Vehicle with an energy storage system

Abstract

Vehicle (10) with an energy storage device (20), a drive inverter (14) and a charging unit (70), which energy storage device (20) has a first control device (22), modules (40), a switching device (58), two first poles (27, 28) and two second poles (127, 128), to which first poles (27, 28) the drive inverter (14) is connected, which modules (40) each have an energy storage unit (50), and which switching device (58) has connections (25) between the modules (40) and first switches (62) provided at the connections (25) in order to allow different interconnections of the modules (40) and different voltages (U) at the first poles (27, 28) depending on the state of the first switches (62), which different interconnections of the modules (40) have the following connection possibilities: - parallel connection of at least two modules (40),- Serial connection of at least two modules (40),- Bridging at least one module (40), and which first control device (22) is configured to control the switching device (58) depending on a voltage setpoint (U_S) in order to influence the voltage (U) at the first poles (27, 28) depending on the voltage setpoint (U_S), wherein the two second poles (127, 128) are connectable to at least one of the energy storage units (50), wherein the maximum voltage at the second poles (127, 128) is lower than the maximum voltage at the first poles (27, 28), and wherein the second poles (127, 128) are connectable via the switching device (58) to the at least one energy storage unit (50) in order to influence the voltage at the two second poles (127, 128) via the first switches (62) of the switching device (58).

Description

The invention relates to a vehicle having an energy store.Conventional electric vehicles (battery electric vehicles, hybrid, fuel cell vehicles, etc.) typically have a large energy storage device (battery) made of individual cells wired firmly in a predetermined series-parallel configuration. The fixed wiring determines the maximum voltage of the system when the battery is fully charged (or optimum concentration of the educts in fuel cells). If the state of charge of the battery decreases or the load current increases sharply or to high values, the voltage of the hard-wired battery pack may decrease by up to 50%.Many vehicles therefore employ a DC / DC converter between the battery and the drive inverter or inverters in order to raise the voltage and keep it as constant as possible, independently of the influences. However, the additional DC / DC converter generates considerable additional losses, takes up installation space and increases the overall weight of the vehicle and the manufacturing costs. Furthermore, as a high power clocked converter, it causes considerable electromagnetic emissions which must be filtered. In addition, the DC / DC converter cannot solve a basic problem of hard-wired battery packs: the production-related tolerances of battery and fuel cells are so large that their properties, such as current capacity, loss behavior, internal resistance, time constants and capacitance, but also the aging, scatter tremendously. In a hard wired battery pack, the weakest cell determines the characteristics of the overall battery (e.g., current capability, heat generation, capacity, etc.). If the smallest cell is empty, the discharge must be terminated for all cells. If the most lossy cell reaches its upper thermal limit, it cannot be individually relieved and the overall load for all cells must be reduced.The more cells the battery pack comprises, the more likely the battery pack's performance is to be far below the average of all battery cells. Assuming a Gaussian distribution of the characteristics, the influence of the edges of the distribution becomes stronger as the probability of having some representatives of these edges in the battery pack increases.The battery pack is usually charged via one or more separate chargers, which convert the alternating voltage (230 V in Europe, 110 V in the USA or as split-phase connection 2 x 110 V=240 V) or three-phase current (400 V in Europe, various voltages between 208 V and 480 V in the USA, 575 V in Canada, etc.) with charge control (current and / or voltage control) into the direct voltage for the battery. The currently existing fast charging stations meet different standards and emit different voltages, where those with -400 V DC voltage are dominant. In recent years, however, the battery voltages used in electric vehicles increase, for example currently to 800 V. The voltage of the charging stations of the currently available infrastructure is often not sufficient to charge such a battery. In order to be able to charge these batteries at charging stations with lower charging voltages, a high additional outlay is required, for example an additional high-power DC-DC converter which adjusts the voltage.Furthermore, the traction battery, which has a voltage of currently typically between 48 V and 1000 V, is mostly the only energy source or (in the case of hybrids) the most efficient energy source for other components in the vehicle. A number of stand-alone power electronics components must adapt the widely varying battery voltage to various other systems. The supply of the on-board power supply systems, for example 12 V and / or 48 V (if the latter is not already the drive system with the battery) generally takes place, even in the case of hybrids with internal combustion engines, instead of via a generator ("alternator") or via a DC-to-DC converter from the drive battery.The motor or motors of current electric vehicles for propulsion are generally polyphase alternating current motors, often with three or more phases, and they require an inverter which converts the DC voltage of the battery into AC voltage. The voltage and frequency of the voltages and currents for the machine(s) change constantly depending on the operating point (speed and acceleration), so that constant readjustment is necessary. Aging processes reduce the voltage of the hardwired battery pack over time. At high load, the voltage also collapses briefly (during the high load and a few seconds up to a few minutes depending on the battery type) until it moves back again onto the decreasing trajectory.The drive inverter or inverters generate the alternating voltage for the drive machine(s) from the alternating direct voltage by switching modulation, for example pulse width modulation (PWM). However, even at low AC voltage amplitudes well below the DC input voltage, the modulation index given by the maximum on-off ratio of the semiconductor switches in the inverter becomes very small. At low modulation indices, the DC voltage falls to the low voltage level of the AC voltage and the voltage and current quality of the AC voltage decreases in particular due to high current ripple amplitudes. Furthermore, the accuracy of the inverter is reduced at low modulation indices, so that the control quality falls and the operating point of the machine fluctuates or cannot be controlled in a stable manner. In present-day inverters, the PWM is generally digitally controlled, as a result of which the temporal resolution capability is limited. For example, with 8-bit digital PWM, 256 levels are possible for the modulation index, with 12-bit corresponding to 4096. In the case of very small modulation indices, it is no longer possible in this case to exactly map a sine, and the modulation index has quantization artifacts even before conversion into a switched signal.US 2010 / 0 261 043 A1 discloses a reconfigurable battery system having a plurality of battery cells, in which each battery cell is connected to an adjacent battery cell via a plurality of switches. A control unit controls the switches to connect the battery cells in series or in parallel to meet a certain output criterion.US 2011 / 0 001 442 A1 discloses a reconfigurable battery, the cells of which can be arranged in series or in parallel to provide different output voltages.US 2014 / 0 183 939 A1 discloses a battery system which can provide an output voltage of 12 V and 48 V. A battery management system (BMS) selectively controls how many modules are connected and provides lower power unless power is drawn from all modules.WO 2016 / 174 117 A1 discloses a battery with battery modules which can dynamically change between a serial and a parallel configuration in order to provide a DC voltage of 12 V, 24 V, 48 V or 60 V.It is known from EP 2 879 266 A1 to dynamically change a selection of battery cells in a cell stack in order to ensure a balanced discharge of the cells.DE 10 2014 223 227 A1 discloses a drive device having an electric motor, an inverter connected to the electric motor and a plurality of battery modules for supplying the inverter with electrical energy and having a connection device for connecting the battery modules to the inverter, which connection device has at least two connection states, wherein in a first connection state all battery modules are connected to the inverter in parallel, in a second connection state all battery modules are connected to the inverter in series and in a fourth connection state at least one battery module is connected to the inverter and at least one battery module is separated from the inverter.DE 10 2016 211 164 A1 discloses a motor vehicle electrical system which has an electric machine that can be operated by motor and generator, an active power converter, a first and a second energy store.DE 10 2012 214 020 A1 discloses a device for dynamically adjusting an operating voltage for an electric motor, which is provided by a modular voltage source.DE 10 2011 007 839 A1 shows a vehicle charging device having a charging station, a charging cable and a charging electric system of a vehicle.DE 10 2015 203 008 A1 discloses a circuit arrangement for operating an electric machine of a motor vehicle, having a first electric drive train, in which a first battery direct converter can be connected to the electric machine via a first switching device.It is an object of the invention to provide a new vehicle with an energy store.This object is achieved by the subject matter of claim 1 and claim 19.A vehicle has an energy storage, a drive inverter and a charging unit. The energy store has a first control device, modules, a switching device and two first poles to which first poles the drive inverter is connected. The modules each have an energy storage unit, and the interconnection device has connections between the modules and first switches provided on the connections in order to enable different interconnections of the modules and different voltages at the first poles depending on the state of the first switches. The different interconnections of the modules have the following interconnection possibilities:parallel connection of at least two modules,serial connection of at least two modules,bridging at least one module,and the first control device is designed to actuate the switching device as a function of a voltage setpoint value in order to influence the voltage at the first poles as a function of the voltage setpoint value.Such an energy store forms together with the drive inverter and the charging unit an advantageous combination which on the one hand enables a high quality of the voltage at the poles and on the other hand also an adaptation of the voltage to the current requirements.In a vehicle, the energy store has two second poles which can be connected to at least one of the energy storage units, wherein the maximum voltage at the second poles is lower than the maximum voltage at the first poles. By providing second poles next to the first poles, the energy store can emit different voltages and thus simultaneously supply different loads. This saves space and weight.According to a preferred embodiment, the maximum voltage at the second poles is 120 V or less. At 120 V, the equivalent definition of the protection low voltage ends in the industrial field, and the voltage range up to 120 V is therefore preferred.According to a preferred embodiment, the maximum voltage at the second poles is 60 V or less. The voltage of 60 V is below the protective low voltage according to different vehicle standards. Therefore, up to this voltage, no safety regulations of the high-voltage range have to be used. This relates in particular to the isolation, isolation distances, test voltages, contact safety and the training and qualification of the workers during production or repair. A voltage in the range of 48 V is particularly interesting. this voltage is mentioned, for example, in the standard VDA 320, a range of 20 V to 60 V being specified as the sub- or overvoltage range to be tolerated, if appropriate, in order to include fluctuations in the battery voltage. A range of 36 V to 52 V with no functional restrictions and a range of 24 V to 54 V with possible functional restrictions is also defined.The second poles can be connected to the at least one energy storage unit via the switching device in order to influence the voltage at the two second poles via the first switches of the switching device. The switching device can thereby be used twice, once for the generation of the voltage at the first poles and additionally also for the voltage at the second poles.According to a preferred embodiment, the first control device is configured to switch the switching device alternately back and forth between a first state and a second state, in which first state the two second poles are connected to the at least one energy storage unit in such a way that the at least one energy storage unit causes a voltage at the two second poles, and in which second state the two second poles are connected in such a way that the at least one energy storage unit causes no or a lower voltage at the two second poles, in order to provide on average a voltage at the two second poles which is lower than the voltage of the at least one energy storage unit in the first state. The individual energy storage units have, for example, a voltage of 20 V or 40 V. For generating a voltage of, for example, 12 V, it is therefore advantageously possible to switch between different states in order to bring about a correspondingly lower voltage on average. If, for example, a voltage of 48 V is to be generated at a basic voltage of an energy storage unit of 20 V, it is possible to switch between a series connection of two and three energy storage units.According to a preferred embodiment, a capacitor is provided between the two second poles in order to smooth the voltage at the two second poles. In particular in the case of clocked interconnection of the energy storage units by the interconnection device, the provision of the capacitor for smoothing the voltage is advantageous.According to a preferred embodiment, the vehicle has a first DC / DC converter with first inputs and first outputs, which first inputs are directly or indirectly connected to the two second poles in order to provide an additional voltage at the first outputs, which additional voltage is preferably smaller than the voltage at the two second poles. By providing the DC / DC converter, an additional voltage can be generated in addition to the voltage at the second poles. This facilitates the interconnection within the energy store. Alternatively, however, the provision of two third poles on the energy store would also be possible.According to a preferred embodiment, the first DC / DC converter has a separating device which is designed to bring about a galvanic separation between the first inputs and the first outputs. The isolation device achieves a reliable isolation between the high-voltage energy store and, for example, a 12 V on-board power supply system, and this increases safety.According to a preferred embodiment, the separating device comprises a transformer or a capacitor. These components are particularly well suited for transmitting a power signal.According to a preferred embodiment, the vehicle has a second control device, and the drive inverter is connected to the second control device via a first data line and is designed to transmit a first data signal to the second control device, and the second control device is designed to transmit a voltage setpoint value to the first control device in dependence on the first data signal. The drive inverter in a vehicle is often the main load on the energy store. It is very advantageous if the drive inverter can influence the voltage of the energy source, since drive inverters usually have different optimum input voltages at the output with different loads. Thus, the data signal can improve the performance of the driving inverter.According to a preferred embodiment, the vehicle has a second DC / DC converter with second inputs and second outputs, which second inputs are connected directly or indirectly to the two second poles, which second DC / DC converter is connected via a second data line to the second control device and is designed to transmit a second data signal to the second control device, and which second control device is designed to preset a voltage setpoint value as a function of the first data signal and the second data signal of the first control device. It is advantageous that the second control device receives data signals from different loads. Thus, in the second control device, a voltage of the energy store advantageous for the overall system can be set.According to a preferred embodiment, the charging unit has a charging connection and an AC / DC converter with third inputs and third outputs, which third inputs are connected to the charging connection and which third outputs are connected to the first poles. The connection of the charging connection to the poles enables a suitable adjustment of the voltage of the energy store for the charging.According to a preferred embodiment, a filter is provided between the third outputs and the first poles. Such a filter can be used to reduce an influence of the energy storage device on the external network. In addition, an at least partial decoupling between the voltage at the first poles and at the charging unit can be achieved. This is advantageous when the form of the voltage at the charging unit is required to regulate the charging current thereto.According to a preferred embodiment, the charging unit has a current regulator and a first measuring device for generating a first signal as a function of the level of the charging current, to which current regulator a current regulator setpoint value is supplied as the setpoint value and the first signal is supplied as the actual value, which current regulator outputs the voltage setpoint value as the actuating variable to the first control device in order to regulate the actual value to the setpoint value. The influencing of the charging current by the reconfiguration of the battery enables good efficiency and low losses, since an additional conversion of the voltage does not necessarily have to take place.According to a preferred embodiment, the actual value is predefined as a function of the voltage at the third outputs. This positively influences the power factor.According to a preferred embodiment, a phase difference between the actual value and the voltage at the third outputs is predetermined in order to influence the power factor. If, for example, many capacitive loads are suspended from a power grid, it is advantageous to set the phase difference in such a way that the vehicle acts as an inductive load. At the high powers, this possibility is very advantageous.According to a preferred embodiment, the phase difference can be preset to the current regulator in a variable manner by means of a transmitter. The vehicle can thereby react to current requirements and, for example, make a corresponding adjustment of the phase difference if this is required by the power grid by a control signal or by the power grid operator.According to a preferred embodiment, the AC / DC converter is formed in that the drive inverter is used for the charging process in the opposite direction. The drive inverter may already be present in the vehicle and typically has all the required functionality. This saves space, weight and costs.According to a preferred embodiment, the charging connection has a first connection point for a neutral conductor, and the first connection point is connected to the two first poles via diodes or via switches, in particular via semiconductor switches. This enables a preferred connection of a neutral conductor.According to a preferred embodiment, the charging connection has a first charging connection unit for a DC voltage and a second charging connection unit for an AC voltage, which first charging connection unit is at least partially connected to the DC side of the drive inverter, and which second charging connection unit is at least partially connected to the AC side of the drive inverter. This results in great flexibility for the loading.According to a preferred embodiment, the AC / DC converter has at least four branches to enable selectively a connection of a three-phase alternating current signal or a single-phase alternating current signal. This allows different alternating current signals to be connected.According to a preferred embodiment, the AC / DC converter is designed to be active or passive. The passive configuration is cost-effective, and the active configuration enables greater flexibility.A reconfigurable energy store or fuel cell, where the original hard-wired serial-parallel electrical interconnection is broken up and broken down into subunits, each with multiple cells, which in turn can be dynamically re-wired by suitable power electronics, allows new fields of application and solutions.The reconfigurable DC voltage battery can dynamically change its battery elements / battery elements / modules between series connection between adjacent battery elements, parallel connection of two or in particular also of a plurality of adjacent battery elements or a bypass of one or more battery elements.The reconfigurable battery may perform various tasks with partly the same hardware simultaneously through a suitable device and associated control, such as powering various aggregates, operating their subunits in ideal electrical, chemical, and thermal conditions, charging the battery in various modes from various sources, and exchanging power between sub-batteries.Thus, the intelligent reconfigurable battery coordinates, for example, the electrical interconnection of the subunits taking into account the load current such that• the charge is compensated as a temporal integral of the partial battery current i TB,j of the module j; and / or• a minimum total resistance of the series-parallel combination for a predetermined voltage is produced; and / or• Temperature hot spots, detected for example by at least one temperature sensor in each sub-battery, can be suppressed, for example by reducing the sub-battery current of the associated sub-battery(s); and / or• The aging of the battery elements, for example determined by SOH estimation, is compensated.Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.The invention is schematically illustrated in the drawings by way of embodiments and is described schematically and in detail with reference to the drawings. It shows FIG. 1 shows a schematic illustration of an embodiment of an arrangement with an energy store, drive inverters and AC motors of the battery system according to the invention, FIG. 2 shows a schematic illustration of a control structure for the energy store, FIG. 3 shows an exploded view of a module of the energy store, FIG. 4 shows the module of FIG. 3, FIG. 5 shows the energy store with the modules from FIG. 3, FIG. 6 shows a schematic illustration of a connection of the module, FIG. 7 is a more detailed view of an embodiment of the module of FIG. 6, FIG. 8 is a more detailed view of an embodiment of the module of FIG. 6, FIG. 9 shows possible interconnections between the modules, FIG. 10 shows a schematic illustration of an interconnection of the modules, FIG. 11 shows a schematic illustration of a structure of a current regulator for the charging current, FIGS. 12 to 29 show exemplary embodiments for the use of the arrangement of FIG. 1, FIG. 30 shows an interconnection between modules in a first state, FIG. 31 shows an interconnection between modules in a second state, FIG. 32 shows a diagram of the voltage arising during a change between the first state and the second state, FIG. 33 shows a sinusoidal signal, and FIG. 34 illustrates a quantized generation of the sinusoidal signal of FIG. 33.The figures are described in connection and across. Like reference numerals designate the same components, and these will usually be described only once.FIG. 1 shows a vehicle 10, in particular an electric vehicle or a hybrid vehicle. An energy store 20 for providing a voltage is provided and can be electrically connected, for example, via drive inverters or power inverters 14 to associated alternating current motors 12. The energy store 20 has a first control device 22 and a plurality of modules 40, which modules 40 can be connected to one another in a reconfigurable manner by a switching device 58 in order to set the voltage U at the poles 27, 28 of the energy store 20. A second control device 21 is provided and connected to the first control device 22 via a data line 30. The second control device 21 is arranged above the first control device 22 and can specify a voltage setpoint value U_S, for example. The second control device 22 is connected via a data line 23 to the drive inverter 14 in order to be able to receive status data therefrom, for example the temperature in the drive inverter 14, a required power or a desired voltage. The first control device 22 is connected to the modules 40 via a data line 24 in order to be able to transmit control signals 26 to the modules 40. Preferably, the modules 40 can also communicate with one another via the data lines 24 or via an additional data line, not shown. By way of example, the energy store 20 has a first branch 31, a second branch 32 and a third branch 33. The branches 31, 32, 33 can be connected at least partially in series or can be connected in parallel with one another in order to provide different voltages U at the poles 27, 28 of the energy store 20.The energy store 20 shown allows, for example, an adaptation of the voltage U to the voltage setpoint value U_S by the reconfiguration of the modules 40, and the voltage U can thereby be increased or decreased by the reconfiguration when the state of charge of the modules 40 changes.A charging unit 70 having a charging connection 72 is provided in order to enable charging of the energy store 20. In the exemplary embodiment, the charging unit 70 is connected to the poles 27, 28. The charging connection 72 is preferably designed as a socket and, as shown, it can also be designed as a plug.A measuring device 29 for measuring the voltage at the poles 27, 28 is provided in order to generate a voltage value U and output it as a signal to the first control device 22 and / or the second control device 21.A measuring device 74 for measuring the charging current for the energy source is provided in order to generate a current value I and output it as a signal to the first control device 22 and / or the second control device 21. The current can be measured directly or indirectly, and preferably both the current 64 during charging of the energy store 20 and the current during discharging of the energy store 20 can be measured.Fig. 2 shows the control structure. The vehicle control device 21 is usually arranged outside the energy storage 20, and communicates with the first control device 22 of the energy storage 20, for example, the vehicle control device 21 transmits a voltage set value signal to the first control device 22, and the first control device 22 transmits, for example, a status and error values of the energy storage 20, and a data line 30, for example, a unidirectional or bidirectional bus, is provided between the vehicle control device 21 and the first control device 22. The first controller 22 determines how to configure the modules 40 and transmits corresponding signals to the module controllers 42 associated with each of the modules 40 via the control line 24. The control line 24 is preferably a data line, in particular a unidirectional or bidirectional bus. The module control device 42 transmits control signals to first switches 62, which first switches 62 are provided for activating or deactivating connections between battery modules 40, a useful current flowing via the first switches 62 when these are switched to the conductive state. The module control device 42 preferably has a monitoring of the assigned module (voltage, state of charge, temperature). The module control device 42 preferably has a communication unit for communication with the first control device 22 and / or the other modules 40.The module control device 42 preferably has an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a CPLD (complex programmable logic device) or a microcontroller. Such electronic components enable a fast communication and can respond very quickly to the application-specific events and switch the first switches 62. This provides a high level of safety.The first control device 22 determines a suitable configuration of the interconnection units 60 and transmits to each interconnection unit 60 a corresponding control signal suitable for the associated module 40. In response to this control signal, the module controller 42 switches the first switches 62.FIG. 3 shows a module 40. the module 40 has an energy storage unit 50, a switching unit 60 and an associated module control device 42. the switching unit 60 forms a modular part of the switching device 58 and it has the first switches 62. depending on the state of the first switches 62, the module 40 can be connected to another module 40. For this purpose, the modules 40 are interconnected to form the energy store 20, such that the interconnection units 60 are interconnected between two assigned modules 40.The interconnection unit 60 preferably has a printed circuit board 61 on which the first switches 62 with connecting lines 63 and preferably also the module control device 42 are provided.Preferably, a measuring device 44 is provided for generating second measured values characterizing the voltage at the module 40. Further preferably, a measuring device 46 is provided for generating third measured values characterizing the state of charge at the assigned module 40. The arrangement of the mentioned elements on the printed circuit board 61 is preferred, but the mentioned elements can also be provided on another printed circuit board or without a printed circuit board.The first control device 22 of FIG. 2 and the module control device 42 are configured together to enable a change in the control of the associated switching unit 60 even during the use of the energy store 20, in order to thus effect a reconfiguration of the energy store 20. In the exemplary embodiment, energy storage unit 50 is made up of battery cells 52, which are firmly connected via a connection 54. In the exemplary embodiment, the battery cells 52 are connected in series by the interconnection 54 in order to achieve a predefined basic voltage level. Depending on the basic voltage of the battery cells 52, a parallel connection or a combined serial and parallel connection is also possible. In the battery cells 52, each battery cell 52 has its own energy tank. As an alternative to the battery cells 52, fuel cells not shown may be used. In fuel cells, it is appropriate to use a shared energy tank with the fuel, wherein the power converters of the fuel cells access the common energy tank. If the battery cells 52 or the fuel cells supply a sufficient voltage, a single battery cell or fuel cell can also be used as energy storage unit 50.FIG. 4 shows the module 40 in the assembled state. The printed circuit board 61 is firmly connected to the energy storage unit 50, wherein, for example, an intermediate plate 48 is provided between the printed circuit board 61 and the energy storage unit 50. The module has terminals 66 to enable connection between adjacent modules 40.FIG. 5 shows an energy store 20 having twelve modules 40, which are interconnected in accordance with the circuit diagram of FIG. 1. The individual modules 40 are connected to adjacent modules via connecting lines 25.FIG. 6 shows a schematic illustration of a module 40 with the associated connections 66, via which the module 40 can be connected to an adjacent module 40 or to one of the poles 27, 28.FIG. 7 shows a schematic illustration of a first embodiment of the module 40, in which a switching unit 60 is provided on two sides of the energy storage unit 50. As a result, the module 40 can be connected to a further module 40 both to the left and to the right.FIG. 8 shows a second embodiment of the module 40, in which a switching unit 60 is provided on the energy storage unit 50 only on one side. As a result, the module 40 can be connected to a further module 40 on the right side. On the left side, for example, a connection to one of the poles 27, 28 can be provided.FIG. 9 shows various embodiments for the interconnection unit 60. The embodiments are designated as 60.1 to 60.5. The energy storage unit 50 is in each case shown schematically, and a possible interconnection is shown on the right of it, in which the useful current 64 can flow via one or more of the first switches 62. The connecting lines between the energy storage units 50 are provided with the reference numeral 25.Listed on the right are the possible interconnections that can be achieved with the corresponding interconnection unit. In this case, S+ denotes a serial positive connection, S- denotes a serial negative connection, P denotes a parallel connection, B+ denotes a bridging via the positive busbar and B- denotes a bridging via the negative busbar. The interconnection unit 60.5 does not allow serial negative interconnection. Not every interconnection is required in every embodiment, and one of the possible interconnections can be selected, which has, for example, as few first switches 62 as possible.The provision of the interconnection units 60 results in high degrees of freedom during reconfiguration within the energy store 20.Further micro topologies are described inWO 2017 / 016 675 A1,WO 2017 / 016 674 A1,DE 10 2011 108 920 A1,DE 10 2010 052 934 A1,S. Goetz, A. Peterchev, T. Weyh (2015), Modular multilevel converter with series and parallel module connectivity: topology and control. IEEE Transactions on Power Electronics, vol. 30, no. 1, pp. 203-215. doi: 10.1109 / TPEL.2014.2310225,M. Perez, S. Bernet, J. Rodriguez, S. Kouro, R. Lizana (2015), Circuit topologies, modelling, control schemes, and applications of modular multilevel converters. IEEE Transactions on Power Electronics, vol. 30, no. 1, pp. 4-17. doi: 10.1109 / TPEL.2014.2310127.FIG. 10 shows a possible interconnection of seven of the modules 40 between the poles 27, 28, as calculated by the first control device 22 and output to the modules 40. The number of modules 40 connected in series determines the voltage between the poles 27, 28. This may be required, for example, if module 40A is not functioning correctly, or if a lower total voltage A is desired at poles 27, 28. The modules 40B, 40D, and 40F are connected in series, and a module 40E is connected in parallel with the module 40D. This may be advantageous, for example, if module 40D is discharged to a greater extent than the other modules, and by connecting module 40E, the discharge of module 40D is reduced. In addition, charge balancing can occur between modules 40D and 40E and the overall resistance is reduced by the parallel connection. A module 40C may be connected in parallel with the module 40B. However, the parallel connection is deactivated (dashed line). This can be advantageous if the module 40C is discharged to a greater extent than other modules 40 or if, during a charging process of the energy store 20, the module 40B is discharged to a greater extent than the other modules 40. In the exemplary embodiment, the first control device 22 has controlled the modules 40 in such a way that a serial connection of modules 40 is provided, wherein one or more further modules 40 can be connected in parallel or not in each case to the serially connected modules 40. This type of interconnection is advantageous compared to a parallel interconnection of modules already connected in series, since higher voltages occur in such a parallel interconnection and, as a result, there are also greater requirements for the first switches 62. The embodiment shown, in which modules 40 that are not already connected in series are additionally connected in parallel, allows the use of low-voltage semiconductor switches. The person skilled in the art refers to such semiconductor switches in vehicles from the low-voltage range if a DC voltage is less than 60 V or the effective value of an AC voltage is less than 30 V. The voltage at the energy storage unit 50 to be connected by the first switch 61 determines how voltage-proof the first switch 61 must be designed.FIG. 11 shows the schematic sequence of a charging device of the energy store 20. Optionally, a transmitter 78 is provided, which specifies a phase angle.phi. to the signal generator 80. The signal generator 80 generates a signal I_S depending on these values and, if applicable, additionally on the desired power, which signal indicates the setpoint value for the charging current. The signal I_S is supplied to a comparator 82, and the comparator 82 calculates the control difference between the setpoint value I_S and an actual current value I. The control deviation is supplied to a current controller 84, which is designated as RGL_I. The current regulator 84 may be, for example, a P regulator or a PID regulator or another regulator, where P is proportional, I is integral, and D is differential. The current regulator 84 preferably outputs as a control value a setpoint voltage U_S, which is supplied to the energy store 20 and brings about there, if appropriate, reconfiguration of the modules 40. The energy store 20 is thus permanently reconfigured in order to generate a current following the voltage value U 1 and thus generate a good power factor. When the voltage setpoint value U_S is reduced, more current flows into the energy store 20 and, when it is increased, correspondingly less current flows. As a function of the setpoint voltage U_S, the charging current I increases or decreases, and this is measured, for example, in the energy store 20 and fed to the comparator 82.As a result, a charging current I is obtained which corresponds over time to the over time profile of the charging voltage, optionally with a selectable phase shift.phi.. This results in a good power factor.The voltage value U 1 of the rectified charging voltage may alternatively be calculated from the input voltages on the AC side of the charging unit 70.The provision of the signal generator 80 is possibly unnecessary if it is a largely constant direct current. Such a largely constant direct current also arises when rectifying a three-phase alternating current signal, and here too a signal generator 80 can be omitted, if appropriate.FIG. 12 shows the drive train of an electric vehicle having an energy store 120 according to the prior art, in which the battery cells are hard-wired. A first DC / DC converter 16 is provided on the energy store 120, which feeds a battery 17 for the on-board power supply system, for example. In addition, a second DC / DC converter 18 is provided on the energy store 120, the output of which converter is connected to a drive inverter 14. The output of the drive inverter 14 is connected to an AC motor 12. The second DC / DC converter 18 is for converting the voltage of the energy storage 120 to a predetermined voltage, and the drive inverter 14 generates an AC voltage suitable for the AC motor from the DC voltage. A charging connection 72 and a charging unit 70 connected thereto are connected to the energy store 120 in order to enable charging of the energy store.The diagram 122 shows the voltage at the energy store 120, plotted over time. It can be seen that the voltage drops over time due to the discharge of the energy store 120, and at very high load there are voltage dips which occur as spikes.FIG. 13 shows an arrangement corresponding to FIG. 12, but with an energy store 20 which is reconfigurable and can provide different voltages at the poles 27, 28. This makes it possible to dispense with the second DC / DC converter 18 from FIG. 12. Energy store 20 has additional second poles 127, 128 in addition to poles 27, 28. The poles 127, 128 are connected to at least one of the modules 40, and the maximum voltage at the poles 127, 128 is lower than the maximum voltage at the poles 27, 28. Depending on the base voltage of one of the modules 40 and the desired voltage across the battery 17B, it may be decided whether one module 40 is sufficient or whether two or more modules 40 are required. It is possible to connect the poles 127, 128 directly to an energy storage unit 50 of a module 40, and thereby the voltage of this energy storage unit 50 is obtained in a fixed manner, but it is also possible to connect the poles 127, 128 to the modules 40 via one or more of the interconnection units 60. As a result, it is possible to influence from which module 40 the supply takes place, and intermediate voltages are also possible, for example, by connecting one of the modules 40 alternately in series or in parallel or bypassing it in a second state. This results in an average voltage which is below the voltage of the corresponding module 40 or modules 40.The vehicle 10 has the second control device 21, and the drive inverter 14 is connected to the second control device 21 via the first data line 23 and is designed to transmit a first data signal 35 to the second control device 21. The second control device 21 is designed to transmit a voltage setpoint value U_S to the first control device 22 as a function of the first data signal 35, cf. FIG. 1.Preferably, the second DC / DC converter 16 is provided with inputs and outputs, which inputs are directly or indirectly connected to the two first poles 27, 28. The second DC / DC converter 16 is preferably connected to the second control device 21 via a second data line 38 and is designed to transmit a second data signal 37 to the second control device 21. The second control device 21 is designed to preset a voltage setpoint value U_S as a function of the first data signal 35 and the second data signal 37 of the first control device 22. Loads such as the DC / DC converter 16 and the drive inverter 14 have fundamentally or depending on the current power different optimum operating points and large suitable ranges for the input voltage. This can be utilized, for example, by setting the voltage of the energy store 20 to a value preferred for this load when one of the loads becomes very hot due to high power losses. As a result, the load can operate at a good operating point and produces less power loss. The temperature may decrease.Fig. 14 shows another embodiment of the arrangement. As in FIG. 13, the energy store 20 has second poles 127, 128, via which a battery 17B can be supplied. The battery 17B has, for example, a voltage of 48 V. The battery 17B is connected via a DC / DC converter 19 to a battery 17A which operates, for example, at a voltage of 12 V. As a result, a plurality of voltages for different loads can be generated via the poles 127, 128.The DC / DC converter 19 preferably has a separating device which is designed to bring about a galvanic separation between the two second poles 127, 128 or between the inputs of the DC / DC converter 19 and the outputs of the DC / DC converter 19. The separating device preferably has a transformer or a capacitor.FIG. 15 shows an arrangement corresponding to FIG. 13, wherein the poles 127, 128 in the energy store 20 are directly connected to an energy store unit 50 and thus directly provide the voltage of the corresponding energy store unit 50. It is also possible for a plurality of energy storage units 50 to be connected in parallel and / or in series.FIG. 16 shows an arrangement corresponding to FIG. 15, wherein the charging unit 70 has an AC / DC converter or rectifier 71. In the present case, a passive AC / DC converter 71 is shown, but the AC / DC converter 71 can also be active. The diagram 130 shows the output voltage at the AC / DC converter 71 of the charging unit 70, which is additionally influenced by the energy store 20. When an alternating voltage is supplied to the charging connection 72, the output voltage has a wavy shape according to diagram 130. On the one hand, it is possible to use a current regulator according to FIG. 11, but without a signal generator 80. This is easily possible with a largely constant voltage at the output of the charging unit 70. However, at a ripple voltage as shown in plot 130, a constant charging current results in a very poor power factor. Therefore, it is advantageous to use the full functionality according to FIG. 11, in which the signal generator controls the charging current depending on the voltage at the charging unit 70. This greatly improves the power factor. The embodiment shown is for a single-phase alternating voltage, as is provided for example for basic consumers in the domestic network.FIG. 17 shows an arrangement corresponding to FIG. 16, wherein an inductance 160 is provided at an output of the charging unit 70 in the connection between this output and one of the poles 27 or 28. The inductance 160 brings about a phase shift and thus also influences the power factor. Since more capacitive loads than inductive loads usually occur in the domestic network, the provision of the inductance 160 is positive.FIG. 18 shows an arrangement corresponding to FIG. 17, wherein a filter 162 is provided between the output of the charging unit 70 and the poles 27, 28. The diagram 122 shows the voltage at the poles 27, 28 of the energy store 20, and the voltage has steps by reconfiguring the modules 40. The filter 162 has, for example, an inductance between the respective outputs of the charging unit 70 and the associated poles 27, 28, and a capacitance in the form of a capacitor is provided in each case between the outputs of the charging unit 70 and also between the poles 27, 28. The filter smoothes out the stability of the voltage at the energy store 20, and this relieves the power grid. In addition, when using a device according to FIG. 11, the measurement of the voltage at the charging unit 70 is facilitated, since this is less influenced by the energy store 20 than without the filter 162.FIG. 19 shows an arrangement corresponding to FIG. 16 However, the charging unit 70 has a three-phase rectifier or AC / DC converter 71 As a result, a three-phase alternating current, which is also referred to as three-phase current, can also be connected to the charging connection 72.FIG. 20 shows an arrangement corresponding to FIG. 19, wherein, as in FIG. 18, a filter 162 is provided between the charging unit 70 and the poles 27, 28. Instead of the filter 162, it is also possible to provide an inductance 160 corresponding to FIG. 17 as a filter.FIG. 21 shows an arrangement corresponding to FIG. 20, wherein the charging unit 70 has a four-phase rectifier. This allows rectification of an alternating current signal with three phases L 1, L 2, L 3 and a neutral conductor N. Here too, a connection between the charging unit 70 and the poles 27, 28 is possible with or without a filter 162.FIG. 22 shows a corresponding arrangement with a filter 162.FIG. 23 shows an arrangement corresponding to FIG. 13, and the charging connection 72 enables both the connection of a DC voltage and an AC voltage. The direct voltage is applied to the poles 27, 28, as in FIG. 13, either with or without a filter. For charging with an alternating current, for example a three-phase alternating current, the charging unit 70 uses the drive inverter 14, and the drive inverter 14 is responsible, in normal operation, for providing a polyphase voltage suitable for the alternating current motor 12 from a direct voltage of the poles 27, 28. For this purpose, the drive inverter 14 has a plurality of phase terminals 141, 142, 143. Such drive inverters 14 can also be used in the opposite direction as an AC / DC converter 71 to convert a polyphase voltage into a DC voltage. For this purpose, the phase terminals L1, L2 and L3 of the charging terminal 72 are connected to the phase terminals 141, 142, 143 of the drive inverter 14. The neutral conductor N is connected to the poles 27, 28 via a neutral conductor circuit 164. By way of example, the neutral conductor circuit 164 has a first diode which is connected from the neutral conductor connection N to the pole 27, the cathode pointing toward the pole 27. A diode is likewise provided between the neutral conductor connection N and the pole 28, the cathode pointing toward the neutral conductor connection N.The charging connection 72 has a first charging connection unit 72.1 for a DC voltage and a second charging connection unit 72.2 for an AC voltage. The first charging terminal unit 72.1 is at least partially connected to the DC side of the driving inverter 14, and the second charging terminal unit 72.2 is at least partially connected to the AC side of the driving inverter 14. In the second charging connection unit 72.2, however, the neutral conductor can be connected to the direct current side of the drive inverter 14.FIG. 24 shows an arrangement corresponding to FIG. 23, wherein the neutral conductor circuit 164 which provides a connection between the neutral conductor terminal 72 and the poles 27, 28 is actively formed with two switches. The switches of the neutral conductor circuit 164 may be switched to act like the diodes of FIG. 23.FIG. 25 shows an arrangement corresponding to FIG. 23, Unlike in FIG. 23, additional inductances are provided between the diodes of the neutral conductor circuit 164 and the respective associated poles 27, 28. The inductances are preferably coupled and they cause a phase shift between the voltage at the neutral conductor N and at the respective pole 27, 28.FIG. 26 shows an arrangement corresponding to FIG. 23, but for a single-phase alternating current connection, as is used, for example, in households. The charging connection 72 is directly connected to the poles 27, 28 on the direct current side. On the AC side, the driving inverter 14 is used in the reverse direction for the AC / DC conversion. For this purpose, three lines L 1, L 2, L 3 are provided, which are connected on the one hand to the phase terminals 141, 142, 143 of the drive inverter 14 and on the other hand to the charging terminal 72 via switches 168. In the case of house connections, it is usually not unambiguously predefined at which connection the neutral conductor and at which connection the phase is present. Therefore, the charging unit 70 can determine which terminal the phase is present at by measuring, and the switching can then be used to set how the connection between the charging terminal 72 and the phase terminals 141, 142, 143 takes place.FIG. 27 shows an arrangement corresponding to FIG. 15 : The charging unit 70 has a rectifier 171, an inverter 172, a transformer 173, a rectifier 174 and a capacitor 175. The charging unit 70 shown enables feeding with both a direct current and an alternating current. In the case of an alternating current, rectification is effected by the rectifier 171. The direct current is then converted by the inverter 172 such that an alternating current occurs on the primary side of the transformer 173. This is transmitted to the secondary side by the transformer 173, and the voltage can be adjusted to a desired value. The signal on the secondary side of transformer 173 is then rectified via rectifier 174 and smoothed via capacitor 175.The AC voltage on the home network usually has a comparatively low frequency of 50 Hz or 60 Hz, and the transformer 173 would be very large at such a frequency. By contrast, it is possible via the inverter 172 to provide an alternating voltage with a significantly higher frequency, and as a result the transformer 173 can be made smaller, for example approximately far-sized.FIG. 28 shows an arrangement corresponding to FIG. 26; unlike in FIG. 26, the charging unit 70 has four connections L 1, L 2, L 3 and N on the AC side, the connections L 1, L 2 and L 3 being connected to the phase terminals 141, 142 and 143 of the drive inverter 14, and the terminal N being connected to the AC motor 12. In a star-connected AC motor 12, the terminal N may be directly connected to the star point of the star-connection. The switches 168 serve to be able to react to charging plugs with different loading of the pins, since, for example, as discussed above, the assignment of the phases to the connections is not unambiguous in the case of domestic connections.FIG. 29 shows an arrangement corresponding to FIG. 28, wherein no switches 168 of the charging unit 70 are provided. This is possible if there is a fixed assignment of the phases to the charging connection 72. At the poles 27, 28, a high-voltage on-board power supply system is additionally shown, which operates at 800 V, for example. By way of the high-voltage on-board power supply system 178, for example, a heater for the interior or a heater for the battery can be supplied with electrical energy. The energy store 20 additionally has second poles 127, 128, at which a further high-voltage on-board power supply system 177 is provided. As a result, further components in the vehicle can be provided with a further voltage, for example with a voltage of 400 V.The high-voltage on-board power supply system 177 is preferably used for supplying power to an air-conditioning compressor.The second poles 127, 128 are preferably connected to the switching device 58 of the energy store 20, wherein a subgroup of the modules 40 is preferably located between the second poles 127, 128, in order to generate a suitable voltage for the high-voltage on-board power supply 177 by the switching device 58.FIG. 30 shows an exemplary embodiment for generating the voltage at the second poles 127, 128 with the aid of the interconnection device 58. the interconnection 60.1 of FIG. 9 was selected by way of example. The generation of the voltage at the second poles 127, 128 is shown by way of example for a serial connection of the energy storage units 50. In the case of a serial connection, the positive pole of an energy storage unit 50 is in each case connected to the negative pole of an adjacent energy storage unit 50. On the left side, pole 127 is connected to the upper arm, and on the right side, pole 128 is connected to the lower side. In the serial connection, either only the upper branch or the lower branch of the connection between the adjacent energy storage units 50 is required. In the interconnection shown, the negative terminal of the energy storage unit 50 is connected to the pole 127, and the positive terminal of the energy storage unit 50 is connected to the pole 128. As a result, the voltage of the energy storage unit 50 is applied to a capacitor 166 provided for smoothing and to the battery 17 connected in parallel therewith. This state is referred to as a first state Z 1.FIG. 31 shows the arrangement of FIG. 30 in a second state Z 2. In this second state Z 2, the energy storage unit 50 is bridged in that the serial connection does not run via the energy storage unit 50, but rather passes by the energy storage unit on the underside. As a result, the voltage of the energy storage unit 50 is not present at the poles 127, 128. In the present interconnection 60.1, the serial interconnection can also be maintained in the second state Z2 without bridging by switching the connection from the energy storage unit 50 to the right via the upper line. Thus, the lower circuit to which the second pole 128 is connected is also disconnected from the energy storage unit 50. Even if the energy storage units 50 are connected in parallel, it is possible to connect or not to connect the corresponding energy storage unit 50 to the second poles 127, 128. In the case of a parallel connection, both the upper and the lower connections are required, but the connection can be effected in such a way that the positive branch is connected either via the upper or via the lower connection and the negative branch is connected via the correspondingly other connection.FIG. 32 shows, by way of example, the voltage profile U66 at the capacitor 166. In state Z 1, the voltage U 50 of the energy storage unit 50 is applied to the second poles 127, 128, and therefore the voltage U 66 on the capacitor 166 increases. During state Z 2, capacitor 166 is not powered by energy storage unit 50, and therefore voltage U 666 drops when the load is connected. A change to state Z 1 is then made again, etc. By utilizing the switching device 58, a predefined voltage can thus be reached on average at the second poles 127, 128. The switchover between the first state Z 1 and the second state Z 2 can be effected, for example, via a voltage regulator or generally via a voltage controller.Fig. 33 shows a sinusoidal signal as preferably generated by the drive inverters 14 for driving the associated AC motor 12. The drive inverters 14 preferably operate with a signal generator which uses a resolution of 8 bits and can thus assume 256 different values. At high powers, the drive inverter 14 produces high currents or high voltages at the AC output. The signal generator can thus make good use of the existing resolution and form a suitable sinusoidal signal.Fig. 34 shows the sinusoidal signal of Fig. 33 when the signal generator has only a few steps or low resolution available. This can be the case, for example, when the AC motor 12 requires only little energy, for example, during parking. In the desired low voltage range, only a few resolution levels of the signal generator are available. In such a case, it is advantageous if the drive inverter 14, as shown in FIG. 13, notifies the second control device 21 that only a low power is required or that a lower voltage of the energy store 20 would be advantageous. The second control device 21 can determine, taking into account the state data of the other loads, whether a lowering of the voltage of the energy store 20 is possible and optionally inform the first control device 22 that the voltage of the energy store 20 is to be lowered. At a lower voltage U across the drive inverter 14, the resolution of the signal generator can be better exploited and a good sinusoidal signal can be generated for the phases of the AC motor 12.In other words, at a very low output voltage of the drive inverter 14, the quantization is no longer sufficient to produce a fine sine. The drive inverter 14 can then request a lower voltage and operate better with it. A better output voltage at the phase connections leads to a higher efficiency and also to a lower distortion.In the same way, a lowering of the voltage U can be advantageous, for example, for the drive inverter 14, if the latter can be moved as a result into a working point at which a higher efficiency is possible.It is understood that many variations and modifications are possible within the scope of the invention.One or more battery cells or fuel cells have been proposed as energy storage unit. However, in principle any voltage source is possible.Wired data lines have been mentioned as data lines. Instead of these, the use of wireless data lines is also possible, either for a part or for all the data lines 30, 24 etc. mentioned.

Claims

Vehicle (10) having an energy store (20), a drive inverter (14) and a charging unit (70), which energy store (20) has a first control device (22), modules (40), a switching device (58), two first poles (27, 28) and two second poles (127, 128) to which first poles (27, 28) the drive inverter (14) is connected, which modules (40) each have an energy store unit (50), and which switching device (58) has connections (25) between the modules (40) and first switches (62) provided on the connections (25) in order to enable different connections of the modules (40) and different voltages (U) on the first poles (27, 28) depending on the state of the first switches (62), which different interconnections of the modules (40) have the following interconnection possibilities: - parallel interconnection of at least two modules (40), - serial interconnection of at least two modules (40), - bridging of at least one module (40), and which first control device (22) is designed to actuate the interconnection device (58) as a function of a voltage setpoint (U_S) in order to influence the voltage (U) at the first poles (27, 28) as a function of the voltage setpoint (U_S), wherein the two second poles (127, 128) can be connected to at least one of the energy storage units (50), wherein the maximum voltage at the second poles (127, 128) is less than the maximum voltage at the first poles (27, 28), and wherein the second poles (127, 128), 128) are connectable via the switching device (58) to the at least one energy storage unit (50) in order to influence the voltage at the two second poles (127, 128) via the first switches (62) of the switching device (58).Vehicle according to claim 1, wherein the first control device (22) is configured to switch the switching device (58) alternately back and forth between a first state (Z1) and a second state (Z2), wherein the first state the two second poles (127, 128) are connected to the at least one energy storage unit (50) in such a way that the at least one energy storage unit (50) causes a voltage at the two second poles (127, 128), and wherein the second state (Z2) the two second poles (127, 128) are connected in such a way that the at least one energy storage unit (50) causes no or a lower voltage at the two second poles (127, 128), in order to provide on average a voltage at the two second poles (127, 128) that is lower than the voltage of the at least one energy storage unit (50) in the first state.Vehicle according to claim 1 or 2, wherein a capacitor (166) is provided between the two second poles (127, 128) in order to smooth the voltage at the two second poles (127, 128).Vehicle according to one of the preceding claims, comprising a first DC / DC converter (19) having first inputs and first outputs, which first inputs are directly or indirectly connected to the two second poles (127, 128) in order to provide an additional voltage at the first outputs, which additional voltage is preferably smaller than the voltage at the two second poles (127, 128).Vehicle according to claim 4, wherein the first DC / DC converter (19) comprises a separation device configured to effect a galvanic separation between the first inputs and the first outputs, which separation device preferably comprises a transformer or a capacitor.Vehicle according to one of the preceding claims, which has a second control device (21), and in which the drive inverter (14) is connected to the second control device (21) via a first data line (23) and is designed to transmit a first data signal (35) to the second control device (21), and which second control device (21) is designed to transmit a voltage setpoint value (U_S) to the first control device (22) as a function of the first data signal (35).Vehicle according to claim 6, which has a second DC / DC converter (16) having second inputs and second outputs, which second inputs are connected directly or indirectly to the two second poles (127, 128), which second DC / DC converter (16) is connected via a second data line (38) to the second control device (21) and is designed to transmit a second data signal (37) to the second control device (21), and which second control device (21) is designed to specify a voltage setpoint value (U_S) in dependence on the first data signal (35) and the second data signal (37) of the first control device (22).Vehicle according to one of the preceding claims, in which the charging unit (70) has a charging connection (72) and an AC / DC converter (71) with third inputs and third outputs, which third inputs are connected to the charging connection (72) and which third outputs are connected to the first poles (27, 28).The vehicle of claim 8, wherein a filter (162) is provided between the third outputs and the first poles (27, 28).Vehicle according to Claim 8 or 9, in which the charging unit (70) has a current regulator (80, 82, 84) and a first measuring device (74) for generating a first signal (I) as a function of the level of the charging current (64), to which current regulator (80, 82, 84) a current regulator setpoint value (I_S) is fed as setpoint value and the first signal (I) as actual value, which current regulator (80, 82, 84) outputs the voltage setpoint value (U_S) as manipulated variable to the first control device (22) in order to regulate the actual value (I) to the setpoint value (I_S).Vehicle according to Claim 10, in which the actual value (I) is predefined as a function of the voltage (U1) at the third outputs.Vehicle according to claim 11, wherein a phase difference (phi) between the actual value (I) and the voltage (U1) at the third outputs is predetermined in order to influence the power factor.Vehicle according to Claim 12, in which the phase difference (phi) can be preset in a variable manner by a transmitter (78) to the current regulator (80, 82, 84).Vehicle according to one of Claims 8 to 13, in which the AC / DC converter (71) is formed by using the drive inverter (14) in the opposite direction for the charging process.Vehicle according to claim 14, wherein the charging connection (72) has a first connection point for a neutral conductor (N), and wherein the first connection point is connected to the two first poles (27, 28) via diodes or via switches.Vehicle according to one of Claims 8 to 15, in which the charging connection (72) has a first charging connection unit (72.1) for a DC voltage and a second charging connection unit (72.2) for an AC voltage, which first charging connection unit (72.1) is at least partially connected to the DC side of the drive inverter (14), and which second charging connection unit (72.2) is at least partially connected to the AC side of the drive inverter (14).The vehicle according to any one of claims 8 to 16, wherein the AC / DC converter (71) has four branches to selectively enable connection of a three-phase AC signal or a single-phase AC signal.Vehicle according to one of Claims 8 to 17, in which the AC / DC converter (71) is designed to be active or passive.Vehicle (10) having an energy store (20), a drive inverter (14) and a charging unit (70), which energy store (20) has a first control device (22), a second control device (21), modules (40), a switching device (58), a second DC / DC converter (16), two first poles (27, 28) and two second poles (127, 128) to which first poles (27, 28) the drive inverter (14) is connected, which modules (40) each have an energy store unit (50), and which switching device (58) has connections (25) between the modules (40) and first switches (62) provided on the connections (25) in order to enable different connections of the modules (40) and different voltages (U) on the first poles (27, 28) depending on the state of the first switches (62), which different interconnects of the modules (40) enable at least two interconnects from the group of interconnects consisting of - parallel interconnect of at least two modules (40), - serial interconnect of at least two modules (40), - bridging of at least one module (40), and which first control device (22) is designed to actuate the interconnect device (58) as a function of a voltage setpoint (U_S) in order to influence the voltage (U) at the first poles (27, 28) as a function of the voltage setpoint (U_S), wherein the drive inverter (14) is connected via a first data line (23) to the second control device (21) and is designed to transmit a first data signal (35) to the second control device (21), and which second control device (21) is designed to transmit a first data signal (35) to the second control device (21), in dependence on the first data signal (35), to transmit a voltage setpoint value (U_S) to the first control device (22), wherein the two second poles (127, 128) are connectable to at least one of the energy storage units (50), wherein the maximum voltage at the second poles (127, 128) is lower than the maximum voltage at the first poles (27, 28), wherein the second DC / DC converter (16) has second inputs and second outputs, which second inputs are connected directly or indirectly to the two second poles (127, 128), wherein the second DC / DC converter (16) is connected via a second data line (38) to the second control device (21) and is designed to transmit a second data signal (37) to the second control device (21), and wherein the second control device (21) is designed to transmit a second data signal (37) to the second control device (21), dependent on the first data signal (35) and the second data signal (37), the first control device (22) specifies a voltage setpoint value (U_S).

Images