Method for monitoring the temperature of an electronic device, and control unit for carrying out said method

Abstract

The invention describes a method for monitoring the temperature of an electronic device (110). The method comprises: (i) specifying a position (111) for temperature monitoring in a region of the electronic device (110); (ii) determining a parameter value of a parameter that is associated with an actual temperature (113) at the position (111); and (iii) calculating a temperature (112) at the position (111) based on the parameter value using a calibrated model, wherein the calibrated model is implemented in a control unit and is calibrated in such a way that the sum of the actual temperature (113) at the position (111) and a specified tolerance threshold is less than or equal to the calculated temperature (112). A corresponding control unit is also described.

Description

[0001] Description

[0002] Method for temperature monitoring of an electronic device and control unit for carrying out the method

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to a method for temperature monitoring of an electronic device and a corresponding control unit for carrying out the method.

[0005] BACKGROUND OF THE INVENTION

[0006] Overheating of electronic components or products can cause serious damage to the components themselves or to connected products. In the worst case, overheating can lead to a fire, thus posing a critical safety risk. For this reason, functional safety requirements in this area are very high, especially for products that operate at high power or current and thus potentially generate large amounts of heat, such as inverters, battery management systems, or electric vehicle chargers.

[0007] Typically, systems or products to be monitored are equipped with temperature sensors at critical locations. However, this requires laborious determination of the respective sensor positions during the design phase, and these positions cannot be changed once the sensors have been installed. The use of sensors is also associated with considerable costs. Furthermore, sensors are often not suitable for use in certain locations due to their spatial dimensions alone, meaning that not all required positions can be monitored. SUMMARY AND EMBODIMENTS

[0008] It is therefore an object of the present disclosure to provide an efficient method for temperature monitoring of an electronic device, which in particular requires only a small number of temperature sensors or even no temperature sensors at all.

[0009] This object is achieved by a method and a control unit according to the independent patent claims. Advantageous embodiments and further developments of the method and the control unit emerge from the respective dependent claims, the following description, and the drawings.

[0010] According to one aspect of the present disclosure, a method for temperature monitoring of an electronic device is provided. The method comprises: (i) specifying a temperature monitoring position in an area of ​​the electronic device; (ii) determining a parameter value of a parameter related to an actual temperature at the position; and (iii) calculating a temperature at the position based on the parameter value using a calibrated model such that the sum of the actual temperature at the position and a predetermined tolerance threshold is less than or equal to the calculated temperature. The method may be computer-implemented.

[0011] According to a further aspect of the present disclosure, a control unit is provided in which the calibrated model is implemented and which is configured to perform the method described above. The control unit may comprise a modeling unit that contains the calibrated model.

[0012] In the context of the present disclosure, the term “electronic device” can mean, in particular, an electronic part or an electronic component of a system, for example a motor vehicle. The motor vehicle can have the electronic device and the control unit. The electronic device can be configured to operate at high power levels and / or high currents. The operation of the electronic component can be associated with high heat generation. The electronic device can be or have, for example, a contactor, an inverter, a battery management system, a fuse, e.g. a pyro-fuse fuse, or an electric vehicle charger. The electronic device can have one or more power components, for example one or more contactors, one or more inverters and / or one or more fuses.The electronic device may have a geometric arrangement of the one or more power components, in particular on a circuit board and / or in a housing. The electronic device may be a control unit.

[0013] In the context of the present disclosure, the expression "in a region of the electronic device" may in particular refer to at least one of a position inside the electronic device, a position on the surface of the electronic device, and a position in an environment of the electronic device. The environment may, for example, comprise a distance of less than 50 cm, in particular less than 10 cm, in particular less than 1 cm, from the electronic device.

[0014] In the context of the present disclosure, a “temperature monitoring position” is in particular a position that is particularly relevant for the safety requirement levels to be met, for example in comparison with other positions in the area of ​​the electronic device. At the temperature monitoring position, for example, particularly large and / or rapid heat development can occur, in particular in comparison with other positions in the area of ​​the electronic device. More than one temperature monitoring position can be specified, for example two, three, four, five or more, in particular more than ten, in particular more than one hundred. The position or positions can be specified with respect to a geometric arrangement of one or more power components. The position or positions can be specified with respect to a printed circuit board or a circuit board on which at least one power component is arranged.The position or positions can be specified relative to a housing in and / or on which at least one power component is arranged. The position or positions can be one or more hotspots, in particular thermal hotspots. The position or positions can be inaccessible for direct measurement.

[0015] In the context of the present disclosure, the term "determining" may, in particular, be or include measuring the parameter value using a corresponding measuring device, for example, a sensor. It may also include measuring a value associated with the parameter value. Determining the parameter value may also be or include modeling the parameter value. Determining the parameter value may also be or include looking up the parameter value in a table.

[0016] In the context of the present disclosure, the term "parameter" can, in particular, refer to a characteristic of the electronic device. Corresponding parameter values ​​of a plurality of parameters can be determined, for example, two, three, four, five, or more than five, in particular more than ten, parameters. The parameter(s) can be a current, a voltage, an internal resistance, a sleep time, or an ambient temperature, or can be representative variables of the aforementioned characteristic variables. The parameter(s) can relate to characteristics that are not device temperatures. Alternatively, the parameter(s) can comprise one or more device temperatures, in particular a device temperature at the position of a temperature sensor. The one or more device temperatures can relate to positions in the region of the electronic device that are different from the predetermined position(s).The parameter(s) can be input variables and / or model parameters for the calibrated model. In the context of the present disclosure, the term "related" can mean, in particular, that the temperature at the position to be monitored correlates with the parameter. In other words, a change in the parameter causes a corresponding change in the temperature and vice versa, particularly if further conditions to be specified are met. For example, a current through the electronic device can be related to the temperature at the position to be monitored because the current flow causes heat to be generated, which in turn influences the temperature of the electronic component. Likewise, a voltage, an internal resistance, and / or an ambient temperature can be related to the temperature at the position to be monitored.

[0017] In the context of the present disclosure, a "calibrated model" may, in particular, mean a model whose results, e.g., the calculated temperatures, have been adjusted or approximated to corresponding actual values, e.g., the corresponding actual temperatures, using experimental data and / or simulations. Such calibration can be achieved by selecting appropriate values ​​for model parameters.

[0018] In the context of the present disclosure, the calculated "temperature" may be a temperature in a predetermined operating state of the electronic device, in particular in a critical operating state. The critical operating state may be defined by a calculated temperature and / or an actual temperature above a predetermined temperature threshold. Critical operating states may include those in which the actual temperature has a peak or maximum and / or in which the actual temperature exceeds 80°C, in particular 100°C, in particular 120°C. The calculated temperature may be associated with an operating state for which the calibrated model was calibrated.

[0019] In the context of the present disclosure, the term "tolerance threshold" can, in particular, mean a predetermined safety margin. The tolerance threshold can define a minimum margin between the actual and calculated temperature. This margin can be set such that it is always maintained during operation, in particular during normal, error-free operation, of the device. The tolerance threshold can also be set such that it is maintained in certain critical operating states and does not necessarily have to be maintained otherwise. The tolerance threshold is preferably positive, but can also be negative or zero. The tolerance threshold can also be defined variably, in particular depending on a respective operating state of the electronic device.The wording that “the sum of the actual temperature at the position and a predetermined tolerance threshold is less than or equal to the calculated temperature” can, in addition to the literal meaning, also be understood to mean that “the temperature calculated by means of the calibrated model is greater by at least one predetermined tolerance threshold than a temperature determined by means of a temperature distribution model and / or by means of thermal investigations of a real example of the electronic device”, in particular if the determined temperature and the calculated temperature refer to the same operating state.

[0020] In the context of the present disclosure, the term "control unit" may, in particular, mean a device configured to control operations or processes. The control unit may comprise a processor in which computing operations are performed and control signals are generated. The control unit may comprise a modeling unit containing the calibrated model.

[0021] With the described temperature monitoring method and the corresponding control unit, it may be possible to eliminate the need for one or more temperature sensors compared to purely sensor-based temperature monitoring, while still ensuring suitable temperature monitoring. For example, temperature modeling may be possible in which not every power component of an electronic device is monitored by a physical temperature sensor attached to the respective power component. Accordingly, expensive temperature measurements can be replaced by other measurement signals that are already available, such as voltage or current measurements. Furthermore, a temperature can be modeled at positions that are not accessible to direct measurement, for example because there is not enough space for a temperature sensor.Temperature signals can be generated at a large number of desired positions in the area of ​​the electronic device with little effort.

[0022] Temperature modeling can therefore help ensure compliance with certain safety requirements, such as those prescribed by law, for the operation of electronic devices. Observance of the tolerance threshold or safety margin can represent an additional safety factor. Such safety requirements can concern protection against overheating, fire, or explosions, for example.

[0023] According to one embodiment, the calibrated model is calibrated using a temperature distribution model of the electronic device and / or using thermal tests of a real specimen of the electronic device. The real specimen can be thermally tested, for example, as part of test bench measurements. The calibration can be performed depending on an operating state of the electronic device. Calibrating the calibrated model for a given operating state can require that the temperature distribution model models this operating state and / or that the real specimen assumes this operating state.

[0024] The calibrated model can be implemented on a control unit, in particular on a modeling unit of the control unit. Thus, there can be two models: a comparatively complex and computationally intensive temperature distribution model of the electronic device, with which a simpler model is calibrated for use as the calibrated model. The temperature distribution model can, for example, be a 3D model of the electronic device or of a part of the electronic device. It can be implemented on an external computer that has greater computing power than the control unit. The simpler model can require less computing power than the temperature distribution model and thus enable faster calculation of corresponding temperature values, in particular real-time calculation.Calibration of the calibrated model can ensure the required accuracy and / or reliability of the calculated temperature values.

[0025] According to one embodiment, the real specimen is a worst-case specimen and / or the temperature distribution model is based on a worst-case scenario. This ensures that the calculated temperature values ​​are not lower, or at least only slightly lower, than the actual temperature values, even if the actual temperature values ​​originate from a specimen of the electronic device that is unfavorable for heat generation. In other words, all possible operating states and / or design profiles of the electronic device can be taken into account with regard to compliance with the tolerance threshold.

[0026] In the context of the present disclosure, a "worst-case example" may be an implementation of the electronic device or a part of the electronic device during whose operation particularly high temperatures develop, in particular at one or more safety-critical positions of the electronic device, in particular at the predetermined position(s). The part of the electronic device may comprise or consist of one or more power components, in particular all power components. The temperatures may be particularly high compared to other average or regular examples of the electronic device. The worst-case example may be characterized by one or more properties that lie at a limit or edge of a tolerance range.Such a tolerance range can be specified by a data sheet associated with the electronic device and / or by data sheets associated with one or more power components. The worst-case sample can, for example, be a sample that is at the end of its specified lifetime and / or whose properties correspond to those expected at the end of the specified lifetime. The worst-case sample can be a sample whose internal resistance is comparatively high, especially compared to regular or average samples.

[0027] A “worst-case scenario” can be defined by one or more worst-case examples and / or by particularly unfavorable operating conditions.

[0028] According to one embodiment, at least one power component of the real-world example is a worst-case power component; in particular, all power components of the real-world example are worst-case power components. With such an approach, which contrasts with the usual expert approach, compliance with the tolerance threshold can be particularly easily achieved.

[0029] According to one embodiment, the temperature distribution model is created on the basis of a worst-case power component, in particular under the assumption that all power components of the electronic device are worst-case power components.

[0030] According to one embodiment, the real instance is a regular instance and / or the temperature distribution model is based on a regular scenario. In the context of the present disclosure, a "regular instance" can be a realization of the electronic device or a part thereof during whose operation average temperatures develop, in particular at one or more safety-critical positions of the electronic device. The average can be determined by comparison to all candidate instances. A "regular scenario" can be defined by one or more regular instances and / or by regular operating conditions.

[0031] According to one embodiment, the calibrated model is characterized by a smaller dimension than the temperature distribution model. In particular, the calibrated model can be one-dimensional, or the dimension can be between one and two. For example, the calibrated model can be implemented within the framework of several interacting nodes, modeling heat exchange between the nodes. This can reduce the computing time for the calibrated model, so that relatively low computing power is required for the control unit. Real-time modeling may also be possible.

[0032] According to one embodiment, the method further comprises: (i) setting a security requirement level for the electronic device, (ii) examining whether the parameter satisfies the security requirement level, and (iii) plausibility-checking the parameter if the parameter does not satisfy the security requirement level.

[0033] In the context of the present disclosure, the term "plausibility" may, in particular, mean that further reasons and / or facts are provided to support the accuracy and / or reliability of the calculation or estimation of the parameter. The parameter may be plausibility-checked in such a way that a certain degree of reliability and / or a certain accuracy is guaranteed, which may be specified by the safety requirement level.

[0034] The plausibility of the parameter can be checked, for example, by considering its dependence on the aging of the electronic device and / or its dependence on operating parameters such as ambient temperature. Furthermore, worst-case assumptions can be made. Finally, specific measured values ​​that support the calculation or estimation of the parameter can also be taken into account for the plausibility check. For example, an additional voltage measurement can be used to determine the internal resistance of the electronic device as an additional input variable for the calibrated model. Or an aging dependency can be defined using corresponding measured values. By checking the plausibility of the parameter, it can be ensured that the parameter meets the safety requirement level.According to one embodiment, the plausibility check of the parameter comprises at least one of the following steps: when determining the parameter value, a dependence of the parameter on aging of the electronic device is taken into account; when determining the parameter value, a dependence of the parameter on operating conditions, in particular an ambient temperature, is taken into account; when determining the parameter value, worst-case assumptions are made; when determining the parameter value, a measured value of at least one characteristic variable that is different from the parameter is taken into account.

[0035] According to one embodiment, the method further comprises specifying a safety requirement level, wherein the tolerance threshold is specified such that the safety requirement level is met. For example, the tolerance threshold can influence at least one of a severity, a probability of occurrence, and a controllability of a fault in the electronic device, in particular such that the combination of severity, probability of occurrence, and controllability satisfies the safety requirement level. A suitable selection of the tolerance threshold can ensure a safety margin between the actual temperature and critical temperature values ​​that characterize faulty operating states.

[0036] According to one embodiment, the tolerance threshold lies between 0°C and 50°C, in particular between 5°C and 50°C, in particular between 15°C and 40°C. The tolerance threshold can assume such values ​​when the electronic device is in an operating state in which the actual temperature at the position is comparatively high and / or reaches a temperature maximum during normal operation. The tolerance threshold can also have negative values, for example, greater than -10°C or greater than -5°C, in particular when the actual temperature at the position is comparatively low in a current operating state. According to one embodiment, the safety requirement level specifies requirements for operation of the electronic device with respect to at least one of a severity of an error during operation of the electronic device, a probability of occurrence of the error, and a controllability of the error.

[0037] The "severity" of the error can be characterized by a danger to the user and / or the environment. The "exposure" can be characterized by a frequency and / or duration of the error or an operating state corresponding to the error. The "controllability" can be determined by the proportion of users who can control a situation corresponding to the error. In the context of the present disclosure, an "error" can be, in particular, a faulty operating state of the electronic device in which a danger to a user and / or their environment is possible, for example due to high temperatures, fire hazard, or explosion hazard.

[0038] The safety requirement level can be determined, for example, by an Automotive Safety Integrity Level (ASIL), specifically ASIL-C or ASIL-D, as defined in the ISO 26262 standard. The safety requirement level determined by ASIL can be determined by risk analysis of a potential hazard, taking into account the severity, exposure, and controllability of the corresponding vehicle operating scenario. ASIL-D defines the highest safety requirements for the electronic device, followed by ASIL-C.

[0039] According to one embodiment, the tolerance threshold is predetermined depending on a respective operating state of the electronic device. For example, in critical operating states, in which the actual temperatures are particularly high, the tolerance threshold can be higher than in non-critical operating states, for example during cooling processes. Critical operating states can include those in which the actual temperature has a peak or maximum and / or in which the actual temperature exceeds 80°C, in particular 100°C, in particular 120°C. Such an embodiment can be advantageous because it can avoid unnecessary power reductions, such as power reductions of the electronic device or a system containing the electronic device. At the same time, safety requirement levels, which primarily relate to critical operating states, can be maintained.

[0040] According to one embodiment, an operating period and / or lifetime of the electronic device is taken into account when calculating the temperature using the calibrated model. For example, the parameter can be an internal resistance, and a lifetime-dependent change in the internal resistance can be taken into account using an aging curve. The aging curve can be determined, for example, based on measured values. This can enable more precise modeling of the parameter and, for example, reduce performance reductions due to compliance with safety requirement levels. As a worst-case assumption, the internal resistance at the maximum possible lifetime can be set as the parameter value.

[0041] According to one embodiment, determining the parameter value comprises: (i) determining a parameter range within which an actual parameter value lies, (ii) determining an unfavorable parameter value from the parameter range at which the calculated temperature is maximum, and (iii) setting the parameter value based on the unfavorable parameter value. The calculated temperature is, in particular, maximum compared to calculated temperatures for other parameter values ​​from the parameter range. For example, the parameter value can be set equal to the unfavorable parameter value. Such an embodiment can be advantageous because a worst-case scenario is assumed, which can guarantee compliance with safety standards.If an internal resistance increases over the lifetime of an electronic device, but the lifetime of the electronic device is not known, the internal resistance at the end of the lifetime can be assumed, for example.

[0042] According to one embodiment, the parameter comprises at least one of the following characteristics: a current, a voltage, an internal resistance, a sleep time, and an ambient temperature. The current can, in particular, be a current at an input and / or output of a power component of the electronic device. The voltage can, in particular, be a voltage between the input and output of a power component of the electronic device. All of these parameters can contribute to heat generation and are therefore indicative of the temperature at the location to be monitored.

[0043] According to one embodiment, the parameter is determined based on a measured value. If the measured value is not available, a predefined substitute value is used instead of the measured value to determine the parameter. In particular, the calculated temperature for the predefined substitute value is at most as high as for the measured value. For example, a constant maximum value can be assumed as the predefined substitute value, such as a constant maximum current. Or the predefined substitute value can be calculated from other variables, with appropriate tolerances being added.

[0044] Such an embodiment can also be advantageous because it assumes a worst-case scenario that can guarantee compliance with safety standards. This embodiment can be advantageous because, for example, compliance with safety standards can be guaranteed even if corresponding measuring devices or sensors fail.

[0045] According to one embodiment, parameter values ​​of a plurality of parameters related to the temperature at the position are determined, and the temperature at the position is calculated based on the parameter values ​​of the plurality of parameters. According to one embodiment, the plurality of parameters includes a temperature measured by a temperature sensor at another position in the region of the electronic device that is different from the position. Such an embodiment can be advantageous for determining temperatures at positions that are not accessible to direct measurement particularly accurately and reliably.

[0046] According to one embodiment, the method further comprises controlling the electronic device such that the calculated temperature remains below a predetermined temperature limit, in particular below 170°C, in particular below 150°C. The predetermined temperature limit can be determined by a critical temperature at which the electronic device overheats and / or at which there is a risk of fire or explosion of the electronic device. The controlling can comprise at least one of cooling, shutting down, and switching off the electronic device.

[0047] According to one embodiment, a current and / or a future temperature at the temperature monitoring position is calculated.

[0048] According to one embodiment, there is no temperature sensor in the region of the electronic device.

[0049] According to one embodiment, the parameter is not a temperature.

[0050] According to one embodiment, the electronic device is at least one of a contactor, a fuse, in particular a pyrofuse fuse, an inverter, a battery management system and an electric vehicle (EV) charger.

[0051] BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and advantageous embodiments and further developments of the method and the control unit emerge from the following exemplary embodiments shown in conjunction with the figures.

[0052] Figures 1, 2 and 3 each show a control unit for temperature monitoring and corresponding positions to be monitored in the area of ​​an electronic device according to embodiments of the present disclosure.

[0053] Figure 4 shows a method for temperature monitoring of an electronic device according to an embodiment of the present disclosure.

[0054] Figures 5 to 10 respectively compare calculated and actual temperatures at temperature monitoring locations of various electronic devices according to embodiments of the present disclosure.

[0055] Identical, similar, or functionally identical elements are provided with the same reference symbols in the figures. In some figures, individual reference symbols may be omitted for clarity. The figures and the relative sizes of the elements depicted in the figures are not to scale. Rather, individual elements may be exaggerated for clarity and / or clarity.

[0056] DETAILED DESCRIPTION OF EMBODIMENTS

[0057] Before exemplary embodiments of the invention are described in more detail with reference to the figures, some basic considerations on the basis of which exemplary embodiments have been developed will be described in general.

[0058] According to an exemplary embodiment, the required temperature information for the monitoring function is generated using a model-based approach using various other signals available in the system, such as current, voltage, internal resistance of components, or ambient temperature. To meet functional safety requirements, such as those within the scope of ASIL-C or ASIL-D, with this approach, the monitoring function is designed with at least one of the following properties.

[0059] 1. The thermally critical components (hotspots) in the system are identified and modeled with corresponding parameters (e.g., contactors as resistance). The corresponding parameters are assumed to be worst-case (e.g., end-of-life internal resistance of the contactors, secured by validation). For parameters that change over the service life or change abruptly in certain situations, the behavior is modeled.

[0060] 2. The available input signals and their corresponding ASIL integrity are identified. Only input signals or information that meet the required ASIL level may be used for the model. Typically, this concerns current, voltage, or available temperatures. If the ASIL level is insufficient, this input signal is appropriately secured (plausibility check, etc.). Optionally, suitable measurement signals are inserted into the system to generate specific information for the model (e.g., additional voltage measurement to calculate internal resistance as input for the model).

[0061] 3. The model is calibrated or fitted using simulations and measurements with the respective worst-case components (e.g. contactors with high internal resistance) and the required design profiles. An example of such a fitting approach is shown in Figure 4. The model always calculates a higher temperature than occurs in reality at the corresponding location (safety margin). This safety margin is the prerequisite for achieving ASIL integrity (cf. the calculated and actual temperatures, as shown in Figures 5 to 10). 4. The safety margin between the actual and calculated temperature is modeled with regard to availability. The margin must not be too high, as otherwise unnecessary performance reductions would occur due to detected overtemperature. All design profiles or operating states must therefore be achieved without restriction.To achieve this, all tolerances and disturbances in the respective signal chain are added together.

[0062] 5. An appropriate substitute value strategy is defined for a possible error scenario. When input signals fail, the model always reacts by increasing the temperature. Therefore, substitute values ​​are defined, such as a constant maximum current value or the current is calculated from other variables, and all tolerances are added together.

[0063] By implementing these measures, it is possible to provide temperature information with the appropriate integrity level.

[0064] Figures 1, 2, and 3 each show a control unit 100 configured to perform a method for temperature monitoring of an electronic device 110. The method comprises the following steps: (i) specifying a position 111 for temperature monitoring in a region of the electronic device 110, (ii) determining a parameter value of a parameter associated with an actual temperature 113 (not shown, see Figures 5 to 10) at the position 111, and (iii) modeling a temperature 112 (not shown, see Figures 5 to 10) at the position 111 based on the parameter value using a calibrated model such that the sum of the actual temperature 113 at the position 111 and a predetermined tolerance threshold is less than or equal to the calculated temperature 112.

[0065] The electronic device 110 is a contactor, i.e., an electrically or electromagnetically operated switch for high electrical power. The contactor, such as a DC charging contactor, can, for example, switch a positive and a negative DC connection (DC+ contactor and DC- contactor). The two elements 110 represent such switches, possibly designed separately, for two electrical lines 114.

[0066] The calibrated model, which calculates the temperature 112 at one or more locations 111 to be monitored, is implemented in the control unit 100. For the modeling, various parameter values ​​are taken into account, which are recorded by corresponding measuring devices or sensors 120, 121, 122, 123, 124 and transmitted to the control unit via signal lines 125.

[0067] In the embodiment shown in Figure 1, there are no temperature sensors in the area of ​​the electronic device 110. The temperature at the position 111 to be monitored is therefore calculated entirely based on other parameters. For example, a current measuring device 121 is arranged in each of the electrical lines 114, which transmits measured current values ​​as parameter values ​​to the control unit 100. Furthermore, an ambient temperature is transmitted as a parameter value to the control unit 110 by a temperature sensor 123 not arranged in the area of ​​the electronic device 110. An operating time counter 120 transmits an operating time and / or a lifetime as a parameter value to the control unit 110. Finally, a sleep time of the electronic device 110 is transmitted as an operating parameter by a corresponding sleep time counter 122.

[0068] In the embodiment shown in Figure 2, temperature sensors 124 are located in the area of ​​the electronic device 110, which transmit corresponding temperature values ​​to the control unit 100 via signal lines 125. The control unit 100 calculates the temperature at the position 111 to be monitored based on these temperature values ​​and other parameters already known from Figure 1, namely an ambient temperature, a sleep time, and current values ​​in electrical lines 121. Compared to temperature monitoring in which the temperature of the electronic device 110 is monitored solely by means of temperature sensors, fewer temperature sensors are required in the area of ​​the electronic device in the embodiment of Figure 2. Such an embodiment can also be referred to as a hybrid approach, in contrast to the purely model-based approach of Figure 1.

[0069] Finally, Figure 3 shows an embodiment in which temperatures are calculated at positions 111 to be monitored in the area of ​​the electronic device 110 that are not accessible or only accessible with difficulty for direct measurement. The temperatures at these positions 111 are calculated exclusively based on temperature values ​​measured in the area of ​​the electronic device by sensors 124.

[0070] Figure 4 shows a method for temperature monitoring of an electronic device according to an embodiment of the present disclosure. First, thermal tests are performed with regular and worst-case examples (step S1), and 3D simulations are performed with worst-case examples, for example, worst-case contactors (step S2). In a subsequent step S3, a hybrid data set is generated by matching and combining the data from the 3D simulation and the thermal tests. In a further step S4, the test and 3D simulation data are interpolated onto 1D pC model nodes. In a subsequent step S5, the nominal resistances are corrected to worst-case resistances for all parts of a hot spot list. In a next step S6, test data on resistors at the beginning of life (beginning of life BOL), at the end of life (end of life EOL), and worst-case scenarios (WC) are interpolated.In a further step (S7), the 1D pC model is fitted with the hybrid dataset. The model can then be validated against the data obtained in steps 1 and / or 2 (step 8).

[0071] Figures 5 to 10 compare calculated temperatures 112 with temperatures measured in a test or actual temperatures 113 at a position for temperature monitoring of various electronic devices. Temperature curves 131 in °C over time 130 in s are shown. The calculated temperature 112 is almost always greater than or equal to the actual temperature 113. Exceptions only concern non-critical phases or operating states in which the actual temperature is particularly low (see, for example, the cooling phase at approximately 5000 s in Figures 5 and 6). In critical phases, when the actual temperature is particularly high, there is a safety margin or tolerance threshold of approximately 10 °C to 40 °C between the actual and calculated temperatures.

[0072] In Figure 5 the electronic device is a negative contactor, in Figure 6 a positive contactor, in Figure 7 a so-called Pyrofuse fuse, ie a pyrotechnic battery separation system, in Figure 8 a

[0073] Shunt, in Figure 9 an A1 connector (neg) and in Figure 10 a B1 connector (neg).

[0074] The invention is not limited to the embodiments described herein. Rather, the invention encompasses any novel feature and any combination of features, including, in particular, any combination of features in the embodiments and claims.

[0075] REFERENCE SYMBOL

[0076] 100 control unit

[0077] 110 electronic device 111 temperature monitoring position

[0078] 112 calculated temperature

[0079] 113 actual temperature

[0080] 114 electrical cable

[0081] 120 Operating time counter 121 Current meter

[0082] 122 sleep time counters

[0083] 123 Ambient temperature sensor

[0084] 124 Device temperature sensor

[0085] 125 Signal line 130 Time

[0086] 131 Temperature

Claims

Patent claims 1 . A method for temperature monitoring of an electronic device (110), the method comprising Specifying a position (111) for temperature monitoring in an area of ​​the electronic device (110); Determining a parameter value of a parameter associated with an actual temperature (113) at the position (111); and Calculating a temperature (112) at the position (111) based on the parameter value by means of a calibrated model, wherein the calibrated model is implemented in a control unit and is calibrated such that the sum of the actual temperature (113) at the position (111) and a predetermined tolerance threshold is less than or equal to the calculated temperature (112).

2. The method according to the preceding claim, wherein the calibrated model is calibrated by means of a temperature distribution model of the electronic device (110) and / or by means of thermal investigations of a real specimen of the electronic device (110).

3. The method according to the preceding claim, wherein the real specimen is a worst-case specimen and / or wherein the temperature distribution model is based on a worst-case scenario.

4. The method according to one of claims 2 or 3, wherein the calibrated model is characterized by a smaller dimension than the temperature distribution model.

5. The method according to any one of the preceding claims, wherein parameter values ​​of a plurality of parameters are determined which are related to the temperature at the position (111), wherein the plurality of parameters comprises a temperature measured by a temperature sensor at a further position in the area of ​​the electronic device which is different from the position (111), and wherein the temperature at the position (111 ) is calculated based on the parameter values ​​of the plurality of parameters.

6. The method according to any one of the preceding claims, further comprising: Setting a security requirement level for the electronic device (110); Examine whether the parameter meets the safety requirement level; and Plausibility check of the parameter if the parameter does not meet the safety requirement level.

7. The method according to the preceding claim, wherein the plausibility check of the parameter comprises at least one of the following steps: when determining the parameter value, a dependence of the parameter on aging of the electronic device is taken into account; when determining the parameter value, a dependence of the parameter on operating conditions, in particular an ambient temperature, is taken into account; when determining the parameter value, worst-case assumptions are made; when determining the parameter value, a measured value of at least one characteristic that is different from the parameter is taken into account.

8. The method according to any one of claims 1 to 5, further comprising: setting a security requirement level for the electronic Device (110), wherein the tolerance threshold is predetermined such that the safety requirement level is met.

9. The method according to one of claims 6 to 8, wherein the safety requirement level specifies requirements for an operation of the electronic device (110) with respect to at least one of the following safety requirement features: a severity of an error in the operation of the electronic device (110), a probability of occurrence of the error and a controllability of the error.

10. The method according to one of the preceding claims, wherein the tolerance threshold is predetermined depending on a respective operating state of the electronic device (110).

11. The method according to any one of the preceding claims, wherein an operating time and / or a lifetime of the electronic device (110) is taken into account when calculating the temperature by means of the calibrated model.

12. The method according to any one of the preceding claims, wherein the parameter comprises at least one of the following characteristics: a current, a voltage, an internal resistance, a sleep time and an ambient temperature.

13. The method according to any one of the preceding claims, wherein the parameter is determined on the basis of a measured value and wherein, if the measured value is not available, a predetermined substitute value is used instead of the measured value for determining the parameter, wherein the calculated temperature (112) for the given substitute value is at most as large as for the measured value.

14. The method according to any one of the preceding claims, further comprising Controlling the electronic device (110) such that the calculated temperature (112) remains below a predetermined temperature limit, in particular below 150° C.

15. A control unit (100) in which a calibrated model is implemented and which is arranged to carry out a method according to one of claims 1 to 14.

Images