Calibrating an electric vehicle charging device

Abstract

Calibration device (60) for a charging device (10) of an electric vehicle, comprising a plug (61) for insertion into a charging socket (31) of a charging device (10) of an electric vehicle and a calibration plate (63) held on the plug (61) and thermally acting on the charging socket (31) when the calibration device (60) is inserted, with a temperature control unit (64) held on the calibration plate (63) and thermally connected to the calibration plate (63) and a control unit (70) operationally connected to the temperature control unit (64) and configured to set a temperature of the calibration plate (63) to a predetermined temperature.

Description

[0001] The invention relates to a calibration device for a charging unit of an electric vehicle. Furthermore, the invention relates to a method for calibrating a charging unit of an electric vehicle.

[0002] Every electric vehicle includes a traction battery, which provides electrical energy to power an electric drivetrain and other electrical components of the vehicle. To charge the traction battery, the electric vehicle also includes a charging device connected to the battery, which allows the vehicle to be connected to an external charging station.

[0003] The charging system comprises an on-board charger (OBC) and a charging socket operationally connected to the charger, which includes a temperature sensor and into which a charging plug from an external charging station can be inserted. The temperature sensor is usually an NTC or thermistor. The charger includes a high-voltage unit connected to the traction battery and the charging socket, and an evaluation unit connected to the temperature sensor of both the charging socket and the high-voltage unit. Furthermore, the charging system includes a bus interface for connecting the charger, and in particular the evaluation unit, to the electric vehicle's bus system.

[0004] During charging of the traction battery, a strong electric current can flow through the connection formed by the charging plug and socket, generating heat at the ohmic resistances of the plug and / or socket. This heat causes the charging socket to warm up, i.e., its temperature rise. Particularly with worn contacts of the plug and / or socket, the ohmic resistance of the connection can increase, consequently amplifying the heat generated and leading to overheating, i.e., a significant temperature increase, of the charging socket. Overheating can damage the charging socket.

[0005] To prevent overheating, the charging socket's temperature sensor continuously monitors the socket's temperature during charging and transmits corresponding sensor signals to the evaluation unit. The evaluation unit compares the transmitted temperature values ​​with one or more predetermined temperature thresholds stored within it and reduces the charging current or interrupts charging if the transmitted temperature value exceeds a corresponding temperature threshold.

[0006] DE 10 2016 218 303 A1 discloses a method for assessing the quality of a charging plug of an electric vehicle charging device. In this method, an electric vehicle charging device compares the temperature of a charging socket, measured by a temperature sensor of the charging device during charging, with a stored reference temperature value. The stored value is measured during charging of the electric vehicle using an ideal reference charging plug, i.e., a reference charging plug of optimal quality. If the charging plug's quality is insufficient, i.e., if the reference temperature is exceeded to an unacceptable degree during charging, the charging current is reduced or the charging process is interrupted.

[0007] A charging socket for an electric vehicle charging device is also known from WO 2020 / 053 739 A1. The charging socket includes a temperature sensor that is movably mounted on the charging socket and configured to vary its position relative to the socket depending on the socket's temperature. A position sensor, arranged at a distance from the temperature sensor, continuously detects the temperature sensor's position, and a control device of the charging device, connected to the position sensor, controls the electrical charging current flowing through the charging socket based on the detected position.

[0008] Any reduction or interruption of the charging current decreases the charging efficiency of the electric vehicle, as the charging process takes longer. If the temperature sensor signals excessively high temperatures, charging efficiency is unnecessarily reduced. Conversely, if the temperature sensor signals excessively low temperatures, the lifespan of the charging socket is shortened. For optimal charging efficiency and a long charging socket lifespan, the temperature sensor must therefore reliably signal the most accurate temperature values ​​possible to the evaluation unit. In other words, the temperature sensor must always be calibrated. However, the temperature sensor calibration can be lost over time due to aging and / or wear and tear during the electric vehicle's use.

[0009] The method disclosed in DE 10 2004 056 434 A1 is generally used for measuring a vehicle's temperature sensor, i.e., for verifying the temperature sensor's calibration. After the vehicle has been driven, the temperature sensor is measured during a rest period by recording various temperature profiles, such as those of the ambient temperature, coolant, engine oil, or fuel, depending on the specific sensor being measured. These recorded temperature profiles are then compared with corresponding characteristic curves from a relevant computational model to detect an impending or existing defect, i.e., a lack of calibration, of the temperature sensor.

[0010] Furthermore, DE 10 2016 206 487 A1 discloses a method for calibrating one or more temperature sensors of a vehicle. Temperature values ​​measured by the temperature sensors are compared with a temperature value provided by a weather service. By comparing the measured temperature values ​​with the provided temperature value and, if necessary, with each other, the temperature sensors can also be calibrated taking into account special environmental conditions, for example, in a garage or in a parking lot without shade.

[0011] However, this calibration method is not suitable for calibrating a charging device, i.e., a temperature sensor of a charging device, or of an electric vehicle.

[0012] Accordingly, there is a need for devices and methods to detect an uncalibrated or defective charging device of an electric vehicle before the electric vehicle is put into operation and during the electric vehicle's lifetime and / or to recalibrate it if necessary.

[0013] The invention is therefore based on the objective of providing a device for calibrating the charging system of an electric vehicle, which allows calibration of the charging system throughout the entire service life of the electric vehicle. Furthermore, it is an objective of the invention to provide a method for calibrating the charging system of an electric vehicle that can be carried out throughout the entire service life of the electric vehicle.

[0014] One object of the present invention is a calibration device for a charging device of an electric vehicle.

[0015] According to the invention, the calibration device comprises a plug for insertion into a charging socket of an electric vehicle charging station and a calibration plate held on the plug and thermally acting on the charging socket when the calibration device is inserted. The device also includes a temperature control unit held on and thermally connected to the calibration plate and a control unit operationally connected to the temperature control unit. It is configured to set the temperature of the calibration plate to a predetermined temperature. In other words, the plug is designed like a charging plug of a charging station, resulting in easy handling and immediate usability of the calibration unit, requiring no installation work on the electric vehicle.

[0016] The connector is equipped with a temperature-controlled calibration plate, which extends perpendicular to the connector's insertion direction and can be rectangular in shape. The calibration plate can be thermally connected to the connector. In this case, the charging socket can be heated via the connector. Alternatively or additionally, the calibration plate can be in thermal contact with the charging socket when the calibration unit is plugged in. In this case, the charging socket can be heated directly.

[0017] The calibration plate heats the charging socket to a predetermined temperature, which is measured by a temperature sensor in the charging socket. A temperature reading from the sensor at the predetermined temperature is essential for identifying a calibration error and, if necessary, recalibrating the charging device.

[0018] In preferred embodiments, the calibration device is configured to automatically adjust the temperature of the calibration plate sequentially to a plurality of predetermined temperatures. These multiple predetermined temperatures can be distributed within a temperature range relevant to the charging device, thus enabling calibration across the entire relevant temperature range. In this way, temperature-dependent deviations from the calibration across a temperature range can also be detected and taken into account during calibration.

[0019] Advantageously, the calibration device includes at least one temperature sensor operationally connected to the control unit, which is designed and arranged to detect the temperature of the charging socket. For example, the temperature sensor can be arranged on the side of the calibration plate facing the charging socket when the calibration device is plugged in.

[0020] In further embodiments, the temperature sensor is designed as an optical sensor. Optical sensors are designed to detect temperature without contact. They therefore enable temperature measurement over a distance.

[0021] In other embodiments, the temperature control unit is designed as an electrothermal transducer. For example, the temperature control unit can comprise a Peltier element thermally connected to the calibration plate.

[0022] Advantageously, the calibration device also includes an interface connected to the control unit for linking the control unit to the on-board diagnostics (OBD) interface of the electric vehicle. This interface enables data exchange with the electric vehicle. Furthermore, the calibration device's interface can allow the use of electrical power supplied by the electric vehicle. In these cases, the calibration device does not require its own electrical power source.

[0023] In these embodiments, the control unit can further be configured to map a temperature value of the charging socket received from the electric vehicle via the interface to a temperature value of the charging socket measured by at least one temperature sensor. In other embodiments, the control unit of the calibration device can establish a paired relationship between simultaneously received and measured temperature values, i.e., group the temperature values ​​into a pair.

[0024] Preferably, the control unit is configured to transmit a pair of corresponding temperature values ​​to the electric vehicle via the interface and the diagnostic interface. The transmitted pair of temperature values ​​can be stored in the control unit and constitutes a calibration of the electric vehicle's charging device. If the calibration device sets several different temperatures, the control unit can transmit a corresponding number of pairs, i.e., a calibration table, to the electric vehicle, which then constitute the calibration of the charging device.

[0025] Ideally, the control unit is configured to calculate the difference between corresponding temperature values ​​and to take an action based on this difference. Using this calculated difference, the control unit can distinguish between two or more cases and handle them differently.

[0026] In preferred embodiments, the measure includes indicating that the charging device is calibrated if the calculated difference is less than a predetermined first tolerance value, and indicating that the charging device is uncalibratable if the calculated difference is greater than a predetermined second tolerance value that is larger than the first tolerance value. This corresponds to determining whether the charging device is to be considered functioning correctly or defective.

[0027] In particularly preferred embodiments, the measure comprises indicating the calibratability of the charging device and / or transmitting corresponding received and recorded temperature values ​​via the interface and the diagnostic interface to the electric vehicle when the calculated difference between the first and second tolerance values ​​is within the specified range. This corresponds to the detection and / or calibration of a calibratable charging device.

[0028] The invention also relates to a method for calibrating a charging device of an electric vehicle. The method ensures high charging efficiency of the electric vehicle and, at the same time, a long service life of the charging socket.

[0029] In the method according to the invention, a plug of a calibration device is inserted into a charging socket of an electric vehicle's charging station, and the calibration device adjusts the temperature of a calibration plate, which is held against the plug and exerts a thermal effect on the charging socket, to a predetermined temperature. In short, the calibration device is essentially connected to the charging socket of the charging station in the same way as a charging plug, which results in particularly simple and readily available handling.

[0030] In preferred embodiments, the method is carried out using a calibration device according to the invention. The calibration device according to the invention is designed and particularly suitable for carrying out the method according to the invention.

[0031] A key advantage of the device according to the invention is that charging problems occurring during the electric vehicle's lifetime can be easily detected, analyzed, and resolved. Consequently, components of the charging system do not need to be replaced on suspicion alone to ensure consistently high charging efficiency over the electric vehicle's long lifespan. This results in greater user satisfaction with the electric vehicle.

[0032] The invention is schematically illustrated in the drawings with reference to one embodiment and is further described with reference to the drawings. It shows: Fig. 1. A schematic block diagram of a charging device for an electric vehicle according to the state of the art; Fig. 2 in a schematic representation a side view of a calibration device according to an embodiment of the invention for the in Fig. 1 charging device shown; Fig. 3 in a schematic representation a front view of the in Fig. 2 calibration device shown; Fig. 4 in a schematic representation a block diagram of the in Fig. 1 shown charging device and the one in the Fig. 2 and Fig. 3 Calibration device shown in a plugged-in state; Fig. 5 in a schematic representation, an enlarged detailed representation of the in Fig. 4 control units shown.

[0033] Fig. Figure 1 shows a schematic block diagram of a charging device 10 for an electric vehicle according to the state of the art. The charging device 10 comprises a charger (On Board Charging, OBC) 20, a charging socket unit 30, which includes a charging socket 31 operationally connected to the charger 20 and into which a charging plug of an external (not shown) charging station can be inserted, and a temperature sensor 32 associated with the charging socket 31. The temperature sensor 32 is designed as an NTC or thermistor.

[0034] The charger 20 also includes a high-voltage unit 21 connected to a traction battery of the electric vehicle and linked to the charging socket 31, and an evaluation unit 22, which is operationally connected to the temperature sensor 32 of the charging socket 31 and the high-voltage unit 21. Furthermore, the charging device 10 includes a bus interface 23 for connecting the charger 20, in particular the evaluation unit 22, to a bus system 40 of the electric vehicle. The bus system also includes a gateway 50.

[0035] Fig. Figure 2 shows a schematic side view of a calibration device 60 according to an embodiment of the invention for the in Fig. 1 Charging device 10 shown. The calibration device 60 is suitable for calibrating the charging device 10 of the electric vehicle and comprises a plug 61 for insertion into the charging socket 31 of the charging device 10 of an electric vehicle. The calibration device 60 further comprises a calibration plate 63 held on the plug 61 and thermally acting on the charging socket 31 when the calibration device 60 is inserted.

[0036] The calibration plate 63 has a rectangular shape and extends transversely to one insertion direction of the plug 61, but is not limited to this shape and direction of extension. Furthermore, the calibration device includes a handle 62, which is arranged opposite the plug 61.

[0037] Fig. Figure 3 shows a schematic front view of the in Fig. 2 Calibration device 60 shown. The calibration plate 30 further comprises a temperature control unit 64 held on the calibration plate 63 and thermally connected to the calibration plate 63, and a control unit 70 operationally connected to the temperature control unit 64. The control unit 70 is configured to automatically and successively set the temperature of the calibration plate 63 to a plurality of predetermined temperatures distributed within a temperature range relevant to the charging socket 31. The temperature control unit 64 is designed as an electrothermal transducer in the form of a Peltier element, but is not limited to this design.

[0038] Furthermore, the calibration device 60 comprises one or more temperature sensors 65 operationally connected to the control unit 70, which are designed to detect the temperature of the charging socket 31 and are arranged on the calibration plate 63. The temperature sensor 65 is designed as an optical sensor.

[0039] Fig. Figure 4 shows a schematic representation of a block diagram of the Fig. 1 shown charging device 10 and the one in the Fig. 2 and Fig. The calibration device 60 shown in Figure 3 is in a plugged-in state. The calibration device 60 further comprises an interface 66 connected to the control unit 70 for connecting the control unit 70 to a diagnostic interface (On-Board Diagnostics, OBD) 80 of the electric vehicle, which is connected to the gateway 50 via the vehicle bus 40. The interface 66 is designed as a private bus and includes a diagnostic connector 67, which is plugged into a diagnostic socket of the diagnostic interface 80, thereby connecting the control unit 70 to the bus system 40 of the electric vehicle and enabling bidirectional data exchange between the control unit 70 and the evaluation unit 22.

[0040] Fig. Figure 5 shows a schematic representation of an enlarged detail view of the in Fig. 4 control unit 70 shown. The control unit 70 is configured to assign a temperature value 72 of the charging socket 31 received from the electric vehicle via the interface 66 to a temperature value 71 of the charging socket 31 measured by at least one temperature sensor 65.

[0041] Furthermore, the control unit 70 is configured to calculate a difference between corresponding temperature values ​​71, 72 and to take a measure dependent on the calculated difference by means of a decision module 73 included by the control unit 70.

[0042] The measure includes indicating that the charging device 10 is calibrated if the calculated difference is less than a predetermined first tolerance value. The measure also includes indicating that the charging device 10 is uncalibratable if the calculated difference is greater than a predetermined second tolerance value that is larger than the first tolerance value.

[0043] Alternatively, the measure includes indicating the calibratability of the charging device 10 and transmitting related received and recorded temperature values ​​71, 72 via the interface 66 and the diagnostic interface 80 to the electric vehicle if the amount of the calculated difference is between the first tolerance value and the second tolerance value.

[0044] The control unit 70 is also configured to transfer calibration data to the electric vehicle. For this purpose, the control unit 70 creates a pair of corresponding temperature values ​​71, 72 for each predetermined temperature, i.e., a calibration table, and transmits each pair, i.e., the calibration table, via interface 66 and diagnostic interface 80 to the evaluation unit 22 to complete the calibration of the charging device 10.

[0045] To calibrate the charging device 10 of the electric vehicle, the plug 61 of the calibration device 60 is inserted into the charging socket 31 of the charging device 10. The calibration device 60 then automatically sets the temperature of the calibration plate 63 to the majority of predetermined temperatures. The temperature sensor 32 of the charging socket unit 30 and the temperature sensor 65 of the calibration device 60 each measure temperature values ​​71, 72 corresponding to the predetermined temperatures.

[0046] The control unit 70 of the calibration device 60 receives the temperature values ​​72 measured by the temperature sensor 32 of the charging socket unit 30, assigns these to the temperature values ​​71 measured by the temperature sensor 65 of the calibration device 60, and compares the received temperature values ​​72 with the temperature values ​​71 measured by the temperature sensor 65 of the calibration device 60. For this purpose, the control unit 70 calculates the differences between the temperature values ​​71 and 72 of each pair of temperature values ​​71 and 72 and takes an action depending on the calculated difference.

[0047] The control unit 70 indicates that the charging device 10 is calibrated if the amount of the calculated difference is less than a predetermined first tolerance value, or indicates that the charging device 10 is not calibrated if the amount of the calculated difference is greater than a predetermined second tolerance value that is different from the first tolerance value.

[0048] Alternatively, the control unit 70 indicates that the charging device 10 is calibrated and transmits the corresponding received and recorded temperature values ​​71, 72 via interface 66 and diagnostic interface 80 to the evaluation unit 22 of the charger 20 of the charging device 10, if the calculated difference between the first and second tolerance values ​​is within the specified range. This completes the calibration of the charging device 10. REFERENCE MARK LIST: 10 Charging equipment 20 chargers 21 High-voltage unit 22 evaluation units 23 Bus interface 30 charging socket unit 31 Charging socket 32 Temperature sensor 40 vehicle buses 50 Gateway 60 Calibration device 61 plugs 62 handle 63 Calibration plate 64 temperature control unit 65 Temperature sensor 66 Interface 67 diagnostic connectors 70 Control unit 71 measured temperature value 72 received temperature value 73 Decision module 80 Diagnostic interface

Claims

[1] Calibration device (60) for a charging device (10) of an electric vehicle, comprising a plug (61) for insertion into a charging socket (31) of a charging device (10) of an electric vehicle and a calibration plate (63) held on the plug (61) and thermally acting on the charging socket (31) when the calibration device (60) is inserted, comprising a temperature control unit (64) held on the calibration plate (63) and thermally connected to the calibration plate (63) and a control unit (70) operationally connected to the temperature control unit (64) and configured to set a temperature of the calibration plate (63) to a predetermined temperature. [2] Calibration device according to claim 1, which is configured to automatically adjust the temperature of the calibration plate (63) successively to a plurality of predetermined temperatures. [3] Calibration device according to one of claims 1 or 2, comprising at least one temperature sensor (65) operationally connected to the control unit (70), which is designed and arranged to detect a temperature of the charging socket (31). [4] Calibration device according to claim 3, which comprises an interface (66) connected to the control unit (70) for connecting the control unit (70) to a diagnostic interface (80) of the electric vehicle. [5] Calibration device according to claim 4, wherein the control unit (70) is configured to assign a temperature value (72) of the charging socket (31) received from the electric vehicle via the interface (66) to a temperature value (71) of the charging socket (31) measured by the at least one temperature sensor (65) and / or wherein the control unit (70) is configured to transmit a pair of corresponding temperature values ​​(71, 72) to the electric vehicle via the interface (66) and the diagnostic interface (80). [6] Calibration device according to one of claims 4 or 5, wherein the control unit (70) is configured to calculate a difference between corresponding temperature values ​​(71, 72) and to take an action dependent on the calculated difference. [7] Calibration device according to claim 6, wherein the measure comprises indicating a calibration of the charging device (10) when an amount of the calculated difference is less than a predetermined first tolerance value, and wherein the measure comprises indicating an uncalibration of the charging device (10) when the amount of the calculated difference is greater than a predetermined second tolerance value that is greater than the first tolerance value. [8] Calibration device according to one of claims 6 or 7, wherein the measure comprises indicating a calibratability of the charging device (10) and / or transmitting related received and recorded temperature values ​​(71, 72) via the interface (66) and the diagnostic interface (80) to the electric vehicle when the amount of the calculated difference is between the first tolerance value and the second tolerance value. [9] Method for calibrating a charging device (10) of an electric vehicle, wherein - a plug (61) of a calibration device (60) is inserted into a charging socket (31) of the charging device (10) of the electric vehicle; and - the calibration device (60) sets the temperature of a calibration plate (63) of the calibration device (60) held on the plug (61) and thermally acting on the charging socket (31) to a predetermined temperature. [10] Method according to claim 9, which is carried out with a calibration device (60) according to any one of claims 1 to 8.

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