Method and device for controlling a refrigeration system for an electric vehicle

Abstract

The invention relates to a method and a device for the demand-based control of a refrigeration system for an electric vehicle, wherein the activated refrigeration system is provided for cooling an interior of the electric vehicle and / or a battery of the electric vehicle. The method comprises the steps: in the case of an activated refrigeration system of the electric vehicle, before or during an actual parking process of the electric vehicle, determining (101) whether external charging of the battery will take place after the parking process has ended and / or determining (102) whether the electric vehicle will be driven after the actual external charging of the battery has ended, and depending on this, controlling (103) a shutdown of the activated refrigeration system, in particular of a compressor of the refrigeration system.

Description

[0001] The invention relates to a method and a device for controlling a refrigeration system for an electric vehicle.

[0002] A refrigeration system within the meaning of the invention is a technical device that serves to extract heat from a space or process in order to cool it or keep it at a low temperature; in particular, the activated refrigeration system is provided here for cooling an interior of the electric vehicle and / or for cooling a battery of the electric vehicle.

[0003] For the purposes of this document, an electric vehicle is understood to mean both a purely electrically powered vehicle and a hybrid vehicle, in particular a hybrid vehicle with a combination of an electric motor and an internal combustion engine.

[0004] In electric vehicles as described above, the cooling system is typically controlled by the so-called "battery management system" and / or a climate control unit. These control units typically communicate via a CAN bus and control the electric compressor, valves, and pumps of the cooling system both while driving and when the vehicle is stationary, for example, when the electric vehicle's battery is being charged externally at a charging station or when the vehicle is being cooled while stationary. If the cooling system remains active when the electric vehicle is switched off (e.g., for battery cooling or cooling the vehicle interior), it typically draws energy from the high-voltage battery. Safety mechanisms ensure that the cooling system only operates when sufficient energy is available and there is no risk to high-voltage components.

[0005] In current technology, the cooling system of an electric vehicle, i.e., the compressor, typically switches off when the driver gets out, for example, to plug in the charging cable from an electric charging station. Once the charging process begins, the cooling system / compressor is reactivated as needed. The compressor starts up slowly, so cooling capacity is lost during the switching off and restarting.

[0006] The object of the invention is to provide an improved control system for the refrigeration system, in which less cooling power is lost.

[0007] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims.

[0008] A first aspect of the invention relates to a method for controlling a cooling system for an electric vehicle, wherein the (activated) cooling system is provided for cooling an interior of the electric vehicle and / or a battery of the electric vehicle. The proposed method comprises the following steps: In the case of an activated cooling system of the electric vehicle, a first step is performed before or during an actual parking process of the electric vehicle to determine whether the battery will be externally charged after the parking process has ended, and / or in an additional or alternative second step, to determine whether the electric vehicle will be driven after the current external charging of the battery has ended. In a further step, a switch-off of the activated cooling system, in particular of a compressor of the cooling system, is controlled depending on the respective result of this determination.

[0009] The proposed method therefore presupposes that the electric vehicle's cooling system is already activated as needed and thus generating cooling capacity. The activation of the cooling system may be triggered, for example, by a battery management system and / or a climate control unit of the electric vehicle, depending on the battery temperature and / or the ambient temperature and / or a preset interior temperature in the electric vehicle, etc. The proposed method for controlling the cooling system thus involves switching off an already activated cooling system, in particular the already activated compressor of the cooling system, in such a way that less cooling capacity is lost compared to the current state of the art.

[0010] In the first step, the system predictively determines, either before or during the current parking process of the electric vehicle, whether the battery will be externally charged after the parking process is completed. For the purposes of this analysis, a "parking process" is advantageously defined as at least one process that results in the electric vehicle coming to a standstill with the parking brake engaged. Advantageously, the completion of the parking process is further defined as the opening of the driver's door. In an alternative or additional second step, the system determines whether the electric vehicle will be driven after the completion of any current external battery charging.

[0011] The battery is best charged externally at a suitable charging station for electric vehicles. For this, the vehicle is parked at the charging station.

[0012] Predictive determination of whether the battery will be externally charged after the shutdown process is advantageously based on: - the current state of charge of the electric vehicle's battery, and / or - a comparison of the current parking position of the electric vehicle with the positions of electric charging stations, and / or - current data from an active navigation / destination guidance system of the electric vehicle, and / or - current data from an electric vehicle's energy management system, and / or - a planned waiting time after completion of the parking process, and / or - historical driving and charging data of the electric vehicle, and / or - an input into an interface of the electric vehicle confirming that the battery is being charged, and / or - a manually activated battery preconditioning by the driver

[0013] The result of predictively determining whether the battery will be recharged after the shutdown process is advantageous, yielding a probability value W1. Advantageously, the shutdown of the activated refrigeration system, particularly the compressor, is controlled based on the determined probability value W1 and at least one predefined condition.

[0014] The current state of charge (SoC) of a battery indicates how much energy is currently stored in the battery relative to its total potential capacity. The lower the measured state of charge, the more likely it is that the battery will need to be charged externally after the vehicle is switched off. If the battery is charged to 100% of its potential capacity, charging is unnecessary and therefore unlikely.

[0015] If a comparison of the current parking position of the electric vehicle with predefined / known positions of electric charging stations reveals that the current parking position of the electric vehicle (almost) matches the position of an electric charging station, then external charging of the battery after the parking process is very likely.

[0016] Navigation / route guidance for an electric vehicle can include data (position, duration of the charging stop, etc.) about planned charging stops. This data may indicate that the stop is intended for charging the electric vehicle's battery. In this case, charging is very likely.

[0017] The energy management system of an electric vehicle is responsible for monitoring, controlling, and optimizing energy flows within the vehicle to maximize efficiency, range, performance, and safety. To this end, the energy management system can advantageously utilize data from the electric vehicle's active destination or route guidance system to determine when and, if necessary, where a charging stop should be made along the route. If the time and / or location at which the vehicle is parked matches the energy management system's data regarding a charging stop, charging after the vehicle is parked is highly likely.

[0018] If the planned standby time after the current parking process is completed corresponds to the time required for a necessary battery charge, then a necessary battery charge after the parking process is very likely.

[0019] If historical driving and charging data of the electric vehicle shows that charging typically takes place at the end position of the current parking process, then charging the battery after the parking process is very likely to be necessary.

[0020] An advantageous further development of the proposed method is characterized by the fact that, if it is determined before or during the current parking process of the electric vehicle that the battery will be charged after the parking process is completed, or that the probability W1 determined for this is above a predefined threshold, the activated cooling system is only switched off after a predefined time difference Δt1 has elapsed, at time t1 = t0 + Δt1, following the completion of the parking process at time t0. This time-delayed switch-off prevents the loss of cooling capacity due to the cooling system's compressor switching off and restarting. Advantageously, the predefined time difference Δt1 is selected from the range of 30 seconds to 10 minutes, in particular Δt1 = 1 minute, 2 minutes, 3 minutes, or 5 minutes.

[0021] Predictive determination of whether the electric vehicle will be driven after the current battery charging process is completed is advantageously based on: - current data from a navigation / destination guidance system of the electric vehicle and / or - historical driving and charging data of the electric vehicle and / or - an input into an interface of the electric vehicle confirming subsequent driving operation.

[0022] The result of determining whether the electric vehicle will be driven after the current battery charging cycle is advantageous, yielding a probability value W2. The deactivation of the activated cooling system, particularly the compressor, is advantageously controlled based on this probability value W2. Driving is advantageously assumed to follow the current battery charging cycle if the probability value W2 reaches or exceeds a predefined threshold.

[0023] The current data from the electric vehicle's navigation / route guidance system can advantageously indicate the planned departure time from the vehicle's current charging position to a destination. The closer the charging completion time is to the planned departure time, the more likely it is that the electric vehicle will be ready to drive after the current battery charge is complete.

[0024] If the historical driving and charging data of the electric vehicle shows that driving typically takes place immediately after the battery charging location, the current probability W2 for subsequent driving after the charging process is high.

[0025] An advantageous further development of the proposed method is characterized by the fact that, if it is determined that the electric vehicle will be driven after the current battery charging process has ended, the cooling system is only switched off after a predetermined time difference Δt2 has elapsed, at time t2 = tA + Δt2. Advantageously, the predetermined time difference Δt2 is selected from the range of 30 seconds to 10 minutes, in particular Δt2 = 1 minute, 2 minutes, 3 minutes, 5 minutes.

[0026] The proposed method prevents the cooling system from switching off (after the electric vehicle is parked) and restarting (after the charging cable is plugged in) when the electric vehicle is stopped charging, and / or from switching off (after the electric vehicle has finished charging) and restarting (when the electric vehicle starts driving again after charging has stopped). This prevents a drop in cooling capacity, especially at high ambient temperatures or high battery temperatures.

[0027] A further aspect of the invention relates to a device for the demand-based control of a refrigeration system for an electric vehicle, and for carrying out a method as described above, wherein the refrigeration system is provided for cooling an interior of the electric vehicle and / or a battery of the electric vehicle. The device is designed and configured to determine (predictively) before or during a current parking process of the electric vehicle, in the case of an activated refrigeration system, whether the battery will be charged after the parking process has ended, and / or (predictively) whether the electric vehicle will be driven after the current charging process has ended, and, depending on the respective results of this determination, to control the deactivation of the activated refrigeration system, in particular of a compressor of the refrigeration system.

[0028] Further advantageous embodiments result from an analogous and meaningful transfer of the features disclosed in connection with the method described above to the device.

[0029] Further advantages, features, and details will become apparent from the following description, in which – possibly with reference to the drawing – at least one embodiment is described in detail. Identical, similar, and / or functionally equivalent parts are identified by the same reference numerals.

[0030] It shows: Fig. 1 a highly schematic procedure.

[0031] Fig. Figure 1 shows a highly schematic procedure for controlling a refrigeration system for an electric vehicle, wherein the refrigeration system is intended for cooling an interior of the electric vehicle and / or a battery of the electric vehicle, with the following steps: In step 101, if the electric vehicle's cooling system is already activated during driving, a predictive determination is made before or during a current parking process to determine whether the battery will be charged externally after the parking process is completed. External charging in this context means charging at a charging station external to the vehicle.

[0032] In this example, the predictive determination of whether the battery will be externally charged after the current parking process is based on the current state of charge of the electric vehicle's battery and a comparison of the vehicle's current parking position (after the current parking process) with known / predefined locations of electric vehicle charging stations. If the current state of charge is determined to be less than 60% of the battery's maximum capacity and the vehicle is parked at a charging station, the result is assumed to be that the battery will be externally charged after the parking process. Conversely, if the current state of charge is, for example, more than 60% of the battery's maximum capacity and the vehicle is not parked at a charging station, the result is assumed to be that the battery will not be externally charged after the parking process.

[0033] In the present embodiment, the battery charge level is 25% and the parking position is at a charging station. The probability W1 that the battery will be externally charged after the parking process is therefore, for example, W1 = 95%.

[0034] The refrigeration system is then controlled depending on the result of the determination in step 103. The result of the determination: W1 = 95% means that the activated refrigeration system, after completion of the current shutdown process at time t0, is only switched off after a predetermined time difference Δt1 has elapsed, at time t1 = t0 + Δt1, where the predetermined time difference Δt1 = 2 minutes.

[0035] During this 2-minute period, the driver has the opportunity to connect the charging cable of the charging station to the electric vehicle to start the charging process, while the cooling system remains continuously activated during this time. If no charging process is started within the 2 minutes, or within the specified time interval Δt1, the cooling system will be switched off after the time interval Δt1 has elapsed.

[0036] It is assumed that, within a 2-minute time difference after the parking process is completed, an external charging process for the electric vehicle is initiated, so that the cooling system remains continuously activated during the charging process. It is further assumed that a journey is planned to begin immediately after the charging process is complete.

[0037] In step 102, a predictive analysis is performed to determine whether the electric vehicle will be driven after the current external charging of the battery is completed. In this example, this is based on historical driving and charging data of the electric vehicle. If the historical driving and charging data of the electric vehicle shows that the electric vehicle is driven in more than 50% of cases after a charging process at the current charging station or parking location, the result of the analysis assumes subsequent driving. If it is less than 50% of the time, it is assumed that no subsequent driving takes place.

[0038] In this exemplary embodiment, historical driving and charging data shows that in 95% of historical cases, driving begins immediately after charging is completed at the current charging station or parking position. Therefore, in this case, the predictive result is that driving will commence after charging. Consequently, in step 103, the refrigeration system is switched off only after a predetermined time difference Δt2 has elapsed, at time t2 = tA + Δt2, where the predetermined time difference Δt1 = 5 minutes.

[0039] During this 5-minute period, the driver has time to unplug the charging cable from the vehicle, pay for the charging process if necessary, and continue their journey, while the cooling system remains active without interruption during this period.

[0040] Although the invention has been further illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived from them by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of possible variations exist. It is also clear that the embodiments mentioned as examples are truly only examples and are not to be understood in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without leaving the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. Reference symbol list 101-103 Procedural steps

Claims

[1] Method for controlling a refrigeration system for an electric vehicle, wherein the refrigeration system is intended for cooling an interior of the electric vehicle and / or a battery of the electric vehicle, comprising the following steps: in the case of an activated cooling system of the electric vehicle - Determine (101) before or during an ongoing parking process of the electric vehicle whether external charging of the battery will take place after the parking process has ended and / or - Determine (102) whether the electric vehicle is driven after the completion of a current external charging of the battery, - and dependent control (103) of a shutdown of the activated refrigeration system, in particular of a compressor of the refrigeration system. [2] Method according to claim 1, wherein if it is determined before or during a current parking process of the electric vehicle that an external charging of the battery will take place after the end of the parking process, the activated cooling system is switched off after the end of the current parking process at time t0 only after the expiry of a predetermined time difference Δt1 at time t1 = t0 + Δt1. [3] Method according to one of claims 1 to 2, wherein if it is determined that after the current external charging of the battery is completed, the electric vehicle is driven, the cooling system is switched off after the current external charging is completed at time tA only after a predetermined time difference Δt2 at time t2 = tA + Δt2. [4] Method according to any one of claims 1 to 3, wherein determining (101) whether the battery is externally charged after the current shutdown process has ended, is based on - the current state of charge of the electric vehicle's battery, and / or - a comparison of the current parking position of the electric vehicle with the positions of electric charging stations, and / or - current data from an active navigation / destination guidance system of the electric vehicle, and / or - current data from an electric vehicle's energy management system, and / or - a planned waiting time after completion of the parking process, and / or - historical driving and charging data of the electric vehicle, and / or - an input into an interface of the electric vehicle confirming that the battery is being charged and / or - a manually activated battery preconditioning by the driver. [5] Method according to any one of claims 1 to 4, wherein the result of determining whether the battery is externally charged after the current shutdown process has ended is a probability value W1. [6] Method according to claim 5, wherein the control of the switching off of the activated refrigeration system, in particular the compressor of the refrigeration system, is dependent on the determined probability value W1. [7] Method according to any one of claims 1 to 7, wherein determining (102) whether the electric vehicle is being driven after the current external charging of the battery has ended, is based on - current data from a navigation / destination guidance system of the electric vehicle and / or - historical driving and charging data of the electric vehicle and / or - an input into an interface of the electric vehicle confirming subsequent driving operation takes place. [8] Method according to claims 1 to 7, wherein the result of determining whether the electric vehicle will be driven after the current external charging of the battery has ended is a probability value W2. [9] Method according to claim 8, wherein the control of the switching off of the activated refrigeration system, in particular the compressor of the refrigeration system, is dependent on the determined probability value W2. [10] Device (200) for controlling a refrigeration system for an electric vehicle, and for carrying out a method according to any one of claims 1 to 9, wherein the refrigeration system is provided for cooling an interior of the electric vehicle and / or a battery of the electric vehicle, wherein the device (200) is designed and configured to, in the event of an activated refrigeration system of the electric vehicle - to determine, before or during an ongoing parking process of the electric vehicle, whether the battery will be externally charged after the parking process has ended and / or - to determine whether the electric vehicle is driven after the completion of an external battery charging process, - and, depending on this, to control the shutdown of the activated refrigeration system, in particular a compressor of the refrigeration system.

Images