Methods for maintaining the functionality of a vehicle system, system and vehicle

Abstract

The invention relates to a method for maintaining the functionality of a vehicle system that includes a voltage changer for defining and changing an electrical voltage. At least one parameter of a medium inside the housing of the voltage changer is monitored for the detection of a heat event. Furthermore, a heat event mitigation measure is initiated if the actual value of the at least one parameter exceeds a threshold value that characterizes the potential future occurrence of the heat event or the heat event that has already occurred.As a measure to mitigate heat events, the medium in the interior is also changed by introducing a gaseous oxygen displacer into the interior, which blocks the occurrence of the heat event in the interior or contains the heat event that has already occurred in the interior in order to maintain the functionality of the vehicle system.

Description

One aspect of the invention relates to a method for maintaining the functionality of a vehicle system which includes a voltage changer for defining and changing an electrical voltage. Further aspects of the invention relate to a system configured to carry out such a method and a vehicle equipped with such a system. It is known that in an unlikely event of a fault within a vehicle system, particularly in a voltage converter unit, heat events can occur, for example, as a result of a short circuit. Such heat events, especially an electrical fire, can pose a risk of damage and / or impairment of the vehicle system's functionality. Particularly in a vehicle, an electrical fire and its spread to other components or systems can have adverse consequences. In the prior art, for example, a housing containing the vehicle system is designed in such a way that the heat event, in particular an electrical fire, cannot spread by limiting its expansion to the interior of the housing. In particular, the housing can only limit the spread for a limited period of time. Furthermore, in contrast, document DE 10 2016 217 064 A1, for example, presents a method for operating a safety device comprising a housing with at least one current-carrying element, wherein the current-carrying element is arranged inside the housing and hermetically sealed by the housing. The gas inside the housing is at least partially removed. In particular, this method only prevents the formation of electric arcs. Such extremely short-term events can also cause damage to the device, but do not have a heat-related cause of impairment. Moreover, the effectiveness of arc suppression is limited in this method by the use of oxygen absorbers, i.e., solids typically contained in housings. The object of the invention is to provide a method for the situation-dependent and comprehensive blocking and / or containment of a heat event in a vehicle system. This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims and the description. According to one aspect of the invention, a method for maintaining the functionality of a vehicle system is presented, which includes a voltage changer for defining and changing an electrical voltage. The method comprises, in particular, the following steps: a) In particular, monitoring at least one parameter of a medium inside a housing of the voltage changer with regard to detecting a heat event; b) In particular, initiating a heat event mitigation measure, especially a fire protection measure, if an actual value of the at least one parameter exceeds a threshold value characterizing the potential future occurrence of the heat event or the heat event that has already occurred;where c) In particular, as a measure to mitigate heat events, a change in the interior medium is also carried out by introducing a gaseous oxygen displacer into the interior, with which the occurrence of the heat event, in particular a fire event, in the interior is blocked in order to maintain the functionality of the vehicle system, or the heat event, in particular a fire event, which has already occurred in the interior is contained. This aspect is based on the understanding that a prerequisite for the occurrence and / or spread of a heat event is the availability of a medium at the point of origin of the heat event, in particular oxygen, for example from the ambient air. In other words, removing or partially removing the medium, especially oxygen, from the point of origin of the heat event can lead to a containment or complete cessation of the heat event. According to the invention, insights gained from this approach can be taken into account when maintaining the functionality of the vehicle system. A heat event is, in particular, one characterized by high temperatures compared to room temperature and / or one that is self-sustaining, especially in the presence of oxygen. It then persists for a duration that can be, for example, at least a few seconds, i.e., at least 5 seconds, and in particular at least 10 seconds. Specifically, the duration lasts until the oxygen is consumed. A heat event is thus characterized by parameter values ​​and / or changes in parameter values, especially parameters of the universal gas law. The heat event can be characterized, for example, by an increase in the actual value of at least one parameter, in particular the temperature and / or pressure and / or the media composition and / or the media change, of the medium, especially an increase to an actual value that is greater than the threshold value. Monitoring can consist of recording the actual value of the at least one parameter at regular time intervals, in particular at closely spaced intervals, which may be, for example, less than or equal to three seconds, in particular less than or equal to two seconds, in particular less than or equal to one second, and comparing it with the threshold value. In particular, a trend of the actual value can also be recorded, stored, and analyzed.For example, an increase in at least one parameter can be analyzed in such a way as to estimate or calculate a time at which the potential future heat event is to be expected. The values ​​of the parameters can be recorded using suitable sensors, such as a temperature sensor, a pressure sensor, or at least a sensor that can detect a media composition, such as a gas composition and / or a proportion of a component of the gas. In particular, a type of heat event can be a fire, i.e., it can also involve fire. Functionality can be described, for example, as full functionality or, alternatively, as partial or limited functionality. Maintenance therefore encompasses both full maintenance and, in particular, a reduced level of functionality compared to full maintenance, which is nevertheless sufficient to allow the function to be actively performed and, in particular, to remain sufficiently reliable. Maintenance, however, does not only concern the degree of functionality but can also refer to the available number of functions. Thus, full maintenance can refer to the entire number of functions.In the case of use still defined as suitable, a limited or reduced maintenance may also be possible, in which the number of still executable functions is less than the total number, but is nevertheless higher than a threshold at which the functionality is then characterized as no longer given. Functionality can, for example, also include functional safety, such that a second function of the at least one function can correspond to the safe operation of the vehicle system. In particular, the safe operation of the vehicle system can be maintained by the method according to the invention. The electrical voltage can be, in particular, a direct current (DC) voltage or have a DC component. The voltage conversion unit can be configured to convert the DC voltage or DC component into an alternating current (AC) voltage. The AC voltage can, for example, be supplied to a fully electric drive system or a hybrid drive system of a vehicle. In a further embodiment, the voltage conversion unit can additionally be configured to receive an input AC voltage and convert it into an output DC voltage. This process can also be referred to as recuperation. In particular, the voltage converter can be configured to accept a high electrical input. For example, this electrical power could be a requirement of the vehicle's fully electric or hybrid drive system. The voltage converter can have a DC input through which it can be supplied with an intermediate circuit DC voltage. This intermediate circuit DC voltage could, for example, correspond to the battery voltage of a vehicle battery. The battery voltage could be a high voltage, specifically in accordance with ECE R 100 or similar standards. For example, the battery voltage could be approximately 60 V or more, particularly around 450 V or even 800 V. The housing can, for example, completely enclose the voltage change unit and, in particular, be gas-tight or airtight. The medium can, in particular, be at least partially gaseous; for example, the medium can correspond to air. In an initial state, such as during the monitoring of at least one parameter of the medium in step a), the medium inside the housing can correspond to a medium in an external space outside the housing. In particular, in the initial state, an oxygen content of the medium can correspond to an oxygen content of air and, for example, be greater than 15% of a volume fraction of the medium, and especially greater than 20% of the volume fraction. Alternatively or additionally, the medium can also contain a solid, for example an electronic component or a populated circuit board of the voltage changer unit, which may be arranged in the housing. In particular, at least one parameter can be temperature and / or pressure. In particular, the first part of the heat event mitigation measure can be initiated at a point in time when the actual value of at least one parameter exceeds an initial threshold, which can serve as an indicator of the potential future heat event. The heat event can then, for example, have an initial state. This initial state could be, for instance, the imminent outbreak of a fire. Similarly, the second part of the heat event mitigation measure can be initiated at a second point in time when the actual value of at least one parameter exceeds a second threshold, which can serve as an indicator of the heat event that has already occurred. The heat event can then, for example, have a second state. This second state could be, for instance, a fire that has already broken out. In addition, monitoring of at least one parameter can be continued after the heat event mitigation measure has been started, particularly with regard to verifying its effectiveness and / or starting another part of the heat event mitigation measure and / or ending the heat event mitigation measure. For example, the heat event mitigation measure can be described as multi-stage or, in particular, two-stage. By changing the medium, for example, the oxygen content can be reduced by introducing a gaseous oxygen displacer. Specifically, the oxygen content can be reduced to less than 20% of the medium's volume, for instance, to less than 15%. Reducing the oxygen content can, for example, prevent a fire from starting indoors or contain an existing fire. In other words, a fire or potential fire indoors can be prevented, contained, and / or completely extinguished after it has broken out. The gaseous oxygen displacer can be contained in at least one container. The container can, for example, consist of at least one high-pressure cylinder and / or at least one gas cartridge and / or at least one gas cylinder and / or at least one gas capsule. The container can be part of an oxygen displacement device. The heat event response measure can, in particular, generate information about the occurrence of a heat event for a user of the vehicle system and, for example, provide it to a user information system. Specifically, the information can include the current value of at least one parameter and / or the status of the process. An advantage of the invention is that it can completely contain existing heat events and comprehensively block potentially imminent ones. This allows the functionality of the vehicle system to be maintained for a wide range of failure scenarios, particularly with regard to the safe operation of the vehicle system. As a result, for example, a temperature-stable or fire-resistant housing design can be dispensed with, and cost savings can also be achieved. According to at least one embodiment, the medium monitored is a gas containing oxygen and located within the housing. During monitoring, the actual state of the gas is compared to a reference state, defined as the threshold value. The actual state of the gas can be, in particular, its temperature or pressure. Specifically, monitoring can consist of recording, preferably also storing and / or analyzing, the actual state of the gas. For this purpose, the temperature and pressure of the gas can be analyzed as a combination of several, i.e., at least two, actual states of the gas. In addition to comparing at least one temperature value with a reference temperature, or comparing a pressure value with a reference pressure, the combination of actual states can also be compared with a reference combination of actual states. One advantage of these designs is that the gas inside the housing is comprehensively monitored and the heat event action measure can be specifically initiated and carried out. According to at least one further embodiment, as already explained above, the heat event is recognized as the fire event in which a fire is potentially imminent or a fire has already broken out. To detect a potentially imminent fire, the first threshold value can be compared with the actual value of at least one parameter. Additionally, to detect a fire that has already broken out, the second threshold value can be compared with the actual value of at least one parameter. One advantage of this design is that the heat event, which can be interpreted as a fire event, is recognized, and the heat event mitigation measure is initiated in a targeted, specific, and adapted manner. Consequently, a critical state of the vehicle system can be avoided. In particular, a time advantage can be gained if a potentially imminent fire is blocked or prevented in time. According to at least one further embodiment, at least one parameter is the temperature of the medium, wherein during monitoring at least one actual value of the temperature of the medium is compared with a reference value as the threshold value. The temperature of the medium can, for example, include the gas temperature inside the housing. It is also possible to measure the temperature of an electronic component inside the housing and / or the temperature of an electrical conductor inside. Specifically, the temperature of the medium can be monitored at one or more locations inside the housing, and each temperature value can be compared to a corresponding reference value, which serves as the threshold. The reference value can differ for each temperature value. In particular, the heat event response measure according to step b) can be initiated when the actual value of exactly one of the temperatures exceeds the corresponding reference value. According to at least one further embodiment, in step b) when the heat event exposure measure is initiated, at least a partially defined and therefore intentional removal of the medium from the interior is carried out. The removal is thus specifically initiated and / or metered. One way to at least partially remove the medium from the interior is to create a negative pressure within the interior, i.e., to reduce the pressure of the medium compared to the ambient pressure. In particular, a gas-tight housing can prevent unwanted and uncontrolled ingress of ambient air from the outside into the housing. An advantage of these embodiments is that the at least partial removal of the medium has a direct consequence in response to a potentially imminent or already occurring heat event. For example, by at least partially removing the medium, the oxygen content of the medium relative to the interior space can be reduced to a value of less than 20%, and in particular to a value of less than 15%, especially without any unwanted re-inflow. A negative pressure, in this context, is specifically a pressure value that is lower than a value of a normally prevailing base pressure in the interior. In particular, a negative pressure must be set that is at least 5%, in particular at least 10%, and in particular at least 50% lower than a value of a normally prevailing base pressure in the interior. In one embodiment, the base pressure can be ambient pressure, i.e., in particular normal pressure, or essentially ambient pressure. In one embodiment, for example, a pump of the vehicle system is used to create a negative pressure in the interior. An advantage of this embodiment is that by generating the negative pressure in the interior, a positive effect can be achieved in advance on the potentially imminent heat event, in order to prevent the occurrence or intensification of the heat event, or at least to inhibit the already occurring heat event from intensifying uncontrollably. According to at least one further embodiment, the change of the medium in step c) concerning the supply of the gaseous oxygen displacer is initiated automatically, in particular only, by the heat event action measure started in step b). In addition to generating the negative pressure, one embodiment can also trigger the desired supply of oxygen to the interior space. In this embodiment, the triggering occurs when the negative pressure value is set to less than or equal to a trigger threshold. Specifically, this trigger threshold is less than or equal to 5%, less than or equal to 10%, and less than or equal to 50% of a value typically found in the interior space. In one embodiment, the base pressure can also be ambient pressure, specifically normal atmospheric pressure, or essentially ambient pressure. In particular, the automatic initiation can also be described as self-control or self-regulation. Specifically, the heat event action measure initiated in step b) can be a prerequisite for introducing the gaseous oxygen displacer into the interior. This results in a particularly needs-based and coordinated concept for maintaining the functionality of the vehicle system in a particularly advantageous way. In particular, this provides a multi-stage concept for influencing a heat event. In particular, monitoring of at least one parameter of the medium can continue during the supply of the gaseous oxygen displacer, and the supply of the gaseous oxygen displacer can be automatically terminated depending on an actual value of the at least one parameter and / or a predetermined time. One advantage of these designs is that the potential future occurrence of a heat event can be prevented in advance, or an already occurring heat event can be effectively and quickly contained. This is also because the automatic introduction of the gaseous oxygen displacer inevitably and effectively alters the current state of the medium once again. According to at least one further embodiment, the generated negative pressure in the interior automatically opens a closure element of a container holding the oxygen displacer. This triggers the automatic introduction of the gaseous oxygen displacer into the interior, in particular in a timely and precisely metered manner. The sealing element can, for example, include a pressure relief valve or a diaphragm. It can be located, for example, inside the housing. It can also be arranged on a wall of the interior. The container can be designed, in particular, as a high-pressure cylinder, a gas cartridge, a gas cylinder, or a gas capsule. The container can be located, for example, inside or outside the housing. In particular, the container has the oxygen displacer in a compressed state, for example, under high pressure conditions compared to the pressure inside or outside the housing. Due to the sealing element, a drop in the pressure inside can, for example, lead to the forced supply of the gaseous oxygen displacer, as the sealing element triggers the supply at a predetermined value of the generated negative pressure. In particular, the pressure in the interior can increase due to the introduction of the gaseous oxygen displacer. This pressure increase can be detected by monitoring at least one parameter of the medium and, for example, trigger a further heat event mitigation measure. Specifically, depending on the actual value of at least one parameter, the generation of the negative pressure can be stopped and / or the introduction of the gaseous oxygen displacer can be stopped. For example, particularly by preventing unwanted re-inflow, such as through a check valve, the state of the medium can stabilize after the heat event mitigation measure has ended, especially with regard to the oxygen content and / or oxygen fraction of the medium, as the ingress of outside air into the interior is prevented. In particular, the procedure after the start of the heat event mitigation measure can also be described as a necessarily cascaded chain of events. According to at least one further embodiment, nitrogen and / or carbon dioxide is supplied as a gaseous oxygen displacer. Nitrogen and / or carbon dioxide, in particular, can be described as inert gases. An inert gas can be unreactive and, as a result, may only participate in a few chemical reactions. Specifically, the introduction of nitrogen and / or carbon dioxide can rapidly reduce the oxygen content of the medium inside the housing to less than 20% of its volume, and especially to less than 15%. The introduction of nitrogen and / or carbon dioxide can make combustion inside the housing more difficult or, in particular, impossible. One advantage of these embodiments is that nitrogen and / or carbon dioxide are industrially widespread and readily available. This allows for an effective and cost-efficient process. According to at least one further embodiment, a displacement purge is carried out by introducing the gaseous oxygen displacer. Displacement purging can be defined as the introduction of a gas into an enclosed space, necessarily resulting in the displacement of any medium already present there. In one embodiment, the displacing medium, in this case the displacing gas, is introduced into the container to be purged, in this case the housing, and acts like a piston, displacing the flow to be purged, in this case the gaseous medium in the interior. In particular, a vaporized displacing medium, for example, vaporized nitrogen, can be introduced. Displacement purging can also refer to the exchange of the medium in the interior, especially the exchange of air by the gaseous oxygen displacer. One advantage of these designs is that displacement purging allows for particularly rapid and comprehensive removal of oxygen from the interior. Specifically, the displacement medium is directed towards the oxygen, eliminating the need to first route the medium from the interior to a stationary reduction unit. Displacement purging therefore represents a particularly efficient and safe solution, especially for preventing fires or containing them quickly. According to at least one further embodiment, an inverter unit is monitored as the voltage conversion unit with regard to maintaining its functionality. The inverter unit may, in particular, comprise at least one electrical inverter. The inverter may, in particular, be a high-voltage inverter. The inverter may, in particular, be configured to receive a DC voltage on the input side and, depending on the DC voltage, to generate an AC voltage and make this available on the output side. The AC voltage from the inverter may, in particular, be supplied to the fully electric drive system or the hybrid drive system of the vehicle. Another independent aspect of the invention relates to a method for monitoring the function of an electronic inverter of a vehicle, in particular comprising the following steps: - In particular, monitoring at least one parameter of a medium in the interior of a housing of the inverter; - In particular, initiating at least partial withdrawal of the medium from the interior if an actual value of the parameter exceeds a threshold value; - In particular, supplying an oxygen displacer, in particular a gaseous one, into the interior after initiating the withdrawal of the medium in order to maintain the functional reliability of the inverter. A further independent aspect of the invention relates to a method for influencing a heat event in a voltage changer unit of a vehicle electronic system, in particular comprising the following steps: - In particular, monitoring at least one parameter of a medium in the interior of a housing of the voltage changer unit with regard to detecting the heat event; - In particular, initiating at least a partial and defined change of the medium in the interior if an actual value of the parameter exceeds a threshold value characterizing the heat event; and - In particular, additionally introducing an oxygen displacer, in particular a gaseous one, into the interior after initiating the change of the medium in order to influence, in particular to control and / or contain and / or keep in check, the heat event in the housing. A further independent aspect of the invention relates to a method for ensuring the functionality of an electronic vehicle system, in particular comprising the following steps: - In particular, monitoring the state of a gas in a housing of the vehicle system; - In particular, comparing the actual state with a reference state of the gas; - In particular, if the actual state exceeds the reference state, supplying nitrogen as an oxygen displacer, in particular gaseous nitrogen, into the housing, so that a displacement purge of the oxygen is carried out with the nitrogen to ensure the functionality of the vehicle system, in particular with regard to the occurrence of a potentially function-impairing heat event or the containment of an occurring, potentially function-impairing heat event. A further independent aspect of the invention relates to a method for ensuring the functionality of an electronic vehicle system, in particular comprising the following steps: - In particular, monitoring the state of a gas in a housing of the vehicle system; - In particular, comparing the actual state with a reference state of the gas; - In particular, if the actual state exceeds the reference state, generating a negative pressure in the housing; - In particular, due to the negative pressure, automatically initiating the supply of an oxygen displacer, in particular a gaseous one, into the housing to ensure the functionality of the vehicle system, in particular with regard to the occurrence of a potentially function-impairing heat event or the containment of a potentially function-impairing heat event that has occurred. A further independent aspect of the invention relates to a method for ensuring the functionality of an electronic vehicle system, in particular comprising the following steps: - In particular, monitoring a temperature in a housing of the vehicle system; - In particular, comparing the actual temperature value with a reference value; - In particular, if the actual value exceeds the reference value, supplying an oxygen displacer, in particular a gaseous one, into the housing, so that oxygen in the housing is displaced by the oxygen displacer and thereby, in order to ensure the functionality of the vehicle system, the occurrence of a heat event that has already occurred and impairs its function is prevented or contained. Embodiments of an independent aspect relating to a method are to be regarded as advantageous embodiments of the other aspects. In particular, abstracted feature specifications of one aspect are also to be regarded as disclosed as such abstracted feature specifications of another aspect. A specification and / or detailing of abstracted features of one aspect for another aspect is likewise to be regarded as disclosed. With regard to the further independent aspects relating to the methods, the maintenance of the functional safety of the vehicle system is provided in particular, and this is achieved specifically through the respective process steps mentioned. According to a further aspect of the invention, a system for maintaining the functionality of a vehicle system is presented, which includes a voltage changer for the defined modification of an electrical voltage. The system can also be referred to as a safety system. The system can also be referred to as a vehicle system monitoring system. In particular, the system includes a monitoring device configured to monitor at least one parameter of a medium inside the housing of the voltage changer with regard to the detection of a heat event.The system also includes, in particular, an action device designed to initiate a heat event action, especially a fire protection measure, if an actual value of at least one parameter exceeds a threshold value characterizing the potential future occurrence of the heat event or the heat event that has already occurred. The action device is designed to modify the medium in the interior as a heat event action measure by introducing a gaseous oxygen displacer into the interior. This displacer blocks the occurrence of the heat event, especially a fire, in the interior, or contains an existing heat event, especially a fire, in order to maintain the functionality of the vehicle system. The monitoring device may include an evaluation unit, such as a computing unit or a microprocessor. It may include at least one sensor. The action device has at least one action unit, such as a pump and / or an oxygen displacement device. In particular, the system may also include a control unit that controls the aforementioned devices and / or evaluates information from these devices. The control unit may also include a data processing system. The data processing system can be characterized, for example, as a device with processing circuits for processing data. The data processing system can, for example, perform arithmetic operations, in particular comprehensive database access for reading and / or storing data. The data processing system can, for example, include a computer and / or a microcontroller and / or one or more integrated circuits. The data processing system can include at least one processor and / or at least one semiconductor chip. Furthermore, the data processing system can include at least one hardware interface and / or one software interface, which can be configured, for example, to receive and / or provide data. The data processing system may also include a storage unit for storing data, for example, as volatile data storage and / or non-volatile data storage and / or persistent data storage. In particular, the data processing system may include semiconductor storage. Further embodiments of the system according to the aforementioned aspect of the invention follow directly from the various configurations of a method according to a aforementioned independent aspect or an advantageous embodiment thereof, and vice versa. In particular, the monitoring device and / or the action device can be used to carry out process steps. Specifically, individual features and corresponding explanations as well as advantages relating to the various embodiments of the methods according to the invention can be transferred analogously to corresponding embodiments of the system according to the invention. In particular, the system according to the aforementioned aspect of the invention is configured and programmed to carry out a method according to the aforementioned aspect of the invention or an advantageous embodiment thereof. In particular, the system according to the invention carries out the method according to the invention. Further independent aspects of the invention also relate to a system configured for carrying out a method according to one of the aforementioned further independent aspects of a method or an advantageous embodiment thereof. Such a system may include a monitoring unit and / or an action device and / or a control unit, etc., in particular to be able to carry out or perform method steps. Another aspect of the invention relates to a vehicle with a system according to the aforementioned aspect of the invention or an advantageous embodiment thereof. According to at least one embodiment, the vehicle has a fully electric drive system or a hybrid drive system with an electric subsystem, wherein the system according to the said aspect of the invention or an advantageous embodiment thereof is part of the electric drive system or the hybrid drive system. Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own. Embodiments of the invention are explained in more detail below with reference to schematic drawings. These show: Fig. 1 a schematic representation of a motor vehicle as an embodiment of a vehicle according to one aspect of the invention with an embodiment of a system, in particular for maintaining the functionality of a vehicle system according to one aspect of the invention; and Fig. 2 a schematic representation of a vehicle system according to one embodiment of the invention; and Fig. 3 a schematic representation of a flowchart to illustrate embodiments of methods, in particular also for maintaining the functionality of a vehicle system according to aspects of the invention. Figure 1 shows a schematic representation of a vehicle 1. The vehicle here is a motor vehicle. It can be a passenger car, a truck, or a bus. The vehicle 1 preferably comprises a vehicle system 2. The vehicle system 2 is, in particular, an electric vehicle system 2. It can be a vehicle electronics system. It can be part of a fully electric drive or a hybrid drive of the vehicle 1. In this embodiment, the vehicle system 2 comprises at least one voltage conversion unit 3. The voltage conversion unit 3 is, for example, an inverter unit or an inverter, such as a high-voltage inverter. As shown in the schematic diagram in Fig. 2, the voltage conversion unit 3 has a housing 4. An interior space 5 is defined by the walls of the housing 4. Electronic components 6 are also arranged in the interior space 5. The interior space 5 contains a medium 7. The medium 7 is, in particular, at least partially, and especially completely, a gas 8. The gas 8 also contains oxygen in its normal state. The vehicle 1 also includes a system 9. In one embodiment, system 9 is designed to maintain the functionality of the vehicle system 1, in particular at least the voltage converter 3. System 9 can also be referred to as a vehicle system monitoring system. In one embodiment, system 9 is designed to monitor the function of the electronic inverter. In one embodiment, system 9 is designed to counteract a heat event in the voltage converter 3. In one embodiment, system 9 is designed to ensure the functionality of the electronic vehicle system 2. In one embodiment, system 9 includes a monitoring device 10. In one embodiment, system 9 includes an action device 11. In one embodiment, the vehicle system 2 has at least one temperature sensor 12. For example, the temperature sensor 12 can be a negative temperature coefficient (NTC) thermistor, a positive temperature coefficient (PTC) thermistor, or a thermocouple. The temperature sensor 12 is designed to detect a temperature value of the medium 7, in particular the gas 8, and / or the electronic component 6. The temperature sensor 12 can be located in and / or on the housing 4, in particular in the interior 5. Furthermore, one embodiment of the vehicle system 2 has at least one pressure sensor 13. For example, the pressure sensor 13 can be an absolute pressure sensor, a differential pressure sensor, a bidirectional differential pressure sensor, or a relative pressure sensor. The pressure sensor 13 is designed to detect a pressure value of the medium 7, in particular the gas 8. The pressure sensor 13 can be located in and / or on the housing 4, in particular in the interior 5. The medium 7 is monitored by means of the temperature sensor 12 and / or the pressure sensor 13, in particular the actual state of the medium 7 is compared with a reference state as a threshold value. In particular, one embodiment includes a pump 14 configured to at least partially remove the medium 7, especially the gas 8, from the interior 5. The pump 14 can, for example, be a vacuum pump and / or a radial blower and / or an axial blower and / or a compressor. As shown in the embodiment in Fig. 2, the vehicle system 2 can include a valve, such as a check valve 15, configured to prevent the ingress of a medium 7 from outside the housing 4, especially from outside air, into the interior 5. The check valve 15 can be configured to allow the medium 7, especially the gas 8, to escape from the interior 5. For this purpose, a check valve 15 is located in series with the pump 14 with respect to a flow of the medium 7. One embodiment also includes at least one container 16 containing the gaseous oxygen displacer. The at least one container 16 can be located within the interior 5, as shown in Fig. 2, or alternatively outside the housing 4. The at least one container 16 can contain, for example, nitrogen and / or carbon dioxide as the oxygen displacer, for example, in pressure-compressed form. A closure element 17 is configured to allow the oxygen displacer to escape from the at least one container 16 into the interior 5 under predetermined conditions, for example, at a predetermined pressure. The closure element 17 is also configured such that the oxygen displacer remains within the at least one container 16 as long as the predetermined conditions have not occurred.For example, the closure element 17 can be a pressure relief valve or a diaphragm located at an outlet of the at least one container 16. Alternatively, the closure element 17 can also be electrically actuated, in particular depending on the vacuum, to allow the oxygen displacer to escape from the at least one container 16 into the interior 5. For example, the closure element 17 can include a valve actuated by an electric valve actuator, which triggers the supply of the oxygen displacer depending on the pressure value of the medium 7. In particular, the system 9 also includes at least one control unit 9a, especially for operating the components and for carrying out processes and / or for evaluating information and / or for generating control signals. With reference to the components shown and described in connection with Fig. 1 and Fig. 2, Fig. 3 shows a schematic representation of a method according to embodiments of the invention. According to step S1, at least one parameter of the medium 7 in the interior 5 of the housing 4 of the voltage change unit 3 is monitored with regard to the detection of a heat event. In this process, at least one parameter, the temperature of medium 7, can be monitored. During monitoring, at least one actual value of the temperature of medium 7 can be compared with a respective reference value, which serves as the threshold. Thus, for example, an increase in the temperature value in the interior 5 can be detected and signaled using temperature sensor 12. In step S2, the heat event action measure, in particular a fire protection measure, is initiated if the actual value of at least one parameter exceeds a threshold value characterizing the potential future occurrence of the heat event or the heat event that has already occurred. When the heat event mitigation measure is initiated, at least a partial removal of the medium 7 from the interior 5 can be carried out. For example, the pump 14 can be activated based on a signal from the temperature sensor 12, and the oxygen-containing gas 8 can be evacuated from the interior 5. This can subsequently result in a negative pressure in the interior 5. In step S3, as a heat event mitigation measure, the medium 7 in the interior 5 is also changed such that in step S4 the gaseous oxygen displacer is introduced into the interior 5. This preferably further component of the heat event mitigation measure can, for example, be triggered automatically, in particular only by at least partial removal of the medium 7 and the resulting negative pressure. For example, the closure unit 17 can be configured to supply the oxygen displacer, in particular nitrogen, located in the at least one container 16 into the interior 5 at a predetermined negative pressure threshold. In step S5a, to maintain the functionality of the vehicle system, the occurrence of a heat event, in particular a fire, in interior 5 is blocked. Alternatively, in step S5b, to maintain the functionality of the vehicle system, the heat event that has already occurred, in particular a fire, is contained in interior 5. Specifically, the oxygen content of gas 8 in interior 5 is reduced to a value that prevents or minimizes combustion. Particularly due to the supply of nitrogen, the pressure in chamber 5 can increase. This pressure can be detected and signaled by pressure sensor 13. Consequently, pump 14 can be deactivated, for example, so that the nitrogen, or a portion thereof, remains in chamber 5. A check valve 15 can be used to prevent, for example, outside air from flowing back into chamber 5. This stabilizes the pressure of the medium 7 in chamber 5. Additionally, as a heat event mitigation measure, a further or supplementary step can be carried out to generate information for a user of vehicle 1 and make it available, for example, to a vehicle information system. This information can, for example, include documentation of the start and / or execution of the heat event mitigation measure. Furthermore, the information can also include the actual value of the temperature sensor 12, the actual value of the pressure sensor 13, the operating status of the pump 14, and / or the operating status of the sealing element 17. Reference symbol list 1 Vehicle 2 Vehicle system 3 Voltage conversion unit 4 Housing 5 Interior 6 Electronic component 7 Medium 8 Gas 9 System 9a Control unit 10 Monitoring device 11 Action device 12 Temperature sensor 13 Pressure sensor 14 Pump 15 Check valve 16 Container 17 Closure element S1 to S5b Steps QUOTES INCLUDED IN THE DESCRIPTION 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 DE 10 2016 217 064 A1

[0004]

Claims

Method for maintaining the functionality of a vehicle system (2) which has a voltage changing unit (3) for defining changes to an electrical voltage, comprising the following steps: a) Monitoring (S1) at least one parameter of a medium (7) in the interior (5) of a housing (4) of the voltage changing unit (3) with regard to the detection of a heat event; b) Initiating (S2) a heat event action measure, in particular a fire protection measure, if an actual value of the at least one parameter exceeds a threshold value characterizing the potential future occurrence of the heat event or the heat event that has already occurred;wherein c) as a heat event mitigation measure a change of the medium (7) in the interior (5) is also carried out (S3) such that a gaseous oxygen displacer is introduced into the interior (5) (S4), with which the occurrence of the heat event, in particular a fire event, in the interior (5) is blocked (S5a) or the heat event, in particular a fire event, which has already occurred, in the interior (5) is contained (S5b).; Method according to claim 1, wherein the medium (7) is a gas containing oxygen located in the housing (4), and wherein the monitoring compares the actual state of the gas with a reference state as the threshold value. Method according to claim 1 or 2, wherein the heat event is the fire event in which a fire is potentially imminent or a fire has already broken out. Method according to one of the preceding claims, wherein at least one parameter is at least one temperature of the medium (7), wherein during monitoring at least one actual value of the at least one temperature of the medium (7) is compared with a respective reference value as the threshold value. Method according to one of the preceding claims, wherein in step b) when starting the heat event action measure, at least partial removal of the medium (7) from the interior (5) is carried out. Method according to claim 5, wherein the at least partial removal is carried out by generating a negative pressure in the interior (5), in particular with a pump (14) of the vehicle system (2). Method according to one of the preceding claims, wherein the change of the medium (7) in step c) with regard to the supply of the gaseous oxygen displacer is initiated automatically, in particular only, by the heat event action measure started in step b). Method according to claims 6 and 7, wherein the generated negative pressure in the interior (5) opens a closure element (17) of a container (16) having the oxygen displacer and thereby automatically introduces the gaseous oxygen displacer into the interior (5). A method according to one of the preceding claims, wherein nitrogen and / or carbon dioxide is supplied as a gaseous oxygen displacer. Method according to one of the preceding claims, wherein a displacement purge is carried out by supplying the gaseous oxygen displacer. Method according to one of the preceding claims, wherein an inverter unit is monitored as the voltage changing unit (3) with regard to maintaining its functionality. System (9) for maintaining the functionality of a vehicle system (2) which has a voltage changer (3) for defining and changing an electrical voltage, wherein: - the system (9) has a monitoring device (10) which is configured to monitor at least one parameter of a medium (7) in the interior (5) of a housing (4) of the voltage changer (3) with regard to detecting a heat event; - the system (9) has an action device (11) which is configured to initiate a heat event action measure, in particular a fire protection measure, if an actual value of the at least one parameter exceeds a threshold value characterizing the potential future occurrence of the heat event or the heat event that has already occurred;wherein- the action device (11) is configured to carry out, as a heat event action measure, a change in the medium (7) in the interior (5) such that a gaseous oxygen displacer is introduced into the interior (5), with which, in order to maintain the functionality of the vehicle system (2), the occurrence of the heat event, in particular a fire event, in the interior (5) is blocked or the heat event, in particular a fire event, which has already occurred, in the interior (5) is contained.; System (9) according to claim 12, wherein the voltage conversion unit (3) comprises an inverter, in particular of a high-voltage system, of the vehicle system (2). Vehicle (1) with a system (9) according to claim 12 or 13 . Vehicle (1) according to claim 14, which has a fully electric drive system or a hybrid drive system with an electric subsystem, wherein the system (9) is part of the electric drive system or the hybrid drive system.

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