 13 For example, a pulse width modulation (PWM) method can be used to generate an alternating voltage, such as a three-phase alternating voltage for an electric machine. 2 The inverter can provide this. 13 with a DC voltage from the intermediate circuit capacitor 12 be supplied, which in turn is supplied from the energy storage device 10 is fed.
[0042] A charger 6 for charging the energy storage cell modules 5 the energy storage device 10for example, via the output connections 10a and 10b They can be coupled across devices. A control unit can be used for a charging process. 9 be provided which are connected to the energy storage device 10 is coupled, and which is designed to connect the energy storage cell modules 5 the energy storage device 10 by selectively controlling the coupling devices 7 the energy storage modules 3 the energy storage device 10 specifically into the energy supply branches or the energy supply branch of the energy storage facility 10 to switch.
[0043] Fig. Figure 6 shows a schematic representation of a control strategy of an energy storage device for charging energy storage cells of the energy storage device, in particular energy storage cells. 5a until 5k the energy storage device 1 in Fig. 1 or Fig. 4 or the energy storage device 10 in Fig. 5. Fig. Figure 7 shows a schematic representation of another control strategy of an energy storage device for charging energy storage cells of the energy storage device, in particular energy storage cells. 5a until 5k the energy storage device 1 in Fig. 1 or Fig. 4 or the energy storage device 10 in Fig. 5.
[0044] In the Fig. 6 and Fig. Figure 7 shows an example voltage diagram illustrating the voltage U of energy storage cells in relation to their state of charge (SOC). For example, lithium-ion batteries in a fully discharged state (SOC = 0%) have a base voltage greater than zero volts. To charge such a lithium-ion battery, it is necessary to provide at least this base voltage. The output voltage of the lithium-ion battery increases with increasing state of charge up to a nominal voltage at a state of charge of 100%. These values increase accordingly when lithium-ion batteries are connected in series.
[0045] An example is a voltage curve k1 for a series connection of energy storage cells. 5a until 5k an energy storage cell module 5 in Fig. 6 and Fig. Figure 7 shows this. In the case of a series connection of several energy storage cell modules. 5 In a power supply branch, corresponding voltage profiles k2, k3, k4, k5 and k6 result. The voltage profiles can be determined, for example, by measuring the output voltages of energy storage cells at different charge levels and stored as reference values in the control unit of the energy storage device.
[0046] In Fig. Step 6 of the charging process begins by determining the state of charge (SOC) of the energy storage cells. For example, if the SOC of all energy storage cells is 0%, the initial charging voltage required is determined based on a SOC of 0%. If the SOC of the energy storage cells is greater than 0%, an analogous approach is used. In this example, the number of energy storage cell modules is determined for which the sum of the output voltages of the energy storage cell modules is just less than the maximum possible charging voltage, Umax. The maximum possible charging voltage, Umax, can be predetermined by the charger used and may, for example, be between 200 volts and 450 volts, although other values are of course also possible.The charger also features a voltage spread, meaning it can provide a charging voltage range between a minimum possible charging voltage Umin and a maximum possible charging voltage Umax. The minimum possible charging voltage Umin should be lower than the sum of the base voltages of all energy storage cells in a fully discharged state, otherwise it cannot be guaranteed that a charging process will always be initiated. It is, of course, possible to flexibly adjust the values of the minimum possible charging voltage Umin and the maximum possible charging voltage Umax to the desired charging situation; that is, it is not absolutely necessary for the values of the minimum possible charging voltage Umin and the maximum possible charging voltage Umax to be predetermined by the charger's technical specifications.
[0047] In the present example of the Fig. The voltage curve k6 is the one whose sum of the output voltages at SOC = 0% with the maximum number of energy storage modules is just below the maximum possible charging voltage Umax. If this number equals the total number of energy storage modules in the respective power supply branch, charging of all energy storage modules can begin immediately. However, if this number is less than the total number of energy storage modules in the respective power supply branch, a selection of energy storage modules must be made, as explained below.
[0048] Once the charging process has begun, the state of charge of the energy storage cells increases, so that the necessary charging voltage of the energy storage cells also increases to a certain extent, as in Fig. Figure 6 illustrates this. At a specific state of charge (SOC) = p1, the required charging voltage of the energy storage cells reaches the value of the maximum possible charging voltage Umax. In this case, the number of energy storage cell modules charged simultaneously is reduced, so that the voltage profile k5 of the reduced number of energy storage cell modules is now decisive for the charging voltage. For example, the voltage profile k5 can correspond to the number of energy storage cell modules reduced by one compared to the number associated with the voltage profile k6.
[0049] In the following charging process, not all energy storage cell modules are supplied with charging voltage simultaneously. Therefore, it is necessary to ensure that all energy storage cell modules remain at the same state of charge by cyclically rotating the active energy storage cell modules. New active energy storage cell modules can be selected after predetermined time cycles so that, on average, each energy storage cell module is supplied with charging voltage for the same cumulative period.
[0050] When the state of charge (SOC) reaches p2, the process repeats itself, so that in the example of Fig. 6. The fully charged state of SOC = 100% is achieved by simultaneously charging a number of energy storage cell modules corresponding to the voltage profile k4.
[0051] In Fig. 7 is a further variation of the control strategy from Fig. Figure 6 shows that at the beginning of the charging process, the maximum number of energy storage cell modules is determined that is just less than a desired charging voltage UL, for example, the maximum possible charging voltage Umax or the minimum possible charging voltage Umin. In this example, this number corresponds to the Fig. 7 of the number associated with the voltage curve k4. At the same time, however, another energy storage cell module with a variable duty cycle t1 is controlled, which can be determined depending on the difference between the charging voltage UL and the sum of the output voltages of the energy storage cell modules as determined by the voltage curve k4. This compensates, on average, for the voltage difference between the charging voltage UL and the voltage curve k4, which is why the charging voltage UL can be kept at a constant value. At a state of charge of SOC = p3, the number of energy storage cell modules permanently connected to the power supply branch is reduced. Otherwise, in Fig. 7 similar to in Fig. 6. All energy storage cell modules permanently connected to the power supply branch are cyclically swapped again. Another of the energy storage cell modules is then controlled with a variable duty cycle t2 from the state of charge (SOC) = p2.
[0052] In the preceding explanations, it was assumed by way of example that the voltage curves k1 to k6 each refer to sums of identical charge states of the energy storage cell modules, meaning that each of the energy storage cell modules is brought to the same final charge state or the same final voltage by a single charging process. With the control strategies detailed above, it may also be possible to bring different energy storage cell modules to different final charge states or final voltages. This can result in voltage curves that differ from those described in Fig. 6 and Fig. The voltage curves shown in the 7 diagrams may differ.
[0053] For example, the output voltages of selected energy storage modules in the power supply branch can be monitored during the charging process. If it is detected that the output voltages of certain energy storage modules exceed a desired final voltage, the coupling elements of these energy storage modules can be controlled in such a way that the energy storage modules are permanently disconnected from the power supply branch, i.e., for the remainder of the charging process. Because energy storage cell modules from different energy storage modules can be selectively coupled into the power supply branch, each energy storage cell module can be brought to a different final voltage without affecting the charging process for the other energy storage cell modules of other energy storage modules in the same power supply branch.
[0054] With the in Fig. 6 and Fig. Seven control strategies, presented schematically and exemplarily, can be found in Fig. 8. Schematic representation of the procedure 20 for charging the energy storage cells of an energy storage device, in particular the energy storage device 1 in Fig. 1 or Fig. 4 or the energy storage device 10 in Fig. 5 will be realized.
[0055] In a first step 21 the procedure 20 A maximum possible charging voltage Umax of a charger is determined. 6 , which provides a charging voltage UL for the energy storage device 1 or 10 provides. In a second step 22 The maximum number of energy storage cell modules is then determined. 5 of an energy supply branch, in which the sum of the current charge states of the energy storage cells 5a until 5k all energy storage cell modules5 output voltages of the energy storage cell modules that depend on a power supply branch 5 even lower than the maximum possible charging voltage Umax.
[0056] Then, in one step 23 selected which coupling elements 7a , 7b , 7c , 7d of energy storage modules 3 of the energy supply branch, so that only those in step 22 specific maximum number of energy storage cell modules 5 is coupled to the power supply branch. It may also be possible to adjust the output voltages of the selected energy storage modules during the charging process. 3 to monitor the energy supply branch so that, if the sum of the output voltages of the selected energy storage cell modules 5exceeding the maximum possible charging voltage Umax, a reduction in the specified maximum number of energy storage cell modules 5 a branch of the energy supply system. The reduction in number can, for example, be incremental, meaning the number of selected energy storage cell modules is gradually reduced. 5 The number can be reduced by one each time an exceedance of the maximum possible charging voltage Umax is detected. This reduces the number of energy storage cell modules that can be charged simultaneously. 5 always maximized, so that the total charging time for a charging process can be minimized.
[0057] In one step 24a A cyclical exchange of the energy storage cell modules coupled to the energy supply branch is possible. 5 by selecting and controlling the coupling elements 7a , 7b , 7c , 7d different energy storage modules3 The charging of the energy supply branch takes place in predetermined time cycles. This ensures a uniform charging of all energy storage cell modules. 5 enabled. At the same time, it may be provided that in one step 24b the coupling elements 7a , 7b , 7c , 7d one of the other unselected energy storage modules 3 The energy supply branch can be controlled with a variable duty cycle. The variable duty cycle depends on the difference between the maximum possible charging voltage Umax and the sum of the output voltages of the energy storage cell modules. 5 Since the charging voltage UL can be advantageously kept at a constant value, the energy storage modules controlled by the variable duty cycle are used. 3On average, this is precisely the difference voltage between the maximum possible charging voltage and the stepped sum output voltage of the currently selected energy storage modules. 3 can be adjusted. QUOTES INCLUDED IN THE DESCRIPTION
[0058] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0059] US 5642275 A1
[0004]
Claims
[1] Procedure ( 10 ) for charging energy storage cells ( 5a , 5k ) an energy storage device ( 1 ), which exhibits: n first output connections ( 1a , 1b , 1c ; 10a ), where n ≥ 1, to output a supply voltage at each of the output terminals ( 1a , 1b , 1c ; 10a ); a second output port ( 1d ; 10b ), where a charger ( 6 ) between the first output terminals ( 1a , 1b , 1c ; 10a ) and the second output port ( 1d ; 10b ) connectable; and n parallel connected power supply branches, each of which is connected between a first output terminal ( 1a , 1b , 1c ; 10a ) and the second output port ( 1d ; 10b) are coupled, with each of the power supply branches having a plurality of energy storage modules connected in series ( 3 ) exhibits, each of which includes: an energy storage cell module ( 5 ), which includes at least one energy storage cell ( 5a , 5k ) exhibits, and a coupling device ( 7 ) with coupling elements ( 7a , 7b , 7c , 7d ), which are designed to power the energy storage cell module ( 5 ) selectively switch to or bridge the respective energy supply branch, where the procedure ( 10 ) which shows the steps: Determine ( 21 ) a maximum possible charging voltage (Umax) of a charger ( 6 ), which provides a charging voltage (UL) for the energy storage device ( 1 ; 10 ) provides; Determine ( 22) the maximum number of energy storage cell modules ( 5 ) of an energy supply branch, where the sum of the current charge states of the energy storage cells ( 5a , 5k ) all energy storage cell modules ( 5 ) of an energy supply branch dependent output voltages of the energy storage cell modules ( 5 ) is even lower than the maximum possible charging voltage (Umax); and Select and navigate ( 23 ) the coupling elements ( 7a , 7b , 7c , 7d ) of energy storage modules ( 3 ) of the energy supply branch, so that only the maximum number of energy storage cell modules ( 5 ) is coupled to the energy supply sector. [2] Procedure ( 20 ) according to claim 1, further comprising the step: cyclic exchange ( 24a ) the energy storage cell modules coupled to the respective energy supply branch (5 ) by selecting and controlling the coupling elements ( 7a , 7b , 7c , 7d ) each other energy storage modules ( 3 ) of the energy supply sector in predetermined time cycles. [3] Procedure ( 20 ) according to one of claims 1 and 2, further comprising the step: Target ( 24b ) the coupling elements ( 7a , 7b , 7c , 7d ) one of the other unselected energy storage modules ( 3 ) of the energy supply branch with variable duty cycle (t1; t2). [4] Procedure ( 20 ) according to claim 3, wherein the variable duty cycle (t1; t2) depends on the difference between the maximum possible charging voltage (Umax) and the sum of the output voltages of the energy storage cell modules ( 5 ) or the difference between the minimum possible charging voltage (Umin) and the sum of the output voltages of the energy storage cell modules (5 ) is determined. [5] Procedure ( 20 ) according to one of claims 1 to 4, further comprising the steps: Monitoring the output voltages of the selected energy storage modules ( 3 ) of the energy supply branch during the charging process; and Reducing the specified maximum number of energy storage cell modules ( 5 ) of a power supply branch, if the sum of the output voltages of the selected energy storage cell modules ( 5 ) exceeds a desired charging voltage. [6] Procedure ( 20 ) according to claim 5, wherein reducing the determined maximum number of energy storage cell modules ( 5 ) reducing the number by one energy storage cell module at a time ( 5 ) includes. [7] Procedure ( 20 ) according to one of claims 1 to 6, further comprising the steps: Monitoring the output voltages of the selected energy storage modules ( 3 ) of the energy supply branch during the charging process; and Controlling the coupling elements ( 7a , 7b , 7c , 7d ) of energy storage modules ( 3 ), whose output voltages exceed a desired final voltage, for permanently disconnecting the energy storage modules ( 3 ) from the energy supply branch during the remainder of the charging process. [8] System ( 100 ; 200 ; 300 ), with: an energy storage device ( 1 ; 10 ), which exhibits: n first output connections ( 1a , 1b , 1c ; 10a ), where n ≥ 1, to output a supply voltage at each of the output terminals ( 1a , 1b , 1c ; 10a ); a second output port ( 1d ; 10b), where a charger ( 6 ) between the first output terminals ( 1a , 1b , 1c ; 10a ) and the second output port ( 1d ; 10b ) connectable; and n parallel connected power supply branches, each of which is connected between a first output terminal ( 1a , 1b , 1c ; 10a ) and the second output port ( 1d ; 10b ) are coupled, with each of the power supply branches having a plurality of energy storage modules connected in series ( 3 ) exhibits, each of which includes: an energy storage cell module ( 5 ), which includes at least one energy storage cell ( 5a , 5k ) exhibits, and a coupling device ( 7 ) with coupling elements ( 7a , 7b , 7c , 7d ), which are designed to power the energy storage cell module ( 5) selectively switch to or bypass the respective power supply branch; and a control unit ( 9 ), which are connected to the coupling devices ( 7 ) is coupled, and which is designed to provide a method for charging the energy storage cells ( 5 , 5k ) the energy storage cell modules ( 5 ) according to any one of claims 1 to 7. [9] System ( 100 ; 200 ; 300 ) according to claim 8, furthermore with: a charger ( 6 ), which is connected to the first n output terminals ( 1a , 1b , 1c ; 10a ) and the second output port ( 1d ; 10b ) is coupled, and which is designed to provide a charging voltage for the energy storage device ( 1 ; 10) to provide in the voltage range between a minimum possible charging voltage (Umin) and the maximum possible charging voltage (Umax). [10] System ( 100 ; 200 ; 300 ) according to claim 9, furthermore with: a switching device ( 6a ), which are located between the charger ( 6 ) and the first n output terminals ( 1a , 1b , 1c ; 10a ) is coupled, and which is designed to connect the charger ( 6 ) selectively from the energy storage device ( 1 ; 10 ) to separate. [11] System ( 100 ; 200 ; 300 ) according to one of claims 8 to 10, wherein the coupling devices ( 7 ) Coupling elements ( 7a , 7b , 7c , 7d ) in full bridge circuit. [12] System ( 100 ; 200 ; 300) according to one of claims 8 to 10, wherein the coupling devices ( 7 ) Coupling elements ( 7a , 7c ) in a half-bridge circuit.