METHOD AND DEVICE FOR CHARGING AN ELECTRICALLY POWERED VEHICLE

Abstract

Method for charging an electrically powered vehicle (110) wherein a maximum charging current (I MAx ) of a charging process (200) for charging the vehicle (110) before the start of the charging process (200) based on an electrical resistance (R) determined during at least one previous charging process A , R B ) at least one interface component (102, 104) of an interface (100) between a charger (108) and the vehicle (110) is predetermined, wherein a resistance determination is used to determine the current electrical resistance (R) K ) of the interface (100) during the current charging process (200) using a current temperature (T K ) the interface (100) and a current charging current (I A / B ) is executed via the interface (100) and the resistance (R K) of the interface (100) using a vehicle resistance value (R) provided by the vehicle (110) representing an estimated electrical resistance of an interface component (104) of the vehicle (110). B,m ) and a charger resistance value (R) provided by the charger (108), representing an estimated electrical resistance of an interface component (102) of the charger (108). A,n ) is determined and the current electrical resistance ( RA , m * ) the interface component (102) of the charger (108) using the current electrical resistance (R) K ) the interface (100) and the vehicle resistance value (R) stored in the vehicle (110). B,m ) of the previous charging process and where the charger resistance value (R) stored in the charger A,n ) using the estimated electrical resistance ( RA , m * ) the interface component (102) of the charger (108) is updated during the current charging process (200).

Description

Technical field

[0001] The present invention relates to a method and a corresponding device for charging an electrically powered vehicle. State of the art

[0002] To quickly charge the traction battery of an electric vehicle, a high charging power is required. Since the traction battery's voltage is fixed, this results in a high current flow in the charging circuit. This current flow causes heating of the current-carrying components within the circuit.

[0003] The components require a sufficiently dimensioned conductor cross-section to achieve low electrical resistance and to limit heating during fast charging within acceptable values.

[0004] A vehicle's charging socket and a charger's charging plug form a plugged interface in the electrical circuit. Changes to the surfaces of the charging socket and plug can create contact resistance at this interface, which, during fast charging, can lead to greater heating of the interface than in the rest of the electrical circuit.

[0005] To avoid damage to the interface, the temperatures of the charging socket and the charging plug can be monitored, and if a certain temperature threshold is exceeded, the charging power can be reduced, i.e., the current flow limited.

[0006] The publication DE 10 2017 209 450 A1 concerns a method and a corresponding control unit for determining temperature information regarding the temperature of a vehicle's charging interface.

[0007] From DE 10 2014 101 485 A1, systems and methods for charging rechargeable energy storage systems contained in a vehicle are known. Description of the invention

[0008] One object of the invention is therefore to provide a method and a corresponding device for charging an electrically powered vehicle using the simplest possible means in terms of construction.

[0009] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims, the description, and the accompanying figures. In particular, the independent claims of one claim category may also be further developed analogously to the dependent claims of another claim category.

[0010] A method for charging an electrically powered vehicle is presented, wherein a maximum charging current for a charging process is predetermined before the start of the charging process based on an electrical resistance of at least one interface component of an interface between a charger and the vehicle, determined during at least one previous charging process, and wherein a resistance determination is performed to determine the current electrical resistance of the interface during the current charging process using a current temperature of the interface and a current charging current through the interface, and the resistance of the interface is determined using a vehicle resistance value provided by the vehicle, representing an estimated electrical resistance of an interface component of the vehicle, and a resistance value provided by the charger.An estimated electrical resistance of an interface component of the charger is determined, representing the charger resistance value, and the current electrical resistance of the interface component of the charger is estimated using the current electrical resistance of the interface and the vehicle resistance value stored in the vehicle from the previous charging process.

[0011] A resistance measurement to determine the current electrical resistance of the interface is performed during the current charging process using the interface's current temperature and charging current. The measured resistance can be used for subsequent charging processes. By measuring the resistance during charging, the stored resistance value used to limit the charging current can be adjusted to account for aging of the interface or at least one of its components. The resistance can be determined using a model. This model can be based on resistance measurements under defined conditions. The model can use the current temperature of at least one of the interface components and the current charging current as inputs and provide the estimated electrical resistance as outputs.

[0012] The interface resistance is determined using a vehicle resistance value provided by the vehicle, representing an estimated electrical resistance of a vehicle interface component, and a charger resistance value provided by the charger, representing an estimated electrical resistance of a charger interface component. Resistance values ​​can be stored from one charging cycle to the next. The estimated resistances of the interface components can be added together. Different maximum charging currents can be preset by using different components at the interface.

[0013] The current electrical resistance of the charger's interface component is estimated using the interface's current resistance and the vehicle resistance value stored in the vehicle from the previous charging process. The current electrical resistance of the charger's interface component can be estimated in the vehicle, as all necessary values ​​are available there. The current electrical resistance of the charger's interface component can be represented as an updated charger resistance value and provided to the charger by the vehicle. This charger resistance value can be provided via the interface or via another communication channel.

[0014] The charger resistance value stored in the charger is updated using the estimated electrical resistance of the charger's interface component during the current charging process.

[0015] Charging a vehicle can refer to charging its traction battery. A detachable interface can be located between a charger and the traction battery. A charging socket and a charging plug can be components of this interface. These interface components can be connected and disconnected. The interface components can have multiple connectors. A charging cable can be located between the charger and the vehicle. The charging cable can have at least one forward and one return conductor for transmitting electrical energy. The charging cable can also have data lines and signal lines. The conductors can be electrically connected and disconnected at the interface. The charging cable can be part of the charger and connected to the vehicle via the interface.The charging cable can also be connected via a first interface on the vehicle and a second interface on the charger. In this case, there are at least two interfaces between the charger and the traction battery. The approach presented here can be applied to any interface. The charger can, for example, be a wallbox or a charging station.

[0016] A charging process can be the period during which the interface components are connected and a charging current flows through the supply and return lines. The charging current is an electrical current flow used to transfer electrical power from the charger to the traction battery or the traction battery's charging electronics. A maximum charging current can be a preset maximum value. The maximum charging current limits the maximum possible power transfer. The actual charging current can be lower than the maximum charging current.

[0017] The maximum charging current can also be predetermined if the electrical resistance of only one of the interface components is known. For example, a vehicle using the approach presented here can also be charged with a conventional charger. Conversely, a conventional vehicle can be charged with a charger using the approach presented here.

[0018] The maximum charging current can be predetermined based on the resistance of at least one interface component of the charger and the resistance of at least one interface component of the vehicle. If the interface is located between the cable and the vehicle, the maximum charging current can be predetermined based on the resistance of at least one interface component of the cable and the resistance of at least one interface component of the vehicle. If the interface is located between the cable and the charger, the maximum charging current can be predetermined based on the resistance of at least one interface component of the cable and the resistance of at least one interface component of the charger. The maximum charging current can be predetermined based on the two different resistances of the interconnected interface components.Since the vehicle can be charged using different chargers, different maximum charging currents can be preset for each charger. Likewise, different vehicles can be charged using the same charger, and different maximum charging currents can be preset for different vehicles using the same charger. By utilizing the resistances of both interface components, the maximum charging current can be preset with increased accuracy.

[0019] The current electrical resistance of the vehicle's interface component can be estimated using the interface's current electrical resistance and the charger resistance value from the previous charging cycle, which is stored in the charger. The current electrical resistance of the vehicle's interface component can be estimated directly in the charger, as all necessary values ​​are stored there. The current electrical resistance of the vehicle's interface component can be represented in an updated vehicle resistance value and provided to the vehicle by the charger. This vehicle resistance value can be provided via the interface or via another communication channel.The vehicle resistance value stored in the vehicle can be updated using the estimated electrical resistance of the vehicle's interface component during the current charging process.

[0020] The process can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example in a control unit.

[0021] The approach presented here also creates a control unit that is designed to carry out, control or implement the steps of a variant of the procedure presented here in appropriate facilities.

[0022] The control unit can be an electrical device with at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, and at least one interface and / or a communication interface for reading or outputting data embedded in a communication protocol. The processing unit can be, for example, a signal processor, a so-called system ASIC, or a microcontroller for processing sensor signals and outputting data signals depending on the sensor signals. The storage unit can be, for example, flash memory, an EPROM, or a magnetic storage device. The interface can be configured as a sensor interface for reading sensor signals from a sensor and / or as an actuator interface for outputting data signals and / or control signals to an actuator.The communication interface can be configured to read or output data wirelessly and / or via a wired connection. The interfaces can also be software modules, such as those found on a microcontroller alongside other software modules.

[0023] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular if the program product or program is executed on a computer or device. Brief character description

[0024] An advantageous embodiment of the invention is explained below with reference to the accompanying figures. These show: Fig. 1. A representation of an interface between a first interface component and a second interface component; and Fig. 2. A representation of a charging process using a method according to an exemplary embodiment.

[0025] The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently identified by the same reference numerals. Detailed description

[0026] For easier understanding, the reference symbols to the following description are used. Fig. Keep 1-2 as a reference.

[0027] Fig. Figure 1 shows a representation of an interface 100 between a first interface component 102 and a second interface component 104 of interface 100. The interface 100 is arranged in a line 106 between two participants A, B of a charging process. Participant A can, for example, be a charger 108 and participant B can be a traction battery of a vehicle 110. Likewise, participant A can be the traction battery of the vehicle 110 and participant B the charger 108. Each participant A, B has a control unit (not shown here) for controlling the charging process. The control units are configured to exchange data with each other and to determine a maximum charging current I. MAx to predetermine via interface 100 before the start of the charging process depending on the aging state of the interface components 102, 104.

[0028] Interface components 102 and 104 are designed as connectors. Here, the first interface component 102 is designed as a socket, while the second interface component 104 is designed as a plug. For simplicity, only one line 106 of interface 100 is shown here. Interface 100 can have several additional lines 106. At a minimum, interface 100 can have a forward line and a return line for transmitting electrical charging power to charge the traction battery.

[0029] An electric current flow I A / B Current flows through line 106 over a contact surface 112 between the interface components 102 and 104. Due to a contact resistance R K An electrical voltage U drops across contact surface 112. K and the contact surface 112 heats up due to a resulting power loss P V. For example, different electrical voltages U can be applied to participants A and B. A , V B be measured. The electric current flow I A / B The situation at participants A and B remains the same. The electric current flow I can be... A / B The current flow I is measured separately at both participants A and B. Due to measurement inaccuracies, slightly different values ​​for the electric current flow I are obtained in each case. A / B via interface 100.

[0030] Interface components 102 and 104 are temperature monitored. A first temperature value T is recorded at the first interface component, 102. A A second temperature value T is recorded at the second interface component 104. B recorded. Since the temperature values ​​T A , T B A temperature T cannot be measured directly at the contact surface 112. K the contact surface 112 from the temperature values ​​T A, T B differ.

[0031] Using the available measured values, the contact resistance R can be determined. K and the power loss P V will be calculated.

[0032] The contact resistance R K is dependent on the state of the contact surface 112. The state of the contact surface 112 is in turn determined by the states of the surfaces of the interface components 102, 104 that form the contact surface 112. For example, the surfaces can age due to environmental influences and may be at least partially covered by oxide layers that exhibit high electrical resistance. Similarly, the contact resistance R can be increased by a K The coating on the surfaces may be damaged mechanically and / or thermally. For example, the coatings can be damaged if the temperature T Kthe contact surface 112 at least locally, even if only briefly, due to an excessively high electric current flow I A / B The damage value increases via interface 100. This exceedance can be determined by the temperature values ​​T. A , T B They can only be displayed with a delay, which means the coating may already be damaged when the temperature values ​​T A , T B exhibit correspondingly high values.

[0033] The approach presented here makes it possible to prevent such an exceedance of the temperature T. K The contact surface 112 can be proactively prevented by taking into account the contact resistance R determined during a previous charging process. K the maximum charging current I MAX is predetermined for the current charging process.

[0034] Fig. Figure 2 shows a representation of a charging process 200 using a method according to an exemplary embodiment. The method can be implemented, for example, at an interface such as that described in Fig. The value shown in Figure 1 is applied. During the charging process, the maximum charging current I is applied. MAX of the charging process 200 for charging the vehicle 110 before the start of the charging process 200 based on the electrical resistance R determined during at least one previous charging process A / BAt least one interface component A, B of interface 100 between a charger 108 and the vehicle 110 is predetermined. The previous charging process was completed before the start of the current charging process 200. Interface 100 was disconnected between the previous charging process and the current charging process 200. The vehicle 110 may have been moved between the charging processes. In one embodiment, the previous charging process was carried out in combination with a different charger or a different vehicle. Interface 100 is also disconnected between the current charging process 200 and a subsequent charging process.

[0035] The resistance R A / B It consists of an electrical resistance R A the first interface component A and an electrical resistor R Bthe second interface component B. The charger 108 represents an electrical resistance R. A the charger resistance value R representing the first interface component A during a previous charging process A,n ready, while the vehicle 110 has an electrical resistance R B the vehicle resistance value R that is represented during a previous charging process of the second interface component B B,m provides the resistance values ​​R A,n , R B,m are combined and the maximum charging current I MAX Predetermined for the current charging process 200.

[0036] During the current charging process, 200 units of actual current flow are present in the charger. A and a temperature T A The first interface component A is detected. Using a model of interface 100, the current resistance R is derived from this. KThe interface is estimated at 200 during the current charging process. Since the charger resistance value R A,n The current resistance R is known and can be used to determine this. K a the estimated electrical resistance R B the second interface component B during the current charging process, representing an estimated vehicle resistance value of 200 RB,n* be determined.

[0037] During the current charging process, the vehicle experiences an actual current flow of 200. B and a temperature T B The second interface component B is detected. Using a model of interface 100, the current resistance R is derived from this. K The interface is estimated at 200 during the current charging process. Since the vehicle resistance value R B,m The current resistance R is known and can be used to determine this. K a the estimated electrical resistance R Athe first interface component A during the current charging process, representing an estimated charger resistance value of 200 R.A.M* be determined.

[0038] The estimated vehicle resistance value RB,n* and the estimated charger resistance value R.A.M* 202 values ​​are exchanged during a data exchange and used as estimates R A,n+1 , R B,m+1 using at least one weighting factor to track the stored resistance values ​​R A,n , R B,m used.

[0039] In one embodiment, the tracked resistance values ​​R A,n , R B,m sent to a higher-level data processing system. There, using the resistance values ​​R A,n , R B,m The need for repair of interface components A and / or B can be assessed. Similarly, the resistance values ​​R can be determined.A,n , R B,m This information is stored in a database, which can be used, for example, to search for advantageous pairings of vehicles 110 and chargers 108. This prevents, for example, a vehicle 110 with a new interface component B from being charged on a charger 108 with a damaged interface component A.

[0040] In other words, a method for determining the charging contact surface quality or for optimizing the charging strategy of electric vehicles is presented.

[0041] Increasing charging currents in electric vehicles necessitate precise determination of the quality of the contact surfaces used to transmit the charging current, in order to prevent thermal overload of the connector. The quality of the contact surfaces determines the contact resistance at the connector pins. Conventionally, the temperature of the contacts can be measured and the charging current reduced accordingly. However, since the temperature can only be measured with a certain time delay or dead time, the reaction time to a faulty connection is limited, and thermal overload cannot always be ruled out.

[0042] The approach presented here uses the measured pin temperature and charging current to estimate the contact resistance of the current connector. This value is continuously updated over the component's lifetime, utilizing data exchange between the vehicle and the charging station to detect aging of the contact elements and thus determine the contribution of the contact resistance from the vehicle and infrastructure sides. This allows the current surface quality of each contact element involved in the charging process to be determined, and the charging strategy to be predictively adjusted. This means that temperature-related derating, or a reduction in the maximum charging current, does not occur only upon detection of overheating, but rather beforehand, thus preventing premature aging of the intact contact element.

[0043] Currently, reactive methods are used to prevent the connector from overheating. This involves continuously measuring the temperature of the contact elements and reducing the charging current if the temperature becomes too high. However, with significant wear or damage to a contact element, leading to a considerably increased contact resistance, temporary overheating and subsequent further damage to the contact cannot always be reliably prevented, especially at very high charging currents such as 500A and above. In the worst-case scenario, even the contacts of, for example, the vehicle's charging socket can be damaged if charging occurs with a heavily worn contact on the infrastructure side. While the contact resistance can already be determined, information about the contact surface condition of the charging partner is lacking, making aging monitoring of one's own contact either impossible or extremely inaccurate.

[0044] Alternatively, a charging socket can be used that allows for particularly fast and accurate temperature measurement. However, the technical implementation of such temperature measurement is very complex and expensive, especially if a high dynamic measurement is required. The integration of the charging station's measured data, as presented here, can reduce the need for such an expensive solution, since age-related and thus gradual degradation of the contacts is continuously detected, and the charging strategy can be proactively adjusted. The approach presented here can, for example, be integrated into future high-performance charging infrastructure.

[0045] By continuously determining the "own" contact resistance during each charging process, and especially with changing charging partners, damage to intact contact elements during a charging attempt with a damaged charging partner can be prevented by adjusting the charging strategy before elevated temperatures occur.

[0046] In the approach presented here, both parties involved in the charging process exchange the necessary data via communication between the vehicle and the infrastructure. This communication can be wired via the interface and, alternatively or additionally, wireless via radio or the cloud.

[0047] The method shown here is based on determining the contact temperature and charging current on both the vehicle and infrastructure sides, i.e., at the charging station or wallbox. These values ​​are already determined with a high degree of accuracy.

[0048] Current measurement within the vehicle is one of the most important parameters to determine in an electric vehicle. Current measurement on the infrastructure side is necessary, among other things, for accurate cost accounting (keyword: calibration). Temperature measurement on both ends is a safety-relevant function to prevent overloading at high charging power. Independent measurement of the positive and negative terminals is a standard requirement.

[0049] These measured values ​​are therefore available in control units A and B as input for determining the contact surface quality. The contact surface quality is directly related to the contact resistance at the contact surface between components A and B.

[0050] Subsequently, no specific distinction is made between the vehicle and infrastructure sides, as the procedure can be applied equally to both. The only distinction made is between the participants in a charging process (A and B).

[0051] The contact resistance between the charging contacts A and B is directly reflected in the temperature measured at the contact. This contact resistance R K During charging, power loss occurs between the contacts, which is directly related to the charging current I A / B related. PLoss=IA / B2⋅RK

[0052] To determine the power loss, a thermal model of the charging system is used, which relates the temperature values ​​and the charging current to the power loss. This takes into account the heat dissipation inherent in the design, e.g., via active cooling or via the connected thermal masses, such as cables or the vehicle body. This behavior can be determined under controlled conditions during the development of the components involved in the charging process.

[0053] By applying a defined power dissipation to the contact element and measuring the temperature profile over time, it is possible to derive a thermal equivalent circuit consisting of thermal resistances and capacitances. Advantageously, this can be done at several points within the overall thermal system. Once a sufficiently accurate thermal equivalent circuit has been created, this model can be used, as in the approach presented here, to deduce the applied power dissipation "backwards" from a temperature profile.

[0054] Furthermore, to determine the power loss, the charging voltage of the charging station can be compared with the measured voltage in the vehicle. The voltage difference multiplied by the charging current yields the exact power loss; however, in this case, factors such as line resistance are also measured, so this voltage measurement alone cannot be used to calculate the power loss at the plug connector.

[0055] It is assumed that the contact resistance is composed of surface-specific components for the individual contacts. RK=RA+RB

[0056] At the beginning of the life cycle of a charging contact, its specific contribution to the contact resistance is given by R. A,0 or R B,0 The value is determined and stored as an initial value in the control unit of the respective charging device A or B. When a charging process is initiated, the contact resistance R is then... Kfor this one specific charging process on both sides, and the respective current specific share R is determined. A or R B Subtracted from this to determine an estimated value for the contact resistance of the charging partner.

[0057] As a concrete example, it is assumed that A is experiencing a charging process for the first time (counter variable n = 0), and therefore still has the initial value R. A,0 has stored. For this first charging process, the control unit determines the current I in A. A and the temperature T A the total contact resistance determined by A RAB,0A. This is composed of the currently deposited share R A,0 and the estimated share RB,0* together. RAB,0A⋅=RA,0+RB,0*

[0058] Upon completion of the charging process, A transmits the estimated share to charging partner B and receives the estimated value in return. RA,0* feedback is given for one's own contribution. This process can be described as "voting," since the charging partners vote on and evaluate each other.

[0059] The estimated value RA,0* A now uses this value to update its internally stored resistance value, resulting in the new value R. A,1 results. RA,1=RA,0+k⋅RA,0*

[0060] The factor k serves to normalize and weight the estimated resistance component. Since the quality of current and temperature measurements can vary between different charging devices, and thus the accuracy of the estimated resistance component can also fluctuate, this estimate is not adopted without further evaluation. For example, the actual electrical resistance value is not used, but rather a comparable substitute value that represents the surface quality of the charging contact in a normalized way. This normalization can be represented, for example, on a percentage scale where 100% = a brand-new contact.

[0061] The new resistance component R A,1The current value is now stored in control unit A and serves as the basis for determining the resistance fraction in the next charging process (n = 1). B performs the same procedure, so that both participants have updated their estimated resistance fraction after the charging process. With changing charging partners, this procedure allows the participants to learn from each other and determine their own resistance fraction with increasing accuracy. A public fast-charging station used daily by various vehicles can serve as an example. Any age-related deterioration of the contact surface quality is thus gradually recorded in the charging station's data.

[0062] If charging partners A and B are always the same, the proportions can be distorted because, if A ages while B maintains the same contact quality, the increasing contact resistance would be distributed equally between both participants. This is because each participant assumes its own contact quality from the previous charging process as its current value. However, if this has decreased since the last charging process, meaning the proportion of contact resistance has increased, this is directly factored into the voting as an error, and the increase in resistance is attributed to the other partner.

[0063] Changing charging partners compensates for such extreme cases, as these errors do not accumulate but are distributed across a larger number of charging partners and are compensated for equally by them. Significant aging of the contacts between two charging processes is considered an extreme case. Alternatively, the weighting factor k can be adjusted, decreasing with repeated charging using the same charging partner, so that a corresponding error does not worsen with each charging cycle.

[0064] The method therefore provides a way to determine the aging effects of the respective contact surface over the lifetime of each charging contact where the temperature and current can be specifically determined, e.g. DC+ and DC- in direct current charging.

[0065] This is particularly advantageous in the scenario of a new electric vehicle with correspondingly new charging contacts. The vehicle is charged at a frequently used public charging station. Let's assume that the charging station contacts already have a significantly increased contact resistance, resulting in very rapid heating of all charging contacts during high-power charging, for example, 500A high-power charging. Since highly dynamic temperature measurement of charging contacts is currently only possible to a limited extent, the temperature at the charging contacts, especially directly at the contact surface, rises very quickly. However, this can only be detected by the integrated temperature sensor with a certain time delay and reduced dynamics. Therefore, the measured temperature increase at the sensor does not correspond to the temperature increase at the contact point, and the measured temperature at the sensor may be significantly lower than the temperature at the contact point.Therefore, if the system reacts to the sensor reading and reduces the charging current after a measured temperature increase, the temperature at the contact point may already be significantly higher, and thermally induced aging of the contact elements may have occurred. For a new vehicle, this means premature aging of the charging contacts due to the lack of awareness of the increased resistance of the charging partner. In this case, the reactive charging strategy could not prevent damage to or unnecessary aging of the charging contacts.

[0066] With the presented method, it is now possible for participants A and B to exchange information about the quality of their charging contacts in advance, and the charging strategy can thus be adjusted preventively in order to prevent thermal aging of the new contacts from the outset.

[0067] The same communication interface used for voting can be used for this. This includes both direct communication between charging partners (e.g., via powerline communication, CAN, or NFC) and cloud-based communication. With the latter option, contact quality could be taken into account when searching for a suitable charging station.

[0068] Furthermore, the method provides a suitable input for predictive maintenance approaches, where the charging contacts of a charging station can be replaced before they can lead to thermal overloads.

[0069] Since the devices and methods described in detail above are exemplary embodiments, they can be modified extensively by a person skilled in the art without departing from the scope of the invention. In particular, the mechanical arrangements and the relative sizes of the individual elements are chosen only as examples. REFERENCE MARK LIST 100 interface 102 first interface component 104 second interface component 106 Management 108 charger 110 vehicles 112 contact area I A / B electric current flow R K Contact resistance U K electrical voltage P V Power loss U A first electrical voltage U B second electrical voltage T A first temperature value T B second temperature value T K temperature I MAX maximum charging current 200 charging process 202 Data exchange R A first electrical resistance R B second electrical resistance R A,n Charger resistance value R B,m Vehicle resistance value I A first current flow estimated vehicle resistance value I B second current flow estimated charger resistance value

Claims

[1] Method for charging an electrically powered vehicle (110) wherein a maximum charging current (I MAx ) of a charging process (200) for charging the vehicle (110) before the start of the charging process (200) based on an electrical resistance (R) determined during at least one previous charging process A , R B ) at least one interface component (102, 104) of an interface (100) between a charger (108) and the vehicle (110) is predetermined, wherein a resistance determination is used to determine the current electrical resistance (R) K ) of the interface (100) during the current charging process (200) using a current temperature (T K ) the interface (100) and a current charging current (I A / B ) is executed via the interface (100) and the resistance (R K) of the interface (100) using a vehicle resistance value (R) provided by the vehicle (110) representing an estimated electrical resistance of an interface component (104) of the vehicle (110). B,m ) and a charger resistance value (R) provided by the charger (108), representing an estimated electrical resistance of an interface component (102) of the charger (108). A,n ) is determined and the current electrical resistance (R.A.M*) the interface component (102) of the charger (108) using the current electrical resistance (R) K ) the interface (100) and the vehicle resistance value (R) stored in the vehicle (110). B,m ) of the previous charging process and where the charger resistance value (R) stored in the charger A,n ) using the estimated electrical resistance (R.A.M*) the interface component (102) of the charger (108) is updated during the current charging process (200). [2] Method according to claim 1, wherein the maximum charging current (I MAX ) based on the resistance (R A ) at least one interface component (102) of the charger (108) and the resistor (R B ) at least one interface component (104) of the vehicle (110) is predetermined. [3] Control unit designed to execute, implement and / or control the method according to one of the preceding claims in appropriate facilities. [4] Computer program product configured to instruct a processor, when the computer program product is executed, to execute, implement and / or control the method according to any one of claims 1 to 2. [5] Machine-readable storage medium on which the computer program product according to claim 4 is stored.

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