Measuring setup and method for determining the value of a state variable of a battery

Abstract

The invention relates to a measuring arrangement (10) for determining a value of a state variable (T) of a battery (38), wherein the measuring arrangement (10) comprises a measuring device (12) and a control device (14) coupled to it, which is designed to determine the value of the state variable (T) as a function of a measurement signal (A1, A2, A3) detected by means of the measuring device (12).The measuring device (12) comprises an electrical resonant circuit (16) with an inductive resonant circuit part (16a) and a capacitive resonant circuit part (16b), and an excitation unit (22) coupled to the resonant circuit (16) for exciting the resonant circuit (16) and for detecting a response signal (A1, A2, A3) of the resonant circuit (16) to the excitation, wherein the control device (14) is designed to determine a quality value of a quality parameter (G) depending on the detected response signal (A1, A2, A3) and to determine a temperature value as the value of the state variable (T) depending on the determined quality value.

Description

[0001] The invention relates to a measuring arrangement for determining the value of a state variable of a battery, wherein the measuring arrangement comprises a measuring device and a control device coupled thereto, which is designed to determine the value of the state variable as a function of a measurement signal acquired by means of the measuring device. The invention further relates to a method for determining the value of a state variable of a battery.

[0002] For batteries, especially those used in motor vehicles, the aim is to gather as much information as possible about the battery's condition by employing various sensors and to detect potential risks early by monitoring the immediate battery environment. Due to the typical size of motor vehicle batteries, particularly high-voltage batteries, multi-cell sensors are often required for this purpose. This makes such monitoring relatively complex and expensive.

[0003] German patent DE 10 2008 042 746 A1 describes a sensor system with a sensor resonant circuit whose quality factor depends on the temperature of the sensor's surroundings, and an evaluation unit with an evaluation resonant circuit inductively coupled to the sensor resonant circuit. The evaluation unit can detect energy transfer from the excited evaluation resonant circuit to the sensor resonant circuit and derive information about the temperature of the surroundings. Temperature compensation can be performed based on the determined temperature. By detecting changes in the sensor's resonant frequency, an environmental condition can be defined. Since the resonant frequency of a sensor circuit is typically also temperature-dependent, the environmental condition can be defined more precisely based on temperature compensation.

[0004] The object of the present invention is to provide a measuring arrangement and a method that enable the determination of a value of a state variable of a battery in the simplest, most cost-effective and most effective way possible.

[0005] This problem is solved by a measuring arrangement and a method with the features according to the respective independent patent claims. Advantageous embodiments are the subject of the dependent patent claims, the description, and the figures.

[0006] A measuring arrangement according to the invention for determining the value of a state variable of a battery comprises a measuring device and a control device coupled to it, which is designed to determine the value of the state variable as a function of a measurement signal acquired by the measuring device. The measuring device includes an electrical resonant circuit with an inductive resonant circuit section and a capacitive resonant circuit section, as well as an excitation unit coupled to the resonant circuit for exciting the resonant circuit and for acquiring a response signal from the resonant circuit to the excitation as the measurement signal. The control device is further designed to determine a quality factor of a quality parameter as a function of the acquired response signal and, as a function of the acquired quality factor, to determine a temperature value as the value of the state variable.

[0007] The invention is based on the understanding that the effects of ambient temperature on an electrical resonant circuit, which are usually considered disruptive and distorting of measurement results, can advantageously also be used to determine the current ambient temperature of such a circuit. This can be done in a particularly simple way by determining the quality factor of the quality parameter based on the response signal of the excited resonant circuit, since the quality of the response signal decreases with increasing temperature. Thus, a current temperature value can advantageously be determined based on the calculated quality factor. Furthermore, the invention is based on the understanding that an electrical resonant circuit allows for a particularly flexible layout.In particular, the capacitive resonant circuit component can, if desired, be deployed over a large area and / or at least in one direction, enabling temperature measurement over any desired area. Therefore, it is especially advantageous to use such a measuring device to determine the temperature of a battery, particularly a vehicle battery, as this allows the temperature to be measured over large areas of the battery using only one or a few such devices. This, in turn, reduces the number of sensors required for battery monitoring, especially temperature sensors, and enables battery temperature measurement to be provided in a particularly simple and cost-effective manner.

[0008] To measure the battery temperature, the measuring device can be easily positioned near the battery. Direct contact with the battery is not required. Such a battery can, in particular, comprise several battery cells. Each battery cell can have a vent opening from which, in the event of thermal runaway, the cell can be vented. In other words, in the event of thermal runaway, correspondingly hot gas escapes from this vent opening. The battery cells can be positioned relative to the measuring device such that their vent openings face the measuring device, especially the electrical resonant circuit, and in particular the capacitive resonant circuit section.Thermal runaway in a battery cell and the resulting outgassing lead to an extreme temperature increase in the area of ​​the capacitive resonant circuit. Therefore, by determining the value of the state variable based on the quality factor of the resonant circuit's response signal, such thermal runaway in a battery cell can be reliably detected by the measuring arrangement. The control unit can detect such thermal runaway, for example, if the measured temperature exceeds a predetermined threshold and / or if a change in the repeatedly measured temperature exceeds a certain threshold, or similar conditions.

[0009] In general, the measuring arrangement can be designed to repeatedly or continuously determine the temperature value. Accordingly, during operation of the measuring arrangement, the excitation unit can, for example, repeatedly and / or continuously excite the resonant circuit and record the corresponding response signal, providing this signal to the control unit for evaluation. The control unit, in turn, repeatedly and / or continuously determines the respective quality factor and, depending on this, the associated temperature value. Thus, the measuring arrangement can also provide continuous temperature monitoring of the battery.

[0010] The quality parameter represents a parameter that characterizes the quality of the response signal. For example, it can be defined as the amplitude of the response signal at the resonant frequency of the resonant circuit. The quality parameter can also be defined as the quality factor, also called the Q-factor, which defines the ratio of stored energy to thermal energy loss during one oscillation period. The quality factor can also be defined as the ratio of the resonant frequency to the bandwidth.

[0011] For example, if the response signal of the resonant circuit is considered when excited at its resonant frequency, it exhibits a corresponding amplitude that decreases with increasing temperature, at least within a certain temperature range, which in particular includes a predetermined operating temperature range of the battery and / or temperatures above it. In the simplest case, the amplitude of the response signal when the resonant circuit is excited at its resonant frequency can therefore simply be evaluated as a quality factor to determine the temperature value.

[0012] According to a further advantageous embodiment of the invention, a mapping is stored in a memory of the control unit, assigning a corresponding temperature value to different value ranges for the quality parameter. The control unit is designed to determine the temperature value based on the determined quality parameter using this mapping. Based on the detected response signal, the control unit can first determine the quality parameter. Using the stored mapping, it can then easily determine the corresponding temperature value assigned according to the mapping. As described, the quality parameter can, for example, simply be the amplitude of the response signal when the resonant circuit is excited at or near its resonant frequency. Thus, only the maximum amplitude needs to be determined from the response signal, and the temperature value can then be determined based on this using the mapping.This allows for a particularly simple temperature determination with a particularly simple evaluation of the response signal.

[0013] According to a further advantageous embodiment of the invention, the excitation unit for exciting the resonant circuit and acquiring the response signal comprises an excitation coil inductively coupled to the inductive resonant circuit section. The inductive resonant circuit section itself can also be in the form of a coil. This allows for simple inductive excitation of the resonant circuit. Furthermore, the excitation unit can be designed to excite the resonant circuit at its associated resonant frequency. This depends in particular on the inductance of the inductive resonant circuit section and the capacitance of the capacitive resonant circuit section. As will be explained in more detail later, a temperature dependence of the resonant frequency can be neglected. The excitation unit can also be designed to excite the resonant circuit at several different frequencies within a frequency range that also includes the resonant frequency of the resonant circuit.The maximum amplitude deflection in the response signal will then automatically occur at the resonance frequency.

[0014] Alternatively, it is also conceivable to provide the resonant circuit with a conductive signal by applying an alternating voltage to one of its inputs. A current flow through the resonant circuit can then be detected as the response signal, for example, using a current sensor. However, excitation using an inductively coupled coil eliminates the need for additional sensors to detect the response signal.

[0015] According to a further advantageous embodiment of the invention, the inductive resonant circuit section is provided by a coil having a first and a second coil end, and the capacitive resonant circuit section is provided by an elongated pair of conductors with two electrical conductors, a first of which is electrically connected or connectable to the first coil end, and a second of which is electrically connected or connectable to the second coil end. The two electrical conductors can be provided, for example, as individual wires, printed circuit boards, or similar. These conductors can be spaced apart along their path, in particular running substantially parallel to each other, with the space preferably being as small as possible, e.g., a maximum of a few millimeters. A smaller space increases the capacitance of the capacitive resonant circuit section.The ends of the two conductors of the conductor pair that are opposite the ends connected to the respective coil ends, or connectable ends of the respective conductors, are open ends. The elongated conductor pair can advantageously be of any length, with the capacitance of the capacitive resonant circuit increasing with the length of the conductor pair. A longer conductor pair is therefore particularly advantageous in order to provide the largest possible capacitance for the capacitive resonant circuit. A large capacitance is, in turn, very advantageous in order to neglect the influence of temperature on the resonant frequency. In other words, the temperature measurement becomes more accurate the larger the capacitance of the capacitive resonant circuit, and a large capacitance can be easily achieved by making the elongated conductor pair correspondingly long.The elongated design of the conductor pair also offers the significant advantage that the capacitive resonant circuit section can be positioned over any area required for temperature measurement. This allows, for example, the temperature of elongated battery modules with multi-cell battery components to be measured.

[0016] The fact that the first coil end is connected or connectable to the first conductor of the conductor pair means that the first conductor can either be permanently connected to the first coil end or connected situationally, for example, via a switch or similar device. The same applies to the second coil end and the second electrical conductor. However, a permanent electrically conductive connection is preferred. This simplifies the construction and design of the resonant circuit. In particular, the conductor pair and the coil can be made from a single, one-piece wire or conductor.

[0017] According to a further advantageous embodiment of the invention, the measuring device comprises a planar substrate on which the resonant circuit is arranged. This enables a particularly flat design of the measuring device. This is especially advantageous in battery applications, as the measuring device can thereby be provided with a particularly large surface area but simultaneously with a particularly low profile. The measuring device can thus be integrated, for example, into the base of a battery housing, or into a lid of a battery housing, or, as explained in more detail below and preferably, arranged on an underride guard.

[0018] According to a further advantageous embodiment of the invention, the measuring arrangement comprises a carrier plate with a first region that corresponds to a battery module of the battery, in particular spatially, wherein the first region of the carrier plate represents the substrate on which the resonant circuit is arranged, or the planar substrate is arranged in the first region of the carrier plate. The resonant circuit can therefore be arranged on a substrate that differs from the carrier plate, and the resonant circuit can be arranged on the carrier plate together with this substrate. However, a separate substrate can also be completely omitted, and the carrier plate itself can function as such a substrate. In other words, the resonant circuit can also be mounted directly onto the carrier plate, printed on it, or integrated into it. The carrier plate can, for example, comprise or be formed from a plastic material.At a minimum, the surface on which the resonant circuit is arranged should be electrically non-conductive, i.e., made of a plastic. The same applies to the substrate, provided that a separate substrate, distinct from the carrier plate, is used.

[0019] According to a further advantageous embodiment of the invention, the first region of the carrier plate has a width and a length greater than its width, and, with respect to the longitudinal direction of the first region, a starting region and an end region, wherein the inductive resonant circuit section is arranged in the starting region and the conductor pair extends to the end region. The starting region and the end region of the first region of the carrier plate are thus opposite each other with respect to the longitudinal direction of the first region. It is particularly advantageous if the conductor pair extends over virtually the entire length of the first region. The conductor pair can have a length of, for example, at least one meter or several meters.On the one hand, this allows for a very large capacity of the capacitive resonant circuit section, which increases measurement accuracy, and on the other hand, it enables a particularly large temperature measurement area to be covered. The first area can, for example, have a length corresponding to the length of the associated battery module that is to be monitored by the measuring device or arrangement. This module can be positioned in a specific direction, e.g., directly above the first area.

[0020] According to a further advantageous embodiment of the invention, the measuring arrangement comprises the battery, which has at least one battery module arranged above and at a distance from the first region of the carrier plate with respect to a defined direction. Thus, the temperature of an entire battery module, which in particular can again comprise several battery cells, can be determined by means of the resonant circuit.

[0021] Furthermore, it is particularly advantageous if the battery cells of the battery module are arranged relative to the carrier plate in such a way that their respective accessible cell degassing vents face the carrier plate. This allows significant temperature increases, such as those occurring in connection with thermal runaway of a battery cell, to be detected particularly reliably by the measuring arrangement.

[0022] According to a further advantageous embodiment of the invention, the carrier plate is designed as an underride guard for a motor vehicle. In its intended installation position in a motor vehicle with a battery located in the underbody area, such an underride guard is positioned below the battery in the vehicle's vertical direction and can extend perpendicular to the vehicle's vertical direction over the entire battery. The underride guard also serves to protect the battery from objects impacting the vehicle from below. A gap between the underride guard and the underside of the battery is very advantageous for this purpose. This provides available installation space that can be advantageously used for integrating the measuring device.At the same time, by positioning the measuring device on the underride protection, it can be placed particularly close to the battery, which enables a particularly reliable determination of the battery temperature.

[0023] Furthermore, the conductor pair can also be configured to extend in one or more loops along the length and / or width of the first area. This increases the length of each conductor, resulting in a greater overall capacity and also extending the covered detection area. The conductor pair does not necessarily have to run in a straight line from the start to the end area, but can, for example, run from the start to the end area, loop back to the start, and then loop back to the end again, and so on. Additionally or alternatively, the conductor pair can also run from the start to the end area in a wave-like, zigzag, or meandering pattern.

[0024] According to a further advantageous embodiment of the invention, the carrier plate has several areas that correspond to the respective battery module in the battery, wherein the measuring arrangement comprises several measuring devices and a measuring device is arranged in each of the several areas of the carrier plate. Thus, for example, a corresponding measuring device can be provided below each battery module. In principle, it would also be possible to route the conductor pair of the measuring device in such a way that it covers the entire area of ​​the carrier plate located below the several battery modules, e.g., by looping it or similarly. However, since there are other components located on the underride guard, or mounting points or similar features are provided, the subdivision into several sub-areas is very advantageous.This allows for a corresponding measuring device with a suitable resonant circuit to be specifically positioned under each battery module. This also makes it possible to determine the temperatures of the respective battery modules independently of each other using their assigned measuring device. Thus, instead of recording an average temperature across all battery modules, the temperature specifically assigned to each battery module is measured.

[0025] In principle, it is possible to provide an arbitrarily precise spatial temperature resolution, even for a single battery module, by distributing a sufficient number of measuring devices over a surface. However, providing only one measuring device per elongated battery module is preferable, as this reduces the complexity and also improves the temperature measurement due to the greater capacitance of the conductor pair.

[0026] Furthermore, the invention also relates to a motor vehicle with a measuring arrangement according to the invention or one of its embodiments.

[0027] Furthermore, the invention relates to a method for determining the value of a state variable of a battery by means of a measuring arrangement comprising a measuring device and a control device coupled thereto, which determines the value of the state variable as a function of a measurement signal detected by the measuring device. The measuring device comprises an electrical resonant circuit with an inductive resonant circuit section and a capacitive resonant circuit section, wherein an excitation unit coupled to the resonant circuit excites the resonant circuit and detects a response signal of the resonant circuit to the excitation as the measurement signal, and wherein the control device determines a quality factor of a quality parameter as a function of the detected response signal and determines a temperature value as the value of the state variable as a function of the determined quality factor.

[0028] The invention also includes further developments of the method according to the invention, which have features already described in connection with the further developments of the measuring arrangement according to the invention. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0029] The invention also includes the control unit for the measuring arrangement. The control unit can comprise a data processing device or a processor circuit configured to perform an embodiment of the method according to the invention. For this purpose, the processor circuit can comprise at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). In particular, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an NPU (Neural Processing Unit) can be used as the microprocessor. Furthermore, the processor circuit can comprise program code configured to perform the embodiment of the method according to the invention when executed by the processor circuit.The program code can be stored in a data memory of the processor device. The processor device can be based, for example, on at least one circuit board and / or on at least one SoC (System on Chip).

[0030] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle. The motor vehicle can be designed as an electric vehicle.

[0031] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0032] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of a measuring arrangement according to an embodiment of the invention; Fig. 2 a schematic representation of an underride guard with a measuring arrangement according to an embodiment of the invention; Fig. 3 a schematic top view of a part of an underride guard with a measuring arrangement according to an embodiment of the invention; Fig. 4 a schematic representation of a measuring arrangement in a cross-section according to an embodiment of the invention; and Fig. 5 a graphical representation of response signals and their quality for different temperatures according to an embodiment of the invention.

[0033] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0034] In the figures, identical reference symbols denote functionally equivalent elements.

[0035] Fig. Figure 1 shows a schematic representation of a measuring arrangement 10 according to an embodiment of the invention. The measuring arrangement 10 comprises a measuring device 12 and a control device 14. The measuring device 12 in turn comprises an electrical resonant circuit 16, which has an inductive resonant circuit section 16a and a capacitive resonant circuit section 16b. The inductive resonant circuit section 16a is provided by a coil 18, and the capacitive resonant circuit section 16b by a pair of conductors 20 with two electrical conductors 20a, 20b. The coil 18 has a first coil end 18a, which is connected to the first electrical conductor 20a, and a second coil end 18b, which is electrically connected to the second conductor 20b of the pair of conductors 20. The coil 18 and the electrical conductors 20a, 20b can also be made from a single conductor, e.g., It may be made, for example, from a wire or a printed conductor track or similar.Furthermore, the measuring device 12 includes an excitation unit 22. This in turn includes an excitation coil 24. An excitation signal can be coupled into the resonant circuit 16 via the excitation coil 24, which is inductively coupled to the coil 18. The corresponding response signal A1, A2, A3 can also be generated by means of the excitation unit 22 (see figure). Fig. 5) are detected after excitation of the resonant circuit 16 and made available to the control unit 14 for evaluation. The control unit 14 can evaluate the detected response signal A1, A2, A3 with regard to its quality G (see Fig. 5) evaluate and, using an assignment Z stored in the control unit 14, which describes a relationship between the quality factor G and the temperature T, determine the temperature T prevailing in the environment 26 of the resonant circuit 16. The evaluation of such a response signal A1, A2, A3 will be discussed later in connection with Fig. 5 explained in more detail.

[0036] Fig. Figure 2 shows a schematic representation of a measuring arrangement 10 according to a further embodiment of the invention. This now comprises a carrier plate 46, which in this example is provided by an underride guard 30, on the upper surface 30a of which the measuring device 12 is arranged. The measuring device 12 can be arranged as described above. Fig. The control unit 14 coupled to the measuring device 12 is not shown here for the sake of clarity. The upper surface 30a of the underride guard 30 can comprise a sub-area 32 that extends over a length L in the x-direction shown. The measuring device 12, more precisely the resonant circuit 16, can also extend over the entire sub-area 32 in the x-direction. The coil 18 is arranged in an initial region 33a of this sub-area 32, and the conductor pair 20 extends in the x-direction to the end 33b or an end region 33b of this sub-area 32. The length L can correspond to the length of a battery module 40 positioned above the underride guard 30 in the z-direction (see Figure 1). Fig. 4) correspond. This advantageously allows temperature measurement to be provided over the entire length L of such a battery module 40.

[0037] Furthermore, the excitation coil 24 is also shown, which in this example is located above the coil 18 of the resonant circuit 16 in the z-direction. It is spaced apart from the resonant circuit coil 18 and is not in electrically conductive contact with it. The coil 24 is therefore electrically isolated from the resonant circuit coil 18. As can be seen, the measuring arrangement 10 allows for a design with an arbitrarily large area, but which is particularly space-saving in the z-direction.

[0038] Fig. Figure 3 shows a schematic representation of a measuring arrangement 10 according to a further embodiment of the invention. In particular, a part of an underride guard 30 is again shown, but here in a top view from above looking in the z-direction. The measuring arrangement 10 can, in particular, be configured as follows: Fig. The resonating circuit 16 can optionally be applied to a separate substrate 36 or laminated into one, which in turn is arranged on the upper surface 30a of the underride guard 30. Alternatively, the resonating circuit 16 can also be applied directly to the support structure, namely the upper surface 30a of the underride guard 30, e.g. by printing, or alternatively be integrated or embedded in the component, i.e., the underride guard 30, or similarly.

[0039] Furthermore, it can be seen here that the conductor pair 20 extends in a loop in the x-direction. In other words, the conductor pair 20 is routed from the starting section 33a to the end section 33b and from there back towards the starting section 33a. This allows the capacitance of the capacitive part 16b of the resonant circuit 16 to be increased.

[0040] Fig. Figure 4 shows a schematic cross-sectional view of a measuring arrangement 10 according to a further embodiment of the invention. This can again be configured as described above. In addition, the measuring arrangement 10 in this example comprises a battery 38 with several battery modules 40, in this example four battery modules 40. Each of the battery modules 40 comprises several battery cells 42, which are arranged next to each other in the x-direction. Each battery cell 42 in turn comprises a releasable cell venting opening 44, e.g. a rupture membrane or similar. If a thermal runaway occurs in such a battery cell 42, it releases gas through the releasable cell venting opening 44. Therefore, it is particularly advantageous if the cells 42 are arranged directly in relation to a carrier plate 46, which in turn may be, for example,The mounting plate 46 can be provided by an underride guard 30, and the measuring device 12 is arranged such that the accessible cell degassing openings 44 face this mounting plate 46. In particular, in the present example, a measuring device 12 is provided for each battery module 40. Each measuring device 12 can be configured as described above and accordingly comprise a resonant circuit 16 and an associated excitation unit 22. The excitation units 22 can all be connected to a common control unit 14, which, however, is not shown here for the sake of clarity. The mounting plate 46, or its upper surface 46a, which can be provided by the upper surface 30a of the underride guard 30, is further divided into several sub-areas 32a, 32b, 32c, 32d. Each sub-area 32a to 32d is assigned to a battery module 40 and is arranged directly below this battery module 40 with respect to the z-direction.In each of the respective sub-areas 32a to 32d, a measuring device 12 is arranged. This allows for a separate temperature measurement for each battery module 40. A temperature monitoring chamber is provided between the underride guard 30 and the battery modules 40, which in this case is divided into four chambers, each of which can, for example, have dimensions of 30 cm x 200 cm.

[0041] Fig. Figure 5 shows a graphical representation of response signals A1, A2, A3 and their quality factor G for different temperatures. The response signals A1, A2, A3 are plotted as a function of the frequency f. The response signals A1, A2, A3 each exhibit a maximum amplitude at the resonance frequency f. Rof the resonant circuit 16. The response signal A1 corresponds to a first temperature T1 and the environment 26 of the resonant circuit 16, the response signal A2 to a second temperature T2 in the environment 26 of the resonant circuit 16, and the third response signal A3 to a third temperature T3 in the environment 26 of the resonant circuit 16. The temperature T1 is lower than the temperature T2, and this in turn is lower than the temperature T3. The quality factor G of the respective response signals A1, A2, and A3 is plotted on the ordinate. As can be seen, the quality factor G decreases with increasing temperature T1, T2, and T3. The second temperature T2 can, for example, correspond to room temperature. Furthermore, the larger the capacitance of the capacitive resonant circuit section 16b, the smaller the influence of temperature on the natural frequency f. R Accordingly, it can be assumed that the natural frequency f RThe temperature of the described resonant circuit 16 remains constant or nearly constant even at varying temperatures, primarily because the conductor pair 20 can be very long, especially several meters in length. Upon receiving a response signal A1, A2, A3, the control unit 14 can determine the quality factor G of the respective response signal A1, A2, A3 based on its amplitude and, based on the stored assignment Z, determine the corresponding temperature T1, T2, T3. This allows for a particularly simple and reliable temperature determination by evaluating the quality factor G and the response signals A1, A2, A3.

[0042] Overall, the examples demonstrate how the invention can provide a planar temperature sensor for a high-voltage battery environment. Such a planar temperature sensor, which can be provided in particular by the described measuring arrangement or measuring device, for a vehicle, especially for a high-voltage battery environment, can comprise a support structure and / or a support substrate, a resonant circuit, in particular with an inductive wire component and a capacitive wire component, and a reading or coupling coil, which was previously also referred to as an excitation coil. The resonant circuit can be applied directly to the planar support substrate, which can then be applied to a further support structure, e.g., the underride guard, or the resonant circuit can also be applied directly to such a support structure as the underride guard or the component, e.g.,...The capacitor can be printed on the component or, alternatively, integrated or inserted directly into it. The capacitor has a defined minimum length, which may be predetermined, for example, by its desired capacitance. The resonant circuit is connected via the coupling or reading unit, e.g., the excitation coil, to an evaluation unit, previously also referred to as a control device. The evaluation unit can, for example, be a vehicle control unit. The resonant circuit is designed to maintain its resonant frequency largely constant, regardless of temperature. Furthermore, the resonant circuit is designed such that the signal quality, characterized by the quality parameter, decreases with increasing temperature and increases with decreasing temperature. At low frequencies or resonant frequencies, as is the case with a long capacitive resonant circuit section or wire pair, the frequency drift due to temperature changes is negligible.The flat temperature sensor can be implemented as a ribbon-like sensor unit by forming the resonant circuit. The rupture membrane, i.e., the releasable cell degassing vent, represents a predetermined breaking point for each cell, which also defines the starting point of a thermal event. This event can be detected simply and reliably using the described temperature monitoring. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2008 042 746 A1

[0003]

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