Method for controlling a charging process of an electrically operated vehicle

Abstract

The invention relates to a method for controlling a charging process of an electrically operated vehicle, which has a charging interface for coupling a charging plug for electrically charging a high-voltage battery of the vehicle. A temperature (24) of the charging interface is maintained above a critical temperature (22) by intermittently feeding a charging current of the vehicle over a predeterminable period of time. The temperature (24) of the charging interface is used as a control variable for the charging current.

Description

[0001] The invention relates to a method for controlling a charging process of an electrically operated vehicle.

[0002] If electric vehicles are charged overnight in winter conditions, for example using an 11 kW or 22 kW AC charging device, the following problem can arise: The waste heat generated during the charging process melts the snow or any snow that may have blown in the area of ​​the charging socket. Once the vehicle is fully charged or has reached its desired charge level, the charging process is terminated. Once the charging process is complete, no more waste heat is generated in the area of ​​the charging plug or charging socket. This can lead to the melted snow, which was previously in the form of water in the area of ​​the plug or charging socket, now returning to the solid state of ice in the area of ​​the charging plug due to the potentially cold outside temperatures. This can also lead to the charging plug freezing to the charging socket or vehicle and becoming impossible to remove.The driver cannot start his journey.

[0003] Charging sockets are generally available in various designs, each of which provides more or less effective protection for the charging plug from snow or moisture, preventing it from becoming covered in snow or water. The disadvantage of this approach is that it requires a correspondingly complex design and may ultimately offer only limited protection.

[0004] DE 102016122009 A1 further discloses a charging cradle with a heating device for heating the charging cradle during the charging process.

[0005] For this purpose, DE 102020125512 A1 discloses the use of waste heat generated by an electrical component of a stationary charging station during the charging process for controlling the temperature of an area of ​​a given surface or volume immediately adjacent to a housing of the stationary charging station.

[0006] An object of the invention is to provide an improved method for controlling a charging process of an electrically operated vehicle.

[0007] The above-mentioned problem is solved by the features of the independent claim.

[0008] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

[0009] According to one aspect of the invention, a method for controlling a charging process of an electrically operated vehicle is proposed. The method comprises a charging interface for coupling a charging plug for electrically charging a high-voltage battery of the vehicle. The temperature of the charging interface is maintained above a critical temperature by intermittently feeding a charging current to the vehicle over a predeterminable period of time. The temperature of the charging interface is used as a control variable for the charging current.

[0010] The charging process is controlled and / or regulated in such a way that a charging current is continuously fed into the vehicle over a specific period of time until departure time and / or until a specified charge level and / or full charge is reached, so that the heat loss at the charging plug prevents freezing. Therefore, the controlling variable for the charging current, the temperature of the charging interface (i.e., at the charging plug and the charging socket), must be kept above a critical temperature, for example, 0°C. This allows for periods of non-charging, as long as the temperature does not drop below this threshold.

[0011] The charging process can advantageously be designed in such a way that the charging plug is always kept warm by the heat loss of the charging current, so that it can be ruled out that the charging plug freezes to the charging socket.

[0012] This can be designed so that, for example, if a fixed departure time is entered in the vehicle, the charging process is aborted shortly before the end of the desired or maximum charge level and is restarted with a sufficient period of time before the entered departure time so that the period until the desired departure is sufficiently short and the water from melted snow or ice cannot freeze again.

[0013] The length of time before the desired departure depends, for example, on the prevailing outside temperature. If it's very cold, for example, the time at which the charging process reaches full charge may be very close to the desired departure time.

[0014] However, once the charging process is complete and the desired or maximum possible charge level of the vehicle has been reached, or the preselected departure time has passed and, according to the determined characteristics, the charging plug is in danger of freezing, further measures can be activated. This can still be achieved with maximum energy efficiency.

[0015] The proposed method advantageously ensures that the driver can drive their vehicle from the charging station at any time, even in adverse and wintry conditions. Furthermore, no additional design measures are required to protect the charging socket or charging plug from snow or ice during the charging process. This means less design effort and correspondingly lower costs.

[0016] For example, the charging current can be regulated to keep the temperature of the charging interface above a critical temperature, especially above freezing. Advantageously, the charging process can be designed so that the charging plug is always kept warm enough by the waste heat from the charging current to prevent the charging plug from freezing to the charging socket.

[0017] According to an advantageous embodiment of the method, given the vehicle's departure time, the charging process can be divided into individual, time-locked phases, interrupted and restarted, and / or stretched over time so that a predeterminable charge level of the high-voltage battery is reached at the departure time. In particular, the phases can have different durations.

[0018] One way to prevent the charging plug from freezing is to repeatedly interrupt the charging process, thus spreading it out over time so that the probability of the charging plug freezing is correspondingly low. This process can be cascaded accordingly, meaning that charging is initially carried out for a very long time, then the charging process is interrupted if necessary until the temperature of the charging interface reaches a critical level. A cooling curve can be stored in the control unit or backend depending on the high-voltage battery. The charging process is then restarted.

[0019] Depending on the outside temperature, these phases can be of different lengths and an appropriate charging strategy can be initiated from the input variables of the state of charge and the ambient temperature as well as the forecast of the ambient temperature, for example based on location, time of day, weather forecast at the respective location, so that freezing of the charging plug can be prevented even under very cold conditions.

[0020] Advantageously, a temporary interruption of the charging process can be set so that the temperature of the charging interface is always kept above the critical temperature. This makes the charging process as energy-efficient as possible, since thawing the charging plug is not necessary when restarting the charging process.

[0021] According to an advantageous embodiment of the method, the charging process can be controlled depending on the vehicle's outside temperature. This allows for flexible response to the respective weather conditions.

[0022] According to an advantageous embodiment of the method, a dependency of the charging process on the outside temperature of the vehicle can be present in at least one characteristic curve, which can be stored in a control unit of the vehicle and / or in a central data processing system, in particular a backend server. The charging process can be controlled via trigger signals according to the at least one characteristic curve. If the location of the vehicle and the outside temperatures to be expected during the charging process are known, corresponding trigger signals can then be sent to control and / or regulate the charging process.

[0023] According to an advantageous embodiment of the method, the vehicle's air conditioning can be started after a predetermined charge level has been reached and / or the departure time has elapsed. For example, the interior heating can be activated so that electrical energy flows into the vehicle via the charging plug or charging station, and the charging plug warms up again, preventing it from freezing. This also has the advantage that the vehicle is preheated accordingly, making heating the vehicle less energy-intensive later on.

[0024] According to an advantageous embodiment of the method, heating of the high-voltage battery can be initiated after a predetermined charge level has been reached and / or the departure time has elapsed. Another possibility is, for example, to warm up the battery accordingly so that it can be brought closer to its ideal operating temperature.

[0025] According to an advantageous embodiment of the method, the charging process can be controlled depending on a weather forecast. This allows for flexible response to the respective weather conditions.

[0026] According to an advantageous embodiment of the method, if a bidirectional charging interface is present and a predetermined state of charge is reached, the high-voltage battery can be at least partially discharged and the charging process can then be restarted.

[0027] In addition, with bidirectional charging connections and a fully charged battery, a discharge can occur after charging to generate charging current with heat loss at the charging connector, and then recharge the discharged energy. This also allows the charging connector to be kept at a temperature above the critical temperature by continuously flowing current, both for charging the high-voltage battery and for discharging and recharging.

[0028] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0029] Showing: Fig. 1 a temperature of a charging interface and a state of charge of a high-voltage battery of an electrically operated vehicle during a charging process according to the prior art; and Fig. 2 a temperature of the charging interface and a state of charge of the high-voltage battery during a charging process according to the method according to the invention.

[0030] In the figures, identical or similar components are numbered with the same reference numerals. The figures show only examples and are not to be understood as limiting.

[0031] Fig. Figure 1 shows a temperature 24 of a charging interface and a charge state 32 of a high-voltage battery of an electrically operated vehicle during a charging process according to the prior art. The vehicle has a charging interface for coupling a charging plug for electrically charging the high-voltage battery.

[0032] Temperature 20 and charge level 30 are in Fig. 1 is plotted as a function of time 10. The charging process takes place in the time interval 40.

[0033] During the charging process, the temperature 24 of the charging interface initially rises steeply and then enters a saturation curve until the specified charge state 32 is reached at the end of the charging process and no more charging current flows.

[0034] After that, the temperature 24 drops again and may fall below a critical temperature 22, such as freezing point, at time 12. This creates the risk that the charging plug will freeze after the charging process is complete.

[0035] Fig. 2 shows a temperature 24 of the charging interface and a charge state of the high-voltage battery during a charging process according to the method according to the invention.

[0036] According to the proposed method, the charging current is regulated such that the temperature 24 of the charging interface is kept above a critical temperature 22, in particular above freezing. For this purpose, the vehicle's charging current is fed in intermittently over a predeterminable period of time, with the temperature 24 of the charging interface being used as the control variable for the charging current.

[0037] For example, as in Fig. As shown in Figure 2, the charging process can be interrupted and restarted at the vehicle's departure time. The charging process is divided into individual, time-locked phases 40, 42, so that a predefined charge level 32 of the high-voltage battery is reached at the departure time.

[0038] In Fig.2, the charging process comprises two charging phases 40, 42. The temperature 24 of the charging interface rises to a maximum value during the first charging phase 40 and falls again after the end of the first charging phase 40. However, the temperature 24 only falls until the second charging phase 42 begins and then rises again during the second charging phase 42. After the end of the second charging phase 42, the desired charge level 32 is reached.

[0039] Thus, the temperature 24 of the charging interface remains above the critical temperature 22 if the vehicle starts driving within a certain period of time after completion of the second charging phase 42.

[0040] The individual charging phases can have different durations. A temporary interruption of the charging process can be advantageously set to keep the temperature 24 of the charging interface above the critical temperature 22.

[0041] Alternatively, the charging phases 40, 42 can also be stretched in time so that a predeterminable charge level 32 of the high-voltage battery is reached at the time of departure.

[0042] Advantageously, the charging process can be controlled based on the vehicle's outside temperature, allowing for flexible response to changing weather conditions.

[0043] In this case, the charging process can be dependent on the vehicle's outside temperature in at least one characteristic curve, which is stored in a control unit of the vehicle and / or in a central data processing system, in particular a backend server. The charging process can thus be controlled via trigger signals according to the at least one characteristic curve.

[0044] The charging process can also be controlled depending on a weather forecast, for example.

[0045] Alternatively, the vehicle's air conditioning can be activated after a specified charge level has been reached and / or the departure time has elapsed. For example, the interior heating can be activated so that electrical energy flows into the vehicle via the charging plug or charging station, and the charging plug warms up again, preventing it from freezing. This also has the advantage of preheating the vehicle accordingly, making heating the vehicle less energy-intensive later on.

[0046] Furthermore, after a specified charge level has been reached and / or the departure time has elapsed, the high-voltage battery can be heated. Additional electrical current flows through the charging interface, heating it. Because the high-voltage battery is now at its optimal operating temperature, the subsequent journey can be more energy-efficient.

[0047] In an alternative embodiment, if a bidirectional charging interface is present and a predetermined charge level is reached, the high-voltage battery can be at least partially discharged, and then the charging process can be restarted. In addition, with bidirectional charging connections and a fully charged battery, a discharge can occur again after charging, so that a charging current with waste heat flows through the charging connector and heats it. The discharged energy can then be recharged, thus also contributing to the heating of the charging interface. List of reference symbols 10 time 12 Time of reaching the critical temperature 20 Temperature 22 critical temperature 24 Temperature of the charging interface 30 Charge level 32 State of charge of the high-voltage battery 40 Charging active 42 Charging process active QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102016122009 A1

[0004] DE 102020125512 A1

[0005]

Claims

[1] Method for controlling a charging process of an electrically operated vehicle which has a charging interface for connecting a charging plug for electrically charging a high-voltage battery of the vehicle, wherein a temperature (24) of the charging interface is kept above a critical temperature (22) by intermittently supplying a charging current of the vehicle over a predeterminable period of time, wherein the temperature (24) of the charging interface is used as a control variable for the charging current. [2] Method according to claim 1, wherein, at the vehicle's departure time, the charging process is subdivided into individual, temporally separate phases (40, 42), interrupted and restarted, and / or extended in time so that a predetermined state of charge (32) of the high-voltage battery is reached at the departure time, in particular wherein the phases (40, 42) have different durations. [3] Method according to claim 1 or 2, wherein the charging process is controlled depending on an outside temperature of the vehicle. [4] Method according to claim 3, wherein a dependence of the charging process on the outside temperature of the vehicle is present in at least one characteristic curve which is stored in a control unit of the vehicle and / or in a central data processing system, in particular a backend server, wherein the charging process is controlled via trigger signals according to the at least one characteristic curve. [5] Method according to one of the preceding claims, wherein after reaching a predetermined state of charge and / or after a certain departure time has elapsed, the vehicle is air-conditioned. [6] Method according to one of the preceding claims, wherein after reaching a predetermined state of charge and / or elapsed departure time, heating of the high-voltage battery is initiated. [7] Method according to one of the preceding claims, wherein the charging process is controlled depending on a weather forecast. [8] Method according to one of the preceding claims, wherein, in the presence of a bidirectional charging interface and upon reaching a predetermined state of charge, the high-voltage battery is at least partially discharged and the charging process is then restarted.

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