VEHICLE, IN PARTICULAR RAIL VEHICLE WITH ENERGY STORAGE AND COOLING EQUIPMENT

Description

[0001] The invention relates to vehicles, in particular rail vehicles, equipped with an energy storage device and a cooling system for cooling the energy storage device. Vehicles with energy storage and cooling systems are described, for example, in German patent applications DE 10 2012 211 259 A1 and DE 10 2018 220 488 A1.

[0002] Document US 2018 / 141458 A1 discloses a vehicle which has a thermal system for a battery and a control system for the thermal system, wherein during a journey of the vehicle the battery is cooled if the temperature of the battery exceeds a lower threshold and power output from the battery is suppressed if the temperature of the battery exceeds an upper threshold, and wherein when connected to a charging station the battery is heated to a temperature between the lower and the upper threshold.

[0003] The invention is based on the objective of providing a vehicle in which overheating of the energy storage device can be prevented in a simple manner.

[0004] This problem is solved according to the invention by a vehicle with the features according to claim 1. Advantageous embodiments of the vehicle according to the invention are specified in the dependent claims.

[0005] According to the invention, a control device is provided for controlling the cooling device, which is designed to predict a cooling requirement based on load data describing a load expected during further travel or a load that may become necessary during further travel of the energy storage device, and to control the cooling device depending on the predicted cooling requirement.

[0006] A significant advantage of the vehicle according to the invention is that the control device and the cooling requirement forecast provided according to the invention enable particularly efficient cooling by means of the cooling system. For example, cooling of the energy storage unit can begin even before it actually heats up due to energy withdrawal, so that only a small cooling capacity is sufficient to prevent overheating. Furthermore, the cooling system does not need to be operated prophylactically or continuously, thus avoiding unnecessary energy consumption for cooling.

[0007] The control unit preferably takes the ambient temperature into account when forecasting the cooling requirement; the higher the ambient temperature, the higher the forecasted cooling requirement is.

[0008] For example, the predictive device can take into account a possible load on the energy storage system that may become necessary during the further journey by considering components that provide a different energy supply than that provided by the energy storage system – for example, a power rail ahead in the journey – as having failed due to a technical defect and assuming that the failed energy supply is to be provided there as a replacement by the energy storage system.

[0009] According to the invention, the control device is designed to check whether at least one trigger condition is met and, if at least one trigger condition is met, to activate the cooling device and cool the energy storage device.

[0010] The control device is preferably designed to determine a target cooling capacity value based on the predicted cooling demand, which indicates the target cooling capacity with which the cooling device should operate to cover the predicted cooling demand.

[0011] According to the invention, the control device is designed to activate the cooling device before the actual load on the energy storage device occurs, upon fulfillment of the triggering condition or at least one of the triggering conditions, and to lower the temperature of the energy storage device, thus creating a cooling buffer for the energy storage device before the actual load occurs.

[0012] The examination of at least one of the triggering conditions preferably consists of determining whether a predetermined point in the route is passed or has been passed and / or an error message from a component required for the regular power supply is received and / or a withdrawal current from the energy storage reaches or exceeds a predetermined withdrawal current threshold and / or the ambient temperature of the energy storage reaches or exceeds a predetermined temperature threshold and / or the housing temperature of a housing containing the energy storage reaches or exceeds a predetermined temperature threshold.

[0013] Vehicle electrical system batteries can be subjected to highly variable or intermittent loads during operation, causing them to overheat temporarily and requiring occasional cooling. This is particularly true when the normal electrical system fails and the battery is used for both powering the vehicle's own electrical components and for emergency driving. Therefore, vehicle electrical system batteries are preferably cooled in the manner described above.

[0014] It is advantageous if the cooling device includes at least one Peltier element or is formed by one. Peltier elements are advantageous because they require little maintenance, have little installation space, and, unlike fans or similar devices, do not cause noise pollution.

[0015] With a view to minimizing installation effort, it is considered advantageous if the cooling device comprises at least one Peltier element attached to an outer surface of a housing wall of the enclosure containing the energy storage device, and / or at least one Peltier element attached to an inner surface of a housing wall of the enclosure containing the energy storage device. In this way, uniform cooling of the energy storage device by the air in the container is achieved without the need for complex cooling structures such as those described in DE 10 2012 211 259 A1, DE 10 2015 220 759 A1 or DE 10 2018 220 488 A1.

[0016] With a view to a simple energy supply for the cooling device, it is considered advantageous if the cooling device includes at least a series connection of Peltier elements, which are supplied with the voltage applied to the terminals of the energy storage device during operation of the cooling device.

[0017] With a view to simple control of the cooling capacity of the cooling device, it is considered advantageous if the cooling device comprises two or more electrically parallel series circuits of Peltier elements, which can be activated individually and, after activation, are each supplied with the voltage applied to the terminals of the energy storage device, and the control device is designed to determine the number of series circuits to be activated depending on the predicted cooling requirement.

[0018] In the latter design variant, it is advantageous if the control device is designed to select the number of series circuits to be activated in such a way that the cooling capacity provided by the activated series circuits corresponds to the respective target cooling capacity that the cooling device is intended to generate to cover the predicted cooling demand.

[0019] The invention further relates to a method for cooling an energy storage device of a vehicle, in particular a rail vehicle, using a cooling device.According to the invention, it is provided that, based on load data describing a load expected during further travel or a load that may be necessary on the energy storage device during travel, a cooling requirement is predicted and the cooling device is controlled depending on the predicted cooling requirement, the control device checks whether at least one trigger condition is met and, if at least one trigger condition is met, the cooling device is activated and the energy storage device is cooled, and, if the trigger condition or at least one of the trigger conditions is met, the cooling device is activated even before the actual load on the energy storage device occurs and the temperature of the energy storage device is lowered, thus creating a cooling buffer for the energy storage device even before the actual load occurs.

[0020] Regarding the advantages of the method according to the invention and advantageous embodiments of the method according to the invention, reference is made to the above statements in connection with the vehicle according to the invention and its advantageous embodiments.

[0021] The invention is explained in more detail below with reference to exemplary embodiments; these show, by way of example, Figure 1 shows an embodiment of a rail vehicle according to the invention, which is equipped with a cooling device whose cooling capacity is adjustable; Figure 2 shows an embodiment of a rail vehicle according to the invention, which is equipped with a cooling device that can be switched on and off; Figure 3 shows an embodiment of a preferred arrangement of a cooling device inside a housing that contains a battery; Figure 4 shows an embodiment of a preferred arrangement of a cooling device outside a housing that contains a battery; Figure 5 shows a diagram of an exemplary temperature profile in the case of temperature-controlled operation of the cooling device; Figure 6 shows a diagram of an exemplary temperature profile in the case of battery-current-controlled operation of the cooling device; and Figure 7 shows a diagram of an exemplary temperature profile in the case of route-related operation of the cooling device.

[0022] For the sake of clarity, the same reference symbols are used in the figures for identical or comparable components.

[0023] The Figure 1 Figure 1 shows an embodiment of a rail vehicle 10 according to the invention, which is connected to an external power supply network 20 by means of a pantograph 11. The rail vehicle 10 is located in the position shown in the illustration. Figure 1 i.e. in an electrified section of a railway network.

[0024] The current collector 11 is connected to one terminal of an inverter 12, which may, for example, be an auxiliary inverter with an integrated charger. A DC link 13 is connected to the other terminal of the inverter, which may, for example, supply power to an on-board electrical system consumer 14.

[0025] Furthermore, an energy storage device in the form of an on-board battery 15 and a cooling device 16 are connected to the DC link 13. The cooling device 16 serves to cool the on-board battery 15 and is therefore located spatially adjacent to the on-board battery 15 or is directly connected to it. Preferred mechanical arrangements of the cooling device 16 relative to the on-board battery 15 are described below in connection with the Figures 3 and 4 explained.

[0026] In the exemplary embodiment according to Figure 1A plurality of series circuits 161, each comprising a plurality of Peltier elements 162 connected in series and a switching element 163 connected in series with them. Each of the series circuits 161 can be individually switched on or off using the switching elements 163, so that the overall cooling capacity of the cooling device 16 can be adjusted by selecting which switching elements 163 are switched on. The cooling device 16 can be deactivated entirely by switching off all switching elements 163; if all switching elements 163 are switched on, the cooling device 16 cools at maximum cooling capacity.

[0027] The cooling unit 16 is controlled by a control unit 17 of the rail vehicle 10. The control unit 17 is equipped with a computer 171 and a memory 172. The memory 172 stores route data SD, a forecast module PM (which, when executed by the computer 171, forms a forecasting unit), and a control program module SPM (which, when executed by the computer 171, determines the control of the cooling unit 16).

[0028] The control program module SPM and the forecasting module PM preferably process, among other things, a location OA, which indicates the respective location of the rail vehicle 10 on the route to be traveled, error messages F, a current measurement Im, which quantifies the respective current drawn from the on-board battery 15, a temperature measurement Tu, which describes the ambient temperature, a temperature measurement Tt, which describes the housing temperature of the on-board battery 15, and / or a temperature measurement Tb, which describes the battery temperature.

[0029] The function of the PM forecasting module is to predict load data based on the route data SD and the respective location information OA. This data describes the load expected during the rail vehicle 10's journey or the load that may become necessary on the on-board battery 15 during the journey. Based on this load data, the PM forecasting module generates a cooling requirement KBA, which indicates the calculated cooling demand. For example, a load on the on-board battery 15 is to be expected if, based on the route data SD, it is foreseeable that the rail vehicle 10 will soon enter a non-electrified section of the railway network and the on-board battery 15 will need to be used to power the on-board electrical system 14.

[0030] The cooling requirement KBA is transferred from the forecasting module PM to the control program module SPM, which takes over the control of the switching elements 163 of the cooling device 16 and thus determines the cooling capacity provided by the cooling device 16 to cover the cooling requirement.

[0031] In the exemplary embodiment, the function of the SPM control program module is as follows: Figure 1 This includes, among other things, determining the number of switching elements 163 to be activated, i.e., the target cooling capacity with which the cooling unit should operate to cover the predicted cooling demand, based on the cooling demand specification KBA. Another task of the control program module SPM is to check whether the triggering conditions that should activate the cooling unit 16 are met.

[0032] The SPM control module can, for example, use a trigger condition to check whether a predefined point X0 has been passed or is currently being passed while the rail vehicle 10 is traveling in an electrified section of track. If the rail vehicle 10 is approaching a non-electrified section of track, it can be assumed that the on-board battery 15 will be under heavy load and that a high current will flow from it. This high current will cause the temperature of the on-board battery 15 to rise, raising concerns that it could exceed a maximum temperature limit Tg. To prevent this, the SPM control module will preferably activate the cooling device 16 while still in the electrified section of track and lower the temperature of the on-board battery 15, i.e., before the load actually occurs.The journey on the non-electrified section of the route actually begins. This creates a cooling buffer dT for the on-board battery 15, so that thermal overload of the on-board battery 15 is avoided after entering the non-electrified section and when the on-board battery 15 is under load.

[0033] Alternatively or additionally, the SPM control module can check, as a trigger condition, whether the current drawn from the on-board battery 15 meets or exceeds a predefined threshold. If this is the case, the SPM control module can output the ST control signal to activate the cooling unit 16, provided that no other trigger condition has yet been met and the cooling unit 16 has not previously been activated.

[0034] It is also possible to output the control signal ST to activate the cooling device 16 when the ambient temperature of the on-board battery 15 and / or the housing temperature of a housing accommodating the on-board battery 15 reaches or exceeds a predetermined temperature threshold.

[0035] The Figure 2 shows a second embodiment of a rail vehicle according to the invention. In contrast to the embodiment according to Figure 1 The cooling device 16 is equipped with only a single series circuit 161, so that the cooling capacity of the cooling device 16 is not adjustable, but can only be switched on or off. Otherwise, the above explanations apply in connection with the Figure 1 in the embodiment according to Figure 2 accordingly.

[0036] The Figure 3Figure 1 and Figure 2 shows a preferred spatial arrangement of the cooling device 16, whose electrical connections are marked with reference numerals 16a and 16b, relative to the on-board battery 15, for the rail vehicles 10 according to Figures 1 and 2.

[0037] In the embodiment according to Figure 3 The cooling device 16 is housed within a casing 100, which also contains the vehicle battery 15. The cooling device 16, with its Peltier elements 162, cools the air inside the casing 100 and thus indirectly the battery cells of the vehicle battery 15.

[0038] To ensure further cooling of the housing 100, the housing 100 can also be equipped with an optional heat sink 110 on the outside.

[0039] In this arrangement, the housing serves as a heat sink and is advantageously thermally connected to the outside air so that it can transfer heat to it, and thermally insulated from the inside air (preferably also by an additional insulating layer 101), so that the Peltier element can supply its cooling power via the inside air of the battery.

[0040] The Figure 4 Figure 1 shows another preferred arrangement of the cooling device 16 relative to the on-board battery 15. In the embodiment shown in Figure 16, the cooling device 16 is arranged in a way that allows for the following configuration: Figure 4 The cooling device 16 is mounted on the outside of the housing 100; the on-board battery 15 is located inside the housing 100.

[0041] A heat sink 110 can optionally be mounted on or near the cooling device 16 to ensure the removal of waste heat generated by the cooling device 16.

[0042] In this arrangement, the housing serves as a cold storage unit and is advantageously thermally connected to the interior air so that it can supply the cooling power of the battery, and is thermally insulated against the outside air (preferably also by an additional insulating layer 102) so that heat input is prevented.

[0043] The Figure 5 shows an exemplary embodiment of a preferred operating mode of the SPM control program module of the control unit 17 in the Figure 1 and 2 more detail, specifically in the form of a diagram showing the temperature T of the on-board battery 15 over time t. In the embodiment according to Figure 5 The control unit 17 switches on the cooling unit 16 as soon as the battery temperature reaches a predefined temperature threshold Ts. This occurs according to the illustration. Figure 5 at time t1.

[0044] By commissioning the cooling device 16, a cooling buffer dT is created, which is preferably dimensioned on the basis of the route data SD such that no overheating will occur when traveling over an upcoming non-electrified section of track and operating the on-board power consumer 14 with the current from the on-board power supply battery 15 - with regard to the respective ambient temperature or the housing temperature; the cooling buffer dT is preferably dimensioned to be larger the longer the journey in the non-electrified section of track is expected to be.

[0045] At time t2, the diagram shows that Figure 5 A current is drawn from the on-board battery 15, causing an increase in the temperature T of the on-board battery 15. However, due to the cooling capacity of the cooling unit 16 and the previously provided cooling buffer dT, an upper maximum limit temperature Tg is not exceeded.

[0046] The Figure 6 shows an alternative temperature profile of the battery temperature T over time t, where the control unit 17 does not activate the cooling unit 16 when the temperature threshold Ts is reached, but only when, at time t3, a withdrawal current from the on-board battery 15 reaches or exceeds a predetermined withdrawal current threshold.

[0047] The Figure 7 shows another preferred mode of operation of the control device 17 according to the Figure 1 and 2In the event that passing a predefined route point X0 while traveling along a predefined route X triggers the cooling device 16, it can be seen that after passing the predefined route point X0, the cooling device 16 is activated and a cooling buffer dT is created by cooling the on-board battery 15. The cooling buffer dT is preferably dimensioned based on the route data SD such that the on-board battery 15 will not overheat when traveling on an upcoming non-electrified section of track.

[0048] If, during the further journey, the rail vehicle 10 reaches another point X1 on the route where it becomes necessary to switch on the on-board battery 15, for example because the non-electrified section of the route is reached, the temperature T of the on-board battery 15 will rise, but will not overheat because the previously created cooling buffer dT prevents the limit temperature Tg from being reached or exceeded.

[0049] The above in connection with the introductory description and the Figures 1 to 7 The described embodiments can have one, several, or all of the following features: The housing (container) of the on-board electrical system battery according to FIG. 3 or the indoor air according to FIG. 4 It is preferably cooled via Peltier elements, which can optionally be powered from the vehicle's electrical system or the battery.

[0050] The Peltier elements can be dimensioned in such a way that, by connecting Peltier elements in series, the optimal operating voltage of the Peltier elements corresponds to the vehicle electrical system or battery voltage, and the required power can be provided by connecting a corresponding number of Peltier elements in parallel.

[0051] The main power connection of the Peltier elements is preferably made to the vehicle electrical system positive or negative terminal, with at least one of the connections being switchable.

[0052] The switching on and off of the Peltier elements can be done by switching elements according to the state of the art, for example contactors, electronic semiconductor switches, or similar.

[0053] Positioning the Peltier elements directly on the battery cells is often mechanically impractical. Instead, the Peltier elements can be mounted on the inside of the housing containing the battery cells (container) and energized in such a way that the cold side of the Peltier elements cools the internal air, while the warm side heats the container wall. The advantages of this design are: the ambient air around the battery cells is cooled directly, the container wall does not need to be cooled, and the container's large surface area may eliminate the need for additional heat sinks (though these can still be provided) to cool down to ambient temperature. This design is advantageous when the battery cells have no thermal contact with the container wall or when the container's inner wall is well insulated.Alternatively, the Peltier elements can be mounted on the outside of the container and powered in such a way that the cold side cools the container wall and the warm side is connected to the ambient air via heat sinks. The advantages of this are: the entire container, including its walls, remains cool; no additional space is required inside the container; and no additional cables need to be run into the container for the Peltier elements. This latter design is advantageous if the battery cells have thermal contact with the container wall or if the container's outer wall is well thermally insulated.

[0054] The following two methods are preferably used to control the Peltier elements: Method 1 (ambient temperature monitoring): The expected heating of the vehicle battery under exceptional load, for example, during an emergency run without an external power supply, is preferably determined by calculation or experiment. The power loss of the vehicle battery thus determined is preferably converted into a temperature increase based on its thermal behavior, either by calculation or experiment. The expected final temperature of the vehicle battery is derived from the assumed or measured ambient or battery cell temperature.The Peltier cooling capacity is preferably dimensioned such that the vehicle battery, when heated (energy input) by the maximum expected ambient temperature, can be maintained at a temperature level that covers the required temperature rise without exceeding the permissible limit temperature of the battery. The Peltier elements are preferably powered by the vehicle's electrical system. If the expected or measured ambient or cell temperature is too high, the battery container, and thus indirectly the battery cells, is preferably cooled by the Peltier elements mounted on the container to a temperature that allows the battery to deliver the expected power without the temperature rise causing overheating.In the simplest case, the Peltier elements are preferably controlled by a two-point controller according to the state of the art, whereby switching on occurs at ambient or battery temperatures of T>Tmax and switching off at T<Tmax-Thysterese, Thysterese ist frei wählbar > 0, for example, 1 K. The temperature-dependent switching on / off of the Peltier elements can be carried out, for example, by the battery management system or the train control system, without requiring any new control elements. The advantage of the latter method is that the Peltier power can be very small, since only the heat input from the environment needs to be compensated for, not the heat input from battery losses. The required energy can be drawn from the vehicle's electrical system, not from the battery. In method 2 (load detection), the assumed temperature rise is preferably calculated as in method 1.The cooling capacity of the Peltier elements is preferably dimensioned such that, when switched on, they can compensate for the power loss of the vehicle battery under the expected load to such an extent that the temperature difference is reduced enough to prevent overheating. The Peltier cooling is preferably activated when the vehicle battery experiences a defined load, which can be determined, for example, by measuring a battery current iBatt exceeding a defined limit iLimit (e.g., 1 A). Since this generally occurs when the vehicle electrical system has failed, the Peltier elements are preferably powered directly by the battery itself in this case. Alternatively, or in combination with current, the battery temperature can also be used directly for control.One advantage of the latter method is that cooling is only activated when the battery is under load, while no energy is consumed for cooling at other times.

[0055] Other possible triggers for switching on the cooling system include, for example, a failure of the vehicle electrical system or the external power supply, the activation of the emergency driving function, manual activation or location-dependent activation, the latter for example via GPS or in locations where a high load occurs during an emergency drive.

[0056] Some components of rail vehicles, especially on-board batteries, can be subjected to highly variable or intermittent loads during operation, causing them to overheat temporarily and requiring periodic cooling. This is particularly relevant for on-board batteries when the normal power supply fails and the battery is used for emergency runs in addition to powering the vehicle's own electrical systems. Therefore, on-board batteries are preferably cooled as described above. When using Peltier elements, the described cooling methods require little maintenance and installation space, and unlike fans or similar devices, they do not generate noise.

Claims

1. Vehicle, in particular rail vehicle (10), having an energy storage unit (15) and a cooling facility (16) which is suited to cooling the energy storage unit (15), wherein in order to actuate the cooling facility (16) a control facility (17) is available, which is designed to predict a cooling requirement and to control the cooling facility (16) as a function of the predicted cooling requirement on the basis of load data which describes a load to be expected during the onward journey or a load of the energy storage unit (15) which will possibly become necessary during the onward journey, characterised in that the control facility (17) is designed to check the fulfilment of at least one trigger condition and when the at least one trigger condition is fulfilled to activate the cooling facility (16) and to cool the energy storage unit (15), and the control facility (17) is designed to activate the cooling facility (16) even before the occurrence of the actual load of the energy storage unit when the trigger condition or at least one of the trigger conditions is fulfilled, and to lower the temperature of the energy storage unit (15) and thus to generate a cooling buffer (dT) for the energy storage unit (15) even before the occurrence of the actual load.

2. Vehicle according to claim 1, characterised in that the control facility (17) is designed to determine a target cooling power value on the basis of the predicted cooling requirement, said target cooling power value specifying the target cooling power with which the cooling facility (16) is to operate in order to cover the predicted cooling requirement.

3. Vehicle according to claim 1 or 2, characterised in that the check of the trigger condition or at least one of the trigger conditions consists in checking whether a predetermined route point (X0) is being or has been passed.

4. Vehicle according to one of the preceding claims, characterised in that the trigger condition or at least one of the trigger conditions is considered to be fulfilled if a discharge current from the energy storage unit (15) reaches or exceeds a predetermined discharge current threshold.

5. Vehicle according to one of the preceding claims, characterised in that the trigger condition or at least one of the trigger conditions is considered to be fulfilled if the ambient temperature of the energy storage unit (15) reaches or exceeds a predetermined threshold value.

6. Vehicle according to one of the preceding claims, characterised in that the trigger condition or at least one of the trigger conditions is considered to be fulfilled if the housing temperature of a housing (100) receiving the energy storage unit (15) reaches or exceeds a predetermined temperature threshold.

7. Vehicle according to one of the preceding claims, characterised in that the cooling facility (16) comprises at least one Peltier element, which is attached to an exterior of a housing wall of a housing (100) receiving the energy storage unit (15).

8. Vehicle according to one of the preceding claims, characterised in that the cooling facility (16) comprises at least one Peltier element, which is attached to an interior of a housing wall of a housing (100) receiving the energy storage unit (15).

9. Vehicle according to one of the preceding claims, characterised in that the cooling facility (16) comprises at least one series circuit (161) of Peltier elements, to which, during operation of the cooling facility (16), the voltage prevailing at the terminals of the energy storage unit (15) is applied.

10. Vehicle according to one of the preceding claims, characterised in that - the cooling facility (16) comprises two or more series circuits (161) of Peltier elements (162), electrically connected in parallel, which can be activated individually and to each of which, after activation, the voltage prevailing at the terminals of the energy storage unit (15) is applied, and - the control facility (17) is designed to fix the number of series circuits (161) to be activated as a function of the predicted cooling requirement.

11. Vehicle according to claim 10, characterised in that the control facility (17) is designed to select the number of series circuits (161) to be activated so that the cooling power through the activated series circuits (161) corresponds to the respective target cooling power which the cooling facility (16) is to generate in order to cover the predicted cooling requirement.

12. Method for cooling an energy storage unit (15) of a vehicle, in particular rail vehicle (10), having a cooling facility (16), wherein on the basis of load data, which describes a load to be expected during the onward journey or a load of the energy storage unit (15) which is possibly required during the journey, a cooling requirement is predicted and the cooling facility (16) is controlled as a function of the predicted cooling requirement, characterised in that the control facility (17) checks the fulfilment of at least one trigger condition and upon fulfilment of the at least one trigger condition the cooling facility (16) is activated and the energy storage unit (15) is cooled, and upon fulfilment of the trigger condition or at least one of the trigger conditions, the cooling facilty (16) is activated even before the occurrence of the actual load of the energy storage unit (15) and the temperature of the energy storage unit (15) is reduced and thus a cooling buffer (dT) is generated for the energy storage unit (15) even before the occurrence of the actual load.