Charging station for simultaneously charging a plurality of electrically driven vehicles

Abstract

The invention relates to a charging station (10) for simultaneously charging a plurality of electrically driven vehicles (14), comprising: a DC voltage intermediate circuit (22); a plurality of basic converters (1a-1h) which are connected to the DC voltage intermediate circuit (22) and each of which is switchably connected to a charging connection (4a-4h) via a connection line (24a-24h); a boost converter (2a, 2b) which is connected to the DC voltage intermediate circuit (22) and which, during an operation of the charging station (10), can be connected to at least one of the charging connections (4a-4h) via a booster line (26a, 26b) and a respective connection node (18a-18h) on different connection lines of the connection lines (24a-24h); a vehicle communication device (31) for communicating charging information between the charging station (10) and the vehicles (14); and a control unit (27) for controlling the basic converters (1a-1h) and the boost converter (2a, 2b) according to a desired power transfer, each connection line (24a-24h) having a safety-related switch (6a-6h) between the charging connection (4a-4h) and the connection node (18a-18h).

Description

[0001] Charging station for simultaneous charging of several electrically powered vehicles

[0002] The invention relates to a charging station for the simultaneous charging of several electrically powered vehicles, a method for charging several electrically powered vehicles with such a charging station, a computer program product for carrying out such a method and a corresponding computer-readable data carrier.

[0003] The demand for charging stations is currently increasing rapidly due to the electrification of the transport sector. Charging stations must meet a variety of requirements. Charging stations transfer electrical energy from a power grid to the vehicle. Some charging stations communicate with the connected vehicles to detect the battery charge level and adjust the charging process accordingly. This communication ensures optimal charging, taking into account the specific requirements of each vehicle. It must be ensured that each vehicle is charged at an optimal speed without exceeding the total capacity of the charging station or the power grid supplying the charging station. For this purpose, the charging current can be regulated, also to avoid overloading the power grid and to efficiently distribute the available power among the connected vehicles.This also includes managing peak load times and distributing energy based on the priority or urgency of the charging need. Safety during the charging process must be ensured at all times. Errors such as overheating, electrical malfunctions, or physical damage must be eliminated as far as possible by design, and detected if a fault occurs.

[0004] However, the charging process of electric vehicles under real-world conditions is subject to various constraints. The maximum charging capacity of electric vehicles is only achieved under ideal conditions and requires a low battery state of charge (SoC). Furthermore, the battery must be preconditioned for fast charging, which is only possible in appropriately equipped vehicles. The maximum charging capacity is therefore rarely reached. Furthermore, maximum charging capacities vary greatly depending on the vehicle type.

[0005] A relevant charging parameter is the time required to charge the vehicle's range (in km). A charging window between 10 and 80% SoC is often considered, as many experts and users consider this to be the optimal charging process. Manufacturers usually also specify charging times for this range.

[0006] A comparison of different electric vehicles has shown that the maximum charging power specified by the manufacturers is only achieved for a few minutes during the charging process - and the vehicle-specific performance varies greatly (Daake, C., Cammerer, M. (2023) "P3 Charging Index: Comparison of the Fast Charging Capability of Various Battery Electric Vehicles", 23rd International Stuttgart Symposium. ISSYM 2023. Proceedings. Springer Vieweg, Wiesbaden).

[0007] Conventional charging stations use electrical converters to provide the required charging power. In some charging stations, each converter is coupled to a connection device. In order to cover the power requirements of each vehicle, the converters are often designed for the maximum power that can be provided at the respective connection device. Such converters must therefore cover a wide power range. However, in many applications, the maximum power range is used for very short periods of time for the reasons mentioned above. With such a one-to-one coupling between converter and connection device, the exclusive use of more effectively usable converters with a lower power range is not possible due to the power range desired for rapid vehicle charging.Converters with a high power output, on the other hand, have a significant reactive capacitance over the entire charging cycle, which reduces the efficiency of the overall system. Converters with a lower power output result in a lower maximum charging power, which leads to longer charging times and thus lower capacity for the same number of charging ports. It is fundamentally possible that more than one converter could provide the required power at a charging port. This could result in a high power transfer within a short period of time. However, since charging stations generally have the potential to transfer high power in the range of kW or MW within a short period of time, stringent safety requirements must be met to prevent the risk of faulty switching and the resulting short circuit.

[0008] For example, patent application US 2021 / 0129701 A1 (US 701 ) discloses a charging station for electric vehicles. The charging station comprises several terminals arranged side by side and adjacent to parking spaces. The terminals include a supply terminal, charging terminals, and auxiliary power terminals. The supply terminal is connected to a utility and distributes power to the other terminals. The charging terminals are used to charge the electric vehicles, and the auxiliary power terminals can supply additional power. The terminals are connected to each other via structural connecting means such as connectors to form a modular structure.

[0009] However, such a simple coupling of multiple converters to transfer additional power when needed results in very complex safety systems even with just a few converters. High complexity, due to the associated risk of failure of individual components, is detrimental to the safety of the charging station and leads to more frequent repairs and thus reduced operating time. This reduced operating time reduces the overall efficiency of the charging station. Safety aspects are particularly relevant because non-technical personnel must be able to use the charging station safely, and some charging stations are intended to be installed in areas where they are not or only partially protected from the elements.

[0010] It is therefore the object of the invention to provide a charging station for the simultaneous, rapid charging of several electrically powered vehicles, which can be operated more efficiently than existing charging stations.

[0011] It is a further object of the invention to provide a charging station that meets the safety requirements for charging stations. This object is achieved by a charging station having the features of claim 1 and a method for charging one or more electrically powered vehicles according to claim 17. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the charging station according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0012] According to a first aspect, the invention provides a charging station for simultaneously charging a plurality of electrically powered vehicles, comprising: a DC intermediate circuit, a plurality of base converters connected to the DC intermediate circuit, each of which is switchably connected to a charging connection via a connecting line, a booster converter connected to the DC intermediate circuit, which can be connected to at least one of the charging connections during operation of the charging station via a booster line and a respective connection node to various of the connecting lines, a vehicle communication device for communicating charging information between the charging station (10) and the vehicles (14), a control unit for controlling the base converters and the booster converter according to a desired power transfer; wherein each connecting line has a safety-related switch between the charging connection and the connection node.

[0013] The invention is based on the surprising discovery that the inventive combination of base converters and booster converters allows the base converters to be designed with relatively lower capacity, with the booster converter only being switched on when a charging connection is available to absorb the additional power provided by the booster converter. In this way, the base converters can be operated more efficiently over longer charging periods, and the booster converter can only be switched on in cases and at charging connections with increased capacity requirements. This increases the service life and operational reliability of the converters and thus of the charging station, and extends repair intervals. Overall, this leads to more efficient operation of the charging station while simultaneously achieving a high level of operational reliability.

[0014] A charging station is defined as a device for simultaneously charging multiple electrically powered vehicles. In particular, the charging station is designed to charge vehicles at their maximum permissible capacity.

[0015] Electrically powered vehicles can, in particular, be electrically powered road vehicles, particularly preferably cars and / or trucks. The advantages of the invention are particularly significant when the charging station is configured to charge cars and trucks simultaneously, since these vehicles exhibit particularly large differences in their maximum charging power.

[0016] A DC link is a DC voltage circuit designed to transmit electrical power to and / or between different charging station units. The voltage provided by the DC link should be as constant as possible, even under load, and can be, for example, 750V. The DC link can also have more than two voltage levels, thus creating a multi-level topology. Instead of a DC link, a DC link can also be used as an alternative or in addition to a DC link.

[0017] A basic converter is an electrical circuit that converts a DC voltage supplied at the input into a DC voltage with a higher, lower, or inverted voltage level and is designed to transfer a base voltage level and / or a base power level via its output. In addition to the application of converting a DC voltage into another DC voltage, the basic converter can also be designed to convert an AC voltage into a DC voltage, an AC voltage into another AC voltage, or a DC voltage into an AC voltage. The conversion takes place using a power electronic circuit and one or more energy storage devices. A base supply power can, for example, be between 20 kW and 300 kW. Basic converters are generally designed to convert electrical power bidirectionally.A connecting cable is an electrical cable designed to connect a base converter to a charging port. The connecting cable is preferably multi-pole.

[0018] A charging port is a device designed to be connected to an electrically powered vehicle for charging. The charging port typically has a charging plug for connection to a vehicle. The charging plug is therefore a vehicle charging plug and can, in particular, include the Type 1, Type 2, or Type 3 charging plug, the CSS or Combo plug, the Chademo plug, the Tesla Supercharger, or the CEE plug, or be one of these plugs.

[0019] Charging information is information suitable for determining a charging current. Some of this information is defined in the SAE J1772:2001 standard. In particular, information about the vehicle's state of charge, the vehicle type, and / or the vehicle's compatibility with a charging mode can be transmitted from the vehicle to the charging station. Furthermore, information about the operating status of the charging station, in particular whether it is ready for operation, can be transmitted to the vehicle as charging information.

[0020] A booster converter, like a base converter, is an electrical circuit that converts a DC voltage supplied at the input into a DC voltage with a higher, lower, or inverted voltage level. Booster converters are also generally designed to convert electrical power bidirectionally and can be configured identically to base converters. However, booster converters are preferably designed to transfer a power level at their output that, at a voltage level matching the base converter, exceeds the base power level.

[0021] Operation of a charging station means that an electrically powered vehicle is connected to the charging port and the vehicle is being charged via the charging station. During this process, power can be transferred to the vehicle, or the charging station can be in a state in which no power is transferred to the vehicle. The power transfer is generally not constant. The ability to connect a booster converter during charging station operation therefore also includes necessary safety features that enable connection and disconnection without causing damage to the charging station or its user.

[0022] A booster cable is an electrical cable originating from a booster converter. Several connecting cables are switchably connected to the booster cable. The booster cable can consist of several sections, for example connected by nodes. In particular, it can be provided that only sections of the booster cable are switchably connected to the several connecting cables. Care must be taken to ensure that only one or no connecting cable is connected to the booster cable at a time when the charging station is in operation. If several connecting cables are connected to the booster cable at the same time when the charging station is in operation, there is a risk of unwanted voltage transfer if different voltages are applied to the connected connecting cables.

[0023] A connection node is a point in the charging station's electrical network where two terminals of the connecting cable and one terminal of the booster cable meet. The current can branch at this point. At the connection node, a current flowing in the connecting cable can thus be superimposed on a current flowing in the booster cable.

[0024] The control unit is configured to control the base converter and the booster converter(s), i.e., to adjust the power to be transferred by the converters. For this purpose, the control unit is signal-coupled to the converters. The control unit knows the contents of the memory unit and the target values ​​for current and / or voltage and / or power and measures or collects the associated actual values. Furthermore, the control device can be configured to determine the current and / or future power requirement of a charging connection. For this purpose, the control device can, in particular, be configured to receive and / or generate a signal about the capacity of a vehicle battery, a signal about the charge state of the vehicle battery, a signal about the type of vehicle, and / or other signals. During normal operation of the charging station, a power transfer is positive, i.e., it leads from the charging station to the vehicle.

[0025] A safety-related switch is a switch constructed according to safety-related design principles that must be adhered to in order to minimize the risk of malfunction. Safety-related switches are designed to detect their own switching state and / or malfunction, or to make them detectable. The switching state of the safety-related switches can be regularly sent to the control unit during operation.

[0026] In the charging station according to the invention, the DC voltage intermediate circuit is preferably connected to a power grid via a mains converter.

[0027] The grid converter converts a voltage available at the charging station, for example, a multiphase mains voltage, into a direct current voltage, known as the intermediate circuit voltage. The grid converter can be a rectifier (AC-DC converter, active front-end converter), such as a switched bridge rectifier. The voltage conversion is typically bidirectional. Converting the AC voltage to a DC voltage results in more precise control, allowing for a smoother input voltage.

[0028] A power grid is a network for the transmission and distribution of electrical energy. The power grid is preferably an alternating current (AC) network, but can also be a direct current (DC) network. If the network is a direct current network, a DC / DC converter is used as the grid converter, which converts the line voltage into a suitable intermediate circuit voltage.

[0029] A further advantage can be achieved if the charging station further comprises a storage device which is configured to transfer power to or from at least one of the charging connections, wherein the storage device is connected to the DC voltage intermediate circuit directly or via additional power electronics. The storage device can be used to temporarily increase the charging power. Furthermore, the storage device can be used to achieve more cost-effective operation of the charging station if it is charged at times of low electricity prices, for example at night, and discharged again at times of high electricity prices. The control device can in particular be configured to operate the storage device depending on the current electricity price.

[0030] The storage device is a device for storing electrical energy and can include accumulators, supercapacitors, or other physical or chemical energy storage devices. The storage device also serves to stabilize the DC link, particularly in situations where the charging station draws a lot of power from the DC link.

[0031] It is also advantageous if the storage device includes a chopper.

[0032] A chopper is a switchable resistor that converts power into heat when needed, thus extracting electrical power from the charging station. The chopper can be actively or passively controlled. In the event of malfunctions that result in increased power consumption, the chopper can release the power back into the charging station, thus increasing the electrical safety of the charging station.

[0033] It is further advantageous if the charging station further comprises an active front-end converter which is designed to transfer power into or from the power grid.

[0034] The active front-end converter is a controllable rectifier with bidirectional power transfer between AC and DC and the ability to feed power back into the power grid. If the charging station is connected to a power grid in such a way that power from the charging station can be fed back into the power grid, the charging station must include an active front-end converter.

[0035] In particular, it can be provided that the base converter is operable in a first power range and the booster converter is operable in a second power range and the first power range is smaller than the second power range.

[0036] In charging stations for charging electrically powered vehicles, the first power range can preferably cover powers up to 100 kW, particularly preferably up to 150 kW, and the second power range can preferably cover powers up to 150 kW, particularly preferably up to 300 kW.

[0037] It is also advantageous if the ratio of the number of booster converters to the number of base converters in the charging station is between 1 / 2 and 1 / 6, in particular between 1 / 3 and 1 / 5.

[0038] The ratio of the number of booster converters to the number of base converters can be optimized depending on the booster converter's utilization. To achieve this, a booster converter should be available when needed to provide higher transfer power, but have short downtimes during which its power is not required. The ratio depends on the specific application, location, and the power ranges of the base converters and booster converters. For charging stations for electrically powered vehicles, a ratio of four base converters per booster converter can represent an operationally efficient compromise.

[0039] It is also advantageous if a voltage measuring device is arranged above each of the safety-related switches.

[0040] The voltage measuring device is designed to measure the voltage on both sides of a switch, preventing the switch from closing if there are undesirable voltage differences on either side. This measurement is preferably performed on all switches in the charging station. The data recorded by the voltage measurement is transmitted to the control unit.

[0041] A further advantage can be achieved if at least one of the safety-related switches has a parallel connection of several switches.

[0042] The parallel circuit can, in particular, consist of a resistance-coupled switch and a resistance-free switch. If the resistance-coupled switch is closed first, voltage differences on both sides of the safety-related switch are balanced in such a way that excessive currents that could cause damage to the vehicle do not flow. In the closed position, the resistance-free switch, which is subsequently closed, conducts the entire current with virtually no loss. In this particular embodiment of the invention, the corresponding safety-related switch comprises a parallel circuit of several switches, with one of the switches in the parallel circuit being designed to conduct direct current and another switch in the parallel circuit being designed to conduct alternating current.In charging stations for electric vehicles, the currents to be transferred are often direct currents (DC) superimposed on an alternating current or ripple current (AC component). The ripple currents can be generated by modulating the setpoint of the booster converter. Typically, the majority of the power is transmitted via the direct current, while a smaller amount is transmitted via the alternating current or ripple current. A simple switch for high power is fundamentally unsuitable for transmitting such superpositions of direct current and alternating current components, since the high currents of the DC component require cables with large diameters, and AC components of the current can only flow on the surface of such cables. By connecting an AC switch and a DC switch in parallel, a better transmission of both components is possible.Due to the different current strengths of the AC and DC components, the AC switch can be designed to conduct smaller currents than the DC switch. In particular, such a parallel circuit can be configured to close the AC switch first and then the DC switch in a switching process.

[0043] The charging station preferably further comprises a charging data acquisition device for acquiring charging data across a plurality of charging processes. The charging data acquisition device acquires the charging station's charging data, in particular data on the duration of the charging processes, the amount of energy transferred per charging process, the maximum charging current, the minimum charging current, the charging current profile, the number of vehicles charging simultaneously, etc. The charging data can be used to evaluate which hardware is required to ensure optimal charging for the vehicles being charged at a given time. Due to the changing number of electrically powered vehicles in operation in a region, location factors, and other parameters, estimating capacity for designing the charging station's hardware components is typically difficult.The charging data acquisition device enables the provision and thus statistical evaluation of charging data from charging stations in operation over longer periods of time. This facilitates the design of the number of required charging stations and the capacities of the base converters and booster converters of future charging stations. The charging station itself can also be equipped with a charging data evaluation device for this purpose.

[0044] Further preferably, it can be provided that the memory device comprises a fast memory with a fast access time and a slow memory with a slow access time, and the fast memory has a smaller capacity than the slow memory.

[0045] The combination of fast and slow storage enables further optimized use of the storage system. While fast storage can absorb and release short-term load changes, thus avoiding voltage peaks, slow storage generally enables the storage of larger amounts of electrical energy with lower losses, thus enabling the trading of electrical energy to / from the power grid and / or to / from the vehicle. Supercapacitors, for example, are suitable for fast storage, while accumulators are suitable for slow storage.

[0046] Particularly preferably, the booster line comprises a booster switch for connecting a booster power to at least one of the charging connections.

[0047] The booster switch can be designed as a contactor switch, but is preferably a power electronics semiconductor switch such as an IGBT or MOSFET. The power electronics semiconductor switch can comprise Si, GaN, SiC or other semiconductor materials as the semiconductor material. When connecting the booster power to the base power, a short switching time is helpful in order to follow the optimal charging process as precisely as possible and to be able to switch off the power even in the event of rapid changes in the power to be transferred, which reduces the risk of failure. The fast switching times of a power electronics semiconductor switch make it possible to switch the booster line off at any time during operation, even during load changes, to one of the several connecting lines.Power electronics semiconductor switches achieve a switching time in the nanosecond range, whereas the switching times of contactor switches are in the range of approximately 10 milliseconds and are thus significantly slower. To prevent multiple charging connections from being short-circuited via the booster cable, the booster switches preferably have a safety-related input. The safety-related input can prevent or allow the switching state of the booster switch to be changed. Such a safety-related input can be easily implemented in a similar way to a safe torque-off switch of a drive converter. The switch can only be closed or opened if the safety-related input allows a change in the switching state. The control unit can also be configured so that only one booster switch can be closed at a time.A channel would therefore only be enabled for activation via the booster switch once it has been ensured that no other channel can be activated. A safety-related input does not generally delay the switching time of the booster switch.

[0048] Further preferably, the base converters and / or the booster converter(s) each have support capacitors and an output capacitance of the support capacitors of the booster converter(s) is smaller than an output capacitance of support capacitors of the base converters.

[0049] The converter output capacitances support the output voltage and keep it stable. However, if one of the base converters or one of the booster converters is not connected to a charging port without voltage, a current flows between the charging port and the support capacitor. The current depends on the size of the connected output capacitance. Such incorrect switching can occur particularly with faulty voltage measurements. It is therefore advantageous to keep the capacitances not located directly at the charging port as small as possible. This particularly includes the output capacitances of the regularly connected booster converters. The booster converter can also comprise a multi-level converter. In this case, an output capacitance can be omitted.

[0050] It is also advantageous if at least one of the base converters is galvanically isolated from the DC link. Galvanic isolation means avoiding electrical conduction between two circuits between which power or signals are to be exchanged. With galvanic isolation, the electrical potentials are separated from each other, and the circuits are then potential-free from each other. Preferably, the booster converter is also galvanically isolated from the DC link. Particularly preferably, all base converters and / or all booster converters are galvanically isolated from the DC link. Galvanic isolation offers greater safety, enables more precise voltage measurements, independent of the DC link, and prevents electromagnetic interference and unwanted interactions between the charging ports.

[0051] A further advantage can be achieved if the safety-related switches are connected to a safety system via signaling.

[0052] The safety system specifically controls the safety-related switches. An insulation monitor measures whether the intended galvanic isolation of the base converters and / or booster converters is intact. If a fault is detected in one or more galvanic isolations, the safety system opens the safety-related switches associated with the fault and / or prevents them from closing. Furthermore, the control device is configured to control the safety-related switches.

[0053] It is also conceivable that the charging station comprises a second booster converter connected to the DC voltage intermediate circuit, which can be connected to the booster line during operation of the charging station.

[0054] A second booster converter can be designed in the same way as or differently from the first booster converter. The second booster converter can be connected to a second booster line, which in turn can be connected to various connecting lines to at least one of the charging ports via a connection node. The second booster converter can be connected to the booster line of the first booster converter via a connector switch connected to both booster lines. Before connection, the voltage is measured via the connector switch and, if necessary, regulated such that connection is voltage-free. In addition to a second booster converter, the charging station can, if required, comprise further booster converters, which can be connected and connected in the same way as the first two booster converters.

[0055] According to a second aspect, the invention provides a method for charging one or more electrically powered vehicles with a charging station, in particular according to one of claims 1 to 16, comprising the steps of: a) connecting an electrically powered vehicle to one of the charging ports, b) communicating charging information between the charging station and the vehicle; c) starting a charging process on the vehicle, d) sending a power request for a connection device to the control unit, e) checking whether the requested power is greater in magnitude than the power transferable by the base converter, f) connecting the booster converter to one of the charging ports if the requested power is greater in magnitude than the power transferable by the base converter, and g) transferring the requested power via the base converter and the booster converter.

[0056] During a charging process, the electrically powered vehicle is charged from a first state of charge to a second state of charge, where the second state of charge is higher than the first state of charge. The sequence of the different charging power levels is determined by the initial state of charge, the vehicle type, and / or other characteristics. Typically, several different charging processes are carried out simultaneously at a charging station with multiple charging ports and / or started at intervals one after the other.

[0057] By transmitting the power request before providing the power, the control unit can equalize the voltages between the parts of the charging station to be switched, thereby improving the switching processes. Furthermore, the invention provides a computer program product comprising instructions that, when executed by a computer, cause the computer to execute the method according to one of claims 17 or 18.

[0058] Finally, the invention provides a computer-readable data carrier on which the computer program product according to claim 19 is stored.

[0059] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show schematically:

[0060] Figure 1 is a perspective external view of a charging station according to the invention for simultaneously charging several electrically powered vehicles;

[0061] Figure 2 shows a plot of the charging power as a function of the state of charge for different electrically powered vehicles;

[0062] Figure 3 is a circuit diagram of a charging station according to the invention according to a particular embodiment of the invention; and

[0063] Figure 4 shows an enlarged section of the circuit diagram in Figure 3, showing additional details.

[0064] Figure 1 shows a charging station 10 according to the invention, at which several vehicles 14 can be charged simultaneously. All elements necessary for operating the charging station are integrated in a housing 5. Several charging ports 4a-4d are arranged on an outer side of the charging station facing several parking spaces 7. The charging ports have charging plugs 8a-8d for connection to a battery-powered vehicle 14. Charging settings can be selected and / or the current charging status can be displayed via displays 15.

[0065] Figure 2 shows a plot of charging power as a function of state of charge for various electrically powered vehicles. Diagram 200 was originally published in "P3 Charging Index: Comparison of the Fast Charging Capability of Various Battery Electric Vehicles" by Christian Daake and Marian Cammerer, ISSYM 2023. The figure shows charging curves of various battery-powered vehicles: charging curve 202 of the Porsche Taycan GTS, charging curve 204 of the Audi eTron GT quattro, charging curve 206 of the Mercedes EQS 450+, charging curve 208 of the BMW iX xDrive 50, and charging curve 210 of the Audi e-tron 55 quattro. The plot shows that the charging power of all vehicles decreases at higher states of charge. At lower states of charge, the charging power is constant or increases slightly. From around 45% state of charge, almost all vehicles in this selection show a significant decrease in charging power. Furthermore, the maximum charging capacities differ significantly.A charging station designed to cover the maximum charging power of these exemplary vehicle types would therefore need to be able to provide an output power of approximately 275 kW at the charging port. For the fastest-charging vehicle types, the Porsche Taycan GTS and the Audi eTron GT, this high charging power range is only achievable for about half of the state of charge. Other vehicle types in this range only achieve maximum charging power of 200 kW, 180 kW, or 140 kW. The efficient design of the charging station's underlying hardware is therefore not trivial if overcapacity is to be avoided.

[0066] Figure 3 shows a circuit diagram of a charging station 10 according to the invention according to a particular embodiment of the invention.

[0067] The charging station 10 is designed to simultaneously charge several electrically powered vehicles 14. For this purpose, the charging station has several charging plugs 8a-8h, each of which can be connected to a vehicle 14.

[0068] The charging station comprises a DC intermediate circuit 22 to which essential elements of the charging station 10 are connected. The DC intermediate circuit 22 has a two-pole design. The charging station 10 also comprises several basic converters 1 a-1 h connected to the DC intermediate circuit 22. The basic converters 1 a-1 h can each be connected to a charging port 4a-4h via a connecting cable 24. There is thus a one-to-one coupling between the basic converter 1 ah and the charging port 4a-h. Each charging port 4a-4h is electrically connected to exactly one of the basic converters 1 a-1 h. Each charging port 4a-4h is connected to a charging plug 8a-8h. The charging plugs 8a-8h are shown here as Type 2 plugs. Other plug types can of course also be provided.In addition to the eight basic converters 1a-1h, the charging station 10 further comprises a first booster converter 2a connected to the DC intermediate circuit 22 and a second booster converter 2b also connected to the DC intermediate circuit 22. The two booster converters 2a-2b can each be connected to various connecting lines 24 to the charging connections 4a-4h via a booster line 26a, 26b and a connection node 18a-18h. Specifically, the connection is made via booster switches 16a-16h, with which a booster line 26a, 26b is switchably connected to several connecting lines. The connecting lines 24 are shown as single-pole in Figure 1 for reasons of clarity, but are generally designed to have at least two poles.The booster converter 2a can be explicitly connected to the charging terminals 4a-4d via the booster line 26a and the booster converter 2b can be connected to the charging terminals 4e-4h via the booster line 26b, at least as long as there is no coupling of the two booster lines 26a-26b, which is discussed further below.

[0069] Each connecting line 24a-24h has a safety-related switch 6a-6h between charging connection 4a-4h and connection node 18a-18h. In principle, each of the safety-related switches 6a-6h is designed so that each individual line of the multi-pole connecting lines 24a-24h can be switched. The position of the safety-related switches 6a-6h is arranged on a connecting line 24a-24h between charging connection 4a-4h and connection node 18a-18h.

[0070] During operation of the charging station 10, the booster converter 2a can be connected to each of the connecting lines 24a-24d via a booster line 26a and a respective connection node 18a-18d, and via these to the respective charging ports 4a-4d. Similarly, the booster converter 2b can be connected to the connecting lines 24e-24h via the booster line 26b and the connection nodes 18e-18h, and via these to the respective charging ports 4e-4h. While the booster lines 26a, 26b can be connected to several of the connecting lines 24a-24h, to prevent short circuits between the connecting lines, it is specified that each of the booster lines 26a, 26b can be connected to only one of the connecting lines 24a-24h at any given time.

[0071] The charging station 10, through the two booster converters 2a, 2b and the two booster lines 26a, 26b, enables the supply of two separate charging ports 4a-4h, one from the group of charging ports 4a-4d and one from the group 4e-4h. The booster lines 26a, 26b are switchably connected to one another via a coupling switch 32 and can be connected to one another by this. This makes it possible to combine the power of a base converter 1a-1h with the power of the first booster converter 2a and the power of the second booster converter 2b. This allows further increased power to be transferred to or from a charging port 4a-4h. The coupling switch 32 is also connected to the safety system 9, which also prevents the coupling of multiple charging ports 4a-4h to one another via a booster line 26a, 26b.

[0072] The charging station 10 further comprises a control unit 27 for controlling the base converters 1a-1h and the booster converters 2a, 2b according to a desired power transfer. For this purpose, the control unit 27 is connected to the base converters 1a-1h and the booster converters 2a, 2b via a first signal line 28a and to voltage measuring devices 30a-30h via a second signal line 28b, which are designed to measure the voltages present at the charging connections 4a-4h. The first signal line 28a is designed to send control signals to the base converters 1a-1h and the booster converters 2a, 2b. A voltage present at the charging connection 4a-4h is measured via the second signal line 28b. The signal lines 28a, 28b, and 28c are shown as dashed lines.

[0073] Furthermore, the charging station 10 comprises a vehicle communication device 31 for communicating charging information between the charging station 10 and an electrically powered vehicle 14 connected for charging. Communication can take place from the vehicle 14 to the charging station 10 or from the charging station 10 to the vehicle 14. The vehicle communication device 31 can thus exchange charging information bidirectionally with the vehicle 14. The charging current can be determined based on the charging information. In the illustrated embodiment, the vehicle communication device 31 is integrated into the control unit 27.

[0074] Furthermore, the control unit 27 is connected to the safety system 9 via a connecting line. Alternatively, the safety system 9 can also be integrated directly into the control unit 27. The safety system 9 is designed to ensure the safety of users and the safety of the vehicles 14 connected to the charging connectors 8a-8h. It is connected to the connecting lines 24a-24h via a signal line 28c and an insulation monitor 11. The insulation monitor 11 is designed to cyclically measure whether the galvanic isolation of the base converters 1a-1h and the booster converters 2a, 2b from the DC voltage intermediate circuit is functioning. Faults in the galvanic isolation would lead to detectable fluctuations in the connecting lines 24a-24h. Furthermore, the safety system 9 is connected via a signal line 28d to the safety-related switches 6a-6h arranged between a charging connection 4a-4h and a connection node 18a-18h.The switching of the safety-related switches 6a-6h is typically performed by a switching signal sent from the control unit 27 to the safety system 9 via the connecting line 29. After checking and approval by the safety system 9, the safety system 9 then switches the safety-related switch 6a-6d according to the received switching signal. Independently of this, the safety system 9 can open any of the safety-related switches 6a-6h and thus interrupt the electrical connection to the charging connections 4a-4h and the charging plugs 8a-8h. This may be necessary, in particular, if a fault in the functioning of the galvanic isolation of the base converters 1a-1h and / or the booster converters 2a, 2b is detected.

[0075] The safety system 9 is also connected via an additional signal line (not shown) to the booster switches 18a-18h, which are configured to connect booster power. The safety system 9's task is to ensure that at any given time, only one or no charging connection 4a-4h is connected to a booster line 26a, 26b. For this purpose, the booster switches 16a-16h are power semiconductor switches equipped with a safety torque-off switch (STO switch). The STO switch does not delay the very fast switching times of the power semiconductor switches, but can prevent the booster switch 16a-16h equipped with it from closing at all. The safety system can only release one of the STO switches at a time, thereby preventing more than one booster switch 16a-16h from being closed per separate booster line 26a, 26b.This prevents a short circuit between two charging ports 4a-4h and the associated unwanted power transfer with potential damage to the charging station 10 and technical personnel.

[0076] Each of the connecting lines 24a-24h leads from a base converter 1a-1h to a charging port 4a-4h and, via this port, to a charging plug 8a-8h. Each connecting line 24a-24h has a safety-related switch 6a-6h between the charging port 4a-4h and the connection node 18a-18h. This arrangement allows for the safety-related switching of both the power provided by the base converters 1a-1h and the power boosted by the boost converters 2a, 2b.

[0077] The DC link 22 is connected to a three-phase power grid 13 via a grid converter 12, which supplies the DC link 22 with electrical power and through which electrical power can be dissipated. For this purpose, the grid converter 12 can be designed as an active front-end converter. Galvanic decoupling of the grid converter 12, as shown in Figure 3, is not absolutely necessary if all base converters 1a-1h and all booster converters 2a, 2b are galvanically decoupled.

[0078] The charging station 10 further comprises a storage device 3 connected to the DC link 22, which is configured to store energy and transfer power to and from the charging terminals 4a-4h via the base converters 1a-1h and the booster converters 2a, 2b. The storage device can comprise a battery, a supercapacitor, and / or a chopper.

[0079] In this embodiment, the charging station has eight base converters 1a-1h and two booster converters 2a, 2b. The ratio of the number of booster converters 2a, 2b to the number of base converters 1a-1h is thus 1 / 4.

[0080] To test the fault-free functioning of the charging station 10, electrical measuring devices are arranged at various positions. Particularly when the charging station is operated in the high-power range, a voltage measurement must be performed across each switch to avoid abrupt, high-power compensating currents. For this purpose, a voltage measuring device 30a-30h is provided above each switch, in particular above each safety-related switch 6a-6h. This voltage measuring device is designed to measure the voltage on both sides of the switch and to ensure that both sides of the switch are at the same potential. In principle, a current measuring device can also be provided at each position where a voltage measuring device 30a-30h is provided. This additionally enables a measurement of the power transfer at the respective location. For reasons of clarity, not all voltage measuring devices 30a-30h are shown in Figure 3.

[0081] Figure 4 shows an enlarged section of the circuit diagram in Figure 3, showing additional details. As described in connection with Figure 3, some features are not shown in detail in Figure 3 for reasons of clarity. In particular, Figure 4 shows in detail that the connecting lines 24a, 24b leading from the base converters 1a, 1b, as well as the DC voltage intermediate circuit, are designed to be two-phase. Furthermore, it is shown in detail that the safety-related switches 6a, 6b are designed to switch each of the phases of the connecting lines 24a, 24b separately. If the safety-related switches 6a, 6b have a parallel connection of several switches, it is provided that each of the phases has such a parallel connection of several switches, although this is not shown in the particular embodiment of the invention shown here.Furthermore, the booster line 26a is two-phase, and the booster switches 16a, 16b are designed to switch the multi-phase booster line. The voltage measuring devices 30a, 30b are arranged such that they measure the voltage between the individual phases of the two-phase charging connection. The charging station 10 is configured in the section not shown in Figure 4 in the same way as the section shown in Figure 4.

[0082] The figures show the invention solely as examples.

[0083] Reference list:

[0084] 1 a-1 h base converter

[0085] 2a, 2b booster converter

[0086] 3 Storage device

[0087] 4a-4h charging port

[0088] 6a-6h safety-related switch

[0089] 8a-8h charging plug

[0090] 9 Safety System

[0091] 10 charging stations

[0092] 11 Isolation monitor

[0093] 12 grid converters

[0094] 13 Power grid

[0095] 14 vehicles

[0096] 16a-16h booster switch

[0097] 18a-18h connection node

[0098] 22 DC link

[0099] 24a-24h connection line

[0100] 26a, 26b booster line

[0101] 27 Control unit

[0102] 28a-28c signal line

[0103] 29 connecting line

[0104] 30a-30h voltage measuring device

[0105] 31 Vehicle communication device

[0106] 32 coupling switch diagram Charging curve of the Porsche Taycan GTS, Charging curve 204 of the Audi eTron GT quattro Charging curve of the Mercedes EQS 450+ Charging curve of the BMW iX xDrive 50 Charging curve of the Audi e-tron 55 quattro

Claims

Claims: 1 . Charging station (10) for the simultaneous charging of several electrically powered vehicles (14), comprising: a DC intermediate circuit (22), several base converters (1a-1h) connected to the DC intermediate circuit (22), each switchably connected to a charging connection (4a-4h) via a connecting line (24a-24h), a booster converter (2a, 2b) connected to the DC intermediate circuit (22), which can be connected to at least one of the charging connections (4a-4h) via a booster line (26a, 26b) and a respective connection node (18a-18h) to various of the connecting lines (24a-24h) during operation of the charging station (10), a vehicle communication device (31) for communicating charging information between the charging station (10) and the vehicles (14), a control unit (27) for controlling the base converters (1a-1h) and the Booster converter (2a, 2b) according to a desired power transfer,wherein each connecting line (24a-24h) has a safety-related switch (6a-6h) between the charging connection (4a-4h) and the connection node (18a-18h).

2. Charging station (10) according to claim 1, wherein the DC voltage intermediate circuit (22) is connected to a power grid (13) via a grid converter (12).

3. Charging station (10) according to claim 1 or 2, further comprising a storage device (3) which is configured to transfer power to at least one of the charging connections (4a-4h) or from at least one of the charging connections (4a-4h), wherein the storage device (3) is connected to the DC voltage intermediate circuit (22).

4. Charging station (10) according to one of the preceding claims, wherein the storage device (3) comprises a chopper.

5. Charging station (10) according to one of claims 2 to 4, further comprising an active front-end converter configured to transfer power into or from the power grid (13).

6. Charging station (10) according to one of the preceding claims, wherein the base converter (1 a-1 h) is operable in a first power range and the booster converter (2a, 2b) is operable in a second power range and the first power range is smaller than the second power range.

7. Charging station (10) according to one of the preceding claims, wherein the ratio of the number of booster converters (2a, 2b) to the number of base converters (1a-1h) in the charging station (10) is between 1 / 2 and 1 / 6, in particular between 1 / 3 and 1 / 5.

8. Charging station (10) according to one of the preceding claims, wherein a voltage measuring device (30a-30h) is arranged above each of the safety-related switches (6a-6h).

9. Charging station (10) according to one of the preceding claims, wherein at least one of the safety-related switches (6a-6h) has a parallel connection of several switches (6a-6h).

10. Charging station (10) according to one of the preceding claims, further comprising a charging data acquisition device for acquiring charging data over a plurality of charging processes. 1 1. Charging station (10) according to one of claims 3 to 10, wherein the memory device (3) comprises a fast memory with a fast access time and a slow memory with a slow access time, and the fast memory has a smaller capacity than the slow memory.

12. Charging station (10) according to one of the preceding claims, wherein the booster line (26a, 26b) comprises a booster switch (16a-16h) for connecting a booster power to at least one of the charging connections (4a-4h).

13. Charging station (10) according to one of the preceding claims, wherein the base converters (1 a-1 h) and / or the booster converter(s) (2a, 2b) each have support capacitors and an output capacitance of the support capacitors of the booster converter (2a, 2b) or the booster converters (2a, 2b) is smaller than an output capacitance of support capacitors of the base converters (1 a-1 h).

14. Charging station (10) according to one of the preceding claims, wherein at least one of the base converters (1 a-1 h) is galvanically isolated from the DC voltage intermediate circuit (22).

15. Charging station (10) according to one of the preceding claims, wherein the safety-related switches (6a-6h) are signal-connected to a safety system (9).

16. Charging station (10) according to one of the preceding claims, wherein the charging station (10) comprises a second booster converter (2a, 2b) connected to the DC voltage intermediate circuit (22), which can be connected to the booster line (26a, 26b) during operation of the charging station (10).

17. A method for charging one or more electrically powered vehicles (20a-20h) with a charging station (10), in particular according to one of the preceding claims, comprising the steps of: a) connecting an electrically powered vehicle (14) to one of the connection devices (4a-4h), b) communicating charging information between the charging station (10) and the vehicle (14), c) starting a charging process on the electrically powered vehicle (14); d) Sending a power request for a charging connection (4a-4h) to the control unit (27), e) Checking whether the requested power is greater in magnitude than the power transferable by the base converter (1a-1h), f) Connecting the booster converter (2a, 2b) to one of the charging connections (4a-4h) if the requested power is greater in magnitude than the power transferable by the base converter (1a-1h), and g) Transferring the requested power via the base converter (1a-1h) and the booster converter (2a, 2b) to the vehicle (14).

18. The method according to claim 17, wherein the power request is sent to the control unit (27) at least 1 ps, preferably at least 100 ps, ​​before the power is provided.

19. A computer program product comprising instructions which, when executed by a computer, cause the computer to carry out the method according to one of claims 17 or 18.

20. A computer-readable data carrier on which the computer program product according to claim 19 is stored.

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