Method for determining a state of health of an electrical energy store and monitoring system

Abstract

The invention relates to a method for determining a state of health (SOH) of a first electrical energy store (10) for an at least partially electrically operable motor vehicle by means of a monitoring system (1), in which at least one parameter characterising the first electrical energy store (10) is detected by discharging or charging to a first target state of charge (Z_min, Z_max) and then charging or discharging to a second target state of charge (Z_max, Z_min) of the first electrical energy store (10), wherein, during the discharging of the first electrical energy store (10) to the first target state of charge (Z_min, Z_max), all transferable energy (E_x) is transferred to a further second electrical energy store (20) electrically coupled to the first electrical energy store (10). The invention further relates to a monitoring system (1).

Description

[0001] Method for determining a health status of an electrical energy storage device and monitoring system

[0002] The invention relates to a method for determining a state of health of an electrical energy storage device for an at least electrically operable motor vehicle according to patent claim 1. Furthermore, the invention relates to a monitoring system.

[0003] Current methods for the metrological determination of residual capacity and / or residual energy in vehicle batteries or electrical energy storage devices for motor vehicles first carry out a complete discharge to, for example, 0% SOC (state of charge) and then a controlled charge to, for example, 100% SOC, whereby the amount of charge and / or energy passed through when charging the battery or electrical energy storage device is measured and used to determine the residual capacity and / or residual energy.

[0004] The object of the invention is to provide a method and a monitoring system for determining the health status of electrical energy storage devices, by means of which energy loss can be avoided particularly efficiently.

[0005] This object is achieved according to the invention by a method having the features of patent claim 1 and by a monitoring system according to the invention. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0006] One aspect of the invention relates to a method for determining a state of health (SOH) of a first electrical energy storage device for an at least partially electrically operated motor vehicle, in particular by means of a monitoring system. It is provided that at least one parameter characterizing the first electrical energy storage device is detected by discharging or charging the first electrical energy storage device to a first target state of charge and subsequently charging or discharging the first electrical energy storage device to a second target state of charge. In other words, the electrical energy storage device can be discharged in its state of charge (SOC) to the first target state of charge of, for example, 0%, which corresponds to an empty electrical energy storage device.This first target charge level thus forms a reference point, around which a reference point or orientation can be established. The electrical energy storage device is then charged to its maximum, thus reaching the second target charge level. The amount of charge or energy required to reach the second target charge level allows this amount of charge or energy to be compared with a reference capacity or reference energy, where the reference capacity or reference energy corresponds to the maximum amount of charge or energy that a new electrical energy storage device can hold. The health status (SOH) can then be expressed as a percentage based on the ratio.

[0007] As an alternative to the proposed discharge, it is also possible to charge the electrical energy storage device to a first target charge level of, for example, 100% in preparation for a complete discharge to, for example, 0%. This first target charge level thus forms an alternative reference point, at which an orientation point or orientation can be established. The electrical energy storage device is now discharged to its minimum, thus reaching the second target charge level. By determining the amount of charge or energy required to reach the second target charge level, it is also possible to compare this amount of charge or energy with a reference capacity or reference energy, whereby the reference capacity or reference energy corresponds to the maximum amount of charge or energy that can be absorbed by a new electrical energy storage device. The state of health SOH can therefore be expressed as a percentage from the ratio.

[0008] When the electrical energy storage device is discharged, it is provided that all of the energy to be discharged is transferred to a second electrical energy storage device coupled to the first electrical energy storage device. The provision is that the energy is not wasted or consumed during discharging, but rather transferred to another electrical energy storage device so that it can be used elsewhere. Accordingly, there is no energy loss here; instead, energy is simply transferred from one electrical energy storage device to the second electrical energy storage device. In other words, one aspect of the invention is to use a V2V charging process for diagnostic purposes. V2V (Vehicle to Vehicle) is being promoted by an increasing number of car manufacturers.The focus is on charging a vehicle battery or an electrical energy storage device with a very low state of charge in order to ensure a remaining driving range using energy from a second vehicle battery. However, the potential for diagnostics resulting from the charge transfer between two motor vehicles or vehicles is not sufficiently explored in this context. For example, this can be used to perform a diagnosis to determine the state of health. The invention described herein demonstrates an energy-saving potential that arises from the energy transfer to another vehicle battery or electrical energy storage device instead of discharging the vehicle battery or electrical energy storage device via auxiliary consumers such as the heater.

[0009] Bidirectional charging / discharging via V2V, V2H (vehicle to home), or V2G (vehicle to grid) makes it possible to exchange energy between different electrical energy storage devices, thus preventing waste. Finally, it is also possible to simultaneously generate a monetary benefit by charging a second electrical energy storage device.

[0010] In an advantageous embodiment of the invention, it is provided that the difference value of the transferred energy during the V2V discharging of the first electrical energy storage device to the first target charge level and / or the subsequent charging of the first electrical energy storage device to the second target charge level, insofar as this also occurs at least partially using V2V, is measured. These two difference values ​​make it possible to determine the energy difference between the first and second energy storage devices after the diagnosis. This also makes it possible to convert this difference value into a bill, whereby a monetary value of a current currency is calculated depending on the difference value for either the first or the second energy storage device.

[0011] In yet another advantageous embodiment of the invention, it is provided that after the first electrical energy store has been discharged, the difference value during charging from the second energy store is loaded back into the first energy store. In other words, the initial charge state of the electrical energy store is resumed and returned to, for example, a customer. In yet another advantageous embodiment of the invention, it is provided that, during recharging, one of the electrical energy stores is charged up to a target charge state with additional energy from a third electrical energy store for determining the customer's own state of health, in addition to the transferable energy from the further electrical energy store. In particular, during recharging, the first electrical energy store can, in addition to the transferable energy from the second electrical energy store orThe difference value can be used to charge the vehicle to a target charge level using additional energy from a third electrical energy storage device to determine the vehicle's own state of health. In other words, this enables bidirectional determination of the respective health levels, with the second being charged while one electrical energy storage device is discharging. To compensate for a difference between the maximum target charge level and the received energy value, the third electrical energy storage device and / or a charging infrastructure is connected and can transmit the difference value. This makes it possible to charge the second electrical energy storage device to the second target charge level, thus enabling maximum charging.

[0012] In another advantageous embodiment of the invention, it is provided that the at least one characterizing parameter is recorded and stored as a historical parameter. In this case, historical information about the motor vehicle is stored, for example, in a log, so that future health states that have been determined can be compared with the current health state. These time-related details can be used accordingly for illustration purposes and can reflect characterizing changes in the electrical energy storage device. Furthermore, it is also possible to record the technical values ​​during V2V charging, such as the current and voltage curves, since these can be evaluated to describe the aging behavior of the respective electrical energy storage devices.

[0013] In another advantageous embodiment of the invention, the characterizing parameter is determined depending on at least one other environmental parameter. Since electrical energy storage devices react depending on environmental parameters, these environmental parameters are included in the calculation of the SOH, thus enabling a more precise determination of the state of health.In another advantageous embodiment of the invention, it is provided that an ambient temperature and / or a mileage of the motor vehicle and / or a battery cell temperature of the first electrical energy storage device and / or a region in which the motor vehicle is located and / or a chip key of the electrical energy storage device and / or an age of the electrical energy storage device and / or an ampere-hour throughput of the electrical energy storage device and / or a number of charging cycles of the electrical energy storage device and / or weather information are recorded as environmental parameters. All of these environmental parameters can influence the health status of the electrical energy storage device, whereby a more precise statement or assessment of the health status of the electrical energy storage device can be recorded by determining it as a function of these environmental parameters.

[0014] A further aspect of the invention relates to a monitoring system with at least one V2V diagnostic charging cable for determining the health status of an electrical energy storage device of an at least partially electrically operated motor vehicle and for measuring an energy / charge quantity as well as other parameters, by means of which at least one parameter characterizing the electrical energy storage device can be detected by discharging and subsequently charging the electrical energy storage device. It is provided that, during the discharging of the electrical energy storage device, the energy can be transferred to another electrical energy storage device.Furthermore, it is provided that, when the first electrical energy storage device is discharged, the second electrical energy storage device can be charged with additional energy from a third electrical energy storage device to determine the patient's own state of health up to a target charge level, in addition to the transferable energy from the first electrical energy storage device. In particular, it is also provided that the system checks the first electrical energy storage device by discharging it to a first target charge level and subsequently charging it to a second target charge level, thus recording a parameter for determining the patient's state of health.

[0015] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own. The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show:

[0016] Fig. 1 is a picture diagram illustrating an inventive

[0017] Method for determining a health status of an electrical energy storage device for an at least partially electrically operated motor vehicle.

[0018] In the figure, identical and functionally identical elements are provided with the same reference numerals.

[0019] Fig. 1 shows a diagram illustrating the method for determining a state of health (SOH) of a first electrical energy storage device 10 in an at least partially electrically operated motor vehicle, in particular a passenger car. This method is controlled by a monitoring system 1. The method comprises a plurality of method steps and components, which are shown in the diagram, whereby a chronological sequence of the subsequent steps is not mandatory.

[0020] First, the first electrical energy storage device 10 of a motor vehicle, whose health status SOH is to be examined, as well as the monitoring system 1, which monitors and coordinates the entire process steps or the entire procedure, are presented.

[0021] For parameter acquisition, the first electrical energy storage device 10 is first discharged, in particular up to a first target charge state Z_min of the charge state SOC, in particular the first electrical energy storage device 10 is completely discharged.

[0022] During this discharge process, the transferable energy E_x is recorded and transferred to a second electrical energy storage device 20, which can, for example, be the electrical energy storage device of another motor vehicle and thus has its own further state of charge SOC* and further state of health SOH*. Subsequently, the first electrical energy storage device 10 is charged to the second target state of charge Z_max, with the amount of energy E_max required for charging being measured. In other words, after the electrical energy storage device 10 has been completely discharged, the same electrical energy storage device 10 is fully charged. The state of health SOH can be recorded depending on the amount of energy E_max used for this purpose.For this purpose, for example, the respective algorithms or software that can be found in the monitoring system 1 are used, which are, for example, stored and applicable in an electrical energy storage device of the monitoring system 1.

[0023] A difference between the transferable energy E_x and the required energy E_max is also measured and can be used, for example, as an important parameter for analysis. Using this difference, the energy required to fully charge the first electrical energy storage device 10 can be calculated.

[0024] In parallel, the second electrical energy storage device 20 is charged with the additional energy E_y from a third energy storage device 30 during the discharge process of the first storage device 10 in order to charge the state of charge SOC up to a target state of charge Z_max and to determine the state of health SOH therefrom.

[0025] Furthermore, it is intended or also possible that operating strategies for the first energy storage device 10 and the second electrical energy storage device 20 can be proposed based on the determined state of health SOH.

[0026] Finally, characterizing parameters are recorded and stored as historical data, and the determination of these parameters is carried out depending on various environmental parameters of an environment of the respective motor vehicles or the respective electrical energy storage devices 10, 20, such as the ambient temperature, the mileage of the respective motor vehicles, the battery cell temperature, the region in which the motor vehicles are located, the type of electrical energy storage device 10, 20, an age, an ampere-hour throughput, a number of charging cycles and other weather conditions.

[0027] Overall, the diagram in Fig. 1 illustrates the method for determining the health status of electrical energy storage devices 10, 20, taking into account various parameters and environmental conditions or environmental parameters.

[0028] 1 surveillance system

[0029] 10 first electrical energy storage

[0030] 20 second electrical energy storage

[0031] 30 third electrical energy storage

[0032] SOH health status

[0033] SOH* Health status

[0034] Z min first target charge level

[0035] Z_max second target state of charge E_x transferable energy E_max necessary energy E_y additional energy SOC state of charge SOC* state of charge

Claims

Patent claims 1. Method for determining a state of health (SOH) of a first electrical energy store (10) for an at least partially electrically operated motor vehicle by means of a monitoring system (1), in which at least one parameter characterizing the first electrical energy store (10) is detected by discharging or charging to a first target state of charge (Z_min, Z_max) and subsequent charging or discharging to a second target state of charge (Z_max, Z_min) of the first electrical energy store (10), wherein during the discharging of the first electrical energy store (10) to the first target state of charge (Z_min, Z_max), all transferable energy (E_x) is transferred to a further second electrical energy store (20) electrically coupled to the first electrical energy store (10).

2. Method according to claim 1, characterized in that a difference value between the transferable energy (E_x) and the energy (E_max) necessary for charging or discharging the first electrical energy store (10) up to the second target charge state (Z_max, Z_min) is measured.

3. Method according to claim 2, characterized in that after the determination of the parameter, the first electrical energy storage device (10) is discharged by the difference value.

4. Method according to one of the preceding claims, characterized in that one of the electrical energy stores (10, 20) is recharged in addition to the transferable energy (E_x) from the further electrical energy store (10, 20) with additional energy (E_y) from a third electrical energy store (30) for determining the own state of health (SOH*) is charged to a target charge level (Z_max, Z_min).

5. Method according to one of the preceding claims, characterized in that at least one operating strategy for the electrical energy storage device (10) is proposed as a function of the determined state of health (SOH, SOH*).

6. Method according to one of the preceding claims, characterized in that the at least one characterizing parameter is recorded and stored as a historical parameter.

7. Method according to one of the preceding claims, characterized in that the determination of the characterizing parameter takes place as a function of at least one further environmental parameter.

8. The method according to claim 7, characterized in that an ambient temperature and / or a mileage of the motor vehicle and / or a battery cell temperature of the first electrical energy storage device (10, 20) and / or a region in which the motor vehicle is located and / or a type code of the electrical energy storage device (10, 20) and / or an age of the electrical energy storage device (10, 20) and / or an ampere-hour throughput of the electrical energy storage device (10, 20) and / or a number of charging cycles of the electrical energy storage device (10, 20) and / or weather information are recorded as environmental parameters.

9. Monitoring system (1) with at least one V2V diagnostic charging cable for determining a state of health (SOH) of a first electrical energy storage device (10) of an at least partially electrically operated motor vehicle (14) and for measuring an energy and / or charge quantity as well as further parameters, by means of which at least one parameter characterising the first electrical energy storage device (12) can be determined by discharging or charging to a first target charge level (Z_min, Z_max) and subsequent charging or discharging to a second target charge level (Z_max, Z_min) of the first electrical energy store (10), characterized in that when discharging to the first target charge level (Z_min), all transferable energy (E_x) can be transferred to a further second electrical energy store (20) electrically coupled to the first electrical energy store (10) by means of the at least one V2V diagnostic charging cable.

10. Monitoring system (1) according to claim 9, characterized in that the second electrical energy store (20) can be charged during the discharging of the first electrical energy store (10) in addition to the transferable energy (E_x) from the first electrical energy store (10) with additional energy (E_y) from a third electrical energy store (30) for determining the own state of health (SOH*) up to a target charge state (Z_max).

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