Vehicle charging station and method of monitoring connector of vehicle charging station

Abstract

Embodiments of the present disclosure relate to a vehicle charging station and a method of monitoring a connector of a vehicle charging station. The charging station includes a DC power source configured to provide charging power for charging the electric vehicle, a charging cable having a connector for electrically contacting a vehicle entrance of the electric vehicle, a connector holder having a station inlet configured to electrically contact the connector when the connector is inserted into the connector holder, and a contact resistance sensor electrically connected to the station inlet. The resistance sensor is configured to measure a resistance of at least one electrical contact formed between the connector and the station entrance. The charging station also includes a controller. The controller is configured to cause the vehicle charging station to perform a connector monitoring routine. The connector monitoring routine includes causing the DC power source to provide measurement power when the connector is inserted into the connector holder such that a measurement current flows between the connector and the station inlet, and receiving a resistance value from the resistive sensor.

Description

Technical Field

[0001] Aspects of the present invention relate to charging of electric vehicles, particularly vehicle charging stations and connectors for vehicle charging stations. Further aspects relate to monitoring a connector when the connector is inserted into a connector receptacle of a vehicle charging station. Further aspects relate to sensing a resistance and deriving a connector status indicator from the resistance value. Background Art

[0002] Electric vehicles typically include an on-board battery to power the vehicle's powertrain. One method of charging the on-board battery includes connecting the electric vehicle to a charging station by inserting a charging connector into a vehicle inlet; and providing charging power by the charging station. Electric vehicles are typically stationary during charging.

[0003] Recent improvements in charging technology aim to reduce vehicle downtime during charging by increasing the charging power. For example, the Megawatt Charging System, known at the time of filing this disclosure, aims to provide up to 3.75 megawatts (MW) of direct current (DC) charging power. Even higher charging powers are envisioned for some applications. Such charging systems can provide charging power at currents up to 3000 amperes (A) and utilize active cooling of the charging cable and / or connector in some configurations. Advantageously, such charging systems can even charge large electric vehicles with limited downtime.

[0004] To provide a reliable and safe charging connection, the electrical contact formed between the connector and the vehicle inlet should have a stable low resistance. An increase in resistance can lead to local heating of the contact, which can result in a reduction in available charging power, charging interruptions, degradation of the contact, or in rare cases even affect safety. Common causes of increased contact resistance can be wear, deterioration, or damage of the connector. Such degradation can be caused by repeated thermal cycles, mechanical stress during connection and disconnection of the connector, or other types of damage due to incorrect operation of the connector. Thus, operating a vehicle charging station may require periodic inspection and / or replacement of faulty connectors. Regular maintenance can be time-consuming and expensive, while extended service intervals may potentially cause an undesired interruption of the charging service.

[0005] Accordingly, there is a need for an improved vehicle charging system and an improved method of monitoring a connector of a vehicle charging station. The present invention at least partially addresses the above problems. Summary of the Invention

[0006] The invention is set forth in the appended claims.

[0007] According to one aspect, a vehicle charging station is described. The charging station includes: a direct current (DC) power source configured to provide charging power for charging an electric vehicle; a charging cable having a connector for electrically contacting a vehicle inlet of the electric vehicle; a connector holder having a station inlet configured to electrically contact the connector when the connector is inserted into the connector holder; and a contact resistance sensor electrically connected to the station inlet. The resistance sensor is configured to measure the resistance of at least one electrical contact formed between the connector and the station inlet. The charging station further includes a controller. The controller is configured to cause the vehicle charging station to perform a connector monitoring routine. The connector monitoring routine includes causing the DC power source to provide a measurement power when the connector is inserted into the connector holder such that a measurement current flows between the connector and the station inlet, and receiving a resistance value from the resistance sensor. The resistance value indicates the resistance of at least one electrical contact.

[0008] According to one aspect, a method of monitoring a connector of a vehicle charging station is described. The vehicle charging station includes: a direct current (DC) power source configured to provide charging power for charging an electric vehicle; a charging cable having a connector for electrically contacting a vehicle inlet of the electric vehicle; and a connector holder including a station inlet configured to electrically contact the connector when the connector is inserted into the connector holder. The method includes: inserting the connector into the connector holder; selectively enabling the DC power source to provide a measurement power when the connector is inserted into the connector holder; and receiving a resistance value from a resistance sensor. The resistance value indicates the resistance of at least one electrical contact.

[0009] According to one aspect, a vehicle is described. The vehicle can be an electric or hybrid vehicle. The vehicle can be a plug-in vehicle, such as a plug-in hybrid vehicle or a battery electric vehicle. The vehicle typically includes an on-board battery for holding charge and powering a powertrain, such as a propulsion system including one or more electric motors. The vehicle can be a passenger vehicle, such as a sedan, or a commercial vehicle, such as a truck or a van. The vehicle can be a construction and / or industrial vehicle. The vehicle can be an aircraft, such as an airplane, a helicopter, or a variant thereof. The electric vehicle can be a watercraft, such as a boat or a ship. The electric vehicle can be a rail vehicle, such as a train or a locomotive.

[0010] According to one aspect, a vehicle charging station is described. Vehicle charging stations are typically provided as static facilities or within static facilities, such as charging points or electric vehicle supply equipment. The vehicle charging station can be configured for direct current (DC) charging, fast charging, and / or even megawatt charging. For example, the vehicle charging station can be configured to provide a charging power of at least 50 kW, 100 kW, 200 kW, at least 350 kW, at least 500 kW, at least 750 kW, at least 1 MW, at least 2 MW, or even at least 3 MW. For example, the vehicle charging station can be configured as a megawatt charging system (MCS). For example, the vehicle charging station can be configured to provide charging power at a current of at least 500 amperes (A), at least 750 A, at least 1000 A, at least 1500 A, at least 2000 A, or even approximately 3000 A. The charging power can have a voltage of at least 100 volts (V), at least 200 V, at least 500 V, at least 750 V, or even at least 1000 V.

[0011] According to one aspect, the vehicle charging station can include a charging post. The vehicle charging station includes a charging cable and a connector provided at an end of the cable. The connector is configured to be inserted and / or plugged into a vehicle inlet to form a transient electrical connection between the charging station and the vehicle. Optionally, the charging station can include additional components, such as a socket outlet, which is configured to receive a plug of the charging cable provided at an end thereof, the plug being provided at an end other than the connector end. Alternatively, the charging cable can be permanently attached to the charging station.

[0012] According to one aspect, the charging station can include a liquid cooling system. The liquid cooling system can be configured to cool the charging cable, the connector, the station inlet, and / or the vehicle inlet. For example, the charging cable can include a liquid channel for circulating a cooling liquid, such as cooling oil. Advantageously, the cooling system can enable the charging cable and / or the connector to transmit a greater charging current and / or charging power than in a non-liquid-cooled charging station, particularly while providing a relatively light charging cable suitable for manual operation (e.g., manual pick-up, positioning around the vehicle inlet, and / or insertion into the vehicle inlet).

[0013] According to one aspect, a charging station includes a DC power source configured to provide charging power, particularly DC charging power, for charging an electric vehicle (e.g., the battery of an electric vehicle). The charging station can be configured to directly charge the battery of the electric vehicle (e.g., by directly docking with the battery), especially in the case where no vehicle converter is provided between the vehicle inlet and the battery. Advantageously, the electric vehicle can be without or not require charging logic and / or a converter, which can advantageously allow a higher charging rate than a charging station that provides AC charging power. The DC power source can be a converter, such as a converter configured to convert AC grid power into DC charging power.

[0014] According to an embodiment, a connector is described. The connector can be a megawatt charging system connector, such as that described in the "CharIN Whitepaper Megawatt Charging System (MCS), Recommendations and requirements for MCS related standards bodies and solution suppliers, Version 1.0, 2022-11-25", and / or according to the standard IEC 61851 known at the time of filing this disclosure. According to an embodiment, the connector can be a connector described in one or more of the standards ISO 5474-3, IEC TS 63379, IEC 61851-23-3, ISO 15118, and / or J3271-1 to -5 known at the time of filing this disclosure.

[0015] Advantageously, the charging station is configured to obtain a resistance value indicative of the resistance of an electrical contact formed between the connector and the station inlet. Based on the resistance value, a connector status indicator can be derived in a simple, efficient, or even automatic manner. Based on the connector status indicator, the connector status can be monitored with less effort, and monitoring and / or maintenance can be performed more effectively. Advantageously, the systems and methods described herein can increase the safety and uptime of the charging station, and / or reduce maintenance and operation costs.

[0016] Other advantages, features, aspects, and details that can be combined with the embodiments described herein are apparent from the dependent claims, the specification, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Details will be described below with reference to the drawings, where

[0018] Figure 1 a schematic diagram of a charging station according to an embodiment is shown;

[0019] Figure 2shows a schematic circuit diagram of a resistance measurement circuit in a charging station according to an embodiment; and

[0020] Figure 3 shows a method for monitoring a connector of a vehicle charging station according to an embodiment. DETAILED DESCRIPTION

[0021] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the figures. Each embodiment is provided by way of explanation and not limitation. For example, features shown or described as part of one embodiment can be used on or combined with any other embodiment to yield yet another embodiment. The present invention is intended to embrace these modifications and variations.

[0022] In the following description of the drawings, like reference numerals denote like or similar components. Generally, only the differences with respect to each embodiment are described. Unless otherwise stated, the description of a part or aspect in one embodiment also applies to the corresponding part or aspect in another embodiment. Some aspects of the present disclosure may be described with reference to a device, and are equally applicable to the methods described herein. Similarly, aspects described with reference to a method apply to a device, such as a controller of the device and / or the use of the device.

[0023] Now refer to Figure 1 , which shows a charging station 100. The charging cable 110 is shown in a charging configuration 110' indicated by a dashed line in Figure 1 and in a standby configuration of the charging cable 110 indicated by a solid line. The charging cable 110 has a connector 112 provided at a first end of the charging cable 110. The connector 112 can be inserted into a vehicle inlet 122 of an electric vehicle 120, particularly for charging the electric vehicle 120. Thus, the connector 112 is configured to form an electrical connection with the vehicle inlet 122, particularly for charging the electric vehicle 120 and / or the battery of the electric vehicle. Figure 1 shows the charging cable in the charging configuration 110' with the connector inserted into the electric vehicle.

[0024] The charging station 100 includes a direct current (DC) power supply 140. According to an embodiment, the power supply 140 can be a converter configured to convert input power (such as grid power received from the grid via an electrical connection 142) into charging power. Similarly, other input power sources known at the time of filing the present disclosure can be used.

[0025] The charging power can be provided to the electric vehicle as DC charging power. As Figure 1As shown, the power source 140 can be electrically connected to the plug 114, and the plug 114 forms the connection between the charging station column 102 and the charging cable 110. Similarly, the power source 140 can be directly connected to the charging cable.

[0026] According to an embodiment, the charging power can be provided to the electric vehicle 120 via the electrical contact formed between the connector 112 and the vehicle inlet 122. For example, the contact can include a -DC contact, a +DC contact, and an optional protective earth (PE) contact. Thus, the charging power can be a DC signal.

[0027] According to an embodiment, the connector 112 can further include communication and / or detection pins or pin receptacles configured to form communication and / or detection contacts between the charging station 100 and the vehicle inlet 122 of the electric vehicle 120. For example, the connector 112 can include four communication pins for forming an interface with the electric vehicle 120 according to electric vehicle charging and / or communication standards such as ISO 15118, particularly ISO 15118-20, which were known at the time of filing this disclosure. The power source 140 can be configured to adjust the charging power according to the communication between the electric vehicle 120 and the charging station, such as the controller 160 of the charging station, to, for example, set and / or limit the power of the charging power or start / stop the charging power according to the signal received via the interface.

[0028] When not connected to the electric vehicle 120, the connector 112 is inserted into the connector holder 130, as Figure 1 shown, for the charging cable 110. The connector 112 inserted into the connector holder 130 can be a standby configuration of the charging station 100, such as the typical configuration of the charging station 100 between charging cycles. The connector holder 130 can be provided, for example, integrally provided and / or integrated in the charging station 100, such as the body of the charging station 100, such as the column 102 of the charging station.

[0029] The connector holder 130 includes a station inlet 132. The station inlet 132 can be similar and / or identical to the vehicle inlet 122. In particular, the station inlet 132 can include some or all of the contacts of the vehicle inlet 122. Thus, the station inlet 132 is configured to electrically contact the connector 112 when the connector 112 is inserted into the connector holder 130.

[0030] The charging station 100 includes a resistance sensor 150. Refer to Figure 2The features of the resistance sensor 150 according to an embodiment are described in further detail. The resistance sensor 150 is electrically connected to the station inlet 132. The resistance sensor 150 is configured to measure the resistance of one or more contacts formed between the connector 112 and the station inlet, particularly when the connector 112 is inserted into the connector holder 130. For example, when the connector 112 is inserted into the connector holder 130, electrical contacts can be formed between the +DC pin and the pin socket of the connector 112, the -DC pin and the pin socket, and / or the PE pin and the pin socket and the station inlet 132. Generally, when charging an electric vehicle, the contact resistance of the electrical contact formed between the connector 112 and the vehicle inlet 122 should be low to provide a safe and reliable electrical connection and minimize resistive losses. A deteriorated and / or damaged connector 112 can have one or more pins and / or pin sockets that have and / or result in an increased contact resistance. Advantageously, by measuring the resistance when the connector 112 is inserted into the connector holder 130, the deterioration of the connector can be monitored, identified, and / or quantified based on the resistance measured by the resistance sensor 150.

[0031] According to an embodiment, the charging station 100 includes a controller 160. As Figure 1 shown, the controller 160 can be communicatively connected to the DC power supply 140 and / or the resistance sensor 150, particularly for providing control instructions to the power supply 140 and / or for receiving measurement values from the resistance sensor 150. Additionally, the controller can be configured to control additional operations of the charging station, such as operations associated with charging the electric vehicle 120. The controller 160 can include a processor and a memory including instructions that, when executed by the processor, cause the controller 160 to operate in accordance with the aspects and / or embodiments described herein. Specifically, these instructions can cause the controller 160 to operate the charging station 100 according to the methods described herein (such as the method 300 described in Figure 3 reference).

[0032] The controller 160 is configured to cause the vehicle charging station to execute a connector monitoring routine. The connector monitoring routine can be executed when the connector 112 is inserted into the connector holder 130. Thus, the controller 160 can be configured to detect whether the connector 112 is inserted into the connector holder 130.

[0033] The connector monitoring routine includes providing measurement power by the DC power supply 140 such that a measurement current flows between the connector 112 and the station inlet 132. Thus, the controller 160 can be configured to cause the DC power supply 140 to provide measurement power.

[0034] The connector monitoring routine further includes receiving a resistance value from a resistance sensor 150, particularly by a controller 160. The resistance value indicates the resistance of at least one electrical contact, particularly the resistance of one or more electrical contacts formed between the connector 112 and the station inlet 132. For example, for one or more of the -DC, +DC, and / or PE contacts, and / or even for communication or detection contacts, the resistance value may include one or more resistances, such as expressed as ohmic resistance or conductance, or any other unit of measurement.

[0035] Now referring to Figure 2 , a schematic circuit diagram of a resistance measurement circuit 200 in a charging station (such as the charging station 100) according to an embodiment is shown. The resistance measurement circuit 200 may be an implementation of a four-terminal sensing application. The measurement circuit 200 may be formed between the power supply 140, the charging cable 110, the connector 112, the station inlet 132, and / or the resistance sensor 150. Figure 2 It can be considered as an equivalent circuit diagram. Figure 2 The circuit shown can be adapted to measure the resistance of a single contact. Similarly, Figure 2 the circuit shown can be adapted to measure the resistance of multiple contacts (such as two or more contacts). For example, when charging power is transmitted through one of the +DC, -DC, and / or PE contacts, a circuit can be formed. Similarly, when charging power is transmitted through two or more of the +DC, -DC, and / or PE contacts, a circuit can be formed, in which case the resistance may indicate the combined resistance of two or more contacts. Thus, the charging station 100 may include one, two, or several measurement circuits 200.

[0036] The resistor 230 indicates the resistance of the charging cable 110 and may further indicate the inherent resistance of other components of the charging station, such as the internal resistance of the power supply 140 and / or the internal electrical connections. The resistor 232 indicates the resistance of the electrical connection between the connector 112 and the station inlet 132. When the connector 112 is inserted into the station inlet 132, a closed loop is formed.

[0037] In the connector monitoring routine, the power supply 140 provides measurement power. The measurement power may be provided for a limited duration, such as about 1 second (s), about 2 s, about 5 s, or about 10 s. The current of the measurement power can be measured by a current sensor 210. The current sensor 210 may be integrated into the power supply 140, may be included in the resistance sensor 150, or may be a separate component of the charging station 100. In some embodiments, the current sensor 210 may be optional, for example, in the case where the power supply 140 is configured as a constant current source providing a known current.

[0038] According to an embodiment, the power supply 140 may be configured for a constant current source, a constant voltage source, and / or a constant power supply while providing measured power.

[0039] The resistor 232 indicates the resistance of the electrical contact formed between the connector 112 and the station inlet 132. For example, in an equivalent circuit diagram, the node 212 may indicate the connector side of the electrical contact, and the electrical contact is represented by the resistor 232. A voltage sensor 220 is provided such that one node of the voltage sensor is connected to the connector side of the contact, and the other node of the voltage sensor is connected to the station inlet side of the contact. Although Figure 2 it is shown that the node 212 is provided between the resistors 230, 232, the connector side node may be provided at other points within the measurement circuit 200. For example, in some embodiments, the voltage sensor 220 may be substantially in parallel with the power supply. In some embodiments, the electrical connection between the voltage sensor 220 and the connector side of the contact may be formed via one or more of the communication and / or detection contacts. The resistor 230 may represent the resistance of the charging cable, and the resistor 232 may represent the resistance of the electrical contact. A voltage drop measurement may be performed on the resistor 232 or the combination of the resistor 230 and the resistor 232.

[0040] As Figure 2 shown, the voltage sensor 220 is configured to sense the voltage drop caused by the resistance of the electrical contact. Therefore, based on, for example, the current sensed by the current sensor 210, the voltage drop sensed by the voltage sensor 220, and / or optionally the known or estimated resistor 230, the resistance value of the connector can be derived by applying Ohm's law.

[0041] Although in Figure 2 the voltage sensor 220 and the current sensor 210 are shown as separate entities, the voltage sensor 220 and / or the current sensor 210 may be included in the resistance sensor 150. Similarly, the resistance sensor may be electrically connected and / or communicatively connected to one or more independently provided current sensors 210 and / or voltage sensors 220 of the charging station 100, and use the provided sensor values to determine the resistance value. In some embodiments, the voltage sensor 220 may be provided within the charging station 100. In some embodiments, the voltage sensor 220 may be provided within the connector 112, for example, integrated into the connector 112.

[0042] According to an embodiment, the measurement power has a measurement current and a measurement voltage. The measurement current is advantageously selected such that the expected resistance of the electrical connection causes a measurable voltage drop across the resistor 232. For example, the measurement current can be at least 50 A, at least 75 A, at least 100 A, at least 200 A, or even at least 500 A. It should be understood that since the resistance measurement circuit 200 typically only has a small total resistance, the measurement power can have a lower voltage than the charging power, such as less than 200 V, less than 100 V, less than 50 V, or even less than 20 V. Advantageously, the power consumption for performing the connector monitoring routine can be low.

[0043] According to an embodiment, the controller 160 is configured to derive a connector status indicator from the resistance value. The connector status indicator can indicate the connector condition of the connector 112. For example, for a connector 112 with an expected and / or nominal resistance value, a connector status indicator indicating the nominal connector condition can be derived. For example, for a connector 112 with a resistance value higher than the expected and / or nominal resistance value of one or more electrical contacts, a connector status indicator indicating a faulty and / or deteriorated connector condition can be derived.

[0044] According to an embodiment, the charging station 100, in particular the controller 160, can be configured to derive device status information from the resistance value. The device status information can include the connector status indicator.

[0045] According to an embodiment, the resistance value and / or the connector status indicator can be used by the charging station 100 or an additional system to control the operation of the charging station. For example but not limited to, in the case where the controller 160 determines that the resistance value is outside a predetermined nominal and / or desired range, the controller 160 can prevent the charging station 100 from performing further charging operations until the connector 112 is repaired or replaced.

[0046] The charging station 100, in particular the controller 160, can include a network interface for connecting the charging station 100 to a data network (in particular a global data network). The data network can be a TCP / IP network, such as the Internet. The controller 160 can be operatively connected to the network interface for executing commands received from the data network. The commands can include control commands for controlling the charging station 100 to perform tasks, such as performing the connector monitoring routine and / or sending device status information to a receiver via the data network. In this case, the controller 160 is adapted to execute tasks in response to the control commands. The commands can include status requests. In response to a status request, or without a previous status request, the controller 160 can be adapted to send status information to the network interface, and then the network interface is adapted to send the status information through the network. The commands can include update commands, and the update commands include update data. In this case, the controller 160 is adapted to initiate an update in response to the update command and use the update data.

[0047] The data network can be an Ethernet using TCP / IP, such as a LAN, WAN, or the Internet. The data network can include a distributed storage unit such as a cloud. Depending on the application, the cloud can be in the form of a public, private, hybrid, or community cloud.

[0048] In Figure 1 the example shown, the network interface is a wireless interface 170 for connecting the charging station 100 to a wireless network (such as a local WLAN) or a mobile data network (such as an LTE or 5G network). Similarly, the network interface can be connected to a wire-based network, such as a (local) Ethernet or a wide area network.

[0049] According to an embodiment, a remote system is described. The charging station 100 can be communicatively connected to the remote system via a network interface, and the remote system is configured to receive data from the charging station 100, such as data including device status information and / or connector status indicators. The remote system can be configured to generate a warning signal based on the connector status indicator, particularly in the case where the connector status indicator indicates connector deterioration. The warning signal can be, for example, an automated message, such as an email message, a service schedule entry, an audio and / or visual indicator, etc. Advantageously, a number of charging stations can be connected to the remote system, which can allow operators of a number of charging stations to easily and remotely monitor the charging stations and perform targeted repairs and / or maintenance.

[0050] According to an embodiment, the controller 160 is configured to automatically execute a connector monitoring routine. In some embodiments, the connector monitoring routine can be automatically executed each time the connector 112 is inserted into the connector holder 130.

[0051] In some preferred embodiments, the monitoring routine can be executed at a predetermined interval. For example, the monitoring routine can be executed after exceeding a predetermined monitoring time interval. For example, the controller can be configured to execute the monitoring routine in the case of exceeding a predetermined time span (such as a time span of 6 hours, 12 hours, 1 day, 2 days, or 5 days) after the last execution of the monitoring routine.

[0052] For example, the monitoring routine can be executed after exceeding a predetermined number of vehicle charging operations. For example, the controller can be configured to execute the monitoring routine in the case of exceeding a predefined number of charging operations (such as 10 charging operations, 20 charging operations, 50 charging operations, 100 charging operations, or 200 charging operations) after the last execution of the monitoring routine.

[0053] For example, a monitoring routine may be performed after a predetermined number of connection events. A connection event may be defined as removing the connector 112 from the connector holder 130, inserting the connector 112 into the vehicle inlet 122, and / or reinserting the connector 112 into the connector holder. A connection event does not require a charging operation to be performed. For example, the controller may be configured to perform the monitoring routine when a predefined number of connection events (such as 10 connection events, 20 connection events, 50 connection events, 100 connection events, 200 connection events, 500 connection events, or 1000 connection events) have occurred after the last execution of the monitoring routine.

[0054] For example, the monitoring routine may be performed in response to receiving an instruction, particularly via a network interface, such as receiving an instruction from a remote system to perform connector monitoring.

[0055] According to an embodiment, the charging station 100 includes one or more temperature sensors. In particular, the connector 112 may include a connector temperature sensor, for example, for measuring the temperature of the connector 112 during charging, for example, for overheat protection during charging. Additionally, the connector holder 130 and / or the station inlet may include an inlet temperature sensor. The (one or more) temperature sensors may be communicatively connected to the controller 160. The controller 160 may be configured to receive temperature values from the one or more temperature sensors and evaluate the temperature values when performing the connector monitoring routine. For example, the controller 160 may be configured to ascertain that the temperature sensed by the connector temperature sensor is within a predetermined, allowable temperature range, such as between -40°C and 90°C, between 0°C and 70°C, or more specifically, 50°C or lower, before performing the monitoring routine. This can advantageously prevent measurements from being taken at inappropriate ambient temperatures and / or when the connector is at risk of overheating. Furthermore, the controller 160 may be configured to determine that the temperatures sensed by the connector temperature sensor and the inlet temperature sensor differ by no more than, for example, ±10°C or greater, more specifically, ±5°C or greater, before performing the monitoring routine. According to an embodiment, the controller 160 may be configured to correlate and / or correct resistance values based on the temperature values. Advantageously, the one or more temperature sensors may allow the controller to more reliably and / or precisely determine the resistance values. For example, the temperature values may be used to determine a more precise value of the (expected) resistance 230 and / or 232, which may be temperature-dependent.

[0056] Now referring to Figure 3 , a method 300 for monitoring a connector of a vehicle charging station is described. The charging station may be as referred to in Figure 1 and Figure 2The described charging station 100. The method can be performed at least in part by the charging station 100, specifically by the resistance sensor 150 and / or the controller 160 of the charging station 100. According to an embodiment, the method 300 can describe the use of the charging station 100.

[0057] The charging station used in the method 300 includes: a DC power supply configured to provide charging power for charging an electric vehicle; a charging cable including a connector for electrically contacting a vehicle inlet of the electric vehicle; and a connector holder including a contact configured to electrically contact the connector when the connector is inserted into the connector holder.

[0058] The method 300 includes inserting 310 the connector into the connector holder. The insertion 310 can be performed by a user of the charging station, for example, after the charging of the electric vehicle is completed. The insertion 310 can include guiding the user of the vehicle charging station to insert the connector, for example, to complete a charging cycle. Inserting the connector can include connecting the connector to the station inlet. The insertion 310 can establish at least one electrical connection between the connector and the station inlet of the charging station, for example, by inserting at least one pin into a corresponding receptacle and / or socket.

[0059] The method 300 can optionally include an operation 320. The operation 320 can be a temperature check. In the operation 320, the connector temperature is sensed, for example, by a temperature sensor such as a connector temperature sensor and / or a station inlet temperature sensor. The operation 320 can include determining whether the connector temperature is outside a predetermined temperature range. The predetermined temperature range can be defined, for example, as between -40°C and 90°C, between 0°C and 70°C, or more specifically, a temperature of 50°C or lower. The operation 320 can also include determining whether the connector temperature differs from the inlet temperature by ±10°C or more, and / or ±5°C or more. In the case where it is determined that the connector temperature is outside the predetermined temperature range, the operation 320 can include delaying the further execution of the method 300, specifically delaying the enabling of the power supply, until the temperature is within the predetermined temperature range.

[0060] The method 300 includes selectively enabling 330 the DC power supply to provide a measurement power when the connector is inserted into the connector holder. Providing the measurement power can cause current to flow through at least one electrical contact formed between the connector and the station inlet. The resistance of at least one electrical contact can affect the current and / or the measurement power. For example, but not limited to, compared with a lower resistance, a higher resistance can reduce the current of the measurement power with a constant voltage.

[0061] Method 300 includes receiving 340 a resistance value from a resistance sensor, the resistance value indicating the resistance of at least one electrical contact. Thus, method 300 may include measuring the resistance of at least one electrical contact. Measuring the resistance may include providing a measurement power at a known or measured current and monitoring the voltage drop across the electrical contact, the voltage drop indicating the resistance of the electrical contact. Additionally or alternatively, the resistance of the electrical contact may be determined by determining the resistance of a circuit including the electrical contact (such as Figure 2 the circuit shown) and subtracting a known or estimated resistance (such as resistance 230) from the resistance of the circuit. Determining the resistance of the circuit may include determining the current generated by the voltage of the measurement power and applying Ohm's law.

[0062] Method 300 may optionally include deriving 350 a connector status indicator from the resistance value. The connector status indicator indicates the connector condition. For example, the connector status indicator may indicate that the connector condition is acceptable based on a nominal and / or desired resistance value. For example, the connector status indicator may indicate that the connector condition is faulty based on a resistance value higher than expected and / or nominal. Advantageously, additional increments may be used for the connector status indicator. For example, the resistance value may be higher than expected but still within the allowable and / or nominal range, and the connector status indicator derived from the resistance value may indicate connector deterioration, which may prompt the operator to schedule future connector maintenance and / or replacement.

[0063] Method 300 may include: after receiving 340 the resistance value and / or after deriving 350 the connector status indicator, transmitting a data packet including the connector status indicator and / or the resistance value to a remote system. For example, the connector status indicator may be transmitted to the remote system. The connector status indicator may be sent at regular intervals, such as daily and / or after each connector monitoring routine. Alternatively, the connector status indicator may be transmitted in the case where the connector status indicator indicates a non-nominal connector status. The remote system may be a computer (such as a server or a cloud-based system) and / or a (centralized) monitoring system configured for multiple charging stations. In the case where the connector status indicator indicates connector deterioration that may include a connector fault, a warning signal indicating the connector deterioration may be generated, for example, by the remote system and / or the charging station. The warning signal may be communicated to maintenance personnel, for example, in the form of an electronic message, an audiovisual signal, an alarm, and / or an entry in a maintenance schedule. Based on the warning signal, maintenance may be performed and / or scheduled. Advantageously, the status of multiple charging stations may be monitored without maintenance personnel performing on-site tests, thereby improving monitoring efficiency.

[0064] According to an embodiment, method 300 may be a connector monitoring routine. In some embodiments, method 300 may include repeatedly executing 360 the connector monitoring routine. In particular, method 300 may include executing a series of connector monitoring routines over a predetermined time frame. For example, the predetermined time frame may be several days, such as 5 days, 10 days, 20 days, 30 days, or more than 30 days. The connector monitoring routine may be executed, for example, after exceeding a predetermined monitoring time interval, exceeding a predetermined number of vehicle charging operations, exceeding a predetermined number of connection events, and / or receiving an instruction to perform connector monitoring according to the connector monitoring routine.

[0065] According to an embodiment, multiple connector monitoring routines may be executed within a predetermined time frame. The resistance values may be stored in a memory of a controller, such as controller 160 of charging station 100, for example, or even stored remotely.

[0066] According to an embodiment, deriving 350 the connector status indicator may include repeatedly executing 360 a series of connector monitoring routines over a predefined time frame, and deriving the connector status indicator from a series of resistance values received in the series of connector monitoring routines. For example, deriving 350 the connector status indicator may include evaluating some or all of the resistance values recorded within a predetermined time frame. The resistance values may be a time series. The evaluation may include applying statistical methods, such as trend analysis, extrapolation, or other pattern detection methods. Advantageously, deriving the connector status indicator from a series of resistance values may allow for a more precise detection of potential future connector failures. For example, the resistance value derived from a single connector monitoring routine may indicate that the connector status is nominal, while evaluating the series of resistance values may show that the connector is deteriorating at a determinable or determined rate and / or will likely enter a failure state within a determinable time span. Additionally or alternatively, the time series may be used to more easily detect sudden changes in contact resistance, for example, by averaging earlier values of the time series to determine a baseline or base value for each contact, which may advantageously be used to account for small differences between contacts due to, for example, manufacturing variations, thereby reducing the likelihood of false positive results.

Claims

1. A vehicle charging station, comprising: A DC power supply configured to provide a charging power for charging an electric vehicle; A charging cable including a connector for making electrical contact with a vehicle inlet of the electric vehicle; A connector holder including a station inlet configured to make electrical contact with the connector when the connector is inserted into the connector holder; A contact resistance sensor electrically connected to the station inlet, the resistance sensor configured to measure a resistance of at least one electrical contact formed between the connector and the station inlet; And A controller, wherein the controller is configured to cause the vehicle charging station to execute a connector monitoring routine, the connector monitoring routine including: Causing the DC power supply to provide a measurement power when the connector is inserted into the connector holder such that a measurement current flows between the connector and the station inlet; And Receiving a resistance value from the resistance sensor, the resistance value indicating the resistance of the at least one electrical contact.

2. The vehicle charging station according to claim 1, wherein the DC power supply is configured to provide a charging power of at least 350 kW.

3. The vehicle charging station according to claim 1, further comprising a liquid cooling system for liquid cooling at least one selected from the group consisting of the charging cable, the connector, and the station inlet.

4. The vehicle charging station according to claim 1, wherein the measurement current is at least 100 A.

5. The vehicle charging station according to claim 1, wherein the controller is further configured to: Derive a connector status indicator from the resistance value, the connector status indicator indicating the condition of the connector.

6. The vehicle charging station according to any one of the preceding claims, the charging station being configured to derive device status information from the resistance value, The charging station further comprising a network interface for connecting the controller to a data network, wherein the controller is operably connected to the network interface for sending the device status information to the data network.

7. The vehicle charging station according to claim 1, wherein the controller is configured to automatically execute the connector monitoring routine in response to at least one selected from the group consisting of: - Exceeding a predetermined monitoring time interval; - Exceeding a predetermined number of vehicle charging operations; - Exceeding a predetermined number of connection events; - Receiving an instruction to perform the connector monitoring.

8. The vehicle charging station according to claim 1, further comprising a temperature sensor for sensing the temperature of the connector.

9. A method for monitoring a connector of a vehicle charging station, the vehicle charging station comprising: A DC power supply configured to provide a charging power for charging an electric vehicle; A charging cable including a connector for making electrical contact with a vehicle inlet of the electric vehicle; A connector holder, including a station inlet configured to electrically contact the connector when the connector is inserted into the connector holder; the method includes: Inserting the connector into the connector holder; Selectively enabling the DC power supply to provide measurement power when the connector is inserted into the connector holder; and Receiving a resistance value from the resistance sensor, the resistance value indicating the resistance of the at least one electrical contact.

10. The method according to claim 9, further comprising: Deriving a connector status indicator from the resistance value, the connector status indicator indicating the condition of the connector.

11. The method according to claim 10, further comprising: Transmitting the connector status indicator to a remote system and generating a warning signal indicating the deterioration of the connector under the condition that the connector status indicator indicates the deterioration of the connector.

12. The method according to any one of claims 9 to 11, further comprising: Sensing the connector temperature before providing the measurement power and delaying the provision of the measurement power until the temperature is within the predetermined temperature range under the condition that the connector temperature is outside the predetermined temperature range.

13. The method according to claim 12, wherein the predetermined temperature range defines a temperature at or below 50 °C.

14. The method according to claim 10, wherein deriving the connector status indicator comprises: Execute a series of connector monitoring routines within a predetermined time frame and derive the connector status indicator from a series of resistance values received in the series of connector monitoring routines.

15. The method according to claim 9 or 10, wherein the method is automatically executed by the vehicle charging station after a predetermined number of vehicle charging operations.

16. The method according to claim 9 or 10, wherein the method is automatically executed by the vehicle charging station after a predetermined number of connection events.

17. A vehicle charging station, comprising: A DC power supply configured to provide charging power for charging an electric vehicle; A charging cable including a connector for electrically contacting the vehicle inlet of the electric vehicle; A connector holder including a station inlet configured to electrically contact the connector when the connector is inserted into the connector holder; A contact resistance sensor electrically connected to the station inlet, the resistance sensor being configured to measure the resistance of at least one electrical contact formed between the connector and the station inlet; And A controller, wherein the controller is configured to cause the vehicle charging station to execute a connector monitoring routine, the connector monitoring routine including: Causing the DC power supply to provide measurement power when the connector is inserted into the connector holder so that a measurement current flows between the connector and the station inlet; Receiving a resistance value from the resistance sensor, the resistance value indicating the resistance of the at least one electrical contact; Deriving a connector status indicator from the resistance value, the connector status indicator indicating the condition of the connector; and Transmit the connector status indicator to a remote system and, under conditions where the connector status indicator indicates connector deterioration, generate a warning signal that indicates the connector deterioration; The charging station further includes: A liquid cooling system configured to liquid-cool at least one selected from the group consisting of the charging cable, the connector, and the station inlet; and A temperature sensor configured to sense the temperature of the connector.

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