DE102015225441A1 - Energy storage cell compensation system for a high-voltage accumulator arranged in a vehicle - Google Patents

Abstract

The present invention relates to an energy storage cell compensation system for a high-voltage accumulator (26) arranged in a vehicle (10). The high-voltage memory (26) has a plurality of energy storage modules (32, 32 '), each having a number of energy storage cells (40, 40'). The vehicle (10) has an electric machine (16) for driving driven wheels (12) of the vehicle (10). For this purpose, the high-voltage storage (26) provides the required electrical energy. The energy storage cell balancing system includes: an energy exchange system (42) to facilitate an exchange of electrical energy between individual energy storage modules (32, 32 '); a connection production system (53) for at least one energy storage module (32, 32 ') to connect at least one energy storage cell (40, 40') contained therein to the energy exchange system (42); and a control unit (52) with which, for at least two energy storage cells (40, 40 '), in each case a charge state variable representing the actual state of charge is determined. As a function of this state of charge state, it is determined whether the respective energy storage cell (40, 40 ') is a receiving energy storage cell (40') that can absorb electrical energy or is a dispensing energy storage cell (40) that emits electrical energy can. The control unit (52) is further configured to determine whether a defined memory operating state is present in which at least one emitting energy storage cell (40) in a first energy storage module (32) and at least one receiving energy storage cell (40 ') in a second energy storage module (32'. ) is arranged, and in the presence of this defined storage operating state, the connection production system (53) to control such that an energy exchange between the donating energy storage cell (40) and the receiving energy storage cell (40 ') can take place.

Description

The invention relates to an energy storage cell compensation system for a vehicle disposed in a high-voltage storage. Likewise, the invention relates to a correspondingly designed high-voltage storage, a correspondingly designed energy storage module, and an associated method for performing a corresponding energy storage cell compensation.

The high-voltage storage device, in which the energy storage cell compensation system according to the invention is used, has a multiplicity of structurally autonomously designed energy storage modules, which in turn each have a number of energy storage cells. The high-voltage storage is configured to drive a vehicle-mounted electrical machine configured to drive powered wheels of the vehicle to provide the electrical energy needed therefor.

A high-voltage battery, which is also referred to as a traction battery, may have a voltage level of more than 250 volts, although there are certainly applications in which the voltage level is significantly higher. This voltage level is achieved in that, on the one hand, the energy storage cells contained in the energy storage modules are connected in series with one another, and, on the other hand, the energy storage modules themselves are also connected in series with one another. The energy storage cells can be rechargeable, in particular as lithium-ion storage cells.

 The vehicle may be a hybrid vehicle or an electric vehicle. In a hybrid vehicle in addition to the electric machine another unit is used for the drive, usually an internal combustion engine. Whereas an electric vehicle is driven exclusively by an electric machine.

The electrical machine used is usually designed as an internal rotor machine, in which a rotatably mounted rotor is enclosed by a stationary stator. The stator has a number of windings which are designed to generate an alternating magnetic field acting on the rotor, as a result of which the rotor carries out a rotary movement. As a rule, such an electric machine has three phases. To generate the alternating magnetic field, these three phases can be connected to the high-voltage accumulator via a power electronics which can be controlled by a drive unit, more precisely via an inverter or converter. The electric machine can be constructed as a synchronous machine, in particular as a hybrid synchronous machine.

As already mentioned, a high-voltage memory is made up of a plurality of series-connected energy storage cells, which usually have slight variations in their cell parameters. Cause of variations in the individual cell parameters may be extrinsic as well as intrinsic factors. Here, intrinsic factors are those resulting from manufacturing tolerances in the manufacturing process. By contrast, extrinsic factors are, for example, uneven thermal and cyclic loads independent of the cell parameters. If necessary, these factors lead to deviations between the energy storage cells and thus significantly influence the asymmetry of a high-voltage storage device during its entire service life.

 For example, cause different internal resistances and / or Kon taktierungswiderstände and / or cell capacity of the individual energy storage cells that over the life of a high-voltage storage device in this creates a charge asymmetry. As a result of this asymmetry, the individual energy storage cells reach their voltage limits, which are valid during operation, at different speeds. Due to the principle, a high-voltage accumulator can be removed only up to a lower discharge level electrical energy. In this case, for safety reasons, a further discharge of all energy storage cells contained in a high-voltage storage must be prevented (avoidance of a deep discharge) as soon as one of the energy storage cells reaches its minimum permissible cell voltage (discharge end voltage). This leads to an unused residual charge in the high-voltage storage. In a corresponding manner, a high-voltage accumulator can be supplied with electrical energy only up to an upper charge level. Consequently, during a charging process, the further charging of all energy storage cells is prevented (avoidance of overcharging) as soon as one of the energy storage cells reaches its maximum permissible cell voltage (charge end voltage). In both cases, the decreasing convertible electrical energy in the high-voltage accumulator ultimately leads to losses in the achievable range in electric driving range. Due to the fact that in the energy storage cells with their increasing age, the differences in the storage capacity of the individual energy storage cells are larger, thus increases with increasing age of the high-voltage storage and its unused amount of residual charge.

To counteract the above-mentioned, expected in the operation of a high-voltage memory impairments and the energy consumption and the life of a high-voltage storage To maximize, measures are taken to balance the energy storage cells contained in a high-voltage storage with respect to the electrical energy stored in them. That is, measures are taken to compensate for the differences in the capacities of the individual energy storage cells, and with which stored in a high-voltage storage total stored electrical energy better on the individual energy storage cells according to their respective structural and the Be adjusting operation Circumstances should be divided.

So far, dissipative systems and non-dissipative systems have been used for this purpose. In dissipative systems, the excess energy contained in a high-voltage battery is converted to heat, i. For example, of the most fully charged energy storage cells, the excess charge is converted to heat at appropriately sized resistors. As a result, the respective cell voltage is adjusted to the lowest cell voltage present in the high-voltage accumulator for all energy storage cells. By means of the dissipative balancing, it is thus prevented that the "weakest" energy storage cells prematurely reach their respective charge end voltage. Although this allows the capacity of these energy storage cells to be fully utilized, the additional capacity of the remaining energy storage cells is lost. By means of a non-dissipative system it can be achieved that the total electrical energy stored in a high-voltage accumulator is distributed optimally to the individual energy storage cells contained in the high-voltage accumulator. That The excess electrical energy is not converted into heat here, but redistributed between the individual energy storage cells.

Even if non-dissipative energy storage cell compensation systems have a decisive advantage over dissipative energy storage cell compensation systems, namely that during balancing the existing in the high-voltage accumulator excess electrical energy is not converted into heat and this is therefore still available for the driving of a vehicle, and thus it offers to use non-dissipative systems in a vehicle rather than dissipative systems, non-dissipative systems are not yet optimal.

 It is therefore an object of the present invention to provide a non-dissipative energy storage cell equalization system that is inexpensive to implement, and reliable and efficient in driving operation that is improved in range that is achievable in driving using the high-voltage memory. and which at the same time is uncomplicated with regard to the compensation of electrical energy to be implemented concretely, and in so doing allows maximum flexibility as to which said units within a high-voltage storage can take place.

This object is achieved by an energy storage cell compensation system of the type mentioned at the outset, which has the following components: an energy exchange system which is designed to facilitate an exchange of electrical energy between individual energy storage modules allow a connection manufacturing system, which is designed to connect at least one energy storage cell contained in this energy storage cell with the energy exchange system, and a control unit, which is adapted for at least two energy storage cells to the actual state of charge of the respective energy storage cell representing state of charge determine, and determine depending on this state of charge size, whether it is the respective energy storage cell is a receiving energy storage cell that can absorb electrical energy due to their actual state of charge, or is a donating energy storage cell that emit stored electrical energy due to their actual state of charge can, wherein the control unit is further adapted to determine whether a defined memory operating state exists, in which at least one emitting energy storage cell in a first energy storage module and at least one receiving energy storage cell is arranged in a second energy storage module, wherein the first and the second energy storage module are different energy storage modules, and in front of this defined storage operating state, the connection production system is such that an energy exchange between the at least one dispensing system and the at least one receiving energy storage cell can take place.

• – Ermitteln einer den Ist-Ladezustand der jeweiligen Energiespeicherzelle repräsentierenden Ladezustandsgröße für zumindest zwei Energiespeicherzellen,
• – Feststellen in Abhängigkeit der Ladezustandsgröße, ob es sich bei der jeweiligen Energiespeicherzelle um eine aufnehmende Energiespeicherzelle handelt, die aufgrund ihres Ist-Ladezustands elektrische Energie aufnehmen kann, oder um eine abgebende Energiespeicherzelle handelt, die aufgrund ihres Ist-Ladezustands gespeicherte elektrische Energie abgeben kann,
• – Feststellen, ob ein definierter Speicherbetriebszustand vorliegt, bei dem zumindest eine abgebende Energiespeicherzelle in einem ersten Energiespeichermodul und zumindest eine aufnehmende Energiespeicherzelle in einem zweiten Energiespeichermodul an geordnet ist, wobei es sich bei dem ersten und dem zweiten Energiespeichermodul um unterschiedliche Energiespeichermodule handelt, und
• – Ansteuern des Verbindungsherstellungssystems bei Vorliegen des definierten Speicherbetriebszustands derart, dass ein Energieaustausch zwischen der zumindest einen abgebenden und der zumindest einen aufnehmenden Energiespeicherzelle erfolgen kann.

The object is further achieved by a method for carrying out an energy storage cell compensation for a vehicle arranged in a high-voltage storage, the high-voltage storage having a plurality of structurally autonomous running energy storage modules, each having a number of energy storage cells, the vehicle having an electric machine, the is configured to drive driven wheels of the vehicle, wherein the high-voltage storage is adapted to provide the electric machine, the required electrical energy, wherein the high-voltage storage further comprises an energy exchange system, which is adapted to allow an exchange of electrical energy between individual energy storage modules a connection production system, which is designed to verb for at least one energy storage module at least one contained in this energy storage cell with the energy exchange system verb inden, and a control unit adapted to carry out the following steps:

• Determining a charge state variable representing the actual charge state of the respective energy storage cell for at least two energy storage cells,
• Detecting as a function of the state of charge state whether the respective energy storage cell is a receiving energy storage cell which can absorb electrical energy on account of its actual state of charge, or is a dispensing energy storage cell which can emit stored electrical energy due to its actual state of charge,
• - Determining whether a defined memory operating state is present, in which at least one emitting energy storage cell in a first energy storage module and at least one receiving energy storage cell in a second energy storage module is arranged, wherein it is the first and the second energy storage module to different energy storage modules, and
• - Driving the connection manufacturing system in the presence of the defined memory operating state such that an energy exchange between the at least one emitting and the at least one receiving energy storage cell can take place.

The energy storage cell compensation system according to the invention or the method according to the invention operate across modules, i. the charge balance or the energy transfer energy storage module is performed or made across the individual energy storage cells. This modular concept, in which an energy balance or an energy exchange between at least one individual donating energy storage cell, which is contained in a first and thus donating energy storage module, and at least one receiving energy storage cell, which is included in a second and thus receiving energy storage module, offers numerous advantages , Thus, this concept allows a very great flexibility, namely, between which units of a high-voltage storage, an energy balance or an energy exchange is performed. And in two ways. On the one hand, an energy balance or energy exchange between individual energy storage cells can be made, which are arranged in different energy storage modules. On the other hand, both the number of emitting and the number of receiving energy storage cells are arbitrary, i. It can be a balance or exchange between individual energy storage cells take place or between a single energy storage cell and a network of energy storage cells, wherein in the case of the composite, it is also conceivable that belonging to the composite energy storage cells may be included in different energy storage modules.

Another advantage over systems where energy balancing or energy exchange is first within one and the same energy storage module, i. initially for the energy storage cell itself contained in an energy storage module, and then made only in a subsequent step between the individual energy storage modules, is that with the inventive cross-module concept, a much greater efficiency can be achieved. This is due to the fact that an energy balance or energy exchange can be performed directly between the energy storage cells contained in different energy storage modules, thus the energy or charge quantities to be exchanged or transferred are much smaller than would be the case if the compensation or Exchange between the energy storage modules would be performed. The lower amount of energy or charge to be exchanged also leads to fewer losses when carrying out the energy exchange or energy compensation. Thus, in comparison with the known systems when driving the vehicle, a larger amount of energy is available, which is why a greater range can be achieved.

Furthermore, the cross-module concept means that much less time is required to carry out the energy balance or energy exchange. First, it is not necessary to first, i. upstream and thus in a first step for the energy storage cells contained in an energy storage cell to carry out a compensation or replacement, and then perform a compensation or exchange in a second step for the energy storage modules as such. This also results in a time advantage that between the individual energy storage cells much smaller amounts of energy or charge are exchanged or to be transferred, as between the energy storage modules. The cost of performing an energy balance or an energy exchange is thus much lower, which also leads to greater reliability during driving.

In addition, because of the much smaller amount to be exchanged electrical energy or electrical charge, the individual components, in particular those on the directly to be distributed electrical energy or electric charge is transferred, less powerful, that must be designed for lower power. Thus, lower cost components can be used.

With the energy storage cell compensation system according to the invention, the energy content of a high-voltage storage device can always be optimally utilized over its service life. Furthermore, a disproportionate aging is prevented for those energy storage cells which have a lower storage capacity compared to the other energy storage cells installed in a high-voltage storage cell. As a result, the total life of the high-voltage storage increases and the expenses for otherwise possibly to be performed warranty and goodwill measures are reduced.

The above object is therefore completely solved.

Before discussing further advantageous embodiments of the energy storage cell compensation system, the fundamental structure of a structurally self-constructed energy storage module will first be described here. Such an energy storage module should contain a number of energy storage cells, which are stacked to at least one row, arranged one behind the other, and are clamped together by means of two end plates and suitable tension elements, preferably tie rods. Furthermore, the energy storage module should contain the following additional components: Isolation components for the insulation of the energy storage cells with respect to the preferably made of a metallic material Endplat th or tension elements. Wärmeleitkomponenten to allow a good removal of heat generated during operation of the energy storage cells heat to a cooling device. Contacting components with which the individual energy storage cells are contacted with each other for the realization of a series connection. Electronic components for carrying out control and monitoring functions.

Advantageously, a state of charge state is determined for all energy storage cells contained in the high-voltage storage, and thus determined for each energy storage cell, whether it is a donating or a receiving energy storage cell. Thus, a complete charge or energy balance can be made for the high-voltage storage and a maximum range increase can be achieved.

In a preferred embodiment of the invention, the energy exchange system is designed as a bus system. The use of a bus system has the advantage that a system for exchanging or balancing or for the transmission of energy or charge is available, in which this is possible between several components, in this case energy storage modules and thus energy storage cells which are connected to a common transmission infrastructure in which the individual components are not involved in the exchange or balancing or transfer between other components, ie the energy storage modules are not part of the transmission path over which energy or charge is exchanged between at least two other energy storage modules. As a result, the greatest possible flexibility or compatibility is ensured, which leads to the energy storage cell compensation system according to the invention being used for differently configured high-voltage memories, i. for high-voltage storage, which may contain a different number of energy storage modules. The bus system is preferably a bus system designed according to the "EnergyBus" standard. This has the advantage that a standardized component can be used, which on the one hand leads to high reliability during driving and on the other hand causes low costs in the realization of the energy storage cell compensation system. In addition, with such a bus system at the same time an energy or charge transfer on the one hand and, if required, a communication transfer on the other hand between individual components connected to the bus system, ie energy storage modules or energy storage cells possible. Advantageously, a bus system implemented in this way has specifications for the voltage (up to 48 V) and current (up to 40 A) that are compatible with the conditions that apply to energy storage modules that are installed in a motor vehicle high-voltage storage, or for the low-voltage vehicle electrical system contained in a motor vehicle apply. Preferably, the bus system should be designed for a voltage which is in a lower range of the aforementioned voltage range, for example for a voltage of the order of 12 V and for a current in the range of a few amperes, for example of the order of 10 A or even at slightly higher values. The numerical values previously given for the current are not intended to have a limiting effect on the current flowing in an energy storage module taking place during energy equalization; this should preferably be about 1 A

In a further preferred embodiment of the invention, the individual energy storage modules are connected to one another via line components, at least for the realization of a series connection, wherein the line components are structurally independent of the energy exchange system. This measure has the advantage That two structurally independent units are used, which makes it possible to optimally adapt each of these two units to their respective application. Consequently, the line components can be optimally designed for the high-voltage application to be satisfied, while the bus system, as described above, can be designed for a low-voltage application. In addition, this measure offers the advantage that both applications, namely the energy or charge exchange between individual energy storage cells on the one hand, and the supply of the electrical machine with electrical energy, on the other hand, can proceed independently of each other.

In a further advantageous embodiment of the invention, the connection production system has a plurality of connection modules, wherein each energy storage module is assigned in each case a connection module. That the connection establishment system has as many connection modules as the high-voltage storage contains energy storage modules. Each energy storage module contains a connection module. This is a measure that consequently promotes or supports the approach that is based on the use of a bus system for the energy exchange system, namely to realize the most flexible possible structure of the energy storage cell equalization system that can be used for a large number of high-voltage storage.

In an advantageous embodiment of the aforementioned measure, the connection modules each have a transducer element and a switching element arrangement. The transducer element allows a voltage adjustment, which is required, for example, when an energy or charge balance between a single energy storage cell and a network of energy storage cells to be made. Under certain circumstances, such a composite may be all energy storage cells contained in an energy storage module. The switching element arrangement enables the targeted selection of a single energy storage cell. Thus, the flexibility is ensured, which is necessary in order to be able to balance between any energy storage cells or energy storage modules within a high-voltage storage. Preferably, all connection modules contained in the high-voltage memory are functionally identical, i. In each energy storage module, a transducer element and a switching element arrangement is contained.

 Consequently, the converter element is designed as a multi-winding transformer having a primary winding and a number of secondary windings, the primary winding being structurally associated with the energy exchange system and the secondary windings structurally associated with the energy storage cells. Preferably, the multi-winding transformer has a number of secondary windings which corresponds to the number of the number of energy storage cells contained in the energy storage module. In a correspondingly consistent manner, the switching element arrangement has a number of secondary-side switching elements, wherein each of the secondary-side switching elements is assigned to a secondary network comprising an energy storage cell and a secondary winding such that the secondary winding and the energy storage cell form a secondary-side energy flow path when the secondary-side switching element is closed. Such a secondary-side energy flow path is cell-related, i. associated with a single energy storage cell. With a transducer element designed in this way, it is possible to connect each of the energy storage cells contained in an energy storage module with the energy exchange system. Thus, for each of the energy storage cells contained in an energy storage module, a charge or an energy balance can be performed. Instead of a multi-winding transformer, a bidirectional DC / DC converter can also be used, in particular a so-called buck-boost converter.

Advantageously, the connection modules further each have a capacitor which is connected in parallel with the respective primary winding. This measure allows the exchange of energy or charge from one energy storage cell to another energy storage cell, since the capacitor allows buffering of the electrical energy or charge that was taken from the donating energy storage cell.

 This measure also contributes to enable the flexibility that is required to the extent that an exchange of electrical energy or charge between individual energy storage cells with each other and between rule energy storage cells and a plurality of Energiespeicherzel len existing composite should be possible.

Advantageously, the connection modules further each have a primary-side switching element, which is associated with the respective primary winding such that when the primary-side switching element is closed, a primary-side energy flow path consisting of the primary winding and the capacitor is formed. Through this primary-side, module-related energy flow path, an energy storage module can deliver or receive electrical energy or charge to the energy exchange system, whereby an exchange or a balance between the energy storage modules and thus between the energy storage cells contained in these modules is possible.

In a further advantageous embodiment of the invention, a further energy store is present in the vehicle, which is connected to the energy exchange system, wherein the control unit is further adapted to control the connection manufacturing system such that at least one of the receiving energy storage cells and / or at least one of the donating energy storage cells is connected to the further energy storage to allow an energy exchange between the respective energy storage cell and the further energy storage. This measure makes it possible for an energy storage cell contained in a high-voltage storage unit to be charged or discharged without having to carry out charge redistribution within the high-voltage storage unit at the same time. It can thus be achieved without a charge redistribution between individual energy storage cells, a charge or energy balance. Preferably, the further energy storage is designed as a low-voltage storage, the voltage level is in the area of the electrical system voltage. Preferably, the further energy storage can be constructed by means of so-called supercapacitors.

In a further embodiment of the invention, the control unit is further configured to determine whether a charging mode is present, in which electrical energy is supplied to the high-voltage storage, wherein the control unit is further adapted to at least temporarily control the connection production system during a present loading operating state, at least supplying an individualized amount of electrical energy to one of the receiving energy storage cells. This measure also contributes to the flexibility required for the energy storage cell balancing system. The charging operating state can be a charging process taking place in-vehicle, as occurs, for example, during recuperation. However, it may also be a charging process, in which the high-voltage storage is supplied by an external energy source, such as the public power grid, electrical energy. Preferably, the procedure should be such that electrical energy is supplied to the high-voltage accumulator as a whole during a charging process and charge equalization is already carried out between the individual energy storage cells during the charging process.

In a further advantageous embodiment of the invention, the control unit is further configured to determine whether there is a removal operating state in which electrical energy is taken from the high-voltage accumulator, wherein the control unit is further configured to control the connection production system at least in a secondary manner during a present removal operating state at least one of the donating energy storage cells to take an individualized amount of electrical energy. This measure also contributes to the flexibility required for the energy storage cell compensation system. A removal operating state may be present, for example, when the electrical machine with which the driven wheels are driven by the high-voltage memory-derived electrical energy is fed. With appropriate design of the energy exchange system Abnahmebetriebszu was also present when, for example, the electrical system or a built-in air conditioning system is supplied with electrical energy by the high-voltage storage. Preferably, the procedure should be such that, for example, during the feeding of the electric machine, the high-voltage accumulator as a whole is taken off electrical energy and a charge equalization takes place between the individual energy storage cells during the discharging process. This measure preferably takes place when the vehicle is being moved.

In a further advantageous embodiment of the invention, the control unit is further configured to perform an evaluation as a function of at least one energy storage cell, the operating state of the respective energy storage cell representing operating state variable and depending on an evaluation result thereby obtained, the energy exchange between the at least one dispensing and the to allow at least one receiving energy storage cell. By this measure, a criterion is created, depending on the implementation of the energy exchange can be controlled. Thus, it is ensured that an energy exchange is carried out as soon as there is a need, i. E. for the high-voltage storage an uneven charge distribution is present, but this is also terminated as soon as in the high-voltage storage a balanced charge distribution is given. It is also ensured that the energy exchange does not even begin when there is an unfavorable operating state for at least one energy storage cell. Thus, an optimal increase in achievable driving range is possible. Allowing an energy exchange should include starting, terminating, and continuing an already existing energy exchange. This should apply in a corresponding manner for subsequent versions, which also relate to the admission of the energy exchange gi.

In a preferred embodiment of the aforementioned measure, the operating state variable is the ascertained state of charge quantity, wherein the control unit is further configured to determine a currently present state of charge maximum value and a currently present state of charge value minimum value as a function of the charge state variables determined for the at least two energy storage cells, and allow the energy exchange when a difference given between the state of charge minimum value and the state of charge maximum value is equal to or greater than a predetermined difference threshold. By using the state of charge magnitude as the operating state quantity, a very meaningful criterion can be created with which the performance of an energy exchange can be controlled, thus creating a particularly reliable energy storage cell compensation system. The determination of a maximum charge state variable value and a minimum state of charge magnitude value and the evaluation of a difference between these two values is a particularly reliable criterion for determining whether there is an uneven charge distribution for a high-voltage storage device and thus charge or energy equalization. For as soon as during operation of a high-voltage memory for at least two energy storage cells, the deviation between the two state of charge variables is greater than a predetermined threshold, this is a sign of an asymmetrical charge distribution, which is why a charge or energy balance is performed.

If the operating state variable is the determined state of charge magnitude, the control unit is advantageously further configured to determine for at least one energy storage cell whether determined state of charge magnitude values lie within a state of charge window defined by a lower state of charge limit and an upper state of charge limit, and to allow the energy exchange, as long as the state of charge magnitude values are within the state of charge operating window. Advantageously, such a charge state operating window based on an energy storage cell charge state variable is provided for each of the energy storage cells and thus such monitoring is performed for each of the energy storage cells. Preferably, both the lower state of charge limit and the upper state of charge limit are each a defined percentage of the current or nominal energy storage cell state of charge magnitude value. Thus, a lower limit is defined, which specifies that a compensation can be made as long as this limit is not exceeded. Accordingly, an upper limit is defined. Thus, a lower limit for the discharge process and an upper limit for the charging process are defined, which ensures that in the case of charging or energy equalization both over-discharge and over-charging of individual energy storage cells and thus lasting impairment of their storage capacity is avoided. Consequently, this measure ensures a particularly high level of reliability of the energy storage cell compensation system during driving operation and makes it possible to achieve the greatest possible range when driving the vehicle.

In a further advantageous embodiment of the invention, the control unit is further configured to evaluate for at least one energy storage cell representing the energy storage cell temperature temperature variable, and to allow the energy exchange depending on an evaluation result obtained thereby. This measure also contributes to the fact that the energy storage cell compensation system according to the invention, particularly when driving, operates particularly reliably. Finally, it can be avoided that overheating and thus failure or disconnection of the high-voltage accumulator occurs in the event of charge or energy compensation. Likewise, a lasting effect on individual energy storage cells is prevented, thus allowing the greatest possible range during driving.

In a further advantageous embodiment of the invention, the control unit is further configured to repeatedly determine the respective state of charge quantities at successive times for the at least two energy storage cells and to determine whether it is a donating or receiving energy storage cell, wherein the statement that it is a donor or a receiving energy storage cell is maintained for the respective energy storage cell, as long as for the respective associated state of charge state, a predetermined condition is met. Characterized in that the determination of the state of charge variables and determining whether it is donating or receiving energy storage cells is carried out at successive times and thus repeatedly, a continuous monitoring of individual energy storage cells and thus the high-voltage memory is given and thus at any time during operation of the high-voltage memory performing a charge or energy exchange between individual energy storage cells possible. The measure that the determination made for an energy storage cell, whether it is a donor cell or a receiving energy storage cell, is maintained as long as the predetermined condition is met, ensures that the assignment of a Energy storage cell to one of the two categories receiving or donating energy storage cell is maintained for a longer period, and not immediately with the onset of charge or energy exchange made a new assignment and thus take place many changes in the assignment of those energy storage cells, between which the charge or Energy balance is made. Thus, a continuous or even-running compensation is possible. Although it can be done at any time advantageously determining and evaluating the state of charge variables, but it must not necessarily be done at any time a change in the energy storage cell allocation.

 In a further advantageous embodiment of the invention, the Steuerein unit is further designed to take into account when determining whether it is a aufneh mende or donating energy storage cell, also a predetermined for the high-voltage storage Hochvoltspeicherbetriebsstrategie. Preferably, the high-voltage storage operation strategy is one of the following strategies: a discharge strategy aimed at achieving a maximum possible discharge for the individual energy storage cells in the case of a discharge process carried out for the high-voltage storage device; or a charging strategy which is designed to achieve a maximum possible charge of the individual energy storage cells for the individual energy storage cells in the case of a charging process carried out for the high-voltage storage. By this measure, an optimal use of the individual storage capacity of the individual energy storage cells is achieved. Overall, the high-voltage storage operating strategy or both strategies are geared towards achieving a performance optimization, so that the total travel distance covered by the vehicle while driving is maximized. Preferably, the high-voltage storage operating strategy can be selected during driving of the vehicle from a variety of different strategies, whereby an adjustment of the charge or energy balance to be performed on driving conditions is possible, which in turn is an optimization of the storage capacity of the high-voltage memory and thus the range is possible. Preferably, the energy storage cells in both strategies should the respective state of charge, i. reach the maximum possible discharge or the maximum possible charge substantially simultaneously.

Advantageously, the state of charge state is at least one of the following variables: energy storage cell voltage, energy storage cell charge or energy storage cell charge state. All three sizes are suitable for reliably representing the actual state of charge of an energy storage cell and are therefore a suitable measure of the actual state of charge of an energy storage cell. The energy storage cell charge is particularly well suited as a state of charge state, since it is a direct measure of the stored in an energy storage cell electrical charge and consequently the energy. With it, the actual state of charge of an energy storage cell can be detected particularly reliable and thus a charge or energy balance between individual energy storage cells can be carried out particularly precisely. Due to the fact that the energy storage cell charge state is related to the energy storage cell charge via the energy storage cell capacitance and in the case of the energy storage cell idle voltage there is a functional relationship between the energy storage cell idle voltage and the energy storage cell charge state, these two variables are well suited for reproducing the actual state of charge of an energy storage cell. It has been found that it is sufficient to use one of the aforementioned sizes in the energy storage cell compensation system according to the invention, i. to carry out the charge or energy balance between the individual energy storage cells based on or in dependence on one of these three variables. Advantageously, however, it is also conceivable to use at least two of these three sizes combined. It is likewise conceivable that, in the energy storage cell compensation system according to the invention, a charge or energy compensation is to be carried out while driving and for the high-voltage storage, one of the three aforementioned variables is selected as the charge state variable. Thus, it is possible to always use the most suitable state of charge state for the respective operating situation of the high-voltage accumulator and consequently to achieve the best result in the charge or energy compensation to be carried out.

In the event that the charge state variable is the energy storage cell voltage, ie the energy storage cell voltage is used as the charge state variable, the control unit is advantageously designed to determine, depending on a comparison made for the respective energy storage cell voltage values, whether it is a receiving or a donating energy storage cell han delt. As far as the implementation of the comparison is concerned, several approaches are conceivable here. On the one hand, based on the determined energy storage cell voltage values, the two extreme values can be determined, ie the maximum and the minimum voltage value. The energy storage cell, which has the maximum voltage value, is then the dispensing energy storage cell. The energy storage cell having the minimum voltage value is then the receiving energy storage cell. On the other hand, the determined Energy storage cell voltage values by size and therefore also the energy storage cells themselves are sorted. In accordance with a suitably chosen assignment criterion or distinguishing criterion, for example, the mean value or the median can be used for this, which both allow categorization into emitting and receiving energy storage cell, then allocations of receiving and donating energy storage cells are formed, wherein a compensation is made in each case within an allocation , The assignments can be an association between a single donor energy storage cell and a single consuming energy storage cell (c2c approach). It may also be an association between a single donating energy storage cell and a composite of receiving energy storage cells (c2s approach) or an association between a composite of donating energy storage cells and a single receiving energy storage cell (s2c approach), in both cases May consist of two or at most n-m energy storage cells, where n represents the number of energy storage cells contained in the high-voltage storage and m represents the number of energy storage cells that are included in the total energy storage module, the single emitting energy storage cell (c2s approach) or contains the single receiving energy storage cell (s2c approach). It is also conceivable that at the same time several of the aforementioned assignments can exist, even in any combination. If the charge state variable is the energy storage cell voltage, then the energy storage cell compensation is performed on the basis of a voltage control made for the energy storage cells.

In a preferred embodiment of the aforementioned measure, the control unit is also designed to take into account a resistance variable representing the internal resistance of the respective energy storage cell. By this measure, in particular systematic errors in performing the energy storage cell compensation can be avoided. Taking into account the internal resistance of an energy storage cell, it is possible to determine the open circuit voltage for each of the energy storage cells. With knowledge of the energy storage cell internal resistance, it is possible to take into account or to calculate the voltages dropping under load in the interior of the energy storage cell. The assumption then applies that energy storage cells which have the same cell voltage at their terminals thus also have the same state of charge.

In the case that the state of charge magnitude is the energy storage cell charge or the energy storage cell state of charge, i. As the charge state variable, the energy storage cell charge or the energy storage cell charging state is used, the control unit is advantageously designed to determine for each of the at least two energy storage cells a difference between the state of charge state and given for each energy storage cell operating limit, and determine depending on the difference sizes, if it is a receiving or dispensing energy storage cell. Preferably, the operational limit is subtracted from the state of charge magnitude to form the difference quantity. In a preferred embodiment of the aforementioned measure, the operating limit value is determined as a function of a high-voltage storage operating strategy specified for the high-voltage storage device.

 In the event that the charge state quantity is the energy storage cell charge, the operating limit value is a charge limit value given for the energy storage cell. In the case of the discharge strategy, this is the permissible charge minimum value, which represents the charge to which an energy storage cell may at best be discharged, or which must be minimally contained in an energy storage cell at the end of a discharge process. Accordingly, the discharge strategy is aimed at balancing the energy storage cells against the minimum allowable amount of charge allowed, so that the discharge strategy may be understood as an operating strategy for achieving full discharge. In the case of the charging strategy, the operating limit value is the permissible maximum charge value, which represents the charge to which an energy storage cell may at best be charged, or which may be contained at most in an energy storage cell at the end of a charging process. As a result, the charging strategy is geared towards balancing the energy storage cells with the respective maximum allowable charge quantity, so that the charging strategy can also be understood as an operating strategy for achieving a full charge.

In the event that the state of charge state is the energy storage cell state of charge, the operating limit value is a state of charge limit state given for the energy storage cell. In the case of the discharge strategy, this is the permissible state of charge minimum value, which represents the state of charge that an energy storage cell should still have at the end of a discharge process. Here, the discharge strategy is geared to or pursues the goal of the energy storage cells in terms of each allowed to balance minimum state of charge. Again, it is an operating strategy to achieve a full discharge. In the case of the charging strategy, the operating limit value is the permissible state of charge maximum value, which represents the state of charge that an energy storage cell is allowed to have at the end of a charging process. Here, the charging strategy is geared to or pursues the goal of symmetrizing the energy storage cells with regard to the respectively permitted maximum state of charge. It is therefore an operating strategy for achieving a full charge.

Preferably, all energy storage cells contained in the high-voltage storage should reach the state of full charge or full discharge, in particular at the same time. Advantageously, both a minimum and a maximum operating limit are known for the individual energy storage cells. Depending on the selected operating strategy, it is then determined or determined whether the operating limit value used is either the minimum operating limit value or the maximum operating limit value. Regarding the energy storage cell charge state, either the current value determined during driving or the nominal value determined during the production of the energy storage cell can be used, whereby the corresponding associated operating limit values are to be used, wherein the current operating limit values and the nominal operating limit values can be converted into one another.

In the event that the charge state variable is the energy storage cell charge, the control unit is advantageously also designed to determine an average value for the difference values and to determine a deviation variable for the at least two energy storage cells as a function of the respective difference quantity and the mean value , and to determine, depending on the deviation quantities, whether it is a receiving or a donating energy storage cell. The difference size represents a Nutzhubladungsmenge. In the case of the charging strategy, it is the payload amount for full charge, i. By that amount of charge that can be supplied to the energy storage cell, starting from the current amount of charge until reaching the maximum charge value. In the case of the unloading strategy, it is the payload amount for full discharge, i. by that amount of charge that can be removed from the energy storage cell, starting from the current amount of charge until it reaches the charge minimum value. The deviation amount represents the payload amount deviation. Preferably, the deviation quantity is formed by deducting the respective difference quantity from the mean value.

In the event that the state of charge state is the energy storage cell charge, the control unit is advantageously also designed to determine, depending on the deviation quantity and a high-voltage storage operation strategy, whether it is a receiving or a donating energy storage cell. Accordingly, in the event that the state of charge magnitude is the energy storage cell state of charge, the control unit is consequently configured to determine whether it is a receiving or a variable depending on the deviation quantity and a high-voltage storage operation strategy or alternatively depending on the difference size and a high-voltage storage operation strategy is a donating energy storage cell. Thus, it is conceivable, for example, to make a general classification into receiving and donating energy storage cells on the basis of the deviation variable or the difference variable. On the basis of the high-voltage storage operating strategy, a selection and / or assignment of the energy storage cells then takes place, between which then the charge or energy balance is to be carried out.

If the state of charge state is the energy storage cell charge, the following approaches are conceivable: In the c2c approach, the discharge strategy selected as the high-voltage storage operation strategy is, for example, the energy storage cell for which, in comparison to the others in the High voltspeicher contained energy storage cells, the deviation size has the maximum value. As the receiving energy storage cell, for example, that energy storage cell is selected for which the deviation has a deviation corresponding to the minimum value. In the event that the charging strategy is selected, the one energy storage cell is selected as the receiving energy storage cell, for which the deviation amount corresponding to the maximum value, and as a donating energy storage cell that energy storage cell is selected, the deviation size corresponding to the minimum value. In order to determine which energy storage cell has the minimum value or the maximum value, the deviation quantities respectively determined for the individual energy storage cells are advantageously compared with each other, thereby determining the smallest negative deviation quantity (minimum value) or the largest positive deviation variable (maximum value) and, consequently, simultaneously detects the associated energy storage cells. Preferably, the deviation quantities can be sorted by size for all energy storage cells. This would make it possible to form multiple pairs of receiving and donating energy storage cells, thus enabling the implementation of multiple c2c based balancing.

However, it is also possible for combinations or allocations to be formed from a single energy storage cell to a stack consisting of several energy storage cells, as is the case with the c2s approach or the s2c approach. In the case of the charging strategy, in the c2s approach, that energy storage cell is selected as a donor energy storage cell for which the deviation quantity has the minimum value, and a plurality of energy storage cells are selected as receiving energy storage cells, one of which may preferably be the one for which the deviation variable has the maximum value and moreover other energy storage cells for which the respective value of the deviation quantity is in the range of the maximum value. In the case of the discharge strategy, in the c2s approach, that energy storage cell is selected as a donor energy storage cell for which the deviation variable has the maximum value, and a plurality of energy storage cells are selected as receiving energy storage cells, where preferably one of them can be the one for which the deviation variable has the minimum value and In addition, other energy storage cells for which the respective value of the deviation quantity is in the range of the minimum value.

In the case of the charging strategy, in the s2c approach, that energy storage cell is selected as the receiving energy storage cell for which the deviation variable has the maximum value, and a plurality of energy storage cells are selected as donating energy storage cells, one of which may preferably be the one for which the deviation variable has the minimum value and moreover other energy storage cells for which the respective value of the deviation quantity is in the range of the minimum value. In the case of the discharge strategy, in the s2c approach, that energy storage cell is selected as the receiving energy storage cell for which the deviation quantity has the minimum value, and a plurality of energy storage cells are selected as donor energy storage cells, one of which may be the one for which the deviation variable has the maximum value and, moreover other energy storage cells for which the respective value of the deviation quantity is in the range of the maximum value.

If the state of charge state is the energy storage cell state of charge, the energy storage cell for which the difference variable has the maximum value is selected in the c2c approach, and the energy storage cell for which the difference variable has the minimum value is selected as the receiving energy storage cell for the charging strategy as well as for the unloading strategy.

In the event that the charge state variable is the energy storage cell charge, the control unit is also designed to carry out a correction of the charge state variable value as a function of a state of aging of the energy storage cell representing the aging state variable before the differential size is formed. By taking into account the state of health (SOH size), the current storage capacity of an energy storage cell can be determined much more accurately, which is why a much more precise charge or energy balance can be carried out. Advantageously, it may generally be provided to take into account the aging state quantity, regardless of which size is used as the state of charge magnitude, or regardless of which high-voltage storage operation strategy is used. For example, the aging state variable can generally be taken into account when determining the energy storage cell state of charge.

In the event that the charge state variable is the energy storage cell charge, the control unit is advantageously further configured to provide default signals for the associated primary-side switching elements as a function of the deviation variable respectively determined for the at least one dispensing energy storage cell and / or the at least one receiving energy storage cell and to determine the associated secondary-side switching elements. Correspondingly, in the event that the state of charge state is the energy storage cell state of charge, the control unit is advantageously further configured to provide default signals depending on the deviation variable or alternatively the difference variable respectively determined for the at least one emitting energy storage cell and / or for the at least one receiving energy storage cell to determine the associated primary-side switching elements and the associated secondary-side switching elements.

Advantageously, both the c2s approach and the s2c approach for performing charge balance for both cell categories, i. Both for the donating energy storage cells and for the receiving energy storage cells, the deviation quantities or the difference sizes required, since in both approaches a division or merger of the electrical energy to be equalized or charge takes place and thus the knowledge of the respective deviation size or difference size is required in order to make an individual control of the respective primary-side switching elements and secondary-side switching elements for the corresponding energy storage cell.

In the event that the state of charge state is the energy storage cell charge, the specification signals can be determined directly from the deviation quantities since the deviation quantities correspond to charge quantities. In the event that the state of charge state is the energy storage cell state of charge, it is advantageously advisable to carry out a conversion of the deviation quantities or difference values into charge quantities, so to speak, so that in both cases one and the same basic algorithm can be used.

In the case of the c2c approach, due to the pairing between the donor and the receiving energy storage cell, it is sufficient to take into account the variance of either the donating energy storage cell or the receiving energy storage cell, since this approach requires matching these sizes for both cell categories.

The two operating states described above, on the one hand, are the charging operating state in which at least one receiving energy storage cell is supplied with an individualized amount of electrical energy and, on the other hand, the removal operating state in which at least one donating energy storage cell is an individualized quantity taken from electrical energy, these quantities can also be represented by said difference size or deviation amount, which is why the determination of the default signals for the primary-side switching elements and the secondary-side Sachaltele elements can be carried out as described above.

In the event that the charge state variable is the energy storage cell voltage, the default signals can be determined in a corresponding manner due to the functional relationship that exists between the energy storage cell idle voltage and the energy storage cell charge state.

Preferably, in both cases, i. in the case of the energy storage cell charge as well as in the case of the energy storage cell charging state, a conversion of the deviation quantity or the difference values into a current value which represents the current required for the realization of the energy exchange can be carried out.

A further advantage is that the energy storage cell compensation system according to the invention allows a much greater flexibility in comparison with known systems, with regard to the design and construction of a high-voltage memory. Thus, energy storage modules with different energy storage module capacities can be arranged or installed within one and the same high-voltage memory. This allows, for example, in the conception phase a much better adaptation of the high-voltage accumulator to the space available in a vehicle for the high-voltage accumulator. For example, geometrically differently configured energy storage modules can be arranged in a high-voltage storage, i. For example, the high-voltage storage may include smaller energy storage modules with a smaller module space volume and larger energy storage modules with a larger module space volume, the smaller energy storage modules should have a lower storage capacity compared to the larger energy storage modules. Thus, energy storage modules with different storage capacity specifications can already be installed from the outset. Furthermore, the energy storage cell compensation system according to the invention also allows a much greater flexibility that, for example, energy storage modules can be installed in a high-voltage storage, which indeed have identical external dimensions, albeit ideally have only small, but demonstrably different energy storage module capacities, for example because first energy storage modules Energy storage cells of a first memory cell manufacturer and second energy storage modules are included with energy storage cells of a second memory cell manufacturer in one and the same high-voltage storage. This allows both in the production of the high-voltage memory as well as in a subsequent replacement of an energy storage module, which is required, for example, because a defect has occurred in the driving on an energy storage module, the use of identical but with respect to the energy storage module capacity different specified energy storage modules.

The charge or energy balance to be carried out can be performed either controlled or regulated, with a regulated compensation tends to yield better results, but is more time consuming. It may be decided case by case on a case-by-case basis whether to control or regulate. According to the above explanations, in both cases, a difference quantity or a deviation quantity is the basis for the compensation to be performed. If the compensation is carried out only under control, symmetry durations are determined as default signals for the affected energy storage cells as a function of the associated difference values or deviation variables, which are then used to drive the associated primary-side switching elements and secondary-side switching elements Charge compensation or energy balance to make. Once the balancing periods have elapsed, releasing and receiving energy storage cells are detected again and, if necessary, a renewed compensation is carried out.

 If, on the other hand, the compensation is carried out in a regulated manner, output signals for the associated primary-side switching elements and secondary-side switching elements are determined for the resulting and receiving energy storage cells as a function of the differential quantities or the deviation quantities while taking into account the high-voltage storage operating strategy. The current taken or supplied to the individual energy storage cells is detected. Depending on the detected current values, an adaptation of the default signals is then carried out in the form of a feedback. Additionally or alternatively, the activation periods of the primary-side and secondary-side switching elements can also be detected and taken into account. Advantageously, in this case, a prognosis can be taken into account which contains a statement about the expected average exchange or symmetrizing current and / or the remaining time, which is expected to be required until completion of the charging or energy compensation. By means of such a prognosis, the driving operation of the vehicle can be carried out more reliably, since, for example, a reliable statement about the charge available for driving in the high-voltage accumulator is possible. In the case of a regulated charge or energy compensation, the current energy storage cell capacity and / or the current energy storage cell maximum capacity are preferably determined and evaluated during the compensation for the energy storage cells.

Preferably, the control unit is designed to perform the charge or energy compensation at least temporarily predictively, i. For example, when approaching the required energy storage cell charge and / or the energy storage cell voltage and / or the energy storage cell charging state, then there is a balanced high-voltage storage to take appropriate action, since a compensation not right up to the end, i. can be carried out directly to the respective required value. For example, the default signals for the primary-side and / or the secondary-side switching elements can be modified in order to preferably achieve a suitably established approach to the respectively required value without an overshoot occurring in the process. With a control unit designed in this way, a predictive balancing can be carried out.

Advantageously, the control unit is designed so that the determination of whether it is a receiving or a donating energy storage cell, at least partially expires using a so-called self-learning algorithm. That the process of detection is based to some extent on so-called machine learning. Thus, it is an at least partially automated diagnostic method. As a result, there is the possibility that the energy storage cell compensation system can adapt to the particular conditions of that high-voltage storage device for which the charge or energy compensation is to be carried out with this system. After the adaptation or learning process has been successfully completed, said compensation can thus be accomplished faster and more reliably. With the aid of this measure, it is possible to optimally carry out the charge or energy compensation in accordance with the statistical conditions present and thus determined for the energy storage cells installed in the high-voltage storage. In order to make the learning or adaptation process more robust, it is preferably provided to take into account a sufficiently large number of operating states of the vehicle in which at least the ignition is switched on, which is the case, for example, during driving of the vehicle.

Should there be serious discrepancies between the above statements and the following description of the exemplary embodiments, the above statements should proceed.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

1 a schematic representation of an electric vehicle equipped with the invention,

2 a schematic representation of a hybrid vehicle equipped with the invention,

3 in the form of a schematic representation of a high-voltage storage in which the energy storage cell compensation system according to the invention is used,

4 in the form of a schematic representation of an energy storage module contained in the high-voltage storage, and

5 in the form of a more detailed schematic representation of details of a connection module contained in an energy storage module.

In 1 is a vehicle 10 shown which driven wheels 12 and non-powered wheels 14 having. The vehicle 10 should be driven only electrically, which is why it is only an electric machine as a drive motor 16 having. The electric machine 16 is about a gearbox 18 and a differential 20 technically with the driven wheels 12 connected to this one the propulsion of the vehicle 10 To generate acting torque. At the electric machine 16 it may be a synchronous machine, in particular a hybrid synchronous machine. The electric machine 16 is via one of a drive unit 22 controllable inverter 24 with a high-voltage storage 26 connectable. The inverter 24 has a plurality of inverter switches arranged to a full bridge designed for three-phase operation, and via which the electric machine 16 in engine operation with out of the high-voltage accumulator 26 originating energy can be supplied or via the generator in the electrical machine 16 at least in part from this energy originating in the high-voltage storage 26 can be fed. The drive unit 22 is adapted to generate depending on a driver specification, resulting for example from the operation of an unillustrated accelerator pedal by the driver Ansteuermus ter, according to which the inverter switches are controlled such that the electric machine 16 is powered during operation of the engine with such a current that on the driven wheels 12 sets a moment corresponding to the driver's specification propulsion of the vehicle 10 causes. In 1 is hinted that the high-voltage battery 26 also via external, ie outside the vehicle 10 located sources can be loaded. For example, it can have an external AC source 23 being charged, being between the external AC source 23 and the high-voltage storage 26 an inverter 25 is interposed with that of the external AC source 23 provided AC voltage is converted into a DC voltage. Just as well, the high-voltage storage 26 via an external DC voltage source 27 getting charged.

For clarity, in 1 only the components relevant for the energy storage cell compensation system according to the invention are shown. Thus, for example, has been dispensed with the representation of components, for example, only the operation of the electric machine 16 relate, such as a sensor for detecting a speed variable, the speed of the electric machine 16 represents. The same applies to those to be described 2 ,

2 shows a vehicle constructed as a hybrid vehicle 10 ' , which is designed as a parallel hybrid vehicle, preferably with the functionality of a plug-in hybrid. In 2 illustrated components having the same or equivalent functionality as components used in the 1 are marked with the same, but with a prime reference numerals, with reference to those in connection with 1 referenced statements. In the following, only the additional components or the changed functionalities are described. In addition to the electric machine 16 ' has the vehicle 10 ' via an internal combustion engine 28 that has a clutch 30 and the gearbox 18 ' as well as the differential 20 ' the driven wheels 12 ' of the vehicle 10 ' can drive. The driven wheels 12 ' can do it alone by the electric machine 16 ' or by the internal combustion engine alone 28 or be driven in combination by both. The schematic representation in 2 is reduced to the essential components of the drive train. The illustration of this removable connection of the electrical machine 16 ' to the gearbox 18 ' should have no limiting effect on the specific mechanical design.

In 3 is a high-voltage storage 26 illustrated, which has a plurality of structurally autonomous running energy storage modules, one of which is exemplified by the reference numeral 32 is marked. The high-voltage storage 26 is about an inverter 24 with an electric machine 16 connected. The inverter 24 is via a drive unit 22 at least so controlled that the electric machine 16 with out of the high-voltage storage 26 powered, stored in this stored electrical energy to thereby driven wheels 12 to be able to drive. As the illustration in 3 it can be seen, are the individual energy storage modules 32 via line components 34 connected in such a way that a series connection of the energy storage modules 32 arises. In the 3 chosen representation should have no limiting effect. Likewise, by the line components 34 a parallel connection or a combined serial and parallel connection of the energy storage modules 32 will be realized. The high voltage resulting from the series connection is due to terminals 36 on, with the high voltage terminals 36 via a so-called S-box 38 is supplied. The S-box 38 contains, among other things, at least one backup for securing the high-voltage memory 26 provided high voltage, as well as at least measuring devices for detecting the at the terminals 36 applied high voltage and the high-voltage storage 26 over the terminals 36 delivered stream. 3 are between the energy storage modules 32 on the one hand and between the line components 34 On the other hand, to take points, which is to indicate that a high-voltage storage 26 Depending on the specification, also a different number of energy storage modules 32 contain can, as the number, the 3 can be seen.

The energy storage modules 32 As will be described below, each contain a number of energy storage cells 40 , The energy storage modules 32 are with an energy exchange system 42 connected, whereby an exchange of electrical energy or electrical charge between individual energy storage modules 32 is possible. As the illustration in 3 it can be seen, are the line components 34 and the energy exchange system 42 structurally independent. Thus, the line components 34 on the one hand and the energy exchange system on the other 42 on the other hand be specified independently of each other. The energy exchange system 42 Accordingly, it can be designed, for example, as a bus system designed for the low-voltage range, whereas the line components 34 designed for high voltage operation.

The vehicle 10 has a further energy storage 44 on that over terminals 46 also with the energy exchange system 42 connected is. Thus, an energy or charge exchange between individual energy storage cells 40 and the further energy storage 44 possible, in both directions. With the further energy storage 44 , which is preferably carried out potential-free, other components are connected. The other components may be a low-voltage vehicle electrical system contained in the vehicle 48 act. Thus, there is the possibility of high-voltage storage 26 derived electrical energy, more specifically from individual in high-voltage storage 26 contained energy storage cells 40 originating electrical energy in the further energy storage 44 between to save and if necessary then in the low-voltage electrical system 48 feed. With respect to the further energy storage 44 puts the low-voltage on-board network 48 an energy sink. The low-voltage on-board electrical system 48 should preferential, an operating voltage in the order of 12 to 14 volts ha ha ha. Furthermore, with the further energy storage 44 at least one energy source 50 connected. At this source of energy 50 it may be, for example, arranged on the vehicle solar cells and / or a power generation unit, which is composed of a so-called turbo steamer and a generator. A turbo-steamer is a combined gas and steam engine that operates on the principle of known gas and steam turbine power plants. The Turbo Steamer uses the waste heat of an internal combustion engine in the vehicle, for which the Turbo Steamer is operatively connected to the exhaust system and / or cooling system of the internal combustion engine. The turbo-steamer converts some of the waste heat generated during operation of the internal combustion engine into rotational energy, which in turn is converted into electrical energy by the generator, which is in operative connection with the turbo-steamer. This electrical energy can then in the further energy storage 44 are then cached and then, for example, to load one in the high-voltage memory 26 contained energy storage cell 40 to disposal. In view of the above, the further energy storage is 44 advantageously designed as a low-voltage storage, ie its voltage level is in the range of the electrical system voltage of the low-voltage vehicle electrical system and thus in the order of 12 to 14 volts. Contrary to the illustration in 3 It is also conceivable that the power source is directly connected to the terminals 46 connected is.

The drive unit 22 is further with one in the high-voltage storage 26 arranged control unit 52 connected, which is one of the aforementioned electronic components. The control unit 52 primarily has the task of the memory management for the high-voltage memory 26 to carry out, ie in her the control or control technical scope of the battery management are implemented. These include, but are not limited to, the following functions or functions: safety and monitoring functions for the energy storage cells and / or for contactors contained in the high-voltage storage and / or for sensors contained in the high-voltage storage; High-voltage safety functions such as, for example, functionalities belonging to the realization of an insulation monitor and / or functional scope belonging to the realization of a high-voltage interlock loop (HVIL); various detection functions, such as a function for determining the state of charge of the high-voltage memory (SoC function) and / or a function for evaluating the power forecast of the high-voltage memory and / or a function for evaluating the aging state of the high-voltage memory (SOH function); Diagnostic function scopes resulting from on-board diagnostics (OBD). Furthermore, in the control unit 52 implements the control and technical scope of the inventive method for performing an energy storage cell compensation. Before going into these dimensions, it should be mentioned that the in 3 chosen representation should have no limiting effect. Of course, it is also conceivable that in the high-voltage storage 26 two independently trained units are included. Namely, a first unit in which the control or control technical peripheries of battery management are implemented, and a second unit in which the control or control technical peripheries of the inventive method for Performing an energy storage cell balancing are implemented.

• – Für zumindest zwei Energiespeicherzellen, Ermitteln einer den Ist-Ladezustand der jeweiligen Energiespeicherzelle repräsentierenden Ladezustandsgröße.
• – Feststellen in Abhängigkeit der Ladezustandsgröße, ob es sich bei der jeweiligen Energiespeicherzelle um eine aufnehmende Ener giespeicherzelle handelt, die aufgrund ihres Ist-Ladezustands elektrische Energie aufnehmen kann, oder um eine abgebende Energiespeicherzelle handelt, die aufgrund ihres Ist-Ladezustands gespeicherte elektrische Energie abgeben kann.
• – Feststellen, ob ein definierter Speicherbetriebszustand vorliegt, bei dem zumindest eine abgebende Energiespeicherzelle in einem ersten Energiespeichermodul und zumindest eine aufnehmende Energiespeicherzelle in einem zweiten Energiespeichermodul angeordnet ist, wobei es sich bei dem ersten und dem zweiten Energiespeichermodul um unterschiedliche Energiespeichermodule handelt.
• – Ansteuern eines noch zu beschreibenden Verbindungsherstellungssystems bei Vorliegen des definierten Speicherbetriebszustands derart, dass ein Energieaustausch zwischen der zumindest einen abgebenden und der zumindest einen aufnehmenden Energiespeicherzelle erfolgen kann.

In the context of the inventive method for performing an energy storage cell compensation are in the control unit 52 essentially carried out the following method steps:

• For at least two energy storage cells, determining a state of charge state representing the actual state of charge of the respective energy storage cell.
• - Determining depending on the state of charge state, whether it is the respective energy storage cell to a receiving energy giespeicherzelle that can absorb electrical energy due to their actual state of charge, or is a donating energy storage cell that can deliver stored electrical energy due to their actual state of charge ,
• - Determining whether a defined memory operating state is present, in which at least one emitting energy storage cell in a first energy storage module and at least one receiving energy storage cell is arranged in a second energy storage module, wherein the first and the second energy storage module are different energy storage modules.
• - Driving a yet to be described connection manufacturing system in the presence of the defined memory operating state such that an energy exchange between the at least one emitting and the at least one receiving energy storage cell can take place.

The step of activating the connection production system may be preceded by a method step in which it is checked whether there are operating states for the energy storage cells which permit the execution of an energy exchange.

Between the control unit 52 and the drive unit 22 different signals or sizes are exchanged. So can the drive unit 22 starting from the control unit 52 For example, results of the performed safety and monitoring functions, and / or results of the performed determination or evaluation functions, such as the state of charge of the high-voltage memory (SoC function) and / or the aging state of the high-voltage memory (SOH function), and / or on-board diagnostic (OBD) results. Starting from the drive unit 22 can the control unit 52 For example, quantities are supplied, which are needed there to determine, for example, whether a loading operation state and / or a removal operating state is present.

As already mentioned, the energy storage cell compensation system according to the invention has a connection production system 53 which is adapted for at least one energy storage module 32 at least one energy storage cell contained in this 40 with the energy exchange system 42 connect to. The connection manufacturing system 53 is in 3 dashed line, which is intended to indicate that the connection manufacturing system 53 has a plurality of connection modules or is constructed from a plurality of connection modules, one of which is associated with one of the energy storage modules. The connection manufacturing system 53 and thus the connection modules from which it is constructed are controlled by the control unit 52 driven,

The fact that in 3 on the in 1 shown components and thus reference is made to an exclusively electrically driven vehicle, should have no limiting effect. Of course, the above and also the following statements apply in a corresponding manner to a hybrid vehicle, as it is in 2 is shown.

In 4 is one in the high-voltage storage 26 contained energy storage module 32 shown, this being the in 3 shown module m can act. The energy storage module 32 has a number of energy storage cells, one of which is exemplified by the reference numeral 40 is marked.

The energy storage module 32 also has a connection module 54 on. The individual energy storage cells 40 are via connection lines with this connection module 54 connected, wherein one of the connecting lines by way of example with the reference numeral 56 is marked. By corre sponding driving the connection module 54 , which means the Steuerein unit 52 can be done via the connection module 54 individual ones in the energy storage module 32 contained energy storage cells 40 with the energy exchange system 42 get connected. Each of the high-voltage memory 26 contained energy storage modules 32 should be a connection module 54 have, wherein the plurality of total in the high-voltage storage 26 contained connection modules 54 a connection manufacturing system 53 result. In other words: the high-voltage storage 26 has a connection manufacturing system 53 on that, from a variety of connection modules 54 is constructed, each energy storage module 32 one connection module each 54 assigned. As a result, it is possible with the connection manufacturing system 53 for at least one energy storage module 32 at least one in this contained energy storage cell 40 with the energy exchange system 42 connect to.

The connection module 54 has a transducer element 58 and a switching element arrangement 60 on. As already stated, the connection module becomes 54 through the control unit 52 driven. For this purpose, default signals from the control unit 52 and one in the connection module 54 included interface 62 fed. In the interface 62 These default signals are processed and the prepared default signals of a switching unit 64 fed. In the switching unit 64 are determined in response to the processed default signals drive signals by which the transducer element 58 and the switching element arrangement 60 be controlled. By the drive signals duty cycles are set for switching elements, both in the transducer element 58 as well as in the switching element arrangement 60 are included. On details hereby becomes in connection with 5 received. At this point, it should only be mentioned in advance that via the transducer element 58 the energy storage module 32 with the energy exchange system 42 can be connected. By means of the switching element arrangement 60 is a targeted selection of one in the energy storage module 32 existing energy storage cell 40 possible. Thus it is by means of a transducer element 58 and switching element arrangement 60 possible, a single one in the energy storage module 32 existing energy storage cells with the energy exchange system 42 connect to.

With the in 4 selected representation according to which the connection module 54 contains several components, it should be indicated that the connection module 54 contains or perceives several different functions. It is thus a functional and less a structural division or structure to be indicated. So for example it is conceivable that by the two components 58 and 60 represented functions are implemented in a single structural unit. Likewise it is conceivable that by the two components 62 and 64 implied functions are implemented in another structural or even the same structural unit.

As 4 further shows, are the energy storage cells 40 via further connecting lines, one of which by way of example with the reference numeral 66 with a cell monitoring unit 68 connected. With the cell monitoring unit 68 is among other things for the individual energy storage cells 40 determines the cell voltage applied to each of the memory cell terminals. In 4 are for one of the energy storage cells 40 the two associated memory cell terminals with the reference numeral 70 characterized. Further, by the cell monitoring unit 68 Temperature signals are provided, each of which is inside an associated energy storage cell 40 represents prevailing temperature. This is advantageously in each of the energy storage cells 40 contain a temperature sensor. The from the cell monitoring unit 68 provided signals and / or sizes are the control unit 52 fed.

At this point it should be mentioned that the control unit 52 With regard to the method according to the invention for performing an energy storage cell compensation, a higher-level or central control or control function is required. Ie at the control unit 52 it is a superordinate or central control component, the subordinate control components, namely at least the connection modules 54 controls.

It should also be mentioned that it is quite conceivable to carry out the associated connection module and the associated cell monitoring unit as a structural unit for the energy storage modules.

• – Austausch zwischen einer einzelnen abgebenden Energiespeicherzelle und einer einzelnen aufnehmenden Energiespeicherzelle. Es findet somit ein Energieausgleich zwischen zwei definierten bzw. individualisierten Energiespeicherzellen statt. Dieser Ansatz wird als c2c-Ansatz bezeichnet, entsprechend dem englischen Ausdruck „cell-2-cell“.
• – Austausch zwischen einer einzelnen abgebenden Energiespeicherzelle und einem aus einer Vielzahl aufnehmender Energiespeicherzellen bestehenden Verbund (stack), wobei die abgebende Energiespeicherzelle mit keiner der aufnehmenden Energiespeicherzellen identisch sein soll. Es findet somit ein Energieausgleich zwischen einer einzelnen definierten Energiespeicherzelle einerseits und einer definierten Vielzahl von Energiespeicherzellen anderseits statt. Dieser Ansatz wird als c2s-Ansatz bezeichnet, entsprechend dem englischen Ausdruck „cell-2-stack“. Mit diesem Ansatz bzw. mit dieser Topologie kann für den Fall, dass eine Energiespeicherzelle bei einem Ladevorgang des Hochvoltspeichers vorzeitig ihre Ladeschlussspannung erreichen sollte und dadurch der gesamte Ladevorgang beendet werden würde, rechtzeitig elektrische Energie bzw. elektrische Ladung von dieser Energiespeicherzelle auf andere Energiespeicherzellen übertragen bzw. verteilt werden, so dass der gesamte Ladevorgang des Hoch voltspeichers fortgesetzt werden kann. Diese Vorgehensweise wird als „top balancing“ bezeichnet.
• – Austausch zwischen einem aus einer Vielzahl abgebender Energie speicherzellen bestehenden Verbund (stack) und einer einzelnen auf nehmenden Energiespeicherzelle, wobei die aufnehmende Energiespeicherzelle mit keiner der abgebenden Energiespeicherzellen identisch sein soll. Es findet somit ein Energieausgleich zwischen einer definierten Vielzahl von Energiespeicherzellen einerseits und einer einzelnen definierten Energiespeicherzelle andererseits statt. Dieser Ansatz wird als s2c-Ansatz bezeichnet, entsprechend dem englischen Ausdruck „stack-2-cell“. Mit diesem Ansatz bzw. mit dieser Topologie kann für den Fall, dass eine Energiespeicherzelle bei einem Entladevorgang des Hochvoltspeichers vorzeitig ihre Entladeschlussspannung erreichen sollte und dadurch der gesamte Entladevorgang beendet werden würde, rechtzeitig elektrische Energie bzw. elektrische Ladung von den anderen Energiespeicherzellen auf diese Energiespeicherzelle übertragen bzw. verteilt werden, so dass der gesamte Entladevorgang des Hochvoltspeichers fortgesetzt werden kann. Diese Vorgehensweise wird als „bottom balancing“ bezeichnet.

Before on 5 will first be considered for the exchange of electrical energy to be made. This exchange can basically be done in different ways. Advantageously, the following topologies are available:

• - Exchange between a single donating energy storage cell and a single receiving energy storage cell. There is thus an energy balance between two defined or individualized energy storage cells instead. This approach is referred to as the c2c approach, corresponding to the English term "cell-2-cell".
• - Exchange between a single donating energy storage cell and one of a plurality of receiving energy storage cells existing composite (stack), wherein the donating energy storage cell with none of the receiving energy storage cells should be identical. Thus, there is an energy balance between a single defined energy storage cell on the one hand and a defined plurality of energy storage cells on the other hand. This approach is called the c2s approach, the equivalent of the English expression "cell-2-stack". With this approach or with this topology, in the event that an energy storage cell should prematurely reach its charge end voltage during a charging process of the high-voltage storage and thus the entire charging process would be terminated, timely electrical energy or electrical charge from this energy storage cell to other energy storage cells be transferred or distributed, so that the entire charging of the highvoltage memory can be continued. This approach is called "top balancing".
• - Exchange between one of a plurality of donating energy storage cells existing composite (stack) and a single on receiving energy storage cell, the receiving energy storage cell should be identical to none of the donating energy storage cells. There is thus an energy balance between a defined plurality of energy storage cells on the one hand and a single defined energy storage cell on the other hand. This approach is called the s2c approach, the equivalent of the English phrase "stack-2-cell". With this approach or with this topology, in the event that an energy storage cell should prematurely reach its discharge end voltage during a discharge process of the high-voltage storage and thus the entire discharge process would be terminated, timely electrical energy or electrical charge transferred from the other energy storage cells to this energy storage cell or be distributed so that the entire discharge of the high-voltage memory can be continued. This procedure is called "bottom balancing".

At this point it should be noted that, in the sense of the invention, the dispensing energy storage cell is arranged in a first dispensing energy storage module, and the receiving energy storage cell is arranged in a second, receiving, wherein the first energy storage module is different from the second energy storage module.

5 shows in the form of a more detailed schematic representation of details of an energy storage module 32 contained connection module.

As already stated, the energy storage module points 32 a number of energy storage cells, one of which by way of example with the reference sign 40 is marked. The connection module 54 has at least the already mentioned components transducer element 58 and switching element arrangement 60 on. At the in 5 illustrated embodiment, the transducer element 58 designed as a multi-winding transformer. This is not intended to be limiting. It is also conceivable, the transducer element 58 as a DC / DC converter. In particular, the use of a bidirectional DC / DC converter is conceivable, which is preferably designed as a so-called buck-boost converter.

As the illustration in 5 can be further seen, the multi-winding transformer 58 a primary winding 72 and a number of secondary windings, wherein one of the secondary windings is exemplified by the reference numeral 74 is marked. The primary winding 72 is technically the energy exchange system 42 assigned. The secondary windings 74 are technically the energy storage cells 40 assigned in such a way that in each case one of the energy storage cells 40 and one of the secondary windings 74 form a secondary network. Of the secondary links is in 5 an example with the reference numeral 76 characterized.

The switching element arrangement 60 has a number of secondary-side switching elements, one of which is exemplified by the reference numeral 78 is marked. Each of the secondary-side switching elements 78 is each a secondary network 76 assigned such that when the secondary side switching element is closed 78 the secondary winding 74 and the energy storage cell 40 a secondary-side energy flow path 80 form.

In addition to the components already mentioned transducer element 58 and switching element arrangement 60 has the connection module 54 a capacitor 82 and a primary-side switching element 84 on. The capacitor 82 is in circuit parallel to the primary winding 72 arranged, with the off capacitor 82 and primary winding 72 existing parallel connection 86 by closing the primary-side switching element 84 is formed, and thus a primary-side energy flow path 88 is formed.

As the illustration in 5 can be seen, is the primary-side energy flow path 88 module-related. Via the primary energy flow path 88 can the energy storage module 32 electrical energy or charge with the energy exchange system 42 and thus with one of the others, also to the energy exchange system 42 connected energy storage modules 32 or another with the energy exchange system 42 replace connected component, ie feed or receive electrical energy or charge. In contrast, the secondary energy flow paths 80 cell-related. Is this a secondary network 76 assigned secondary-side switching element 78 closed, can be connected to the respective secondary network 76 belonging secondary winding 74 that have an iron core 90 with the primary winding 72 is magnetically coupled, an exchange of electrical energy or charge between the to the secondary composite 76 belonging energy storage cell 40 and the energy exchange system 42 respectively. That is, the energy storage cell 40 can electrical energy or charge to the energy exchange system 42 leave or record from this.

In 5 are the primary-side switching element 84 and the secondary-side switching elements 78 general, ie not specified with regard to their concrete execution. Preferably, both types of switching elements should be designed as semiconductor elements, wherein various concrete embodiments are conceivable. In a particularly preferred embodiment, both the primary-side switching element 84 as well as the secondary-side switching elements 78 as transistors, preferably as MOSFET transistors or as IGBTs.

As for the training of the control unit 52 As a matter of fact, according to all the above explanations, a number of specifications result.

This is the control unit 52 for example, adapted to the connection manufacturing system 53 or the connection manufacturing system 53 making connection modules 54 such that at least one of the receiving and / or at least one of the donating energy storage cells 40 with the further energy storage 44 is connected to an energy exchange between the respective energy storage cell 40 and the further energy storage 44 to enable.

It should be stated at this point that when there is talk of the connection manufacturing system 53 or the connection manufacturing system 53 making connection modules 54 through the control unit 52 To be addressed, actually meant is that in the connection modules 54 contained primary-side switching elements 84 and secondary-side switching elements 78 through the control unit 52 be controlled.

Further, the control unit 52 configured to determine if a loading condition exists in which the high-voltage memory 26 electrical energy is supplied. If a charging mode is present, then controls the control unit 52 the connection manufacturing system 53 or this constituting connection modules 54 at least at times so on to at least one of the receiving energy storage cells 40 to supply an individualized amount of electrical energy. It can also be provided, as described above, to remove individual energy storage cells electrical energy.

Similarly, the control unit 52 configured to determine whether a picking operation condition exists, in which the high-voltage storage 26 electrical energy is taken. If there is an unloading operation, then the control unit controls 52 the connection manufacturing system 53 or this constituting connection modules 54 at least in a second manner, in order to store at least one of the emitting energy 40 to take an individualized amount of electrical energy. It can also be provided, as described above, to supply individual energy storage cells electrical energy.

Next is the control unit 52 designed to, depending on at least one for at least one energy storage cell 40 determined, the operating state of the respective energy storage cell 40 representing an operating state variable an evaluation and, depending on an evaluation result obtained thereby, the energy exchange between the at least one emitting and the at least one receiving energy storage cell 40 permit.

The operating state variable may be the determined state of charge state. In this context, the control unit 52 further adapted to, depending on the for the at least two energy storage cells 40 determined charge state variables to determine a currently present state of charge maximum value and a present state of charge magnitude minimum value, and to allow the energy exchange when a difference between the state of charge and the maximum state of charge maximum value is equal to or greater than a predetermined difference threshold value. In the case that the operating state quantity is the determined state of charge state, the control unit is 52 further adapted for at least one energy storage cell 40 determining if determined state of charge magnitude values are within a state of charge operating window defined by a lower state of charge limit and an upper state of charge limit and allowing the energy exchange as long as the state of charge magnitude values are within the state of charge operating window.

It can be provided that the control unit 52 Furthermore, it is designed for at least one energy storage cell 40 to evaluate a temperature size representing the energy storage cell temperature, and to allow the energy exchange as a result of an evaluation result obtained thereby.

In addition, it can be provided that the control unit 52 is further adapted to, at successive times for the at least two energy storage cells 40 repeatedly to determine the respective charge state variables and determine whether it is a donating or receiving energy storage cell 40 is. The statement that it is a donor or a receiving energy storage cell 40 then remains for the respective energy storage cell 40 retained as long as a predetermined condition is fulfilled for the respective state of charge state.

• – Eine Entladestrategie, die darauf ausgerichtet ist, bei einem für den Hochvoltspeicher 26 durchgeführten Entladevorgang, für die einzelnen Energiespeicherzellen 40 jeweils eine maximal mögliche Entladung zu erzielen; oder
• – eine Ladestrategie, die darauf ausgerichtet ist, bei einem für den Hochvoltspeicher 26 durchgeführten Ladevorgang, für die einzelnen Energiespeicherzellen 40 jeweils eine maximal mögliche Ladung der einzelnen Energiespeicherzellen zu erzielen.

It can also be provided that the control unit 52 is further adapted to determine whether it is a receiving or donating energy storage cell 40 and one for the high-voltage storage 26 given high-voltage storage operating strategy. The high-volume storage operational strategy can be one of the following strategies:

• - An unloading strategy aimed at one for high-voltage storage 26 performed unloading process, for the individual energy storage cells 40 each to achieve a maximum possible discharge; or
• - A charging strategy, which is aimed at one for the high-voltage storage 26 carried out charging, for the individual energy storage cells 40 each to achieve a maximum possible charge of the individual energy storage cells.

As far as the charge state quantity is concerned, this may be at least one of the variables energy storage cell voltage, energy storage cell charge, or energy storage cell charge state. Depending on which of these sizes is used as state of charge state, resulting in different configurations for the control unit 52 and thus also proce- dures, as far as the actual implementation of the energy storage cell is concerned. In this context, again several approaches are grateful. It can be provided that only one of the aforementioned variables is used as the state of charge variable, or alternatively that the energy storage cell compensation is performed on the basis of a selection-based combination of state of charge variables. In both cases, both the single size and the combination of state of charge magnitudes are set in the design phase, which results in both the control unit 52 as well as the method for performing the energy storage cell compensation are determined accordingly and thus formed. That is, both the control unit 52 as well as the method are predetermined so that based on the one size or based on the combination of state of charge quantities of the energy storage cell compensation is made. Alternatively it can be provided that the control unit and thus the method should be designed so that during operation of the control unit and thus during the execution of the method from time to time one of the aforementioned sizes are arbitrarily selected as a state of charge state, and thus the energy storage cell equalization, for example can be done in an optimally adapted to the respective driving operation of the vehicle way. In this case, it is determined in the design phase that both the control unit 52 as well as the running in their process are formed so that an energy storage cell compensation can be made no matter which of the three aforementioned variables during the operation of the vehicle ultimately selected as the state of charge state and thus used.

As stated above, the control unit 52 and thus to form the method running in it according to the selected size or according to the combination used in terms of sizes. In the following individual measures are mentioned, which each refer to a specific one of the aforementioned variables. If the energy storage cell balance is to be based on a single one of these quantities or based on a combination of variables, then the individual measures may have to be combined. If the energy storage cells equal to the other hand done in the way that during the operation of the ve hicle always the most suitable size can be selected as a state of charge state, so all the below mentioned, related to the individual sizes measures strands are taken into account.

In the case where the state of charge is the energy storage cell voltage, the controller is 52 designed to determine, depending on a comparison made for the respective energy storage cell voltage values, whether it is a receiving or a donating energy storage cell 40 is. In this case, several approaches are conceivable: Firstly, in the comparison of the maximum and the minimum voltage value can be determined, wherein the energy storage cell 40 with the maximum value the issuing and the energy storage cell 40 with the minimum voltage value the receiving energy storage cell 40 is. On the other hand, the energy storage cells 40 be sorted according to the voltage value, and then then according to an assignment criterion assignments of receiving and donating energy storage cells 40 be formed. Overall, in this case, the energy storage cell balance using a for energy storage cells 40 performed voltage control performed. In this type of energy storage cell balancing is the control unit 52 further advantageously designed to be an internal resistance of the respective energy storage cell 40 to take into account the representative resistance value.

In contrast, when the state of charge is the energy storage cell charge or the energy storage cell state of charge, the control unit is 52 to formed, for the at least two energy storage cells 40 in each case a difference size between the Ladezu stand size and one for the respective energy storage cell 40 determined operating limit, and determine depending on the difference sizes, whether it is a receiving or a donating energy storage cell 40 is. Advantageously, the operating limit value should be subtracted from the state of charge quantity in order to form the difference quantity. The operating limit can be a function of one for the high-voltage storage 26 predetermined high-voltage storage operating strategy are determined.

In the event that the state of charge is the energy storage cell charge, the operating limit is one for the energy storage cell 40 given charge limit. In the case of the discharge strategy, the operating limit is the allowable charge minimum value representing the charge to which an energy storage cell 40 can be discharged to a maximum, or in an energy storage cell 40 must be minimally contained at the end of a discharge process. As a result, the discharge strategy is aligned with the target, the energy storage cells 40 can be balanced against the respective minimum amount of charge allowed, insofar the discharge strategy can also be understood as an operating strategy for achieving a full discharge. In the case of the charging strategy, the operating limit is the allowable charge maximum value representing the charge to which an energy storage cell 40 can be loaded at maximum, or in an energy storage cell 40 maximum may be included at the end of a charging process. As a result, the charging strategy is aligned with the target, the energy storage cells 40 To balance against the maximum amount of charge allowed in each case, so far, the charging strategy can also be considered as an operating strategy to achieve a full charge.

In the event that the state of charge state is the energy storage cell state of charge, the operating limit is one for the energy storage cell 40 given charge state limit value. In the case of the discharge strategy, the operating limit value is the permissible state of charge minimum value, which represents the state of charge that an energy storage cell 40 must have minimal at the end of a discharge. Here, the discharge strategy is geared towards or pursues the goal, the energy storage cells 40 with regard to the respectively permitted minimum state of charge. Again, it is an operating strategy to achieve a full discharge. In the case of the charging strategy, the operating limit value is the permissible state of charge maximum value, which represents the state of charge that an energy storage cell 40 maximum allowed at the end of a charging process. Here, the charging strategy is geared towards or pursues the goal, the energy storage cells 40 with regard to the maximum permissible state of charge. It is therefore also an operating strategy for achieving a full charge.

In the event that the state of charge is the energy storage cell charge, then the controller is 52 further adapted to determine an average value for the difference sizes, and for the at least two energy storage cells 40 depending on the respective difference size and the mean value in each case to determine a deviation quantity, and to determine, depending on the deviation quantities, whether it is a receiving or a donating energy storage cell 40 is. Preferably, the deviation quantity is formed by subtracting the respective difference quantity from the mean value.

Next in this case is the control unit 52 adapted to determine, depending on the amount of deviation and a high-voltage storage operating strategy, whether it is a receiving or a donating energy storage cell 40 is.

In the case of the c2c approach, when the discharge strategy is selected as the high-voltage storage operating strategy, it is used as the issuing energy storage cell 40 for example, that energy storage cell 40 chosen for, in comparison to the rest in high-voltage storage 26 contained energy storage cells 40 , the deviation amount has the maximum value, and as the taking energy storage cell 40 for example, that energy storage cell 40 for which the deviation quantity has the minimum value. In the event that the charging strategy is selected, it is considered the receiving energy storage cell 40 the energy storage cell 40 selected for which the deviation amount corresponding to the maximum value, and as a donor energy storage cell 40 becomes the energy storage cell 40 chosen, the deviation size corresponding to the minimum value has.

To determine the energy storage cell 40 , which has the minimum value or the maximum value, are advantageously those for the individual energy storage cells 40 respectively determined deviation variables are compared with each other, and thereby the smallest negative deviation quantity (minimum value) or the largest positive deviation variable (maximum value) is determined and consequently also the energy storage cells 40 that have these deviation quantities detected. Preferably, for all energy storage cells 40 the Variance variables are sorted by size. This would allow multiple pairings of receiving and donating energy storage cell 40 and thus enable the implementation of several c2c-based balances.

But it can also combinations or assignments of a single energy storage cell 40 to one of several energy storage cells 40 existing stack, as is the case with the c2s approach or the s2c approach. In the case of the charging strategy, the c2s approach becomes the energy storage cell 40 as donating energy storage cell 40 for which the deviation quantity has the minimum value, and as receiving energy storage cells 40 become several energy storage cells 40 one preferably being one for which the deviation quantity has the maximum value and also other energy storage cells 40 for which the respective value of the deviation quantity lies within the range of the maximum value. In the case of the discharge strategy, the c2s approach becomes that energy storage cell 40 as donating energy storage cell 40 for which the deviation quantity has the maximum value, and as receiving energy storage cells 40 become several energy storage cells 40 one preferably being one for which the deviation quantity has the minimum value and also other energy storage cells 40 for which the respective value of the deviation quantity lies in the range of the minimum value.

In the case of the charging strategy, the s2c approach becomes the energy storage cell 40 as receiving energy storage cell 40 selected for which the deviation quantity has the maximum value, and as dispensing energy storage cells 40 become several energy storage cells 40 one preferably being one for which the deviation quantity has the minimum value and also other energy storage cells 40 for which the respective value of the deviation quantity lies in the range of the minimum value. In the case of the discharge strategy, the s2c approach becomes that energy storage cell 40 as receiving energy storage cell 40 for which the deviation quantity has the minimum value and as output energy storage cells 40 become several energy storage cells 40 one preferably being one for which the deviation quantity has the maximum value and also other energy storage cells 40 for which the respective value of the deviation quantity lies within the range of the maximum value.

In addition, in the event that the state of charge is the energy storage cell charge, the controller may 52 Furthermore, before the differential quantity is formed, it may be configured to correct the state of charge value as a function of the state of aging of the energy storage cell 40 representative aging state variable.

Further, in this case, the control unit 52 designed to, depending on the for the at least one donating energy storage cell 40 and / or for the at least one receiving energy storage cell 40 respectively determined deviation variable default signals for the associated primary-side switching elements 84 and the associated secondary-side switching elements 80 to investigate.

In the event that the state of charge state is the energy storage cell state of charge, the controller is 52 adapted to determine, depending on the difference size and a high-voltage storage operation strategy, whether it is a receiving or a donating energy storage cell 40 is. Here, in the c2c approach, that energy storage cell 40 as donating energy storage cell 40 for which the difference size has the maximum value and as the receiving energy storage cell 40 becomes the energy storage cell 40 for which the difference magnitude has the minimum value, this applies to both the charging strategy and the unloading strategy.

Regardless of whether the charge state quantity is the energy storage cell charge or the energy storage cell charge state, it is conceivable that the general classification into receiving and donating energy storage cell 40 Based on the deviation size and the difference size to make using the high-voltage storage operating strategy then still a selection and / or assignment of the energy storage cells 40 he follows.

In the event that the state of charge state is the energy storage cell state of charge, the controller is 52 further adapted to, depending on the cell for the at least one donating energy storage 40 and / or for the at least one receiving energy storage cell 40 respectively determined difference size default signals for the affiliated gene primary-side switching elements 84 and the associated secondary-side switching elements 78 to investigate.

Advantageously, both the c2s approach and the s2c approach for both cell categories, ie for the donor and for the receiving energy storage cells 40 the deviation quantities or the difference sizes are required, since in these two approaches a division or merging of the electric energy or charge to be compensated takes place and thus the knowledge of the respective deviation variable or Difference size is required for each energy storage cell 40 an individual control of the respective primary-side switching elements 84 and secondary-side switching elements 78 to be able to make.

With regard to the course of the energy storage cell compensation, the following procedure is followed, after at least one emitting energy storage cell contained in a first and thus donating energy storage module, and at least one receiving energy storage cell, in a second and thus receiving different from the first energy storage module Energy storage module is included, intended to control both for the first energy storage module and for the second energy storage module in each of these contained primary-side switching elements and the secondary-side switching elements such that a to be carried out replacement of electrical energy or electrical charge is possible. Preferably, the dispensing energy storage cell should be that energy storage cell that is most heavily charged, i. has the largest amount of electrical energy or electrical charge, although other selection criteria are conceivable.

With reference to 3 it should be at the first energy storage module, for example, the module m and the second energy storage module to the module n act. The following examples continue for both the module m and the module n using the more detailed representation of 5 should be done. Both in the donating and in the receiving energy storage cell, it should be both in the 5 with the reference number 40 characterized energy storage cell, wherein it is in the in 5 illustrated energy storage module 32 in the case of the donating energy storage cell around the module m and in the case of the receiving energy storage cell to the module n act. In order to better understand the statements, in the case of the receiving energy storage module, the reference numerals are provided with a dash 'as an addition. In this context, it should be mentioned that this labeling should not express that this energy storage module or the associated high-voltage storage is necessarily installed in a vehicle, as in 2 is shown, in which some components are provided with a dash 'as an addition. Rather, the use is both an in 1 shown vehicle as well as a in 2 illustrated vehicle conceivable.

If the following is the driving of a switching element, so it is to understand the driving of the switching element by means of a rectangular signal. As a result, such a controlled switching element occupies an alternating sequence of open states and closed states with respect to time, the switching element conducting in an open state and blocking in a closed state. The activation preferably takes place by means of a pulse-width-modulated signal, so that the value of a physical variable, for example a voltage, can additionally be set by the activation of the switching element. The above statements should apply to both a primary-side and a secondary-side switching element.

According to the c2c approach, an energy or charge exchange between a single donor and a single female energy storage cell proceeds as follows: By driving that secondary-side switch element 78 , that of the donating energy storage cell 40 is assigned, can stream based on the donating energy storage cell 40 in the secondary winding assigned to it 74 or secondary coil flow. The donating energy storage cell 40 Thus, electrical energy or charge is removed. By driving that primary-side switching element 84 that in the first energy storage module 32 is arranged, that is the energy storage module 32 with the donating energy storage cell 40 , that can be in the iron core 90 of the multi-winding transformer 58 existing magnetic flux across the primary winding 72 be degraded in such a way that by the at the primary winding 72 induced voltage of both the capacitor 82 of the first energy storage module 32 as well as the capacitors 82 ' the rest in high-voltage storage 26 contained energy storage modules 32 ' to be charged. The of the donating energy storage cell 40 originating electrical energy is thus in the capacitors 82 . 82 ' cached. The driving of both the secondary-side switching element 78 as well as the primary-side switching element 84 takes place until a previously determined and thus defined amount of electrical energy or charge of the donating energy storage cell 40 taken and thus in the capacitors 82 . 82 ' is cached. Achieving this predetermined or defined amount of charge or amount of energy can be achieved by integrating the output of the energy storage cell 40 taken, detected by a suitable measuring element discharge current can be determined.

The supply of electrical energy or charge, the donating energy storage cell 40 taken and in the capacitors 82 . 82 ' is latched to the in the second energy storage module 32 ' contained, receiving energy storage cell 40 ' , is characterized by the fact that both the primary-side switching element 84 ' of second energy storage module 32 ' as well as the receiving energy storage cell 40 ' assigned secondary-side switching element 78 ' be controlled. By driving the primary-side switching element 84 ' will be the on the capacitors 82 . 82 ' voltage applied to the in the second energy storage module 32 ' contained primary winding 72 ' created, resulting in the iron core 90 ' of the multi-winding transformer 58 ' forms a magnetic flux, which at the secondary windings 74 ' each causes an induced voltage. By driving the receiving energy storage cell 40 ' associated secondary-side switching element 78 ' becomes for the receiving energy storage cell 40 ' a secondary-side energy flow path 80 ' formed over the receiving energy storage cell 40 ' the electrical energy or charge is supplied, and at the same time the existing magnetic flux is reduced.

With the energy storage cell compensation system according to the invention, exchanges can also be carried out according to a different approach than the c2c approach described above.

Thus, for example, according to the c2s approach, an exchange between a single donating energy storage cell and a plurality of receiving energy storage cells can be performed. The donating energy storage cell should be included in a first energy storage module. As far as the receiving energy storage cells are concerned, they can either be contained in a single second energy storage module, or they can be divided into a plurality of different second energy storage modules. In any case, none of the second energy storage modules should be identical to the first energy storage module.

For the first energy storage module 32 the driving of the primary-side switching element takes place 84 and the secondary-side switching element 78 as described above in connection with the c2c approach. In the event that each of the receiving energy storage cells 40 ' in another second energy storage module 32 ' is included, that is, each of the second energy storage modules 32 ' only a single receiving energy storage cell 40 ' contains, takes place for each of these second energy storage modules 32 ' the driving of the primary-side switching element 84 ' and the secondary-side switching element 78 ' in principle, as described above in connection with the c2c approach, wherein by a corresponding pulse width modulation, ie by a corresponding variation or adjustment of the corresponding duty cycle of the drive signal of the respective primary-side switching element 84 ' a division of the electrical energy that the donating energy storage cell 40 was taken on the individual second energy storage modules 32 ' and thus the individual receiving energy storage cells 40 ' is possible. In contrast, at least one of the second energy storage modules 32 ' more than one receiving energy storage cell 40 ' on, so is the respective second energy storage module 32 ' supplied electrical energy by a corresponding pulse width modulation, ie by a corresponding variation or adjustment of the corresponding duty cycles of the drive signals of those secondary-side switching elements 78 ' that the receiving energy storage cells 40 ' are assigned to the individual in the second energy storage module 32 ' contained receiving energy storage cells 40 ' divided up. In the event that all receiving energy storage cells 40 ' in a single second energy storage module 32 ' are included, is a division of the second energy storage module 32 ' total supplied electrical energy to the individual receiving Energiespei cherzellen 40 ' by a corresponding pulse width modulation, ie by a corresponding variation or setting of the corresponding duty cycles of the drive signals of the receiving energy storage cells 40 ' respectively associated secondary-side switching elements 78 ' make.

Furthermore, according to the s2c approach, an exchange between a plurality of emitting energy storage cells and a single receiving energy storage cell can be performed. The receiving energy storage cell should be included in a second energy storage module. As far as the issuing energy storage cells are concerned, they can either be contained in a single first energy storage module or divided into a plurality of different first energy storage modules. In any case, none of the first energy storage modules 32 be identical to the second energy storage module.

For the second energy storage module 32 ' the driving of the primary-side switching element takes place 84 ' and the secondary-side switching element 78 ' as described above in connection with the c2c approach. In the event that each of the donating energy storage cells 40 in another first energy storage module 32 is included, that is, each of the first energy storage modules 32 only a single donating energy storage cell 40 contains, takes place for each of these first energy storage modules 32 the driving of the primary-side switching element 84 and the secondary-side switching element 78 in principle, as described above in connection with the c2c approach. In contrast, at least one of the first energy storage modules 32 more than one donating energy storage cell 40 on, so are the secondary-side switching elements 78 that the donating Energy storage cells 40 are assigned, so controlled that each of the donating energy storage cells 40 a previously defined amount of electrical energy or charge is removed. The in these first energy storage modules 32 contained primary-side switching elements 84 are controlled such that the of the donating energy storage cells 40 derived electrical energy or charge in the capacitors 82 . 82 ' is cached, the second energy storage module 32 ' and thus the receiving energy storage cell 40 ' can be supplied. In the event that all donating energy storage cells 40 in a single first energy storage module 32 are included, those secondary-side switching elements 78 that the donating energy storage cells 40 are assigned to control such that each of the donating energy storage cells 40 a previously defined amount of electrical energy or charge can be removed. That in this first energy storage module 32 contained primary-side switching element 84 is controlled such that the of the donating energy storage cells 40 derived electrical energy or charge on the corresponding capacitors 82 . 82 ' is cached, the second energy storage module 32 ' and thus the receiving energy storage cell 40 ' can be supplied.

It is also conceivable, a total for a high-voltage storage 26 To be made to compensate for electrical energy or charge not by a single compensation, which is based on one of the approaches described above, but by a plurality of successive individual balances, each of which may be based on another of the approaches described above. For example, it is conceivable to carry out several times in succession an energy or charge exchange according to the c2c approach, but each time for a different pairing of donor and receiving energy storage cell.

At this point, some general remarks on individual components will be made. Through the multi-winding transformer 58 can with a suitable choice of the number of turns for the primary winding 72 on the one hand and the number of turns for the secondary windings 74 on the other hand, a voltage transformation in the desired height. For example, the adaptation of the voltage of a single energy storage cell to the total voltage of a stack formed from a plurality of energy storage cells can be achieved. In addition, galvanic isolation of the energy storage cells contained in an energy storage module from the energy storage cells contained in another energy storage module is possible by the use of a transformer. By means of a secondary-side switching element 78 is virtually the selection of a specific energy storage cell possible, for which then an exchange of electrical energy or charge is to be performed, this applies to both a donating and for a receiving energy storage cell. By means of the primary-side switching elements 84 individual energy storage modules can be interconnected with the interposition of the energy exchange system. The capacitor 82 , which is connected in parallel to the primary winding, allows the buffering a defined energy or charge exchange, in particular from a single donating energy storage cell to a single receiving energy storage cell. It should also be mentioned that the described embodiment of the connection module 54 corresponds to the structure of a flyback converter, is stored in the due to the driving of a switching element energy of the magnetic field in the air gap of the primary coil. Non-activated switching elements should be open, ie do not allow current flow. Whereas controlled switching elements should be closed, ie to enable a current flow. Also, the in 5 selected form of presentation, according to which an energy storage module contains only three energy storage cells have no limiting effect. Of course, an energy storage module may include any other number of energy storage cells.

With the energy storage cell compensation according to the invention, a compensation of the charges stored in the individual energy storage cells is achieved, whereby, if possible, all energy storage cells contained in a high-voltage storage cell reach their operating limits as simultaneously as possible.

As can be seen from the above, it is a high-voltage storage, which contains individual energy storage cells, in which the electrical energy is stored, which is required for the operation of an electrical machine with which the driven wheels of a vehicle to be driven. In this respect, the above statements are largely directed to the balance of electrical energy between individual energy storage cells. This is not intended to be limiting. Since, in the case of an energy storage cell, the electrical energy stored in it is known to be related to the charge stored in the energy storage cell via the voltage present at the terminals of the energy storage cell, and thus a conversion between these two variables is possible, a charge equalization between individual components can also be achieved with the inventive compensation system Energy storage cells are performed. In that respect should the statements made with regard to an energy exchange also apply or can be used for a charge exchange, and also in the other direction, since at most a corresponding conversion is to be provided for.

In order to carry out a charge or energy compensation with the energy storage cell compensation system according to the invention, it may be necessary for the ignition of the vehicle to be switched on. That An embodiment of the energy storage cell compensation system is conceivable in which it is necessary for the ignition to be switched on. Likewise, a configuration is conceivable in which this is not required. However, it is not absolutely necessary that the vehicle drives and thus the high-voltage battery electrical power is removed.

 The energy storage cell balancing system on which the underlying control algorithm for carrying out the charge or energy compensation is structured vertically, into a higher-level control algorithm and a lower-level control algorithm. The scope of the higher-level control algorithm includes the selection of the energy storage cells to be balanced, i. detecting the donor and the receiving energy storage cells. Also included in this scope is the monitoring of compliance with a properly specified operating window for the charge or energy balance to be performed. The task scope of the subordinate control algorithm includes carrying out the actual charge or energy compensation, determining the default signals for the primary-side and secondary-side switching elements, and detecting and evaluating current values for a feedback possibly to be performed within the scope of a control. Overall, the control algorithm is designed so that it for different topologies (c2c or c2s or s2c approach) using different or appropriate state of charge variables (energy storage cell voltage, energy storage cell charge, energy storage cell state of charge) and thus associated Steuerbzw. Control method allows performing a charge or energy balance.

• – Ermitteln, ob ein Ladungs- bzw. Energieausgleich durchgeführt wer den kann, d.h. ob die in dem Hochvoltspeicher enthaltenen Energie speicherzellen symmetriert werden können; dies erfolgt beispielsweise durch Auswerten von Temperaturwerten und/oder Überwachen eines Betriebsfensters.
• – Feststellen und somit Festlegen der abgebenden und aufnehmenden Energiespeicherzellen, also derjenigen Energiespeicherzellen, die symmetriert werden sollen.
• – Ermitteln der Ladungs- bzw. Energiemenge, die zwischen den einzelnen Energiespeicherzellen auszutauschen ist. Optional kann auch der hierfür vorzusehenden Symmetrierstrom ermittelt werden. Hierbei wird die vorliegende Hochvoltspeicherbetriebsstrategie berücksichtigt. Ferner kann der vorzunehmende Ladungs- bzw. Energieausgleich geregelt oder gesteuert durchgeführt werden. Ggf. kann prädiktiv symmetriert werden.

At this point fundamental aspects of the control algorithm are to be presented in a somewhat generalized form: it is important for the implementation of a charge or energy balance that the current actual state of charge and also the respective current maximum energy storage cell capacity are determined as precisely as possible for the energy storage cells so as to be able to determine a reliable measure of the residual capacity of the respective energy storage cell. The charge balance or the energy balance can be carried out based on the energy storage cell voltage and / or the energy storage cell charging state and / or the energy storage cell charge. Roughly subdivided, the sequence of the control algorithm can be divided into the following steps:

• - Determine whether a charge or energy balance can be performed who can, ie whether the energy storage cells contained in the high-voltage storage can be balanced; This is done, for example, by evaluating temperature values and / or monitoring an operating window.
• - Determining and thus determining the donating and receiving energy storage cells, ie those energy storage cells to be balanced.
• - Determining the amount of charge or energy to be exchanged between the individual energy storage cells. Optionally, the symmetrizing current to be provided for this purpose can also be determined. Here, the present high-voltage storage operating strategy is taken into account. Furthermore, the charge or energy balance to be carried out can be regulated or controlled. Possibly. can be symmetrically predicted.

It should also be stated at this point that the energy storage cell compensation system according to the invention is designed in such a way that an energy compensation can be carried out with it for any desired number of energy storage cells. Starting with two energy storage cells (minimum value), which are located in a high-voltage storage and which were specifically picked out to carry out a compensation, to a balance that is carried out for all energy storage cells (maximum value) contained in a high-voltage storage.

LIST OF REFERENCE NUMBERS

 10

vehicle

 12

powered wheels

 14

non-powered wheels

16

electric machine

18

transmission

20

differential

22

control unit

23

external AC source

24

inverter

25

inverter

26

High-voltage battery

27

external DC voltage source

28

internal combustion engine

30

clutch

32

Energy storage module

34

management component

36

clamp

38

S-Box

40

Energy storage cell

42

Energy exchange system

44

further energy storage

46

clamp

48

Low-voltage onboard network

50

energy

52

control unit

53

Connection-formation system

54

connecting module

56

connecting line

58

Transducer element, multi-winding transformer

60

Switching element arrangement

 62

interface

 64

switching unit

66

further connection line

68

 Cell monitoring unit

70

 Memory cell terminals

72

primary

74

secondary winding

76

secondary composite

78

secondary-side switching element

80

secondary-side energy flow path

82

capacitor

84

primary-side switching element

86

parallel connection

88

primary-side energy flow path

90

iron core

Claims (30)

Energy storage cell equalization system for one in a vehicle ( 10 ) arranged high-voltage storage ( 26 ), the high-voltage storage ( 26 ) a plurality of structurally autonomous energy storage modules ( 32 . 32 ' ) each having a number of energy storage cells ( 40 . 40 ' ), wherein the vehicle ( 10 ) an electric machine ( 16 ), which is adapted to driven wheels ( 12 ) of the vehicle ( 10 ), the high-voltage memory ( 26 ) is adapted to the electric machine ( 16 ) to provide the electrical energy required therefor, comprising: an energy exchange system ( 42 ), which is adapted to an exchange of electrical energy between individual energy storage modules ( 32 . 32 ' ) to enable a connection manufacturing system ( 53 ), which is designed for at least one energy storage module ( 32 . 32 ' ) at least one energy storage cell contained therein ( 40 . 40 ' ) with the energy exchange system ( 42 ) and a control unit ( 52 ), which is designed for at least two energy storage cells ( 40 . 40 ' ) one the actual state of charge of the respective energy storage cell ( 40 . 40 ' ), and to determine, as a function of this state of charge state, whether the respective energy storage cell ( 40 . 40 ' ) around a receiving energy storage cell ( 40 ' ), which can absorb electrical energy due to its actual state of charge, or a donor energy storage cell ( 40 ), which due to its actual state of charge can deliver stored electrical energy, the control unit ( 52 ) is further formed to determine whether a defined memory operating state is present, in which at least one emitting energy storage cell ( 40 ) in a first energy storage module ( 32 ) and at least one receiving energy storage cell ( 40 ' ) in a second energy storage module ( 32 ' ), wherein the first and the second energy storage module ( 32 . 32 ' ) are different energy storage modules, and in the presence of this defined storage operating state, the connection production system ( 53 ) such that an energy exchange between the at least one emitting energy storage cell ( 40 ) and the at least one receiving energy storage cell ( 40 ' ). Energy storage cell compensation system according to claim 1, characterized in that the energy exchange system ( 42 ) is designed as a bus system. Energy storage cell compensation system according to one of the preceding claims, characterized in that the individual energy storage modules ( 32 . 32 ' ) at least for the realization of a series connection with one another via line components ( 34 ), the line components ( 34 ) compared to the energy exchange system ( 42 ) are designed structurally independent. Energy storage cell compensation system according to one of the preceding claims, characterized in that the connection production system ( 53 ) a plurality of connection modules ( 54 . 54 ' ), each energy storage module ( 32 . 32 ' ) each a connection module ( 54 . 54 ' ) assigned. Energy storage cell compensation system, according to claim 4, characterized in that the connection modules ( 54 . 54 ' ) each have a transducer element ( 58 . 58 ' ) and a switching element arrangement ( 60 . 60 ' ) exhibit. Energy storage cell compensation system according to claim 5, characterized in that the transducer element ( 58 . 58 ' ) is designed as a multi-winding transformer having a primary winding ( 72 . 72 ' ) and a number of secondary windings ( 74 . 74 ' ), wherein the primary winding ( 72 . 72 ' ) technically the energy exchange system ( 42 ) and the secondary windings ( 74 . 74 ' ) technically the energy storage cells ( 40 . 40 ' ), and that the switching element arrangement ( 60 . 60 ' ) a number of secondary-side switching elements ( 78 . 78 ' ) wherein each of the secondary-side switching elements ( 78 . 78 ' ) each a secondary network ( 76 . 76 ' ), consisting of an energy storage cell ( 40 . 40 ' ) and a secondary winding ( 74 . 74 ' ), is assigned such that when the secondary side switching element is closed ( 78 . 78 ' ) the secondary winding ( 74 . 74 ' ) and the energy storage cell ( 40 . 40 ' ) a secondary-side energy flow path ( 80 . 80 ' ) form. Energy storage cell compensation system according to one of claims 4 to 6, characterized in that the connection modules ( 54 . 54 ' ) each further a capacitor ( 82 . 82 ' ) facing the respective primary winding ( 72 . 72 ' ) is connected in parallel. Energy storage cell compensation system according to claim 7, characterized in that the connection modules ( 54 . 54 ' ) Furthermore, in each case a primary-side switching element ( 84 . 84 ' ), which the respective primary winding ( 72 . 72 ' ) is assigned such that when the primary-side switching element is closed ( 84 . 84 ' ) one from the primary winding ( 72 . 72 ' ) and the capacitor ( 82 . 82 ' ) existing primary energy flow path ( 88 . 88 ' ) is formed. Energy storage cell compensation system according to one of the preceding claims, characterized in that in the vehicle ( 10 ) another energy store ( 44 ) associated with the energy exchange system ( 42 ), the control unit ( 52 ) is further adapted to the connection manufacturing system ( 53 ) in such a way that at least one of the receiving energy storage cells ( 40 ' ) and / or at least one of the donating energy storage cells ( 40 ) with the further energy storage ( 44 ) is connected to an energy exchange between the respective energy storage cell ( 40 . 40 ' ) and the further energy store ( 44 ). Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted to determine whether a charging operation state is present, in which the high-voltage storage ( 26 ) electrical energy is supplied, the control unit ( 52 ) is further adapted, during a present loading operation state, for the connection production system ( 53 ) at least temporarily so as to at least one of the receiving energy storage cells ( 40 ' ) to supply an individualized amount of electrical energy. Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted to determine whether a removal operating state is present, in which the high-voltage storage ( 26 ) electrical energy is taken, the control unit ( 52 ) is further adapted, during a present unloading operating state, for the connection production system ( 53 ) at least in a second manner to control at least one of the donating energy storage cells ( 40 ) an individualized amount of electrical energy to entneh men. Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted, as a function of at least one for at least one energy storage cell ( 40 . 40 ' ), the operating state of the respective energy storage cell ( 40 . 40 ' ) representing an operating state variable and, depending on an evaluation result obtained thereby, the energy exchange between the at least one emitting energy storage cell ( 40 ) and the at least one receiving energy storage cell ( 40 ' ). Energy storage cell compensation system according to claim 12, characterized in that the operating state variable is the determined charge state quantity, wherein the control unit ( 52 ) is further adapted, depending on the for the at least two energy storage cells ( 40 . 40 ' ) determining a current present state of charge maximum value and a present state of charge minimum size value, and to allow the energy exchange when a given between the state of charge minimum value and the state of charge maximum value is equal to or greater than a predetermined difference threshold value. Energy storage cell compensation system according to claim 12 or 13, characterized in that the operating state quantity is the determined charge state quantity, wherein the control unit ( 52 ) is further adapted for at least one energy storage cell ( 40 . 40 ' ) to determine whether detected state of charge magnitude values are within a state of charge regime defined by a lower state of charge limit and an upper state of charge limit, and to allow for energy exchange as long as the state of charge values are within the state of charge operating window. Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted for at least one energy storage cell ( 40 . 40 ' ) to evaluate a temperature size representing the energy storage cell temperature, and depending on a thereby obtained Evaluation result to allow the energy exchange. Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted, at successive times for the at least two energy storage cells ( 40 . 40 ' ) repeatedly determine the respective charge state variables and determine whether it is a donating energy storage cell ( 40 ) or receiving energy storage cell ( 40 ' ), wherein the determination that it is a donor or a receiving energy storage cell, retained for the respective energy storage cell, as long as for the respective associated state of charge state, a predetermined condition is met. Energy storage cell compensation system according to one of the preceding claims, characterized in that the control unit ( 52 ) is further adapted, when determining whether it is a receiving or donating energy storage cell, also one for the high-voltage storage ( 26 ) given high-voltage storage operating strategy. Energy storage cell compensation system according to claim 17, characterized in that the high-voltage storage operation strategy is one of the following strategies: a discharge strategy, which is aimed at a high-voltage storage ( 26 ) discharge process, for the individual energy storage cells ( 40 . 40 ' ) each to achieve a maximum possible discharge; or a charging strategy aimed at one for the high-voltage storage ( 26 ) carried out for the individual energy storage cells ( 40 . 40 ' ) each to achieve a maximum possible charge of the individual energy storage cells. Energy storage cell compensation system according to one of the preceding claims, characterized in that the state of charge state is at least one of the following variables: energy storage cell voltage, energy storage cell charge or energy storage cell state of charge. Energy storage cell compensation system according to one of the preceding claims, characterized in that the charge state variable is the energy storage cell voltage, wherein the control unit ( 52 ) is designed to determine, depending on a comparison made for the respective energy storage cell voltage values, whether it is a receiving or a donating energy storage cell. Energy storage cell compensation system according to claim 20, characterized in that the control unit ( 52 ) is further adapted to a the internal resistance of the respective energy storage cell ( 40 . 40 ' ) to take into account. Energy storage cell balancing system as claimed in any one of claims 1 to 19, characterized in that it is in the charging state quantity to the energy storage cell charge or energy storage cell charging state, wherein the control unit ( 52 ) is designed for the at least two energy storage cells ( 40 . 40 ' ) in each case to determine a difference size between the state of charge magnitude and a given for the respective energy storage cell operating limit, and determine depending on the difference sizes, whether it is a receiving or a donating energy storage cell. Energy storage cell compensation system according to claim 22, characterized in that the operating limit as a function of one for the high-voltage storage ( 26 ) predetermined high-voltage storage operating strategy is determined. Energy storage cell compensation system according to claim 22 or 23, characterized in that it is the charge state quantity is the energy storage cell charge, wherein the control unit ( 52 ) is further adapted to determine an average value for the difference sizes, and for the at least two energy storage cells ( 40 . 40 ' ) in each case to determine a deviation quantity as a function of the respective difference size and the mean value, and to determine, depending on the deviation quantities, whether it is a receiving or a donating energy storage cell. Energy storage cell compensation system according to one of claims 22 to 24, characterized in that the control unit ( 52 ) is further configured, in the event that the charge state quantity is the energy storage cell charge, depending on the deviation quantity and a high-voltage storage operating strategy, to determine whether it is a receiving or a donating energy storage cell, and in the event that the state of charge magnitude is the energy storage cell state of charge as a function of the difference magnitude and a high-voltage storage operation strategy to determine whether it is a receiving or a donor energy storage cell. Energy storage cell compensation system according to claim 22, characterized in that the charge state variable is the energy storage cell charge, wherein the control unit ( 52 ) is further adapted, before formation of the difference quantity, a correction of the state of charge variable value as a function of a state of aging of the energy storage cell ( 40 . 40 ' ) representing aging state variable. Energy storage cell compensation system according to one of claims 22 to 26, characterized in that the control unit ( 52 ) is further configured, in the event that the charge state variable is the energy storage cell charge, as a function of the charge for the at least one donating energy storage cell ( 40 ) and / or for the at least one receiving energy storage cell ( 40 ' ) respectively determined deviation variable default signals for the associated primärsei term switching elements ( 84 . 84 ' ) and the associated secondary-side switching elements ( 78 . 78 ' ), and in the event that the state of charge state is the energy storage cell state of charge as a function of the energy storage cell (s) to which at least one 40 ) and / or for the at least one receiving energy storage cell ( 40 ' ) respectively determined difference quantity default signals for the associated primary-side switching elements ( 84 . 84 ' ) and the associated secondary-side switching elements ( 78 . 78 ' ) to investigate. High-voltage accumulator, which is adapted to an electric machine ( 16 ) in a vehicle ( 10 ) is arranged and which is designed to driven wheels ( 12 ) of the vehicle ( 10 ) to provide the required electrical energy, comprising: a plurality of structurally independently designed energy storage modules ( 32 . 32 ' ), wherein the energy storage modules ( 32 . 32 ' ) each have a number of energy storage cells ( 40 . 40 ' ), and an energy storage cell balancing system according to one of claims 1 to 27. Energy storage module, which is designed in a high-voltage storage ( 26 ) according to claim 28. Method for performing energy storage cell balancing for a vehicle ( 10 ) arranged high-voltage storage ( 26 ), the high-voltage storage ( 26 ) a plurality of structurally autonomous energy storage modules ( 32 . 32 ' ) each having a number of energy storage cells ( 40 . 40 ' ), wherein the vehicle ( 10 ) an electric machine ( 16 ), which is adapted to driven wheels ( 12 ) of the vehicle ( 10 ), the high-voltage memory ( 26 ) is adapted to the electric machine ( 16 ) provide the electrical energy required for this, the high-voltage storage ( 26 ), an energy exchange system ( 42 ), which is adapted to a exchange of electrical energy between individual energy storage modules ( 32 . 32 ' ) to enable a connection manufacturing system ( 53 ), which is designed for at least one energy storage module ( 32 . 32 ' ) at least one energy storage cell contained therein ( 40 . 40 ' ) with the energy exchange system ( 42 ), and a control unit ( 52 ), which is designed to carry out the following steps: - determining the actual state of charge of the respective energy storage cell ( 40 . 40 ' ) representative state of charge state for at least two energy storage cells ( 40 . 40 ' ), - determining depending on the state of charge state, whether it is in the respective energy storage cell ( 40 . 40 ' ) around a receiving energy storage cell ( 40 ' ), which can absorb electrical energy due to its actual state of charge, or a donor energy storage cell ( 40 ), which can deliver stored electrical energy due to its actual state of charge, - determining whether there is a defined storage operating state in which at least one emitting energy storage cell ( 40 ) in a first energy storage module ( 32 ) and at least one receiving energy storage cell ( 40 ' ) in a second energy storage module ( 32 ' ), wherein the first and the second energy storage module ( 32 . 32 ' ) to different energy storage modules ( 32 . 32 ' ), and - driving the connection manufacturing system ( 53 ) in the presence of the defined memory operating state such that an energy exchange between the at least one emitting energy storage cell ( 40 ) and the at least one receiving energy storage cell ( 40 ' ).

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