Measurement device for a redundant measurement of a current of a battery device

Abstract

The present invention is related to a measurement device (10) for redundant measurement of a current (CI) at a battery device (110) during charging and / or discharging having a first measurement lane (20) with a first electronic circuit (22) and a second measurement lane (40) with a second electronic circuit (42), wherein the first measurement lane (20) comprises a first current sensor (24) and the second measurement lane (40) comprises a second current sensor (44), wherein further the first electronic circuit (22) comprises first electronic components (26) for receiving a first measurement signal (1MS) from the first current sensor (24) and for providing the received first measurement signal (1MS) at a first data output (28), and wherein further the second electronic circuit (42) comprises second electronic components (46) for receiving a second measurement signal (2MS) from the second current sensor (44) and for providing the received second measurement signal (2MS) at a second data output (48), characterised in that the second current sensor (44), being dissimilar to the first current sensor (24) is additionally connected to the first electronic circuit (22), wherein the first electric circuit (22) comprises additional electric components (27) for receiving an additional measurement signal (AMS) from the second current sensor (44) and for providing the received additional measurement signal (AMS) at an additional data output (29).

Description

[0001] 2024LI0207P-W001 Lilium GmbH

[0002] 1

[0003] Measurement device for a redundant measurement of a current of a battery device

[0004] The present invention is related to a measurement device for redundant measurement of a current at a battery device, an aircraft having such a measurement device as well as a method for a redundant measurement of current at a battery device.

[0005] It is known that for the control of a battery device in a vehicle the exact knowledge about the charging and discharging current is of advantage. In particular for security relevant vehicles like aircrafts or the like the knowledge about the current going into the battery device or leaving the battery device is crucial for a save use of the battery device within the vehicle. Therefore, according to commonly known systems, measurement devices are known providing a redundancy in terms of electric components. The measurement is typically sensed by one common sensor but then processed by two separate measurement lanes. This provides a redundancy in terms of taking care of the sensed measurement information and provides separate and redundant processed measurement signals.

[0006] One disadvantage of the present systems is the fact that the sensor technology itself is not redundant. Providing redundant sensors would increase the weight significantly. Moreover, by using the commonly known shunt sensors and temperature problem would occur based on the resistors used in those shunt sensors. Since only one single sensor is used for the redundant measurement lanes of commonly known systems, failure of that sensor can be crucial. This is countered by the fact that the used sensors are of a very high security standard and thus come along with a high technical security thereby involving an increased cost and complexity.

[0007] It is an object of the present invention to overcome aforementioned disadvantages at least partly. In particular, it is an object of the present invention to show a cost-efficient way to provide an increased redundancy for a current measurement at the battery device.

[0008] Aforesaid object is achieved with the measurement device according to independent claim 1 , an aircraft with the features of independent claim 13 as well as a method with the features of independent claim 14. Features discussed in detail with respect to the sub claims can be combined freely if of technical sense. 2024LI0207P-W001 Lilium GmbH

[0009] 2

[0010] According to the present invention the measurement device for redundant measurement of a current at a battery device is meant for a measuring during a charging and / or a discharging situation. To provide that functionality the measurement device has a first measurement lane with a first electronic circuit and a second measurement lane with a second electronic circuit. The first measurement lane comprises a first current sensor and the second measurement lane comprises a second current sensor. Furthermore, the first electronic circuit comprises first electronic components for receiving the first measurement signal from the first current sensor and for providing the received first measurement signal at a first data output. In a similar way the second electronic circuit comprises second electronic components for receiving a second measurement signal from the second current sensor and for providing the received second measurement signal to a second data output. According to the present invention the second current sensor, being dissimilar to the first current sensor, is additionally connected to the first electronic circuit, wherein the first electric circuit comprises additional electric components for receiving an additional measurement signal from the second current sensor and for providing the received additional measurement signal at an additional data output.

[0011] With an inventive measurement device, it is possible to reduce the number of hardware components and still comply with high safety standard as well as to provide a desired level of high accuracy. This combination is in particular and advantage when using such a measurement device in an electric aircraft.

[0012] According to the present invention the measurement device is based on commonly known systems. It provides two separate and distinguished measurement lanes which are separate in terms of receiving measurement signals and processing of the received measurement signal. Each of the electronic circuits can have several electronic components to receive and process each of the measurement signals. Such electronic components can for example include control elements like PI controllers, predictors, circuit models or other processing components to provide the present current as exact as possible to estimate the state of health and / or the state of charge of the battery device.

[0013] Based on commonly known systems with two parallel measurement lanes now the inventive measurement device also has a redundancy in terms of the number of 2024LI0207P-W001 Lilium GmbH

[0014] 3 measurement sensors. The current sensors are specific for each of the measurement lanes meaning that first measurement lane has a dedicated first current sensor and separated from that one the second measurement lane comprises a second current sensor. In contrast to the commonly known systems, it is possible that also the sensing functionality for the current is provided in a redundant manner. The first current sensor can sense the present current going into the battery device during charging or leaving the battery device during discharging. In a similar way the second current sensor can measure the same charging and / or discharging current in a parallel way and provide that as a second measurement signal which most likely should have a similar or identical value than the first measurement signal. In other words, the present invention provides a sensor redundancy compared to the state of the art systems. In contrast to commonly known systems, the two measurement lanes are completely separated from the sensing part via the processing part to the output part. Therefore, if an issue arises with one of the sensors the sensor redundancy still can fulfil a safe and secure information about the present current situation. The redundancy is now extended to sensing, providing, processing and outputting each of the two separate measurement signals.

[0015] The inventive device now further comprises the second current sensor which is additionally connected to the first electronic circuit. Since it is already integrated in the second measurement lane the second current sensor can be defined as shared current sensor for both measurement lanes being one single sensor component but having to connections to provide the measurement signal to the two separate measurement lanes.

[0016] In contrast to the commonly systems now the increased redundancy leads to several advantages. Beside the fact that an increased redundancy is in particular of advantage in terms of high security vehicles like aircraft vehicles, further advantages can be achieved with this structure. For example, since at least two separate and redundant current sensors are provided none of those current sensors needs to meet the high technology security standards compared with the single sensor of the commonly known systems. Since in case of failure of one of the sensors the remaining sensor can still provide the sensing technology due to the redundancy of the sensing part, the costs and the burden at level of security for the sensors can be reduced. 2024LI0207P-W001 Lilium GmbH

[0017] 4

[0018] Beside the fact that now redundancy is provided, costs and complexity can be reduced by an inventive measurement device.

[0019] It is further of advantage that the measurement device now can provide different security levels for the different measurement lanes. For example, one of the measurement lanes can be defined to reach a higher security level or the second and thereby redundant measurement lane can meet a lower security level. The respective security standard applies to the possible choice, technology, costs and complexity of the provided electronic components as well as the provided current sensor in the respective measurement lane. In other words the inventive measurement device does provide an specific or distinguishable redundancy by having distinguished and thus dissimilar separate measurement lanes.

[0020] Beside the fact that the measurement signal itself can be provided and output directly as a current information, the electronic circuit in particular are processing the measurement signals in terms of evaluating the state of charge and / or the state of health to give and / or gather further information to control the charging procedure and / or the discharging procedure of the device.

[0021] Depending on the specifically used, different electric components, in particular the first measurement lane can use a model based estimation for calculation and / or estimation of the state of charge. This is in particular helpful to compensate potential reduced accuracy in the sensing technology of the current sensor, for example a Hall sensor, in the respective measurement lane. If the measurement lane is equipped with a current sensor having a higher accuracy, a different and more accurate analysis is possible, like a Colomb Counting for a shunt sensor as discussed later on.

[0022] In one embodiment, the first current sensor can be used to calculate the SoC and the second current sensor providing the additional measurement signal can be used to calculate the SoH. Thus, the use of the respective measurement signal as well as the applied algorithm can be adapted to the specific type of the sensor and the specific type of further processing. In other words, the first measurement lane is now enabled to make use of two separate measurement signals, the first measurement signal provided by the first current sensor and the additional measurement signal provided by the shared, second current sensor. Those two separate measurement signals can further be used separately for different calculations like SoH for the additional 2024LI0207P-W001 Lilium GmbH

[0023] 5 measurement signal and SoC for the first measurement signal. For both calculations different and specific algorithms can be used based on the specific type of the respective first and second current sensor. Beside the advantage of redundancy, this leads to an increased accuracy for the first and main measurement lane. In other words, the shared second current sensor can provide additional used during normal operation by providing higher accuracy for a specific part of the measurement signal processing, for example the SoH calculation. This is in contrast to a usual redundancy, where the redundant sensor would remain unused for most of the times being just a safety related embodiment.

[0024] It can be an advantage if according to the present invention the measurement device is characterized in that the first current sensor having a different sensing mechanism than the second current sensor, more in particular chosen from the list below:

[0025] - hall sensor,

[0026] - MR Sensor

[0027] - shunt sensor.

[0028] Aforesaid list is non exhaustive. In particular being different as to the type of the current sensors the redundancy between the two measurement lanes as well as the specific separate uses for measurement signal calculation in the first measurement lane can be optimized. While the general redundancy is already achieved by two separate current sensors of the same type, a different type of sensors provides additional redundancy in particular in situations when one of the technologies of one of the two sensors maybe dysfunctional due to circumstance parameters. Beside Hall sensors also magneto-resistive (MR) sensors can be sued. In case sensor types with the same technology are used they are sensing in particular with different sensing resolutions. By further providing different sensing technologies for example some sensors with a crucial temperature range might lose their sensing capability by reaching a risky temperature area. In such a situation the other, remaining sensor will so be able to provide the sensing functionality and the redundancy expands the usability of the measurement device across wider temperature ranges. Having a hall sensor as first current sensors as well as a shunt sensor as second and thus shared current sensor the different sensor mechanisms is a very easy and cost-efficient way to 2024LI0207P-W001 Lilium GmbH

[0029] 6 provide the redundancy on the sensor technology for the inventive measurement device. Additionally, the different sensor technologies come with different advantages as to the useability of the measurement. Shunt sensor technology is quite accurate to be used for estimating the State of Health (SoH). The measurement signal from a shunt sensor can in particular be used by a Coulomb Counting method using an integration of the measured current over time. Such a Coulomb Counting would comprise significant disadvantages if used with signals measured by a Hall sensor. Thus, for the Hall sensor technology, a different estimation method for the SoC can be used. This can be the use of a model-based estimation for SoC. In other words, each measurement lane having a different sensor technology is in particular combined with each measurement lane having a different and sensor-specific estimation algorithm for SoC. The discussed embodiment in particular help to avoid or at least reduce any common mode failure.

[0030] It is further of advantage if according to the present invention the measurement device according to the present invention is characterised in that the first measurement lane has a higher safety level than the second measurement lane, in particular each having a current sensor, an electronic component matching this respective safety level. If the measurement device according to the present invention is for example used in an aircraft vehicle the security level can be specifically assigned for the different measurement lanes. For example, the first measurement lane can be defined as a DAL-A and the second measurement level can be defined as a DAL-C lane. DAL meaning “design assurance level” and being correlated with a specific security standard for this specific measurement lane. By having a specific and different safety level for each of the measurement lanes, all of the electrical components as well as the sensors providing that measurement lane apply to that safety level. In other words, each of the measurement lanes now fulfils a certain standard while those standards can be different between the different measurement lanes. Again, the redundancy leads to an increased security by still keeping costs and complexity low in particular for the second measurement lane having a lower security standard than the first measurement lane. This can also be true due to the fact that most of the components in particular all of the electrical components as well as the sensors can be dissimilar between the two measurement lanes by specifically fulfilling the needs of the respective security level. 2024LI0207P-W001 Lilium GmbH

[0031] 7

[0032] It is further of advantage if a measurement device according to the present invention is characterised in that the first electronic components and the second electronic components are at least partly dissimilar or at least partly in general dissimilar. As mentioned further above, dissimilarity provides redundancy according to the present invention. The redundancy is increased by not only having different and dissimilar sensor technologies but also having dissimilar or at least partly dissimilar electronic components. In an embodiment as described in the paragraph above having different securities standards, dissimilarity leads to an increased and optimised redundancy by reduced costs and complexity.

[0033] Further advantages can be achieved if a measurement device according to the present invention is characterised in that the second current sensor being arranged electrically in series to the first current sensor. This leads to the mentioned internal or lane redundancy for the first measurement lane. While overall the measurement device provides a device redundancy by providing those two redundant measurement lanes, the additional incorporation of the second sensor inside of the first measurement lane provides an internal or lane specific redundancy inside of that first measurement lane. By having in particular the above mentioned dissimilar current sensors inside of the first measurement lane the redundancy is extended to different sensing technology, so that this can be understood as a first measurement lane with a shared double sensor functionality. In other words, this can also be defined as an in-lane redundancy. The measurement and the processing of the provided two measurement signals, namely the first and the additional measurement signal can in particular be done by the same electronic components so that the redundancy inside of the measurement lane only is provided by two separate sensors and by still using a common electronic circuit of this first measurement lane. Of course also separate electronic components can be possible for processing the first and the additional measurement signal separately. Beside the lane redundancy, the two different sensor can be used for different types of processing of the measurement signals, for example a model based algorithm for a first current sensor in the form of a Hall sensor for calculating the SoC and a coulomb counting algorithm for the third current sensor in the form of a Shunt sensor for calculating the SoH.

[0034] According to the present invention the complexity is not increased by having an additional sensor for the first measurement lane but the second current sensor is used as 2024LI0207P-W001 Lilium GmbH

[0035] 8 a shared sensor for both measurement lanes. For example, if a hall sensor is used for the first measurement lane and the shunt sensor is used for the second measurement lane, the second current sensor being connected also to the first measurement lane can also use the shunt sensing technology as shared sensor. Thereby, the redundancy is achieved by a minimum increase of complexity of the first measurement lane so that an increase of usability comes along with the same technology that is already been used and provided for the second measurement lane. This type of redundancy in particularly can also provide a validity check so that the shunt measurement now can calibrate or challenge the validity of the measurement signal being provided by the first or the second current sensor. Having a shunt sensor embodying the second current sensor as one single, shared sensor provides the option to estimate state of health SOH for both lanes. This might result in a drift away from the real SOH value but is acceptable for having the more desired reduction in hardware components.

[0036] It is further an advantage if a measurement device according to the present invention is characterised in that the first measurement lane comprises a third current sensor being similar to the first current sensor in particular having the same sensing mechanism with different sensing expression. In particular for battery devices charging and discharging over a wide range of current values, for different current ranges different types of current sensors might be more or less applicable. By having at least two different current sensors having the same sensing mechanism, for example having two different hall sensors with two different accuracies and / or two different measurement ranges, the usability of the first measurement lane can be increased even further. In a preferred embodiment the first measurement now can comprise a first, the shared second and a third current sensor while the second measurement lane still is quite simple using only one single second current sensor. This also shows very clearly, that the redundancy of the overall device by providing two separate measurement lanes underlines the complexity and the usability for an optimal measurement by in this case three separate current sensors at the first measurement lane. For example, the two different current sensors being the first and the third current sensor can be used for a different flight status of an air vehicle, for example distinguishing between a cruise situation, a landing situation, a starting situation or a charging situation. Furthermore, a switch can be provided to switch between the first and the third current sensor for example depending on the different flight charging situations. 2024LI0207P-W001 Lilium GmbH

[0037] 9

[0038] It is further an advantage if according to the present invention the measurement device is characterised in that the second current sensor is configured by one single current shunt sensor, in particular having two separate measurement connections, one with the first measurement lane and another one with the second measurement lane each having a separate measurement output. This reduces the complexity for an embodiment having the two separate current sensors build into the first measurement lane. Since the redundancy with the second current sensor is provided in particular by having a separate and dissimilar sensing technology for the second current sensor compared with the first current sensor, the second current sensor already having this dissimilar technology can be used in parallel. In other words, one single electronic component, for example the shunt sensor of the second measurement lane, can be used as a second shunt sensor with the same embodiment and thereby providing the device redundancy as well as the lane redundancy in the same way. Having a reduced complexity and a reduced weight, for additional measurement and redundancy purposes the functionality of a second current sensor is provided. By having the measurement signal from the shunt sensor used in both measurement lanes as second measurement signals as well as as additional measurement signal, a change in the processing algorithm for the first measurement lane is possible. While a current signal for the first current sensor, being a Hall sensor, can still be used for a model-based SoC estimation, the current signal from the second current sensor, being embodied as a shunt sensor, can be used in a Coulomb Counting estimation algorithm for SoC. Additionally or alternatively, the second current sensor can feed a separate state of health (SoH) estimation in the first measurement lane. Furthermore, the first electronic circuit can comprise specific electronic components for processing the current signal from the second current sensor. Those electronic components, for example electronic amplifiers for the sensing voltage, can be specifically made redundant for the two separate electronic circuits. Moreover, the electronic components in the first electronic circuit can be used for processing the first measurement signals as well as the additional measurement signal, while the second measurement signal, coming from the same sensor component like the additional measurement signal, is processed by the second electronic circuit.

[0039] According to the present invention the measurement device provides further advantages if characterised in that the first measurement lane comprises a first temperature sensor and / or the second measurement lane comprises a second temperature 2024LI0207P-W001 Lilium GmbH

[0040] 10 sensor. Since temperature is an important additional information and / or even a parameter for processing and interpreting the measurement signals, in particular for estimation of state of charge SOC and state of health SOH, that additional measurement information can be quite helpful. If a shunt sensor technology is used for one of the current sensors the additional temperature information can be used to control and compensate the temperature shift usually coming along with shunt sensor technology. Compensation of a temperature shift enable to increase the accuracy in sensing even further since the temperature has influence on the electrical resistance. In particular also the temperature sensors can be either similar or preferably dissimilar for example the identical temperature sensor can be used but in a specific and separate way for both of the measurement lanes to provide the additional temperature sensing redundancy.

[0041] The measurement device according to the present invention can further be characterised in that the additional electronic components comprise additional integration hardware and / or the second electronic components comprise second integration hardware, the integration hardware being configured to provide an integration of the received measurement signal respectively, in particular coulomb counting, and provide the integration of the received measurement signal to the respective data output to estimate the State of Health of the battery, wherein the additional electronic components and the and the second electronic components comprise a temperature compensation unit receiving the signal of the temperature sensors and the additional measurement signal and the second measurement signal respectively. Integration hardware provides a mathematical integration functionality to integrate the sensed measurement signal. This can be defined as a hardware integration so that a reduced software effort is applicable. In other words, also the processing by integration via hardware is provided in a redundant manner by having that integration hardware built into redundant manners in the two separate measurement lanes.

[0042] The measurement device according to the present invention can further be characterised in that the first electronic components comprises a processing unit receiving the first measurement signal and the third measurement signal to calculate the State- of charge of the battery; and wherein the second electronic components comprise a second processing unit receiving the second measurement signal to calculate the 2024LI0207P-W001 Lilium GmbH

[0043] 11

[0044] State-of-charge of the battery. In other words, the two different signals are used for two different types of calculation, namely to calculate the SoC as well as the SoH.

[0045] The measurement device according to the present invention can further be characterised in that the first current sensor and the second current sensor have a combined current interruption device , wherein the current interruption device is triggered when an overcurrent is determined on the first measurement lane and the second measurement lane. Having a combined current interruption device reduces the overall complexity and weight. An internal trigger for the current interruption device, for example sensing an over-current by overcurrent measurement, can execute and release the current interruption device. Of course, also external triggers or external switches can be used to activate the current interruption device and disconnect the battery device from a charging or discharging component. In particular the two lanes are combined logically by an “AND” connection, meaning the current interruption device is only triggered, when for both measurement lanes and overcurrent is detected at the same time.

[0046] It can be of further advantage if the measurement device according to the present invention is characterised in that the first measurement lane and the second measurement lane are enclosed at least partly in a common housing. By providing all of the different, redundant and separate measurement lanes within a common housing, the usability and the mountability is increased. The overall complexity is decreased and handling becomes more easy and efficient.

[0047] A further advantage can be achieved if according to the present invention the measurement device is characterised in that the first measurement lane and the second measurement lane comprise one single bus connection for electrical connection to a battery bus of the battery device. That single bus connection can in particular be connected for the respective sensing technology, so that the separate measurement current sensors now connect to the same and identical electrical connection of the battery bus. Parallel wiring goes into inside of the separate housing and all are combined and connected with a single connection flap. The power can be received or measured at the HV bus and no separate power supply is necessary.

[0048] It is a further embodiment of the present invention to provide an aircraft having at least one electricity driven engine powered by at least one battery device, wherein 2024LI0207P-W001 Lilium GmbH

[0049] 12 the battery device is equipped with an inventive measurement device. Thereby, the inventive aircraft comes along with the same advantages as discussed in detail with respect to the inventive measurement device.

[0050] It is further an embodiment of the present invention to provide a method for redundant measurement of current at a battery device during charging and / or discharging of a measurement device with the features of the present invention, comprising the following steps:

[0051] - measuring a first current value during charging and / or discharging via the first measurement lane,

[0052] - measuring a second charging current value during charging and / or discharging via the second measurement lane,

[0053] - providing the first and the second charging current value for redundant estimation of at least one battery device parameter.

[0054] By using an inventive measurement device, the inventive method comes along with the same advantages discussed in detail with respect to the inventive measurement device. In particular it can be used for estimation of the state of charge and / or the state of health of the battery device. Also, validation procedures can be applied for measurement in lane and / or measurement across the lanes. Also, double measurement for increased safety and / or fuse activation can be provided by the inventive method.

[0055] A further advantage can be achieved if according to the present invention the method is characterised in that the first current value is provided in the form of the first measurement signal to the first electronic components the second current value is provided in the form of the second measurement signal to the second electronic components and in the form of the additional measurement signal to the additional electronic components. In particular the different measurement signals can be used for different calculations, for example one for SoH calculation and another one for SoC calculation, as described in more detail further above.

[0056] The present invention is discussed in more detail with the respect to the accompanying drawings. Those show in a schematically way: 2024LI0207P-W001 Lilium GmbH

[0057] 13

[0058] Figure 1 a first embodiment of a measurement device,

[0059] Figure 2 a further embodiment of an inventive measurement device,

[0060] Figure 3 a further embodiment of an inventive measurement device,

[0061] Figure 4 a further embodiment of an inventive measurement device,

[0062] Figure 5 a further embodiment of an inventive measurement device and

[0063] Figure 6 an embodiment of an inventive aircraft.

[0064] Figure 1 shows a first embodiment of a measurement device. It is provided to measure current Cl to be sensed by two different measurement lanes, a first measurement lane 20 and a second measurement lane 40.

[0065] The first measurement lane 20 has two connectors for measurement connections 60 to sense a current Cl with a first current sensor 24. The result of that sensing step is the provision of one first measurement signal 1 MS and providing that first measurement signal 1 MS to a first electronic circuit 22. Several first electronic components 26 can now process the first measurement signal 1 MS and provided directly or in an amended and processed way a first data output 32.

[0066] In a similar way, second measurement lane 40 comprises at least one measurement connection 60 to sense a current Cl connected in series to the same battery bus 112 with a second current sensor 44. The sensed second measurement signal 2MS is now provided to the second electronic circuit 42 and several second electronic components 46 can now be used to process the second measurement signal 2MS. After processing the second measurement signal, this second measurement signal 2MS can directly or in a processed way be communicated to a second data output 48.

[0067] As it can be clearly seen in figure 1 the two measurement lanes 20 and 40 are completely redundant. In particular the redundancy extends over the sensor functionality provided by two separate current sensors 24 and 44. Moreover, the redundancy is provided by also having separate measurement connections 60 being specific and distinguished for each of the separate current sensors 24 and 44. 2024LI0207P-W001 Lilium GmbH

[0068] 14

[0069] Figure 3 shows an embodiment of the inventive measurement device 10 that is based on the embodiment of figure 1 . In the embodiment of figure 3 now the second current sensor 44 is connected within the first measurement lane 20. This can be defined as an in-lane redundancy since the second current sensor 44 has its own measurement connections 60 connected in series to the same battery bus 112 so that now the different sensors sense the present current Cl. Thereby, within the first measurement lane 20 an additional measurement signal AMS is provided to the first electronic circuit 22 and processed in parallel all together with the first measurement signal 1MS but by separate additional electronic components 27 and provide to a separate additional data output 29. Now in this situation a double redundancy is provided namely an in-lane redundancy between the first current sensor 24 and the shared second current sensor 44 as well as a lane redundancy between the two different measurement lanes 20 and 40. The first current sensor 24 can be embodied by a Hall sensor to provide calculation of SoC while the shared second current sensor 44 can be embodied by a Shunt sensor to calculate the SoH.

[0070] Figure 2 increases complexity but also security of the figure 3 and figure 1 measurement devices 10 even further. In this case now first measurement lane 20 additionally comprises a third current sensor 30. The third current sensor 30 can in particularly be of the same or similar type than the first current sensor 24, for example both having a hall sensing technology. Also, in the case of figure 2 now a third measurement signal 3MS is provided to the first electronic circuit 22 thereby even more increasing the redundancy and the security for the security level of the first measurement lane 20.

[0071] In figure 3 the second current sensor 44 is embodied by one electronic component but still having measurement connections 60 connected in series to the same battery bus 112. This can be defined as being a shared sensor for both measurement lanes 20 and 40. Thereby, by the double usability of electronic component of the shared second current sensor 44 two separate measurement signals namely the second measurement signal 2MS and the additional measurement signal AMS are provided. Redundancy is thereby provided by a reduced complexity of the measurement device 10.

[0072] Figure 4 shows a situation similar to figure 2 but with additional sensing information.

[0073] In this situation now the first measurement lane 20 comprises an additional 2024LI0207P-W001 Lilium GmbH

[0074] 15 temperature sensor 21 and the second measurement lane 40 comprises a second temperature sensor 41 . Thereby, the electronic circuits 22 and 42 can have an additional integration hardware 25 and second integration hardware 45 to provide a hardware and mathematical integration algorithm built into each of the electronic circuits 22 and 42 for processing the measurement 2MS and AMS. Furthermore, temperature compensation units are provided for the additional measurement signal AMS and the second measurement signal 2MS.

[0075] Figure 5 shows a further embodiment by having a single common current interruption device 70 being connected in series to all of the measurement connections 60. Also, a single battery bus 112 is provided for sensing the current signal Cl. Additionally a common housing 80 is provided to cover all of the measurement lanes 20 and 40 and in particular most of the parts of the measurement device 10.

[0076] In figure 6 an inventive aircraft 100 is described and depicted. It has separate wings 130 all of them being equipped with electrical working engines 120 being provided with power by a battery device 110 being connected by a battery bus 112.

[0077] The present invention is described with respect to the drawings only by the way of examples.

[0078] 2024LI0207P-W001 Lilium GmbH

[0079] 16

[0080] Reference signs

[0081] 10 measurement device

[0082] 20 first measurement lane

[0083] 21 additional temperature sensor

[0084] 22 first electronic circuit

[0085] 23 temperature compensation unit

[0086] 24 first current sensor

[0087] 25 additional integration hardware

[0088] 26 first electronic components

[0089] 27 additional electronic components

[0090] 28 first data output

[0091] 29 additional data output

[0092] 30 third current sensor

[0093] 40 second measurement lane

[0094] 41 second temperature sensor

[0095] 42 second electronic circuit

[0096] 43 temperature compensation unit

[0097] 44 second current sensor

[0098] 45 second integration hardware

[0099] 46 second electronic components

[0100] 48 second data output

[0101] 60 measurement connection

[0102] 70 combined current interruption device

[0103] 80 housing

[0104] 100 aircraft

[0105] 110 battery device

[0106] 112 battery bus

[0107] 120 engine

[0108] 130 wing

[0109] Cl current

[0110] 1 MS first measurement signal 2024LI0207P-W001 Lilium GmbH

[0111] 17

[0112] 2MS second measurement signal

[0113] AMS additional measurement signal

[0114] 3MS third measurement signal

Claims

2024LI0207P-W001 Lilium GmbH18 claims1. Measurement device (10) for redundant measurement of a current (Cl) at a battery device (110) during charging and / or discharging having a first measurement lane (20) with a first electronic circuit (22) and a second measurement lane (40) with a second electronic circuit (42), wherein the first measurement lane (20) comprises a first current sensor (24) and the second measurement lane (40) comprises a second current sensor (44), wherein further the first electronic circuit (22) comprises first electronic components (26) for receiving a first measurement signal (1 MS) from the first current sensor (24) and for providing the received first measurement signal (1 MS) at a first data output (28), and wherein further the second electronic circuit (42) comprises second electronic components (46) for receiving a second measurement signal (2MS) from the second current sensor (44) and for providing the received second measurement signal (2MS) at a second data output (48), characterised in that the second current sensor (44), being dissimilar to the first current sensor (24), is additionally connected to the first electronic circuit (22), wherein the first electric circuit (22) comprises additional electric components (27) for receiving an additional measurement signal (AMS) from the second current sensor (44) and for providing the received additional measurement signal (AMS) at an additional data output (29).

2. Measurement device (10) according to claim 1 , characterised in that the first current sensor (24) having a different sensing mechanism than the second current sensor (44), in particular chosen from the list below:- Hall sensor- MR sensor- Shunt sensor3. Measurement device (10) according to any of the preceding claims, characterised in that the first measurement lane (20) has a higher safety level than the second measurement lane (40), in particular each having a current sensor (24, 44) and electronic components (26, 46) matching the respective safety level.2024LI0207P-W001 Lilium GmbH194. Measurement device (10) according to any of the preceding claims, characterised in that the first electronic components (26) and the second electronic components (46) are at least partly dissimilar or at least partly in general dissimilar.

5. Measurement device (10) according to any of the preceding claims, characterised in that the second current sensor (44) being arranged electrically in series to the first current sensor (24).

6. Measurement device (10) according to any of claims 5, characterised in that the first measurement lane (20) comprises a third current sensor (30) being similar to the first current sensor (24), in particular having the same sensing mechanism with different sensing expression.

7. Measurement device (10) according to any of the preceding claims, characterised in that the first measurement lane (20) comprises a first temperature sensor (21 ) and / or the second measurement lane (40) comprises a second temperature sensor (41 ).

8. Measurement device (10) according to any of the preceding claims, characterised in that the additional electronic components (27) comprise additional integration hardware (25) and / or the second electronic components (46) comprise second integration hardware (45), the integration hardware (25, 45) being configured to provide an integration of the received measurement signal (2MS, AMS) respectively, in particular by coulomb counting, and provide the integration of the received measurement signal (2MS, AMS) to the respective data output (29, 48) to estimate the State-of-Health of the battery, wherein the additional electronic components (27) and the second electronic components (46) comprise a temperature compensation unit (23, 43) receiving the signal of the temperature sensors (21 , 41 ) and the additional measurement signal (AMS) and the second measurement signal (2MS) respectively.

9. Measurement device (10) according to any of the preceding claims, characterised in that the first electronic components (26) comprises a processing unit receiving the first measurement signal (1 MS) and the third measurement2024LI0207P-W001 Lilium GmbH20 signal (3MS) to calculate the State-of charge of the battery; and wherein the second electronic components (46) comprise a second processing unit receiving the second measurement signal (2MS) to calculate the State-of-charge of the battery.

10. Measurement device (10) according to any of the preceding claims, characterised in that the first current sensor (24) and the second current sensor (44) have a combined current interruption device (70), wherein the current interruption device (70) is triggered when an overcurrent is determined on the first measurement (20) lane and the second measurement lane (40).11 . Measurement device (10) according to any of the preceding claims, characterised in that the first measurement lane (20) and the second measurement lane (40) are enclosed at least partly by a common housing (80).

12. Measurement device (10) according to any of the preceding claims, characterised in that the first measurement lane (20) and the second measurement lane (40) comprise one single bus connection for electrical connection to a battery bus (112) of the battery device (110).

13. Aircraft (100) having at least one electricity driven engine (120) powered by at least one battery device (110), wherein the battery device (110) is equipped with a measurement device (10) with the features of any of claims 1 to 12.

14. Method for redundant measurement of current (Cl) at a battery device (110) during charging and / or discharging with a measurement device (10) with the features of any of claims 1 to 12, comprising the following steps:- Measuring a first current value during charging and / or discharging via the first measurement lane (20),- Measuring a second charging current value during charging and / or discharging via the second measurement lane (40),Providing the first and the second charging current value for redundant estimation of at least one battery device parameter.2024LI0207P-W001 Lilium GmbH2115. Method according to claim 14, characterised in that the first current value is provided in the form of the first measurement signal (1 MS) to the first electronic components (26) the second current value is provided in the form of the second measurement signal (2MS) to the second electronic components (46) and in the form of the additional measurement signal (AMS) to the additional electronic components (27).

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