Cell monitoring system for an energy storage device for an electrically powered motor vehicle, energy storage device and motor vehicle

Abstract

Cell monitoring system (70) for an energy storage device (55) for an electrically powered motor vehicle (50) with a vehicle-side electrical interface (80), wherein the cell monitoring system (70) is connectable to a plurality of voltage taps (71), and the voltage taps (71) are each configured for electrically contacting a cell (57) of the energy storage device (55); the cell monitoring system (70) has a control device (75) for controlling the voltage taps (71); and the cell monitoring system (70) is configured for electrically connecting the cells (57) to the vehicle-side electrical interface (80) via the plurality of voltage taps (71).

Description

[0001] The present disclosure relates to a cell monitoring system for an energy storage device for an electrically driven motor vehicle having a vehicle-side electrical interface, wherein the cell monitoring system is connectable to a plurality of voltage taps, and the voltage taps are each configured to electrically contact a cell of the energy storage device. The disclosure further relates to an energy storage device for an electrically driven motor vehicle, comprising a plurality of cells and a cell monitoring system, and to an electrically driven motor vehicle, comprising a cell monitoring system and / or an energy storage device.

[0002] Electrically powered motor vehicles are well known in the art. In particular, battery-electric vehicles are known, for example, as plug-in hybrid electric vehicles (PHEVs) or battery electric vehicles (BEVs). Such motor vehicles typically have an energy storage device known as a traction battery or high-voltage battery for storing and providing electrical energy.

[0003] It is known to configure the motor vehicle or the energy storage device for so-called bidirectional charging in order to selectively draw or supply electrical energy to the energy storage device. For example, a user can thus power 230 V devices and / or use the motor vehicle or the energy storage device for bidirectional operation as a stationary storage device in their own home. Charging and bidirectional charging are currently primarily carried out via the motor vehicle's charging socket. Therefore, it is known that such motor vehicles have an interface for transmitting electrical energy between the energy storage device and an external power grid.

[0004] DE 10 2008 031 125 A1 discloses a method for controlling a bidirectionally operable voltage converter device and a multi-voltage vehicle electrical system.

[0005] Furthermore, it is known that motor vehicles have a solar cell which is designed to feed electrical energy into the energy storage device.

[0006] DE 10 2009 057 919 A1 discloses an electrical on-board network for a motor vehicle with at least two voltage levels, with at least one consumer for each of the two voltage levels and with at least two energy storage devices, wherein the on-board network comprises a first generator which generates a first electrical voltage, the amplitude of which essentially determines an electrical potential of a first voltage level, and that the on-board network comprises a second generator which generates a second electrical voltage, the amplitude of which essentially determines the electrical potential difference between the first voltage level and a second voltage level, the electrical potential of which is higher than that of the first voltage level, wherein the second generator is designed as a solar generator of a solar roof.

[0007] However, especially for bidirectional charging, multiple control units and bus systems in the vehicle must be woken up and operated. These control units and bus systems are secondary consumers and can impact the energy balance. This can be due to the often distributed functions of the multiple control units regarding the control of various actuators such as contactors, converters, etc., and regarding function monitoring, for example, to achieve electrical safety, functional safety, etc. The combined electrical energy consumption of the control units and the bus system can be so high that the power consumption of small consumers becomes inefficient and / or uneconomical. This is particularly evident in the frequent use of a stationary vehicle.

[0008] A similar approach applies to the supply of electrical energy via a solar cell, which is also connected to the energy storage device for supplying electrical energy via an electrical interface in the vehicle. In this case, particular care should be taken to ensure that the auxiliary devices consume very little power, otherwise the energy storage device cannot be charged or can only be charged to a negligible extent.

[0009] Against the background of this prior art, one object of the present disclosure is to enrich the prior art and to improve at least the aforementioned aspects of the prior art. In particular, the object of the disclosure is to reduce or largely avoid the load from secondary consumers when electrical energy is drawn from the energy storage device and / or fed into the energy storage device, each at a low power level.

[0010] The problem is solved by the features of the independent claims. The subclaims contain further developments of the disclosure.

[0011] According to this, the object is achieved by a cell monitoring system for an energy storage device for an electrically driven motor vehicle having a vehicle-side electrical interface, wherein the cell monitoring system is connectable to a plurality of voltage taps, and the voltage taps are each configured to electrically contact a cell of the energy storage device; the cell monitoring system has a control device for controlling the voltage taps; and the cell monitoring system is configured to electrically connect the cells to the vehicle-side electrical interface via the plurality of voltage taps.

[0012] The energy storage device can comprise a plurality of cells. The cells can be logical and / or physical cells. The cell monitoring system can electrically connect the cells to the interface via the voltage taps in a controlled manner by the control device, thus controlling the extraction of electrical energy from one or more of the cells or the charging of one or more of the cells with electrical energy.

[0013] It was recognized that a cell monitoring system according to the prior art typically measures data relating to the cells. For this purpose, such cell monitoring systems have voltage taps as measuring lines (sensing lines). Such monitoring voltage taps can be routed separately from the electrical contacts for a power interface, for example, for supplying the electric drive with electrical energy. The voltage taps can be connected to a cell contacting system in order to save costs and / or space and to control the feed-in and / or withdrawal of electrical energy. It was recognized that at low power levels, it is not necessary to wake up, operate and / or monitor various other control devices separate from the cell monitoring system and the bus system for controlling the feed-in and / or withdrawal of electrical energy.Accordingly, the cell monitoring system is proposed which can measure almost any voltage at the voltage taps, especially for voltage monitoring, even when the voltage of the energy storage device decreases.

[0014] The cell monitoring system forms a front end where all voltage taps are consolidated. This allows for continued cell monitoring. Furthermore, the measurement front end provided by the cell monitoring system can be used to tap the voltage for electrically connecting the cells to the electrical interface. The control device can be referred to as a "smart cell supervising circuit" or smart CSC. The voltage taps can be used selectively for feeding and discharging, i.e., controlled and / or regulated by the control device.

[0015] By selectively connecting the cells or the voltage taps to the interface, electrical energy can also be transmitted at low power and, in particular, at low voltage. This simplifies the control of the transmission of electrical energy, as the transmission of energy is less safety-relevant and results in fewer thermal losses. Complex monitoring by various control units can therefore be dispensed with. By using the voltage taps, a different path is used to provide and / or feed in electrical energy than the main current path, thus bypassing the other vehicle control units. The energy storage device can be connected directly to the electrical interface as a source or sink. Power can be drawn separately from the main intermediate circuit to which, for example, an electric drive is connected.The cell monitoring system with the voltage measurement taps requires additional monitoring due to the power, voltage and / or dynamics, but critical thresholds are reached less quickly than in the main current path. This may make it unnecessary to operate auxiliary consumers, such as control units and the vehicle's bus system. Alternatively, a main control unit of the energy storage device and / or another control unit can be awakened if more functions are necessary and / or requested, e.g. for diagnostics. This can, for example, make bidirectional charging and / or feeding in of electrical energy more efficient, particularly by a vehicle-mounted solar cell or a vehicle-mounted photovoltaic module arranged, for example, on and / or on an outer skin of the vehicle, because interference from auxiliary consumers is reduced.In addition, the voltage taps act as a natural fuse in the event of an overload, which can obviate the need for functional safety measures (FuSi for short) and also prevent the bus system and various control devices from waking up. Optionally, one or more measuring lines can be reinforced as voltage taps, i.e., with a larger cross-section, to be able to carry higher currents. An additional overcurrent protection device can be provided as an option.

[0016] Optionally, the control device is configured to selectively connect one or more of the plurality of voltage taps to the electrical interface. In other words, the control device can selectively connect one or more voltage taps, i.e., several different sets or subsets of voltage taps, and thus selectively connect one or more of the battery cells to the electrical interface. In particular, a different number of cells can also be connected to the electrical interface to achieve different voltages and / or currents.

[0017] Optionally, the control device is configured to be supplied with electrical energy by the cell and / or multiple cells. This avoids, for example, the need to operate the entire energy storage device and possibly a voltage converter for it to operate the control device. Instead, the control device can be supplied with electrical energy by one or more cells via one or more voltage taps directly connected to the control device.

[0018] Optionally, the control device comprises a plurality of control modules; each of the control modules is configured to selectively connect the electrical interface to a predetermined number of cells. It has been recognized that the control and / or monitoring of a predetermined number of cells by a control module can provide an effective architecture for the cell monitoring system. Each of the control modules can, for example, control six to twenty-four cells. The energy requirement of each of the control modules is such that the respective control module can be effectively supplied with electrical energy from the cells connected to the control module to operate the control module. The control modules can be combined into a unit, e.g.on a circuit board to effectively utilize the installation space, and / or arranged separately to allow for different arrangements of the control modules. Furthermore, the control modules or switching elements can be arranged on one or more circuit boards or chips (silicon), thus allowing cost-effective production.

[0019] Optionally, the cell monitoring system includes a cooling device for passively cooling the control device. This makes it possible to avoid the need for an auxiliary load for cooling the control device. This is possible because the control device typically controls the transport of electrical energy with comparatively low power.

[0020] Optionally, the control device is configured to regulate the connection of the electrical interface to one or more of the plurality of voltage taps depending on the load. The control device can have an optimizer function that, for example, regulates the voltage and thus the cell taps for feeding electrical energy from a photovoltaic module until an optimal power output from the photovoltaic module is achieved. Different cells can be subjected to different voltages or loads. In addition, a quasi-active balancing of the cells can be ensured without the need to convert energy into heat.

[0021] Optionally, the control device is configured to regulate the connection of the electrical interface to one or more of the plurality of voltage taps in a time-dependent manner. Time-dependent regulation can, for example, achieve uniform charging of individual cells and / or uniform withdrawal of electrical energy from individual cells. Furthermore, this enables comparatively fast temporal regulation and, optionally, conversion to simulate an alternating voltage, whereby the amplitude of the alternating voltage can be determined in a time-dependent manner based on the number of connected voltage taps or cells.

[0022] Optionally, the control device is configured to regulate the connection of the electrical interface to one or more of the plurality of voltage taps in such a way that an alternating current is modulated. Thus, an alternating current can be provided by the regulation, thus simulating an inverter output. This principle can be applied analogously to energy supply.

[0023] Optionally, the control device comprises an inverter for applying and / or loading the interface with an alternating current; and a subset of the voltage taps is connected to the inverter. By connecting the subset to the inverter, not every voltage tap needs to be routed to the DC / AC converter, but rather, for example, only every nth one with a natural number nb. Thus, only the relevant voltage taps need to be designed with a correspondingly large cross-section, i.e., with a larger cross-section, to reduce losses and efficiently enable the conduction of a sufficient amount of electrical energy.

[0024] Optionally, the control device comprises an inverter with a resonant converter for applying and / or loading an alternating current to the interface. The resonant converter can comprise a switchable capacitor and a switchable inductor to further reduce conversion losses. The resonant converter, or the switchable inductor and / or the switchable capacitor, can be particularly advantageously operated in the resonant range using flexible voltage taps.

[0025] According to one aspect of the disclosure, an energy storage device for an electrically driven motor vehicle is provided, comprising a plurality of cells and the cell monitoring system described above. Optionally, the cell monitoring system has one or more features described as advantageous or optional in order to achieve an associated technical effect.

[0026] According to one aspect of the disclosure, an electrically driven motor vehicle is provided, comprising the cell monitoring system and / or the energy storage device described above. Optionally, the cell monitoring system has one or more of the features described as advantageous or optional in order to achieve an associated technical effect.

[0027] Optionally, the motor vehicle includes a photovoltaic module designed to connect to the cells via the vehicle's electrical interface and the cell monitoring system. This allows the cells to be charged.

[0028] In the following, one embodiment is described with reference to the figures. Fig. 1 schematically shows an electrically driven motor vehicle with an energy storage device according to the prior art; Fig. 2 schematically shows an electrically driven motor vehicle with an energy storage device according to one aspect of the disclosure; Fig. 3 schematically shows a cell monitoring system and a plurality of cells according to one aspect of the disclosure; and Fig. 4 schematically shows two possibilities for selectively connecting one or more voltage taps to an electrical interface of an energy storage device and a voltage waveform of a cell monitoring system according to one aspect of the disclosure.

[0029] Fig. Figure 1 schematically shows an electrically driven motor vehicle 50 with an energy storage device 55 according to the prior art. Fig. 1 an external charging point 100.

[0030] The charging point 100 may comprise a charging station or a wallbox and be configured for charging and / or bidirectional charging of the motor vehicle 50 or the energy storage device 55. For this purpose, the charging point 100 has a charging-point-side connection element 110, for example, a charging plug.

[0031] The motor vehicle 50 has a motor vehicle-side connection element 51, for example, a charging socket. The charging point-side connection element 110 and the motor vehicle-side connection element 51 are configured to be operatively connected to one another so that the motor vehicle 50 or the energy storage device 55 of the motor vehicle 50 can be supplied with electrical energy for charging and / or electrical energy can be drawn from the energy storage device 55, for example, to operate a device external to the vehicle and / or to feed the energy into an external power grid. The charging point 100 and the motor vehicle 50 are configured for rapid charging.

[0032] The motor vehicle 50 has a high-voltage line 52 or a line arrangement and / or a cable harness. The high-voltage line 52 is configured to electrically connect the motor vehicle-side connecting element 52 to the energy storage device 55 in order to transport electrical energy between the charging point 100 and the energy storage device 55.

[0033] The motor vehicle 50 has two electrical interfaces 80. One of the interfaces 80 is a direct current interface 81, and the other of the interfaces 80 is an alternating current interface 82. The interfaces 80 are electrically connected to the high-voltage line 52 in order to electrically connect the interfaces 80 to the energy storage device 55.

[0034] The motor vehicle 50 has a photovoltaic device 91. The photovoltaic device 91 is connected to the direct current interface 81 in order to supply electrical energy generated by the photovoltaic device 91 in the form of a direct current (DC) to the energy storage device 55. The voltage of the direct current (DC) can be, for example, 60 V and is thus only a fraction of the voltage of the entire energy storage device 55.

[0035] The AC interface 82 is connectable to a vehicle-external power network 92. The vehicle-external power network 92 may include a consumer that can be powered by an AC current. For this purpose, the AC interface 82 may be configured as a vehicle-mounted power outlet.

[0036] The energy storage device 55 is configured to store and provide electrical energy, in particular for powering the motor vehicle 50. The energy storage device 55 is a high-voltage battery and includes a battery control unit 56, a cell monitoring system 70, a cell contact system 72, a plurality of cells 57, and a temperature control device 58.

[0037] The battery control unit 56, also called the main control unit, battery management unit, or BMU, is configured to control, i.e., to regulate, and / or monitor the function of the entire energy storage device 55. For this purpose, the battery control unit 56 can comprise a data processing device and a cooling device on the battery control unit side.

[0038] The cell contacting system 70 is configured to electrically contact the cells 57 of the energy storage device 55, thus enabling the transport of electrical energy. The cell monitoring system 70 comprises a control device 75 and is configured to electrically contact the cells 57 of the energy storage device 55 in order to measure data relating to the cells 57 and transmit it, for example, to the battery control unit 56 and / or other motor vehicle components.

[0039] The cells 57 are physical cells 57" connected to logical cells 57' (see Fig. 3). The cells 57 are arranged in so-called battery modules (not shown). The cells 57 are configured to perform an electrochemical reaction to store or provide electrical energy. For example, the cells 57 comprise lithium-ion cells and / or lithium iron phosphate cells.

[0040] The temperature control device 58 is configured to control the temperature of the cells 57, i.e., to control the temperature of the cells 57. In particular, the temperature of the cells 57 can be regulated by the temperature control device 58 in order to bring the cells 57 to a thermally favorable operating point. For this purpose, the temperature control device 58 is configured to monitor the temperature of the cells 57 and to cool and / or heat the cells 57.

[0041] The motor vehicle 50 has a vehicle-mounted cooling system 53. The cooling system 53 is configured to cool components of the motor vehicle 55, for example, an electric drive and / or power electronics (not shown). The cooling system 53 is also configured to cool the energy storage device 55 and can be operatively connected to the temperature control device 58 for this purpose.

[0042] When transporting electrical energy between the interfaces 80 and the energy storage device 55, according to the prior art, the entire energy storage device 55 must be operated. Therefore, for example, the battery control unit 56 and the temperature control device 58, which are otherwise required to operate the electric drive, are operated. In addition, a bus system (not shown) is operated so that various components of the energy storage device 55 and / or the motor vehicle 55 are connected for communication purposes, for example, to exchange information about the transport of electrical energy. This can result in considerable electrical energy consumption.

[0043] Fig. 2 schematically shows an electrically driven motor vehicle 50 with an energy storage device 55 according to one aspect of the disclosure. Fig. 2 is made with reference to Fig. 1 described.

[0044] In the Fig. 2, the interface 80 is directly electrically connected to the cell monitoring system 70 for supplying the interface 80 with electrical energy from the cells 57 and / or for supplying the cells 57 with electrical energy from the interface 80. A connection between the interface 80 and the high-voltage line 52 can thus be dispensed with. Thus, the cells 57' can be monitored as with reference to Fig. 3 and Fig. 4, the battery control unit 56 and other auxiliary loads can be electrically connected to the interface 80 via the cell monitoring system 70. For example, the battery control unit 56 and other auxiliary loads can remain passive, as shown by boxes with dashed lines.

[0045] Fig. 3 schematically shows a cell monitoring system 70 and a plurality of cells 57 according to one aspect of the disclosure. The cell monitoring system 70 according to Fig. 3 is a cell monitoring system 70 for an energy storage device 55 for an electrically driven motor vehicle 50 with a vehicle-side electrical interface 80. Such a motor vehicle 55, such an energy storage device 55 and such a cell monitoring system 70 are described with reference to Fig. 2 described. Fig. 3 is made with reference to Fig. 2 described.

[0046] The cell monitoring system 70 has a plurality of voltage taps 71 and a control device 75 for controlling the cell monitoring system 70. Each of the voltage taps 71 is configured to electrically contact one of the electrical cells 57 and the control device 75. The voltage taps 71 are measuring lines for monitoring the cells 57. The voltage taps 71 are also used to transport electrical energy between the cells 57 and the interface 80; thus, the voltage taps 71 are used as power lines.

[0047] The control device 75 is electrically connected to the interfaces 80. Thus, the cell monitoring system 70 is configured to electrically connect the cells 57 to the interface 80, wherein the control device 75 is configured to selectively connect one or more of the plurality of voltage taps 71 to the electrical interface 80.

[0048] The cell monitoring system 70 has a voltage tap 71 for each logical cell 57'. In the diagram according to Fig. 3, two physical cells 57" are interconnected in parallel to form a logical cell 57'. In another embodiment (not shown), more than two physical cells 57" can be interconnected to form a logical cell 57'. Each of the cells 57 has a cell voltage that may depend on the cell chemistry, the charge state, and the aging state. The cell voltage during operation is, for example, in the range of approximately 4 V to 6 V.

[0049] By selectively connecting one or more of the voltage taps 71 to the electrical interface 80, all natural multiples of the cell voltage up to the voltage across all cells 57, i.e., the pack voltage, can be represented simply by clever wiring. Selective connection means that any one or more voltage taps 71 can be switched. The cell voltage can be tapped at one voltage tap 71. With n voltage taps 71, the cell voltage can be tapped n times, where n is a natural number. Analogously, one cell 57 or n cells 57 can be supplied with electrical energy. By selectively connecting, any number of n voltage taps 71 can be interconnected, i.e., connected to the interface 80.

[0050] The control device 75 has a plurality of control modules 76. Each of the control modules 76 is configured to selectively connect the electrical interface 80 to a predetermined number of cells 57. The predetermined number of cells 57 is connected to the respective control module 76 via a corresponding predetermined number of voltage taps 71. In other words, each of the control modules 76 can electrically connect one or more of the predetermined number of voltage taps 71 to the interface 80. The predetermined numbers are selected such that the control device 75 can address each of the voltage taps 71.

[0051] The control device 75 is configured to be supplied with electrical energy by the cell 57 and / or a plurality of cells 57. For this purpose, the control device 75 and / or each of the control modules 76 comprises a supply DC-DC converter. The supply DC-DC converter is configured to receive a DC voltage from the cell 57 and / or the cells 57 and to convert the DC voltage into a supply voltage for supplying the control device 75 with electrical energy.

[0052] The control device 75 is configured to regulate the connection of the electrical interface 80 to one or more of the plurality of voltage taps 71 depending on the load. The control device 75 is thus configured to change the switching of the voltage taps 71 for load compensation, for example in the event of a sharp drop in the cell voltage during the withdrawal of electrical energy from the cells 57. The switching of the voltage taps 71 serves to load different sub-areas of the energy storage device 55 and / or different quantities of cells 57 at different times. The control device 75 is thus configured for load balancing. Different cells 57 can be subjected to different voltages or loaded in each case, thus ensuring a quasi-active balancing of the cells 57 without having to convert energy into heat.

[0053] The control device 75 is configured to regulate the connection of the electrical interface 80 to one or more of the plurality of voltage taps 71 in a time-dependent manner and thus to approximate an alternating current by switching the voltage taps 71 (see Fig. 4 (C)) and / or load balancing. In other words, the control device 75 is configured to regulate the connection of the electrical interface 80 to one or more of the plurality of voltage taps 71 such that an alternating current AC is modulated.

[0054] The cell monitoring system 70 has a cooling device 77 for passively cooling the control device 75. The control device 75 or each of the control modules 76 (not shown) has, for example, heat pipes and / or is conductively coupled to heat sinks, for example, a cooling system 53 of the motor vehicle 50.

[0055] The control device 75 has an inverter 78 for applying and / or loading the interface 80 with an alternating current AC; and a subset of the voltage taps 71 is connected to the inverter 78. The inverter 78 has a resonant converter 79. The resonant converter 79 has a switchable capacitor 79a and a switchable inductor 79b. The switchable capacitor 79a and a switchable inductor 79b can be switched independently of one another in order to adjust the resonant behavior of the resonant converter 79. The subset of the voltage taps 71 can have a smaller cross-section than other voltage taps 71, because the higher the voltage of the DC voltage tap, the smaller the cable cross-section can be selected for the same power. The inverter 78 is electrically connected to the AC interface 82 in order to supply the AC interface 82 with electrical energy.

[0056] The control device 75 includes a DC-DC converter 83. The DC-DC converter 83 is electrically connected to the DC interface 81 to enable the transport of electrical energy between the DC interface 81 and the cells 57. The DC-DC converter 83 provides galvanic isolation between the cells 57 and the DC interface 81.

[0057] The control device 75 additionally has fuses (not shown), for example 8A / 16A fuse for protecting the AC interface 82 and / or for protecting a DC measuring line.

[0058] Fig. Fig. 4 schematically shows two possibilities for selectively connecting one or more voltage taps 71 to an electrical interface 80 of an energy storage device 55 and a voltage profile of a cell monitoring system 70 according to one aspect of the disclosure. The cell monitoring systems 70 are each a variant of the system described with reference to Fig. 2 and Fig. 3 described cell monitoring system 70. Fig. 4 is made with reference to Fig. 2 and Fig. 3 described.

[0059] Fig. Figure 4 (A) shows a configuration in which the cells 57 are connected in series. By connecting n cells 57 in series, the output voltage is n times the cell voltage, where n is a natural number. A voltage curve is shown in Fig. 4 (C), where the voltage U is plotted as a function of time t. The number n of connected cells 57 changes successively to approximate an alternating voltage or an alternating current AC.

[0060] By switching, any wave and / or step profile can be created. For this purpose, a specific connection combination, i.e., a switched set of voltage taps 71, is present for a certain time t and then switches to another set of voltage taps 71 with a potentially different number of voltage taps 71 to generate a different voltage. It is possible to simulate a sine wave through a switching sequence, as in Fig. 4 (C). A 230 V (Europe) or 120 V (USA) voltage can be simulated. Optionally, a smoothing capacitor is installed on the output side to smooth the voltage curve shown.

[0061] Fig. 4 (B) shows a variant of Fig. 4 (A), where cells 57 can be connected in parallel.

[0062] The Fig. 4 (A) and Fig. The variants shown in 4 (B) can be combined as desired. Reference symbol (part of the description) 50 motor vehicles 51 vehicle-side connecting element 52 high-voltage line 53 vehicle-side cooling system 55 Energy storage device 56 Battery control unit 57 Cell 57' logical cell 57" physical cell 58 Tempering device 70 Cell Monitoring System 71 Voltage tap 72 Cell contact system 75 Control device 76 Control module 77 Cooling device 78 inverters 79 resonant converters 79a switchable capacity 79b switchable inductance 80 interface 81 DC interface 82 AC interface 83 DC-DC converters 91 Photovoltaic device 92 vehicle-external power grid 100 charging points 110 charging point-side connecting element AC alternating current DC direct current QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2008 031 125 A1

[0004] DE 10 2009 057 919 A1

[0006]

Claims

[1] Cell monitoring system (70) for an energy storage device (55) for an electrically driven motor vehicle (50) with a vehicle-side electrical interface (80), wherein - the cell monitoring system (70) is connectable to a plurality of voltage taps (71), and the voltage taps (71) are each configured to electrically contact a cell (57) of the energy storage device (55); - the cell monitoring system (70) comprises a control device (75) for controlling the voltage taps (71); and - the cell monitoring system (70) is configured to electrically connect the cells (57) to the vehicle-side electrical interface (80) via the plurality of voltage taps (71). [2] Cell monitoring system (70) according to claim 1, wherein - the control device (75) is configured to selectively connect one or more of the plurality of voltage taps (71) to the electrical interface (80). [3] Cell monitoring system (70) according to claim 1 or 2, wherein the control device (75) is arranged to be supplied with electrical energy by the cell (57) and / or a plurality of cells (57). [4] Cell monitoring system (70) according to one of the preceding claims, wherein - the control device (75) has a plurality of control modules (76); and - each of the control modules (76) is arranged to selectively connect the electrical interface (80) to a predetermined set of cells (57). [5] Cell monitoring system (70) according to one of the preceding claims, wherein the cell monitoring system (70) comprises a cooling device (77) for passively cooling the control device (75). [6] Cell monitoring system (70) according to one of the preceding claims, wherein the control device (75) is configured to regulate the connection of the electrical interface (80) to the one or more of the plurality of voltage taps (71) in a load-dependent and / or time-dependent manner. [7] Cell monitoring system (70) according to one of the preceding claims, wherein the control device (75) is arranged to regulate the connection of the electrical interface (80) to the one or more of the plurality of voltage taps (71) such that an alternating current (AC) is modulated. [8] Cell monitoring system (70) according to one of the preceding claims, wherein - the control device (75) comprises an inverter (78) for applying and / or loading the interface (80) with an alternating current; and - a subset of the voltage taps (71) is connected to the inverter (78). [9] Cell monitoring system (70) according to claim 8, wherein the control device (75) comprises an inverter (78) with a resonant converter (79) for applying and / or loading the interface (80) with the alternating current. [10] Energy storage device (55) for an electrically driven motor vehicle (50), comprising a plurality of cells (57) and a cell monitoring system (70) according to one of the preceding claims. [11] Electrically driven motor vehicle (50) comprising a cell monitoring system (70) according to one of claims 1 to 9 and / or an energy storage device (55) according to claim 10.

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