Energy store for an electrically drivable vehicle

Abstract

The invention relates to an energy store (1) having a housing (2), a first plurality of storage battery units (3a, 3b), a second plurality of storage battery units (4a, 4b), a first electrical connection assembly (8), a second electrical connection assembly (9) and a switching device (10). The switching device (10) is provided for connecting the first plurality of storage battery units (3a, 3b) to the first electrical connection assembly (8), for connecting the second plurality of storage battery units (4a, 4b) to the second electrical connection assembly (9) and / or for connecting the first plurality of storage battery units (3a, 3b) to the second plurality of storage battery units (4a, 4b).

Description

TECHNICAL FIELD

[0001] The present invention relates to an energy store, in particular for an electrically drivable vehicle. The invention in particular relates to a flexible and energy-efficient mode of operation of an energy store. BACKGROUND

[0002] Current electric vehicle solutions comprise, in addition to the passively connected battery pack, active components, including inverters, DC-DC converters, additional 12V / 48V batteries, power conversion units (PCU), soft start protection and charging regulators. This is a sometimes laborious and cost-intensive system. Due to the passive connection of the individual battery cells, for example with a single source voltage of 3.7V, and the manufacturing-dependent differences in internal resistance and capacity, the load on the individual battery cells also differs significantly and possible further drifts from one another during operation. The capacity of the entire battery pack is therefore determined by the performance of the battery cell with the worst state of health or worst state of charge, whereby it is necessary to limit the available capacity to 60% to 80% of the rated capacity in advance in order to avoid harmful deep discharge of the battery cell with the lowest capacity. The invention pursues the task of shifting the functionality to the individual battery cells, so that each individual battery cell can also be optimally utilized or can optimally react to external power take-off (driving operation, operating operation or the like) or power supply (charging operation, regenerative operation or the like) and can contribute if necessary. SUMMARY

[0003] To this end, the invention proposes a system, for example with ASIC, sensors and switches, which can be implemented on each individual battery cell. In other words, intelligent battery cells can be used as a basic unit for the invention. The ASIC of the individual battery cell or of the individual system comprises a memory / data store with a clear identification, so that each battery cell is clearly assigned, and sensors which identify and save, for example, temperature, current, number of charge / discharge cycles, battery cell voltage and possible battery cell faults such as deep discharge, high temperature, etc. A bus system enables each individual battery cell to communicate with a load or charging station. Active switches, for example MOSFET, on each individual battery cell enable the various battery cells to be connected in series and / or in parallel and to apply the respective voltage to different external loads. An algorithm on each ASIC of the individual system of the individual battery cell enables the corresponding battery cell to assess how the individual battery cell can contribute to the power requirement or whether this is not reasonable in the current situation.

[0004] In other words, the above-mentioned tasks are solved by an energy storage having a housing, a first plurality of storage battery cells, a second plurality of storage battery cells, a first electrical connection assembly, a second electrical connection assembly and a switching device. The housing can be made of plastic, for example, in order to ensure acid resistance and insensitivity to corrosion. The storage battery cells of the first plurality of storage battery cells can be configured as power battery cells, energy battery cells, and alternatively or additionally as a mixture of the aforementioned battery cells, for example. To this end, the individual storage battery cells of the first plurality of storage battery cells can also be configured as supercapacitors, as are all the storage battery cells. The same applies to the second plurality of storage battery cells. In particular, the first plurality of storage battery cells can have storage battery cells of a different nature than the second plurality of storage battery cells. In particular, all the storage battery cells of the first plurality of storage battery cells have a different nature than the second plurality of storage battery cells (and / or vice versa). The first electrical connection assembly and the second electrical connection assembly can be provided for supplying an external load with electrical energy from the energy storage, i.e. from the storage battery cells. Here, the electrical load can be supplied with electrical energy by the first electrical connection assembly, in particular independently of the second electrical connection assembly. In particular, the first electrical connection assembly and the second electrical connection assembly are provided for outputting different voltages in that the first electrical connection assembly and the second electrical connection assembly are electrically connected to different pluralities of storage battery cells. To this end, the first plurality of storage battery cells can be connected to the first electrical connection assembly, while the second plurality of storage battery cells is connected to the second electrical connection assembly. Furthermore, the switching device is provided for electrically connecting the first plurality of storage battery cells to the second plurality of storage battery cells, optionally also. In this way, the energy, voltage and / or current strength of the storage battery cells can be output from the energy storage, optionally via the first electrical connection assembly, the second electrical connection assembly and / or not only by the first electrical connection assembly but also by the second electrical connection assembly. The switching device can be provided for operating depending on the operating state of the power machine or the corresponding means of transport to be supplied with electrical energy by the energy storage. In this way, the storage battery cells of the energy storage can be supplied with energy by different terminal voltage characteristics, which improves the use of the energy storage according to the invention compared to assemblies known from the prior art.

[0005] The dependent claims show preferred refinements of the invention.

[0006] The first and / or second joint assembly can have at least two electrical contacts, through which the electrical energy of the storage battery cells can be transmitted. That is, depending on the purpose of use or the mode of operation of the energy store, the electrical energy of the first plurality of storage battery cells can be transmitted to the second plurality of storage battery cells and / or output to a load arranged outside the housing by means of the corresponding electrical contacts. The electrical loading of the individual electrical contacts is achieved by means of the switching device of the energy store. In particular, the necessity of activating the switching device within the energy store according to the application is also analyzed. This increases the flexibility in the case of use of the energy store according to the application and saves a higher-ranking logic / control unit and the associated wiring outlay.

[0007] If reference is made to "energy battery cells" in the context of the present disclosure, this relates to a plurality of storage battery cells which are essentially set up for providing high energy. In other words, the storage battery cells referred to as energy battery cells have as high an energy capacity as possible. In contrast thereto, "power battery cells" refer to a plurality of storage battery cells which are essentially set up for outputting high electrical power. The maximum power output of the power battery cells can be significantly higher than the maximum power output of the aforementioned energy battery cells, in particular in comparison with their energy capacity. By using storage battery cells having different characteristics, the energy store according to the application can react to requests for providing electrical energy in a particularly suitable and flexible manner.

[0008] The switching device can be set up, for example, for electrically decoupling the first plurality of storage battery cells and the second plurality of storage battery cells from one another and for electrically connecting the first plurality of storage battery cells or the second plurality of storage battery cells to the first joint assembly in response to an energy supply request of a first (external) load. That is, the first load is electrically connected to the energy store via the first joint assembly and to the storage battery cells of the first plurality of storage battery cells contained in the energy store. At the same time, the first load can be electrically decoupled from the second plurality of storage battery cells, so that the second plurality of storage battery cells is not loaded by the first load and is freely available for supplying other external loads. In this way, compromises in the supply of electrical loads are not necessary, so that, for example, voltage-sensitive electrical loads can be supplied by means of a plurality of storage battery cells which are not loaded by further (for example, power-intensive) loads. As a result, the electrical characteristic variables of the first load can be met as well as possible by means of the first plurality of storage battery cells.

[0009] The switching device of the energy store according to the application can be configured to electrically connect the first load to the first plurality of storage battery units or to the second plurality of storage battery units depending on the rated voltage of the first load. In other words, the actual power consumption of the first electrical load can determine whether it is helpful for the switching device to electrically connect the first load to the second plurality of storage battery units and not to the first plurality of storage battery units or, alternatively, to electrically connect the first load not only to the first plurality of storage battery units but also to the second plurality of storage battery units. Alternatively, in the knowledge of the load to be powered by the energy store and its characteristic parameters, the switching device can already make a decision before the electrical energy is taken from the energy store whether the first load can be better supplied with electrical energy by the first plurality of storage battery units and / or by the second plurality of storage battery units. This decision can also be made in consideration of further loads currently supplied with energy by the electrical energy store or which should be supplied with energy by the electrical energy store in the future. In this way, the electrical energy to be supplied to the electrical load to be supplied can be supplied as well as possible and with as low conversion losses as possible by the storage battery units contained in the energy store.

[0010] According to the application, each storage battery unit can have an analysis and evaluation unit which is configured to decide, in response to a request and depending on its state of health and / or state of charge, whether it should be connected to the first electrical connection assembly and / or to the second electrical connection assembly. The "analysis and evaluation unit" can be understood as the "intelligence" of the respective storage battery unit, so that there are a plurality of intelligent storage battery units within the energy store according to the application. These intelligent storage battery units can form a "swarm intelligence". In this way, the signaling requirements within the energy store configured according to the application can be reduced. In particular, data communication lines between the storage battery units can be dispensed with in that each storage battery unit has a respective analysis and evaluation unit. The analysis and evaluation unit can have a communication unit or be connected to such a communication unit in an information-technical manner. In particular, the communication unit can be contained in each storage battery unit in correspondence with the analysis and evaluation unit. Furthermore, the respective sensor unit within the storage battery unit can be coupled to the analysis and evaluation unit in an information-technical manner. In this way, the storage battery unit can monitor its effective power, its state of charge and its state of health as well as possible and independently decide, depending on the aforementioned parameters, whether it participates in the energy supply to an external load. With this modularity, the energy store according to the application can also be maintained flexibly, since only the electrical connection between the old storage battery unit and the replaced / additionally added storage battery unit has to be connected, while the communication with the higher-ranking, possibly more distant analysis and evaluation unit is cancelled.

[0011] When the storage battery units of the energy store according to the application have a respective analysis evaluation unit (and optionally a respective communication unit), the analysis evaluation unit can be set up to decide, in response to the additional electrical connection of further storage battery units to the first electrical connection assembly, whether the analysis evaluation unit is connected to the first electrical connection assembly. In other words, the storage battery unit can (for example by means of its own electrical sensor device) ascertain the switching process and, in response thereto, decide anew whether it is reasonable for the storage battery unit to participate in the energy supply to the electrical load in the present case. In other words, the storage battery unit, by means of its analysis evaluation unit, can make the decentralized decision in the composite structure of the energy store according to the application as to whether the storage battery unit is electrically connected to further storage battery units and / or to an external electrical load by means of the switching device of the energy store.

[0012] The sensor device mentioned above, which is optionally provided in each storage battery unit or at least in a single storage battery unit, can have a temperature sensor and, alternatively or additionally, a voltage sensor (in particular an under-voltage sensor) and, alternatively or additionally, a sensor / counter for ascertaining the number of cycles of the storage battery unit and, alternatively or additionally, a current sensor for measuring the battery unit current of the storage battery unit. Alternatively or additionally, the sensor device can carry out a battery unit spectroscopy of the storage battery unit in such a way that the sensor device electrically loads the storage battery unit in a predefined manner and ascertains the reaction of the storage battery unit from the loading in accordance with a predefined reference. From the ascertained result, the state of health and / or the battery cell chemistry can be inferred.

[0013] The energy store according to the application can be provided, for example, in an electrically drivable means of transport. Alternatively or additionally, the electrical energy store can be provided in a work machine and / or for supporting an island network. The above-mentioned features, feature combinations and advantages are derived in a corresponding manner for these and other use purposes, so that, in order to avoid repetition, reference is made in this regard to the above-mentioned embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0014] Embodiments of the application are described in detail below with reference to the accompanying drawings. In the drawings:

[0015] Figure 1 a schematic diagram showing an embodiment of an energy store according to the application, and

[0016] Figure 2 a schematic diagram showing a detailed embodiment of a switching device according to the application in the form of a switching matrix. DETAILED DESCRIPTION

[0017] Figure 1An embodiment of the energy storage device 1 according to the invention is shown, wherein two electrical connector assemblies 8 and 9 are connected to a first electrical load 11 and a second electrical load 12 on the housing 2 of the energy storage device. An optional communication bus line 15 connects the loads 11 and 12 to battery cell modules 20a, 20b, 20c, and 20d arranged within the housing 2. Battery cell module 20a is configured as a power battery cell. The storage battery cells 3a and 3b of this battery cell module can output electrical power relatively high compared to the storage capacity of the storage battery cells. Conversely, the energy battery cells 4a and 4b of battery cell module 20b can store a large amount of energy compared to the maximum power that the energy battery cells can output. The supercapacitors 5a and 5b of battery cell module 20c are configured to output extremely high power for short periods of time with particularly low electrical losses and small capacity. Furthermore, battery cell module 20d is provided with shunts 6a and 6b, which provide a flexible possibility for converting (“eliminating”) electrical energy within the energy storage device 1 according to the invention. The switching device 13 of the battery cell modules 20a to 20d enables the ASIC 7, which serves as an analysis and evaluation unit, to electrically connect the power battery cells 3a and 3b, the energy battery cells 4a and 4b, the supercapacitors 5a and 5b, and the shunts 6a and 6b to the central switching device 10. In this way, the combined... Figure 2 The switching device 10, which is discussed in detail, can flexibly utilize the energy of battery cell modules 20a to 20d or the shunt to supply electrical energy to external loads 11 and 12 via electrical connector assemblies 8 and 9. Sensors 14 within battery cell modules 20a to 20d can monitor the voltage or temperature and the current flowing through them. Furthermore, the storage battery cells 3a, 3b, 4a, 4b, 5a, and 5b can be checked for undervoltage, cycle count, and battery cell chemistry (e.g., by means of battery cell spectroscopy analysis) using their respective sensors 14. Through the communication bus 15, the ASIC 7 of each battery cell module 20a to 20d can obtain information about the current or expected operating status of the external loads 11 and 12, or communicate with them. The ASIC 7 of each battery cell module 20a to 20d can store information about the status of the battery cell modules 20a to 20d and the communications to date. In addition, ASIC7 can store information about battery cell configuration files and battery characteristic models for battery cell modules 20a to 20d.

[0018] Figure 2 This illustrates one possible implementation of the energy storage device 1 according to the invention, which corresponds to... Figure 1The battery has a plurality of battery cell modules 20a and 20b and a switch device 10 in the form of a switch matrix, which is shown in detail. A first plurality of storage battery cells can be bridged within the battery cell modules 20a or 20b by means of corresponding switches S. The electrical contacts 8a, 8b or 9a, 9b of the arrangement of electrical connection elements 8, 9 outside the housing (not shown) can be flexibly electrically connected to any number of battery cell modules 20a, 20b by means of a plurality of switches arranged in the switch device 10 and thus flexibly supplied with energy by means of a suitable plurality of storage battery cells.

[0019] In other words, Figure 2 A possible implementation of the dynamic connection of battery cells on a battery string is shown. Here, each battery cell controls the switches assigned to it. A string represents the switches shown one above the other in the switch device 10. The battery cells of the battery cell modules 20a, 20b can be dynamically hooked into these switches. If none of the battery cell modules 20a, 20b decides to electrically access the corresponding string, the short-circuit switch S is automatically closed. Here, the string can generate different voltages by means of different storage battery cells. Feedback via a common bus (see Figure 1 ) enables each battery cell module 20a, 20b to make a decision taking into account the decisions of the other battery cell modules.

[0020] By means of the invention, decentralized regulation of the energy flow of the energy store in combination with the surroundings of the energy store is made possible. In this way, the advantages of an optimized matching between energy provision (energy store side) and energy consumption (load side) can be realized without large central switches, battery management systems, etc. Each energy flow is dynamically switched and takes into account the current state of the battery cells and the load. As a result, not only the service life of the energy store is improved, but also the efficiency of the entire system is optimized.

[0021] All battery cells can be operated at an optimized operating point by means of the above-described structure. The battery cell load can depend on the current effective power of the battery cells. In the entire system with active battery packs, central components such as inverters, ECUs, battery management systems (BMS), DC-DC converters, etc. are dispensed with. New systems and system configurations can be combined very simply. In particular, new vehicle types or on-board power grid requirements can be met flexibly and quickly. The system is highly flexible, for example, when expanding the capacity, when removing individual battery cells, in the case of maintenance, in the case of intercepting a fault, etc.

[0022] Furthermore, the failure of an individual battery cell no longer leads to the failure of the entire system, since individual battery cells can be bridged. Thermal runaways, for example in the event of mechanical damage, of individual battery cells can be intercepted in such a way that other battery cells, dividers and loads are dynamically connected. Individual (weak) battery cells can be identified and replaced individually. With a single switch, it is possible to ensure at all times that there is no voltage during repair work. Charging energy can be optimally distributed to the battery cells: battery cells that are less charged can receive more energy, and the total charge of the battery pack is thus increased more quickly, thereby shortening the charging time. The range can be increased by efficiently using the stored energy in a mix of energy battery cells, power battery cells and supercapacitor battery cells at the respective optimum operating point. The lower load on cycled battery cells in relation to critical battery cells due to deep discharges, which occurs when operating at the optimum operating point of each battery cell, can be ruled out. As a result, the service life of the energy store can be significantly increased.

Claims

1. Energy storage (1) comprising: - a housing (2), - a first plurality of storage battery cells (3a, 3b), - a second plurality of storage battery cells (4a, 4b), - a first electrical terminal assembly (8), - a second electrical terminal assembly (9), and - a switching device (10) in the form of a switch matrix, which is arranged for - connecting the first plurality of storage battery cells (3a, 3b) with the first electrical terminal assembly (8), - connecting the second plurality of storage battery cells (4a, 4b) with the second electrical terminal assembly (9), and / or - connecting the first plurality of storage battery cells (3a, 3b) with the second plurality of storage battery cells (4a, 4b), so that the switching device - can supply an electrical load with electrical energy via the first electrical terminal assembly (8) independently of the second electrical terminal assembly (9), and - can connect the first plurality of storage battery cells (3a, 3b) with the first electrical terminal assembly (8) and the second plurality of storage battery cells (4a, 4b) with the second electrical terminal assembly (9), wherein the electrical contacts (8a, 8b, 9a, 9b) of the first and second electrical terminal assemblies (8, 9), which are arranged externally on the housing (2), can be flexibly electrically connected to any number of the storage battery cells (3a, 3b, 4a, 4b) by means of a plurality of switches arranged in the switching device (10) and thus flexibly supplied with energy by means of a suitable plurality of storage battery cells.

2. The energy store (1) according to claim 1, wherein The first electrical terminal assembly (8) and the second electrical terminal assembly (9) each have at least two electrical contacts (8a, 8b, 9a, 9b) via which the electrical energy of the storage battery cells (3a, 3b, 4a, 4b, 5a, 5b) can be transmitted.

3. Energy storage (1) according to claim 1 or 2, wherein - the first electrical terminal assembly (8), and - the second electrical terminal assembly (9) are arranged externally on the housing (2).

4. The energy store (1) according to claim 1 or 2, wherein The first plurality of storage battery cells (3a, 3b) comprises a plurality of energy battery cells and / or the second plurality of storage battery cells (4a, 4b) comprises a plurality of power battery cells.

5. The energy store (1) according to claim 1 or 2, wherein The switching device (10) is arranged for, in response to an energy supply request of a first load (11), - electrically decoupling the first plurality of storage battery cells (3a, 3b) and the second plurality of storage battery cells (4a, 4b) from one another, and - electrically connecting the first plurality of storage battery cells (3a, 3b) or the second plurality of storage battery cells (4a, 4b) with the first electrical terminal assembly (8).

6. The energy store (1) according to claim 1 or 2, wherein The switching device (10) is arranged for, in response to an energy supply request of a first load (11) and a second load (12), - electrically decoupling the first plurality of storage battery cells (3a, 3b) and the second plurality of storage battery cells (4a, 4b) from one another, and - electrically connecting the first plurality of storage battery cells (3a, 3b) with the first electrical terminal assembly (8), and - electrically connecting the second plurality of storage battery cells (4a, 4b) with the second electrical terminal assembly (9). - electrically connecting the second plurality of storage battery units (4a, 4b) with the second electrical connection assembly (9).

7. The energy store (1) according to claim 5, wherein The switching device (10) is arranged for electrically connecting the first load (11) with the first plurality of storage battery units (3a, 3b) or with the second plurality of storage battery units (4a, 4b) depending on the rated voltage of the first load.

8. The energy store (1) according to claim 1 or 2, wherein Each storage battery unit (3a, 3b, 4a, 4b) has an analysis evaluation unit (7) which is arranged for deciding, in response to a request and depending on its state of health and / or state of charge, whether the analysis evaluation unit is connected with the first electrical connection assembly (8) and / or with the second electrical connection assembly (9).

9. The energy store (1) according to claim 1 or 2, wherein Each storage battery unit (3a, 3b, 4a, 4b) has an analysis evaluation unit (7) which is arranged for deciding, in response to other storage battery units (3a, 3b, 4a, 4b) being electrically additionally switched on to the first electrical connection assembly (8), whether the analysis evaluation unit is connected with the first electrical connection assembly (8).

10. The energy store (1) according to claim 1 or 2, wherein Each storage battery unit (3a, 3b, 4a, 4b) has a sensor device (14) which is arranged for - measuring the temperature of the storage battery unit (3a, 3b, 4a, 4b) and / or - the under-voltage and / or - the number of cycles and / or - the battery unit current, and / or - carrying out a battery unit spectroscopy of the storage battery unit (3a, 3b, 4a, 4b).

11. The energy store (1) as claimed in claim 4, wherein The first plurality of storage battery units (3a, 3b) consists of energy battery units and / or the second plurality of storage battery units (4a, 4b) consists of power battery units.

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