Thermal protection of connectors

Abstract

The present invention relates to a connector system for establishing an electrical connection with a battery system, the connector system comprising: a connector for establishing an electrically conductive connection with a suitable counterpart of the connector, wherein the connector comprises a negative connection element and a positive connection element; a first temperature sensor thermally connected to the negative connection element; a second temperature sensor thermally connected to the positive connection element; and a control device adapted to generate an alarm signal when the absolute value of the difference between a first value and a second value exceeds a predefined threshold value. The present invention also relates to a battery system comprising the connector system, a battery module having the battery system, a vehicle employing the connector system or the battery system according to the present invention, and a method for operating the connector system.

Description

Technical Field

[0001] The present invention relates to a connector system for establishing an electrical connection to a battery system, and in particular to a connector system in which the connecting elements are protected from thermal overload. The present invention also relates to a battery system comprising a connector system according to the invention. In addition, the present invention relates to a battery module comprising several of these battery systems. In addition, the present invention relates to a vehicle using a battery system or a battery module according to the invention. In addition, the present invention relates to a method for controlling an electrically conductive connection to a battery system using a connector system according to the invention. Background Art

[0002] In recent years, vehicles for transporting goods and people have been developed that use electricity as a power source. Such electric vehicles are cars that are propelled by an electric motor using energy stored in rechargeable batteries. Electric vehicles can be powered solely by batteries or can be in the form of hybrid vehicles that are additionally powered by, for example, a gasoline generator. In addition, vehicles can include a combination of an electric motor and a conventional internal combustion engine. Generally speaking, an electric vehicle battery (EVB) or traction battery is a battery used to power the propulsion of a battery electric vehicle (BEV). Electric vehicle batteries differ from starting, lighting, and ignition batteries in that they are designed to provide power for a sustained period of time. Rechargeable or secondary batteries differ from primary batteries in that they can be repeatedly charged and discharged, while the latter only provide an irreversible conversion of chemical energy into electrical energy. Low-capacity rechargeable batteries are used as power sources for small electronic devices such as cell phones, notebook computers, and camcorders, while high-capacity rechargeable batteries are used as power sources for hybrid vehicles and the like.

[0003] In general, a rechargeable battery includes an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes; a housing that receives the electrode assembly; and electrode terminals electrically connected to the electrode assembly. An electrolyte solution is injected into the housing to enable the battery to be charged and discharged via an electrochemical reaction of the positive electrode, the negative electrode, and the electrolyte solution. The shape of the housing (e.g., cylindrical or rectangular) depends on the intended purpose of the battery. Lithium-ion (and similar lithium polymer) batteries, widely known for their use in laptop computers and consumer electronic devices, dominate the latest wave of electric vehicles under development.

[0004] Rechargeable batteries can be used as battery modules, formed from multiple battery cells connected in series and / or parallel, to provide high energy density, particularly for hybrid vehicle motor drives. Specifically, to achieve high-power rechargeable batteries, a battery module is formed by interconnecting the electrode terminals of multiple battery cells, depending on the required power.

[0005] A battery pack is a group of any number of (preferably identical) battery modules. They can be configured in series, in parallel, or a mixture of the two to deliver the desired voltage, capacity, or power density. The components of a battery pack include the individual battery modules and the interconnects that provide electrical connectivity between them.

[0006] To meet the dynamic power demands of the various power-consuming devices connected to a battery system, static control of battery power delivery and charging is insufficient. Therefore, a stable information exchange between the battery system and the controllers of the power-consuming devices is required. This information includes the battery system's actual state of charge (SoC), potential electrical performance, charging capability, and internal resistance, as well as the actual or predicted power requirements or remaining capacity of the power-consuming devices.

[0007] A battery system typically includes a battery management system (BMS) and / or a battery management unit (BMU) for processing the aforementioned information. The BMS / BMU can communicate with the controllers of various power-consuming devices via a suitable communication bus (e.g., SPI or CAN interface). The BMS / BMU can also communicate with each of the battery submodules, particularly with the cell supervisory circuit (CSC) of each battery submodule. The CSC can further be connected to the cell connection and sensing unit (CCU) of the battery submodule, which interconnects the battery cells of the battery submodule.

[0008] Thus, a BMS / BMU is provided for managing the battery pack, such as by protecting it from operating outside its full operating area, monitoring its status, calculating secondary data, reporting that data, controlling its environment, validating it, and / or balancing it.

[0009] To establish an electrical connection between a vehicle's battery and the loads powered by the battery, a connector or connector system is required. The lifespan of a connector or connector system is fundamentally dependent on the temperature to which it is exposed during use. If a maximum temperature is exceeded, the connector or connector system may be damaged. The temperature to which the connector or connector system heats up, in turn, is fundamentally dependent on the current conducted through it. Therefore, appropriate protection mechanisms are employed to prevent the connector or connector system from heating above a certain maximum temperature, which must be determined in advance, i.e., during the design of the connector or connector system.

[0010] Currently, connectors are protected using fuses or by detecting the current conducted through the connector.

[0011] When using a fuse, the tolerances of the connector and fuse need to be taken into account to ensure that the fuse does not react to current flow during normal use (i.e., within a predefined current range), but that it blows in the event of an overload on the connector. Therefore, based on the tolerances and the estimated environment, the connector needs to be oversized to ensure that the connector temperature remains within the specified range.

[0012] When monitoring current, additional current measurements are required, which increases costs. Estimate the actual overload of the connector, including all possible tolerances (e.g., boundary temperature, internal resistance, etc.). Similarly, based on the tolerance and the estimated environment, the connector needs to be oversized to ensure that the connector temperature remains within the specified range.

[0013] It is therefore an object of the present invention to overcome or alleviate at least some of the disadvantages of the prior art and to provide a connector system and a battery system comprising the same, in which tolerance considerations and consequently oversizing of components can be avoided. It is also an object of the present invention to provide a method for controlling an electrically conductive connection to a battery system using the connector system according to the present invention. Summary of the Invention

[0014] Embodiments of the present disclosure attempt to address at least one problem present in the prior art to at least some extent. In particular, a connector system for establishing an electrical connection with a battery system is provided, the connector system comprising: a connector for establishing an electrically conductive connection with a suitable counterpart of the connector, wherein the connector comprises a negative connection element and a positive connection element; a first temperature sensor thermally connected to the negative connection element; a second temperature sensor thermally connected to the positive connection element; and a control device configured to receive a first temperature signal from the first temperature sensor and a second temperature signal from the second temperature sensor. The control device is adapted to generate a first value based on the first temperature signal and a second value based on the second temperature signal. The control device is further adapted to generate an alarm signal when the absolute value of the difference between the first value and the second value exceeds a predefined threshold.

[0015] By directly measuring the temperature of the connected elements, highly accurate protection is possible and the connector can be minimized to the required normal current without the high shock of unknown environmental conditions.

[0016] The temperature signal may be monotonically (or strictly monotonically) dependent on the corresponding measured temperature. In other words, the temperature signal may be a monotonic (or strictly monotonic) function of the measured temperature.

[0017] If the absolute value of the difference between the first and second values exceeds a predefined threshold, there is a probability that the contact resistance between one of the connection elements and its respective counterpart connection element (the latter is not part of the present invention) is increased, which in turn may indicate a connection fault.

[0018] The decision whether to generate an alarm signal is based on the absolute value of the difference between the first value and the second value and is therefore independent of the algebraic sign of the difference. However, the signal itself (i.e., such a signal) may depend on the algebraic sign of the difference; in this case, the signal may generate an indication, i.e., which of the two connection elements may be affected by a connection fault.

[0019] The alarm signal itself may be an electrical signal provided at an output of the control device. Alternatively, the alarm signal may be provided wirelessly, for example via an NFC signal or a WLAN signal or the like.

[0020] Instead of "negative connecting element," the term "first connecting element" can also be used. Accordingly, the expression "second connecting element" can be used instead of "positive connecting element." In this context, the terms "negative connecting element" and "positive connecting element" are simply used to clarify that the "negative connecting element" can be adapted to be connected to the anode of a battery cell (or battery cell stack), and the "positive connecting element" can be adapted to be connected to the cathode of a battery cell (or battery cell stack). Generally, however, one of the connecting elements can be used to establish a connection to the anode, and the other to establish a connection to the cathode of a battery cell or battery cell stack.

[0021] In an embodiment of the connector system according to the invention, the predefined threshold value depends on the first temperature signal or the second temperature signal or an average value of the first temperature signal and the second temperature signal.

[0022] The higher the voltage, the greater the tolerance for the absolute difference in temperature between the negative and positive connection elements. To account for this, a relative temperature difference can be used. To this end, the absolute temperature difference can be divided by the temperature of the negative connection element, by the temperature of the positive connection element, or by the average value (e.g., the arithmetic mean) of the negative and positive connection elements.

[0023] In an embodiment of the connector system according to the invention, the connector is formed as a socket connectable with a suitable plug.

[0024] In an embodiment of the connector system according to the invention, the connector is formed as a plug connectable with a suitable socket.

[0025] In an embodiment of the connector system according to the invention, the negative connection element and the positive connection element are each configured to establish a high voltage (HV) connection.

[0026] In one embodiment of the connector system according to the invention, at least one of the temperature sensors is a thermistor, such as a negative temperature coefficient (NTC) thermistor or a positive temperature coefficient (PTC) thermistor, or a thermocouple.

[0027] In an embodiment of the connector system according to the invention, the control device is further adapted to generate an alarm signal if the first value or the second value indicates that the absolute temperature of the negative connection element or the positive connection element exceeds a predefined maximum value.

[0028] In an embodiment of the connector system according to the invention, the connector is integrated in a housing, which is adapted to accommodate a battery cell stack.

[0029] Another aspect of the present invention relates to a battery system comprising a battery cell stack and a connector system according to the present invention (see above), wherein the battery cell stack is accommodated in the housing and wherein the negative connecting element is electrically connected to the anode of the battery cell stack and the positive connecting element is electrically connected to the cathode of the battery cell stack.

[0030] In one embodiment of the battery system, the battery system comprises a battery cell stack and a connector system according to the invention, wherein the negative connecting element is electrically connected to the anode of the battery cell stack and the positive connecting element is electrically connected to the cathode of the battery cell stack.

[0031] In one embodiment of the battery system, the battery system further comprises a battery management device, and wherein the control device is integrated into the battery management device.

[0032] Yet another aspect of the present invention relates to a battery module comprising two or more battery systems according to the present invention.

[0033] A further aspect of the present invention relates to a vehicle comprising the battery system according to the present invention or the battery module according to the present invention.

[0034] A further aspect of the present invention relates to a method for controlling an electrically conductive connection to a battery system using a connector system according to the present invention. The method comprises the following steps:

[0035] measuring a temperature of a negative connection element by a first temperature sensor and generating a first temperature signal based on said measured temperature of said negative connection element;

[0036] sending the first temperature signal to a control device;

[0037] measuring a temperature of a positive connection element by a second temperature sensor and generating a second temperature signal based on said measured temperature of said positive connection element;

[0038] sending the second temperature signal to the control device;

[0039] generating, by the control device, a first value based on the first temperature signal and a second value based on the second temperature signal;

[0040] calculating, by the control device, a difference between the first value and the second value; and

[0041] An alarm signal is generated by the control device when the absolute value of the difference exceeds a predefined threshold value.

[0042] In one embodiment of the method, each of the steps is performed or repeated consecutively in time.

[0043] In one embodiment of the method, each of the steps is repeated after a predefined time interval.

[0044] Further aspects of the invention can be learned from the dependent claims or the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0046] Figure 1 is an exemplary diagram for designing a connector according to the prior art;

[0047] Figure 2 A schematic diagram of a conventional connector system with a fuse is shown, wherein the connector system is integrated into a battery system;

[0048] Figure 3 A schematic diagram of a conventional connector system with an ammeter is shown, wherein the connector system is integrated into a battery system;

[0049] Figure 4 shows a schematic diagram of a connector system according to an embodiment of the present invention, wherein the connector system is integrated into a battery system; and

[0050] Figure 5 A schematic diagram of a connector system according to yet another embodiment of the present invention is shown, wherein the connector system is integrated into a battery system. DETAILED DESCRIPTION

[0051] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. The effects and features of the exemplary embodiments and their implementation methods will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals indicate the same elements, and redundant descriptions are omitted. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. In addition, when describing embodiments of the present invention, the use of "may" refers to "one or more embodiments of the present invention."

[0052] It should be understood that although the terms "first" and "second" are used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element can be named a second element, and similarly, a second element can be named a first element, without departing from the scope of the present invention.

[0053] In the following description of the embodiments of the present invention, terms in the singular may include plural forms unless the context clearly indicates otherwise.

[0054] It will also be understood that the terms “include,” “comprise,” “including,” or “comprising” specify features, regions, fixed numbers, steps, processes, elements, parts, and combinations thereof, but do not exclude other features, regions, fixed numbers, steps, processes, elements, parts, and combinations thereof.

[0055] The embodiments are provided as examples so that this disclosure will be thorough and complete and fully convey the aspects and features of the present invention to those skilled in the art. Therefore, processes, elements, and techniques that are not necessary for a person of ordinary skill in the art to fully understand the aspects and features of the present invention may not be described. In the accompanying drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

[0056] It will be understood that when an element or layer is referred to as being “on,” “connected” or “coupled” to another element or layer, it can be directly “on,” “connected” or “coupled” to the other element or layer, or one or more intervening elements or layers may be present. Additionally, it will be understood that when an element or layer is referred to as being “between” two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

[0057] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation rather than terms of degree, and are intended to illustrate the inherent variation in measured or calculated values that would be recognized by one of ordinary skill in the art. Furthermore, if the term "substantially" is used in conjunction with a feature that can be expressed with a numerical value, the term "substantially" indicates a range of + / - 5% of the value centered around that value. Furthermore, when describing embodiments of the present invention, the use of "may" refers to "one or more embodiments of the present invention."

[0058] The electronic or electrical devices and / or any other related devices or components according to the embodiments of the present invention described herein can be implemented using any suitable hardware, firmware (e.g., application specific integrated circuits), software, or a combination of software, firmware, and hardware. For example, the various components of these devices can be formed on an integrated circuit (IC) chip or on separate IC chips. In addition, the various components of these devices can be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on a substrate. In addition, the various components of these devices can be processes or threads running on one or more processors in one or more computer devices, thereby executing computer program instructions and interacting with other system components to perform the various functions described herein. The computer program instructions are stored in a memory that can be implemented in a computing device using a standard storage device, such as, for example, a random access memory (RAM). The computer program instructions can also be stored in other non-transitory computer-readable media, such as, for example, a CD-ROM, a flash drive, etc. In addition, those skilled in the art will recognize that, without departing from the scope of the exemplary embodiments of the present invention, the functions of various computing devices can be combined or merged into a single computing device, or the functions of a particular computing device can be distributed on one or more other computing devices.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or this specification, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0060] Figure 1FIG2 is an exemplary diagram for designing a connector system according to the prior art. It shows the lifetime (in seconds (s), also on a logarithmic scale) of components of a conventional connector system, such as the connector itself (connector I; see the legend of the figure) and a fuse, as a function of the current (in amperes [A], on a logarithmic scale). A conventional connector system using a fuse is explained in more detail below. Because the behavior of a fuse depends significantly on its temperature, two different temperatures, −40°C and +20°C, are plotted in the figure (see the legend of the figure).

[0061] The lines describing the behavior of a fuse can be interpreted as follows: These lines each specify (for a corresponding temperature, here: -40°C and +20°C) how many seconds it takes for the fuse to operate (i.e. stop the flow of current) if a certain current measured in amperes flows through the fuse. Figure 1 As can be seen in the graph, the fuse operates more slowly at lower temperatures (the curve for the fuse at -40°C runs above the curve for the fuse at +20°C). Since the worst-case scenario must be considered when designing safety-critical connector systems, the upper curve showing the behavior of the fuse at -40°C will be considered below. To facilitate the following description, the graph is divided into two non-intersecting regions separated by a line showing the behavior of the fuse at -40°C: Region A is the region below this line in the graph, and Region B indicates the region above this line in the graph.

[0062] Figure 1 The graph also shows the life of the battery cells under conditions of rapid charging of the battery system and under conditions of an exemplary drive cycle (i.e., during use in a vehicle) (see the legend for the corresponding lines in the graph). Both the line showing rapid charging and the line showing the exemplary drive cycle run below the curve indicating the behavior of the fuse, i.e., these lines run entirely in region A. This is necessary because otherwise, under normal use of the battery system, the fuse would operate and stop the flow of current.

[0063] Furthermore, the curve in the figure showing the life of the connector can be interpreted as follows: it specifies how many seconds it takes for the connector to become damaged if a certain (over)current, measured in amperes, flows through it. Thus, the curve showing the life of the connector of a conventional connector system with a fuse (i.e., the curve for connector 1; see the legend of the figure) runs above the line indicating the behavior of the fuse, i.e., the curve for connector 1 runs entirely in area B. Otherwise, i.e., if the curve for connector 1 were to touch or intersect the curve for the fuse, the conventional connector system would not be properly designed, since in this case a situation would occur in which the connector would be damaged by the overcurrent before the fuse would operate and stop the current. In other words, area B indicates the area protected by the fuse (at a fuse temperature of -40°C).

[0064] When designing a connector system, the tolerances of its components must also be considered. Therefore, a minimum distance (in the vertical direction) must exist between the fuse curve and the connector curve to ensure that even if the connector is damaged earlier than expected (for a certain overcurrent) as assumed, or even if the fuse operates later than expected (for a certain overcurrent), the fuse will still operate before the connector is damaged. Furthermore, since the boundary conditions of a specific application are unknown, the worst-case scenario must always be considered. Based on these conditions, the connector, fuse, and / or current measurement device must be selected to design a conventional connector system.

[0065] As can also be seen from the figure, the most critical influence on the lifespan of the connector system or its components is caused by temperature, which in turn directly depends on the current transmitted through the connector system. The greater the current transmitted through the connector system (and therefore the higher the temperature of its components), the shorter the lifespan of the connector system and its components. This is reflected in the curves shown in the figure, each of which decreases as the current increases. Of course, similar relationships also apply to the curves showing the lifespan of battery cells for rapid charging and use (driving cycles).

[0066] By measuring the temperature inside the connector as described in the present invention, load estimation no longer requires major boundary conditions (see below). Figure 4 and Figure 5 Based on the measured temperature, the load on the connector can be monitored. In an emergency, countermeasures can be initiated, for example, by a battery management unit (BMU) or a battery management system (BMS). In most cases, this is therefore in contrast to conventional connector systems (see Figures 1 to 3 ) a more efficient connector system can be used; therefore, when using a connector system according to the present invention a smaller and therefore cheaper design for the connector system can be selected.

[0067] This is Figure 1 The figure is represented by a line showing the behavior (i.e., lifetime in dependence on overcurrent) of a connector employed in an exemplary connector system according to the present invention (connector II; see the legend of the figure). Since a fuse is no longer required, a less robust connector (connector II) can be selected compared to the connector required in a conventional connector system (connector I), i.e., the lifetime of the connector employed in the connector system according to the present invention (connector II) under a certain overcurrent can be reduced compared to the lifetime of the connector (connector I) of the conventional system. Consequently, the curve showing the behavior of the connector (connector II) of the system according to the present invention runs below or above the curve showing the behavior of the connector (connector I) of the conventional system. Generally, less robust connectors are less expensive; therefore, the manufacturing costs required for the connector system are reduced by the present invention.

[0068] The advantage lies in the current range below Figure 1 The diagram of indicates a specific current c0 for a current at which the line showing the behavior of the connector employed in the connector system according to the invention (connector II) intersects the curve of the fuse of a conventional connector system, since within this range the curve runs in area A and the connector will therefore not be protected by the fuse (see above).

[0069] Figure 2 A schematic diagram of a conventional connector system with a fuse 70 is shown, wherein the connector system is integrated into a battery system. The battery system can be adapted as a power source for a vehicle. A battery cell stack 10 is housed within a housing 20. The battery cell stack 10 has an anode (not shown) and a cathode (not shown). A connector 40 is integrated into the wall of the housing 20, the connector having a negative connection element 41 and a positive connection element 42. The negative connection element 41 is connected to the anode of the battery cell stack 10 via a first electrical connection line 31. Correspondingly, the positive connection element 42 is connected to the cathode of the battery cell stack 10 via a second electrical connection line 32. The fuse 70 is integrated into the second electrical connection line 32. The fuse 70 is adapted to interrupt the electrical connection via the second electrical connection line 32 if the current exceeds a predefined value. Instead of being integrated into the second electrical connection line 32, in alternative embodiments of the conventional connector system and / or battery system, the fuse can also be integrated into the first electrical connection line 31.

[0070] In use, for example when implemented in a vehicle, the connector 40 is connected to a suitable counterpart (not shown) such that the negative connection element 41 is connected to a corresponding counterpart connection element 51 and the positive connection element 42 is connected to a corresponding counterpart connection element 52. Via the external counterparts 51, 52 of the negative connection element 41 and the positive connection element 42, electric current can then be transmitted to a load (not shown), such as a motor.

[0071] The current with which the fuse 70 interrupts conduction must be adjusted to the maximum current that is allowed to be transmitted through the connector 40 and therefore through each of the negative connection element 41 and the positive connection element 42 of the connector 40. When adjusting to the maximum fuse current of the connector 40, the tolerances of the fuse 70 and of the connector 40 must be taken into account, i.e., for safety reasons, the fuse 70 must be adapted to disconnect the electrical connection at a current that is less than the current that the connector 40 can actually transmit.

[0072] During normal use, i.e., when the current conducted through the connector 40 remains within a certain predefined range (i.e., within the range from 0 amperes to the maximum fuse current), the fuse 70 allows the current to pass through the second electrical connection line 32. However, if the current at a certain point in time exceeds a predefined threshold defined by the maximum fuse current of the fuse 70 (i.e., in the event of an overcurrent), the fuse 70 interrupts the electrical connection within the second electrical connection line 32, interrupting the circuit with the load (not shown) and the battery cell stack 10, or in other words, electrically disconnecting the battery cell stack 10 from the load. Thus, the connector 40 is protected from overcurrent by the fuse 70.

[0073] Fuses generally present the disadvantage of being only disposable devices. Therefore, in the above assembly, the fuse 70 can be replaced by an ammeter 80 connected to a control device 90. This Figure 3 The ammeter measures the current flowing through the second electrical connection line 32, and a signal corresponding to the current (i.e., the current signal) is sent to the control device 90. The control device 90 then monitors the intensity of the current signal (which corresponds to the measured current) continuously or at sufficiently small time intervals, and checks whether the intensity of the current signal exceeds a predefined threshold value corresponding to the maximum current allowed to be transmitted through the connector 40. Once the current exceeds the predefined threshold value, the control device 90 triggers the battery system to be electrically disconnected from the load. This can be done, for example, by means of a relay (not shown) that is implemented in Figure 3 In the battery system or connector system shown (ie, in one of the first electrical connection line 31 and the second electrical connection line 32) or in Figure 3 The exterior of the battery system or connector system is shown (eg in one of the counterparts 51 , 52 of the connection elements 41 , 42 ).

[0074] Similar to Figure 3 For example, the current at which the control device 90 interrupts electrical conduction (i.e., the threshold value) must be adjusted to the maximum current allowed to be transmitted through the connector 40 and therefore through each of the negative connection element 41 and the positive connection element 42 of the connector 40. When adjusting the threshold value to the connector 40, the tolerances of the ammeter 80 and of the connector 40 must be taken into account, i.e., for safety reasons, the threshold value must be selected so that the control device 90 disconnects the electrical connection at a current that is less than the current that the connector 40 can actually transmit.

[0075] One embodiment of the connector system according to the present invention integrated into a battery system is Figure 4 The basic setup of the battery system is similar to that described above. Figure 2 and Figure 3The arrangement is described in the context of FIG. A battery cell stack 10 is housed in a housing 20. The battery cell stack 10 has an anode (not shown) and a cathode (not shown). A connector 40 is integrated into the wall of the housing 20, the connector having a negative connection element 41 and a positive connection element 42. The negative connection element 41 is connected to the anode of the battery cell stack 10 via a first electrical connection line 31. Correspondingly, the positive connection element 42 is connected to the cathode of the battery cell stack 10 via a second electrical connection line 32.

[0076] However, with Figure 2 and Figure 3 Compared to the assembly shown, neither a fuse nor an ammeter is integrated into one of the first electrical connection line 31 and the second electrical connection line 32. Instead, the first temperature sensor 61 is thermally connected to the negative connection element 41, and the second temperature sensor 62 is thermally connected to the positive connection element 42. Each of the first temperature sensor 61 and the second temperature sensor 62 can be a thermistor, such as a negative temperature coefficient thermistor (NTC thermistor) or a positive temperature coefficient thermistor (PTC thermistor), or a thermocouple. However, other types of temperature sensors can also be used. Preferably, the first temperature sensor 61 and the second temperature sensor 62 are of the same type.

[0077] The first temperature sensor 61 measures the temperature of the negative connection element 41 and generates a corresponding first temperature signal encoding the measured temperature of the negative connection element 41. The first temperature signal is then transmitted to the control device 90. Similarly, the second temperature sensor 62 measures the temperature of the positive connection element 42 and generates a corresponding second temperature signal encoding the measured temperature of the positive connection element 42. The second temperature signal is then also transmitted to the control device 90. Each of the first and second temperature signals can be an electrical signal (e.g., a voltage level) that monotonically depends on the measured temperature. However, the temperature signal can also be a wireless signal, such as a near field communication (NFC) signal or a WLAN signal.

[0078] The control device 90 then compares the temperature signals received from the first temperature sensor 61 and the second temperature sensor 62. The comparison can be performed using an analog (non-digital) method or a digital method. The control device generates a first value based on the first temperature signal and a second value based on the second temperature signal. In particular, when an analog method is used for the comparison and when the first temperature sensor 61 and the second temperature sensor 62 are of the same type, the first value can be directly the intensity of the first temperature signal, and the second value can be directly the intensity of the second temperature signal. If the sensors are of different types, at least one of the first temperature signal and the second temperature signal can be converted so that the first value and the second value produce temperature values on the same temperature scale. The first value and the second value can correspond to temperatures on a standardized temperature scale (e.g., corresponding to units of ° C). However, the first value and the second value can correspond to any other temperature scale that can be linear or nonlinear. Preferably, the first value and the second value encode or correspond to the measured temperature on the same scale.

[0079] Instead of values corresponding to the absolute temperatures measured by the first and second temperature sensors 61, 62, relative values may be used for comparison. For example, the measured temperature (on a particular temperature scale) may be divided by the measured temperature of the negative connection element 41 (on the same scale) or by the measured temperature of the positive connection element 42, or by the average (e.g., arithmetic mean) of the temperatures of the first and second connection elements 41, 42.

[0080] The comparison can be performed by calculating the difference between a first value (based on the first temperature signal) and a second value (based on the second temperature signal). If the absolute value of this difference exceeds a predefined value, the control device 90 generates an alarm signal. The alarm signal can be provided at an output of the control device. The alarm signal can be an electrical signal (e.g., a voltage level) and / or a wireless signal, such as a near field communication (NFC) signal or a WLAN signal.

[0081] If the absolute value of the difference between the first and second values exceeds a predefined threshold, there is a probability that the contact resistance between one of the connection elements 41, 42 and its respective counterpart connection element 51, 52 (the latter not being part of the present invention) has increased, which in turn may indicate a connection fault.

[0082] Additionally, the absolute temperature measured at the negative connecting element 41 and / or the positive connecting element 42 may also be supervised by the control device 90. The control device 90 may then also output an alarm signal indicating that a maximum permissible temperature of one of the connecting elements 41, 42 has been exceeded.

[0083] The alarm signal can be configured so that it is directly suitable for controlling Figure 5Relay 98 is shown. In the example shown in the figure, relay 98 is implemented in the second electrical connection line 32 between the positive connection element 42 and the cathode of the battery cell stack 10. However, relay 98 can also be implemented in the first electrical connection line 31 instead. The control device 90 is connected to the relay 98 via a signal line 96 and operates the relay 98 so that the relay 98 interrupts the second electrical connection line 32 when it receives a corresponding signal (current) from the control device 90. Instead of being integrated into one of the first electrical connection line 31 and the second electrical connection line 32 connecting the connection elements 41, 42 to the battery cell stack 10, the relay 98 can also be positioned outside the battery system (for example, connected to the corresponding element 52 of the positive connection element 42) at a certain position in the circuit powered by the battery system that allows the battery system to be disconnected from the load. Alternatively, the alarm signal can also be transmitted to the load itself or another control device (not shown) that controls the load so that the load is shut down in response to receiving the alarm signal.

[0084] Alternatively, the alarm signal may be transmitted from the control device 90 to the battery system's battery management unit (BMU; not shown in the drawings). The BMU may then control operations upon receiving the alarm signal from the control device 90. For example, the BMU may be configured to control a relay to interrupt a circuit powered by the battery system, or may be configured to shut down a load driven by the battery system. In an embodiment, the control device 90 may be integrated within the BMU.

[0085] Reference numerals

[0086] 10 battery cell stacking

[0087] 20 Battery system housing

[0088] 31 Connection between the negative connection element and the anode of the battery cell stack

[0089] 32 Connection between the positive connection element and the cathode of the battery cell stack

[0090] 40 connectors

[0091] 41 Negative connection element

[0092] 42 positive connection element

[0093] 51 Counterpart of negative connection element

[0094] 52 Counterpart of positive connection element

[0095] 61 First temperature sensor

[0096] 62 Second temperature sensor

[0097] 70 Fuse

[0098] 80 Ammeter

[0099] 90 Control Device

[0100] 91 Signal line between the first temperature element and the control device

[0101] 92 Signal line between the second temperature element and the control device

[0102] 94 Signal line between ammeter and control device

[0103] 96 Signal line between control device and relay

[0104] 98 relay

Claims

1. A connector system for establishing an electrical connection with a battery system, the connector system comprising: a connector (40) for establishing an electrically conductive connection with a suitable counterpart of the connector, wherein the connector (40) comprises a negative connection element (41) and a positive connection element (42); a first temperature sensor (61) thermally connected to the negative connection element (41); a second temperature sensor (62) thermally connected to the positive connection element (42); as well as a control device (90) configured to receive a first temperature signal from the first temperature sensor (61) and a second temperature signal from the second temperature sensor (62); wherein the control device (90) is adapted to generate a first value based on the first temperature signal and a second value based on the second temperature signal; and wherein the negative connecting element (41) is electrically connected to the anode of the battery cell stack (10) via a first electrical connecting line (31), and the positive connecting element (42) is electrically connected to the cathode of the battery cell stack (10) via a second electrical connecting line (32), wherein the control device (90) is further adapted to output a first alarm signal based on at least one of a first value and a second value, wherein the control device (90) is further adapted to generate the first alarm signal if the first value indicates that the absolute temperature of the negative connection element (41) exceeds the maximum permissible temperature of the negative connection element (41) or the second value indicates that the absolute temperature of the positive connection element (42) exceeds the maximum permissible temperature of the positive connection element (42), and The first alarm signal is a signal directly suitable for controlling a relay (98) implemented in one of the first electrical connection line (31) and the second electrical connection line (32).

2. The connector system according to claim 1, wherein the control device (90) is further adapted to generate a second alarm signal when the absolute value of the difference between the first value and the second value exceeds a predefined threshold. 3 . The connector system according to claim 2 , wherein the predefined threshold value depends on the first temperature signal or the second temperature signal or an average value of the first temperature signal and the second temperature signal.

4. The connector system according to any one of claims 1 to 3, wherein the connector (40) is formed as a socket capable of being connected to a suitable plug; or The connector (40) is formed as a plug that can be connected to a suitable socket.

5. The connector system according to any one of claims 1 to 3, wherein the negative connection element (41) and the positive connection element (42) are each configured to establish a high voltage connection.

6. The connector system according to any one of claims 1 to 3, wherein at least one of the temperature sensors (61, 62) is a negative temperature coefficient thermistor or a positive temperature coefficient thermistor, or a thermocouple.

7. The connector system according to any one of claims 1 to 3, wherein the connector (40) is integrated in a housing (20), the housing being adapted to accommodate a battery cell stack (10).

8. A battery system comprising a battery cell stack (10) and the connector system and relay (98) according to claim 7, wherein the battery cell stack (10) and relay (98) are accommodated in the housing (20).

9. The battery system according to claim 8, wherein the battery system further comprises a battery management device, and wherein the control device (90) is integrated into the battery management device. 10 . A battery module comprising two or more battery systems according to claim 8 . 11 . A vehicle comprising the battery system according to claim 8 or the battery module according to claim 10 .

12. A method for controlling an electrically conductive connection to a battery system using the connector system according to any one of claims 1 to 6, the method comprising the steps of: measuring the temperature of the negative connecting element (41) by a first temperature sensor (61) and generating a first temperature signal based on the measured temperature of the negative connecting element (41); sending the first temperature signal to a control device (90); measuring the temperature of the positive connection element (42) by a second temperature sensor (62) and generating a second temperature signal based on the measured temperature of the positive connection element (42); sending the second temperature signal to the control device (90); generating, by the control device (90), a first value based on the first temperature signal and a second value based on the second temperature signal; wherein the method further comprises outputting, by the control device (90), a first alarm signal based on at least one of a first value and a second value, wherein the method further comprises generating, by the control device (90), the first alarm signal if the first value indicates that the absolute temperature of the negative connecting element (41) exceeds the maximum permissible temperature of the negative connecting element (41) or if the second value indicates that the absolute temperature of the positive connecting element (42) exceeds the maximum permissible temperature of the positive connecting element (42), wherein the negative connecting element (41) is electrically connected to the anode of the battery cell stack (10) via a first electrical connecting line (31), and the positive connecting element (42) is electrically connected to the cathode of the battery cell stack (10) via a second electrical connecting line (32), and, The first alarm signal is a signal directly suitable for controlling a relay (98) implemented in one of the first electrical connection line (31) and the second electrical connection line (32).

13. The method according to claim 12, wherein each of the steps is performed or repeated continuously in time. The method of claim 12 , wherein each of the steps is repeated after a predefined time interval.

15. The method according to claim 12, further comprising: The control device (90) calculates the difference between the first value and the second value, A second alarm signal is generated by the control device (90) when the absolute value of the difference exceeds a predefined threshold value.

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