Fast charging station for electric vehicles

Abstract

The invention relates to a fast charging station for electric vehicles, wherein the fast charging station (1) has a power converter arrangement (9) for converting an alternating voltage as input voltage of the fast charging station (1) into a direct voltage as output voltage of the fast charging station (1), wherein the power converter arrangement (9) has at least one energy storage device (10).It is proposed that the converter arrangement (9) has a discharge circuit (12) connected to the energy storage device (10) for discharging the energy storage device (10), that the discharge circuit (12) is in a discharged state by default in which the energy storage device (10) is discharged via the discharge circuit (12), that the discharge circuit (12) is actively brought into an inactive state by a control unit (15) during operation of the converter arrangement (9) in which the discharge circuit (12) does not discharge the energy storage device (10), and that the discharge circuit (12) automatically enters the discharged state in the event of a failure, in particular an emergency shutdown, of the control unit (15).

Description

[0001] The present invention relates to a fast charging station for electric vehicles according to the preamble of claim 1 and to a method for operating a fast charging station according to the preamble of claim 14.

[0002] Fast charging stations, also known as high-performance chargers, are direct current (DC) charging stations for electric vehicles, especially cars, but also trucks, ships, and similar vehicles. Fast charging stations deliver high voltages and currents and are operated by non-professionals. They must therefore meet the highest safety standards. In the event of an abrupt disconnection between the electric vehicle and the fast charging station, or during maintenance when a service hatch on the fast charging station is opened, the energy stored in the fast charging station must be dissipated quickly. This also applies to unauthorized access, accidents, and similar incidents where a controlled termination of the charging process and a controlled shutdown of the fast charging station are not possible.

[0003] The invention is based on a well-known fast-charging station with an integrated energy storage system. Such energy storage devices are virtually indispensable in power electronic circuits and are therefore usually present. These energy storage devices can be used, for example, to smooth the output voltage and thus have correspondingly high capacities. Even if one or more components of the fast-charging station fail, the energy stored in the energy storage devices must be quickly brought down to a level that is no longer dangerous.

[0004] The challenge lies in dismantling the energy stored in energy storage systems in a cost-effective and rapid manner.

[0005] The invention is based on the problem of designing and further developing the known fast charging station in such a way that further optimization is achieved with regard to the aforementioned challenge.

[0006] The above problem is solved by the features of the characterizing part of claim 1.

[0007] The fundamental principle is that a discharge circuit can be used to discharge an energy storage device, specifically by short-circuiting it. This discharge circuit is designed so that it must be actively prevented from discharging the energy storage device during operation of the fast-charging station. If this active prevention measure is removed, the energy storage device discharges automatically. In this way, the energy storage device is discharged extremely quickly and efficiently. A failure of functionality, even in the event of damage to essential parts of the fast-charging station, is unlikely. The resulting operational reliability is therefore very high.

[0008] Specifically, it is proposed that the power converter arrangement includes a discharge circuit connected to the energy storage device for discharging the energy storage device, that the discharge circuit is in a discharged state by default, in which the energy storage device is discharged via the discharge circuit, that the discharge circuit is actively brought into an inactive state by a control unit during operation of the power converter arrangement, in which the discharge circuit does not discharge the energy storage device, and that the discharge circuit automatically enters the discharged state in the event of a failure, in particular an emergency shutdown, of the control unit.

[0009] In particularly preferred embodiments according to claim 2, the discharge circuit is not programmable and / or does not require a supply voltage. According to claim 3, it may be provided that an NC switching element is used in a short-circuit branch for discharging the energy storage device. In an embodiment according to claim 4, it is further provided that a PTC heating element is arranged in the short-circuit branch. In this combination, discharging the energy storage device is achieved in a simple manner, while simultaneously ensuring that the discharge current does not become too high. If the discharge current increases, the PTC heating element heats up and its resistance increases, thereby reducing the discharge current.

[0010] Claims 5 and 6 specify a preferred topology of the power converter arrangement.

[0011] According to claim 7, it may be provided that a different or additional discharge of the energy storage device is provided for normal operating conditions. This can, for example, ensure that the PTC heating element does not wear out.

[0012] Claim 8 relates to a preferred embodiment in which the fast charging station has one or more power modules which may be flexibly distributed over several connection points.

[0013] A further preferred embodiment, which also has independent relevance separate from the discharge circuit and can interact with the other embodiments described herein in any combination, is the subject of claim 9. Accordingly, a fast charging station with at least one power module can be provided with a monitoring circuit that can preferably trigger an emergency shutdown of a control unit via a shutdown signal. In combination with the proposed discharge circuit, an emergency shutdown including discharge is thus achieved very quickly and with very little control engineering effort, and therefore robustly.

[0014] In an embodiment according to claim 10, it is provided that several monitoring circuits are arranged in galvanically isolated areas of the power module. According to claim 11, it can then be further provided that a shutdown by one monitoring circuit triggers at least one further monitoring circuit in a cascading manner. Thus, no galvanically isolated transmission of the shutdown signal is necessary; instead, the different parts of the power module switch off via their own monitoring circuits.

[0015] A further preferred embodiment, which also has independent relevance regardless of the discharge circuit and can interact with the other embodiments described herein in any combination, is the subject of claim 12. Accordingly, in a fast charging station, it can be provided that an overall limit value for the output current of a connection point is distributed across the power modules. A further shutdown in the event of excessively high output current at the connection point can thus be avoided, making the fast charging station more cost-effective.

[0016] A further preferred embodiment, which also has independent relevance separate from the discharge circuit and can interact with the other embodiments described herein in any combination, is the subject of claim 13. Accordingly, in a fast-charging station, it can be provided that not all power modules are active at a given time or provide the same amount of power. If the power modules are then designed to be bidirectional, meaning they can also absorb power, at least some of it, or even feed it back into the grid, then in the event of an emergency shutdown, one power module can also dissipate the energy stored in another power module. This allows the energy to be dissipated more quickly overall, thus increasing operational reliability.

[0017] According to a further teaching as claimed in claim 14, which has independent significance, a method for operating a fast charging station is claimed.

[0018] It is essential that the power converter arrangement has a discharge circuit connected to the energy storage device for discharging the energy storage device, that the discharge circuit is in a discharged state by default in which the energy storage device is discharged via the discharge circuit, that the discharge circuit is actively brought into an inactive state by a control unit during operation of the power converter arrangement in which the discharge circuit does not discharge the energy storage device, and that the discharge circuit automatically switches to the discharged state in the event of a failure, in particular an emergency shutdown, of the control unit.

[0019] Reference may be made to all statements regarding the proposed fast charging station.

[0020] The invention will now be explained in more detail with reference to a drawing that merely illustrates exemplary embodiments. The drawing shows Fig. 1 a proposed fast charging station, Fig. 2. Take a look inside the fast charging station and at the power modules, Fig. 3 DC busbars with a switching matrix and connection points, as well as associated power modules with converter arrangement and filter stages, Fig. 4 an AC / DC converter, Fig. 5 a DC / DC converter with monitoring circuits (in Fig. 4 not shown) and Fig. 6. An overview of the power module and the signal and power paths in the power module.

[0021] Fig. Figure 1 shows an external view of a proposed fast charging station 1 for electric vehicles. This station has at least one connection point 2 for an electric vehicle, in this case a permanently attached charging cable. Preferably, the fast charging station 1 has at least, and in this case exactly, two connection points 2. A fast charging station 1 is used to charge an electric vehicle using direct current and a power output of usually at least 50 kW. The fast charging station 1 is typically connected to an alternating current network for this purpose.

[0022] As seen in the open view in Fig. As can be seen from Figure 2, the fast charging station 1 has at least one individually controllable power module 3. Here, the fast charging station 1 has seven power modules 3, each of which provides a portion of the total power of the fast charging station 1, for example, 30 kW each. The power modules 3 can be flexibly distributed among the connection points 2. This distribution preferably enables a switching matrix 4 ( Fig. 3) In the upper area of ​​the fast charging station 1, DC voltage rails 5 are visible for distributing the output power of the power modules 3 to the connection points 2. The AC voltage input is located in the lower area and is not shown.

[0023] The term "individually manageable" is to be interpreted broadly here. For example, power module 3 weighs approximately 39 kg, so it is not easy to handle. However, it can be removed individually, and the components of power module 3 are not individually installed in fast charging station 1.

[0024] The DC voltage rails 5 are interrupted, or can be interrupted, here preferably by switches 6 (contactors) such that the DC voltage rails 5 can be divided into two strings of any length of power modules 3, which are assigned to the two connection points 2. For example, all power modules 3 can be assigned to one connection point 2, or the DC voltage rails 5 can be split anywhere between the connection points 2, thus creating two strings. The arrangement of the switches 6 is therefore referred to as a switching matrix 4.

[0025] Further shows Fig. 3 here and preferably present output switches 7 per connection point 2 and a preferably also present output fuse 8 per connection point 2. The two outer power modules 3 are according to Fig. 3 and preferably not separately assignable to a connection point 2, so that although all power modules 3 can be assigned to a connection point 2, when using both connection points 2 at least two power modules 3 are assigned to a connection point 2.

[0026] The embodiment shown in the figures, which is preferred in this respect, relates to a fast charging station 1 for electric vehicles, wherein the fast charging station 1 includes a power converter arrangement 9 ( Fig. 4 and Fig. 5) for converting an alternating voltage as input voltage of the fast charging station 1 into a direct voltage as output voltage of the fast charging station 1, wherein the converter arrangement 9 includes at least one energy storage device 10. Here, and preferably, the energy storage device 10 is a capacitor, in particular a smoothing capacitor, between two DC voltage terminals 11.

[0027] It is now proposed that the power converter arrangement 9 includes a discharge circuit 12 connected to the energy storage device 10 for discharging the energy storage device 10. The discharge circuit 12 is in a discharged state by default, particularly in a state without any input. In this discharged state, the energy storage device 10 is discharged via the discharge circuit 12. Fig. Figure 5 shows the discharge circuit 12, which is used with an exemplary total of four capacitors. Here, and preferably, the capacitors are smoothing capacitors at the input and / or output of a DC / DC converter 13, which has an exemplary topology in Fig. 5 is shown. The entrance (left) in Fig. 5 corresponds to the exit (right) of the in Fig. 4 AC / DC converters shown 14.

[0028] The discharge circuit 12 is actively placed in an inactive state by a control unit 15 during operation of the power converter arrangement 9, in which the discharge circuit 12 does not discharge the energy storage device 10. In the event of a failure, particularly an emergency shutdown, of the control unit 15, the discharge circuit 12 automatically switches to the discharging state. Therefore, the control unit 15 must actively keep the discharge circuit 12 in the inactive state for the operation of the power converter arrangement 9.

[0029] Preferably, the discharge circuit 12 is not programmable, and / or the discharge circuit 12 does not require or use a supply voltage to transition from the inactive state to the discharged state. Here, and preferably, the discharge circuit 12 therefore has no programmable logic whatsoever. This includes FPGAs, which are also not present as part of the discharge circuit 12. Further preferably, the discharge circuit 12 has no logic whatsoever.

[0030] Here, and preferably, the discharge circuit 12 has a normally closed (NC) switching element 16 which is arranged in a short-circuit branch 17 through which the energy storage device 10 is discharged.

[0031] In the short-circuit branch 17, a positive temperature coefficient (PTC) heating element 18 is preferably arranged, which limits a discharge current of the energy storage device 10 by a temperature-dependent increase in the electrical resistance of the short-circuit branch 17. Fig. Figure 4 shows two discharge circuits 12, depicted with solid lines. Alternatively, four discharge circuits 12 could be provided, as shown with dashed lines. It is conceivable to provide one discharge circuit 12 for each smoothing capacitor of the DC / DC converter 13.

[0032] Here, and preferably, the situation is such that as long as the control unit 15 actively applies a voltage to the NC switching element 16, the latter is open and the energy storage device 10 can be used. If the voltage to the control unit 15 is lost, in particular because the control unit 15 has been switched off in an emergency, the energy storage device 10 is immediately discharged, with the discharge current being limited by the PTC heating element 18.

[0033] How Fig. 6 composed and the Fig. 4 and Fig. As shown in Figure 5, the power converter arrangement 9 may be provided with an AC / DC converter 14, a DC / DC converter 13, and a connecting circuit 19 on the output side of the AC / DC converter 14 and on the input side of the DC / DC converter 13. Preferably, the DC / DC converter 13 provides galvanic isolation. Additionally or alternatively, a diode 20 may be arranged between the power converter arrangement 9 and a connection point 2 of the fast charging station 1. Fig. 3) The connecting circuit 19 here has two capacitors that form the smoothing capacitors of the DC / DC converter 13 (input side). These also form the output-side smoothing capacitors of the AC / DC converter 14. The exact assignment is not important here. The connecting circuit 19 can also consist of just an electrical connection without any components.

[0034] Generally speaking, it is preferably provided here that an energy storage device 10 with discharge circuit 12 is arranged on the input side of the galvanic isolation and / or on the output side of the galvanic isolation, in particular in front of the diode 20.

[0035] In cases where the control unit 15 is not shut down in an emergency, it is preferably provided that the control unit 15 discharges the energy storage device 10 in a shutdown routine by activating switching elements 21 of the DC / DC converter 13 and / or the AC / DC converter 14. However, if the control unit 15 fails, it does not execute the shutdown routine and preferably does not continue to activate the switching elements 21 of the DC / DC converter 13 and / or the AC / DC converter 14. Thus, the normal discharge method is omitted, and the discharge circuit 12 is used. Accordingly, it is preferably provided that the switching elements 21 of the DC / DC converter 13 and / or the AC / DC converter 14 are normally open (NO) switching elements 21.

[0036] As in Fig. As shown in Figure 5, the power converter arrangement 9 preferably includes a DC / DC converter 13, in particular a dual-active-bridge DC / DC converter 13, which can increase and decrease an input voltage of the DC / DC converter 13.

[0037] Preferably, the DC / DC converter 13 rectifies an output AC voltage of the transformer 22 in a first operating state and functions as a charge pump in a second operating state, rectifying and increasing, in particular doubling, the output AC voltage of the transformer 22. The DC / DC converter 13 is a modified dual-active bridge. When a switching element 21 shown is closed, the output side 23 functions as a charge pump. When the switching element 21 is open, the output voltage of the transformer 22 is only rectified. For further understanding, reference is also made to EP 4 109 724 A1.

[0038] In detail, it is preferably provided here that the DC / DC converter 13 has a DC+ terminal 24 and a DC- terminal 25 on its output side; that the DC / DC converter 13 has a first circuit branch 26 on its output side between the DC+ terminal 24 and the DC- terminal 25, which comprises two series-connected semiconductor switching elements 27, in particular transistors, between which a first output-side terminal 28 of the transformer 22 is connected; that the DC / DC converter 13 has a second circuit branch 29 on its output side between the DC+ terminal 24 and the DC- terminal 25, which comprises two series-connected semiconductor devices 30, in particular diodes 20, between which a second output-side terminal 31 of the transformer 22 and a connecting branch 32 are connected; that the DC / DC converter 13 has a third circuit branch 33 on its output side between the DC+ terminal 24 and the DC connector 25,The device comprises two capacitors connected in series, between which the connecting branch 32 is connected, and the connecting branch 32 has a switching element 21 with which the connecting branch 32 can be closed and opened, thereby effecting a change between the operating states. In the first operating state, the switching element 21 is preferably open, and in the second, it is closed. Instead of the diodes 20, transistors can also be provided, in particular, thereby enabling bidirectional use. The switching element 21 can be a relay, a contactor, or a semiconductor switching element 27.

[0039] Further and in Fig. As shown in Figure 4, and preferably in this arrangement, the converter assembly 9 comprises a T-type AC / DC converter 14, the AC / DC converter 14 having a neutral point 34 and a DC output with neutral point connection 35, the neutral point 34 being coupled to the input of the AC / DC converter 14 via at least one, preferably three, coupling capacitors 36, and preferably, the neutral point 34 being coupled to three phases of the input of the AC / DC converter 14 via one coupling capacitor 36 each. Here, and preferably, the T-type AC / DC converter 14 is a Vienna rectifier. Such common-mode coupling reduces self-induced interference, thereby improving the control dynamics of the converter assembly 9. The AC / DC converter 14 and the DC / DC converter 13 are connected here and preferably via the connecting circuit 19, which has two connecting circuit capacitors 37.

[0040] Furthermore, it is preferably provided that the fast charging station 1 has at least one power module 3 which has the power converter arrangement 9, preferably that the fast charging station 1 has several power modules 3 with power converter arrangements 9, and more preferably that the power modules 3 can be flexibly distributed over at least two connection points 2 of the fast charging station 1 ( Fig. 2 and Fig. 3) Regarding the converter arrangements 9 of the further power modules 3, reference may be made to the previous explanations concerning the converter arrangement 9 of a power module 3. The diode 20 between converter arrangement 9 and connection point 2 is here, and preferably, assigned to one power module 3 at a time. In this case, the power modules 3 are not bidirectionally usable.

[0041] With regard to the emergency shutdown itself, it is preferably provided that the power module 3 has at least one monitoring circuit 38 which monitors, in particular, a current and / or a voltage and / or a temperature and generates a shutdown signal if a limit value is exceeded. The limit value preferably relates to at least an excessively high temperature and / or an excessively high current and / or an excessively high voltage. Preferably, the shutdown signal leads to an emergency shutdown of the control unit 15, whereby the discharge circuit 12 automatically switches to the discharge state. Fig. Figure 6 shows that a power module 3 here and preferably has an AC / DC driver stage 39 and / or a DC / DC driver stage 40 and / or a higher-level power module control unit 41, which may be connected to an external 24V power supply via an auxiliary voltage input 42 and / or may have a CAN connector 43.

[0042] The described control unit 15 is here, and preferably, the AC / DC driver stage 39 and / or the DC / DC driver stage 40; that is, there can also be two control units 15, each of which actively keeps at least one discharge circuit 12 in the inactive state and / or which are immediately switched off by a shutdown signal from one of the at least one monitoring circuits 38. Alternatively, the higher-level power module control unit 41 can also form the control unit 15 or a control unit 15.

[0043] Further shows Fig. 6 an AC input 44, an input filter stage 45 and an output filter stage 46. Dashed communication lines preferably indicate galvanically isolated communications, for example via optocouplers.

[0044] Furthermore, and preferably, the power module 3 is provided to have at least two galvanically isolated monitoring circuits 38, each of which monitors, in particular, a current and / or a voltage and / or a temperature and generates a shutdown signal if a limit value is exceeded. Preferably, each of the shutdown signals leads to an emergency shutdown of the control unit 15, whereby the discharge circuit 12 automatically switches to the discharge state. Here, and preferably, the shutdown signal of one monitoring circuit 38 switches off the AC / DC driver stage 39, and the shutdown signal of another monitoring circuit 38 switches off the DC / DC driver stage 40.

[0045] More generally, and preferably, it is provided that one of the galvanically isolated monitoring circuits 38 is arranged on the input side of the galvanic isolation of the DC / DC converter 13, and one of the galvanically isolated circuits is arranged on the output side of the galvanic isolation of the DC / DC converter 13. A shutdown signal from the monitoring circuit 38 located on the output side of the galvanic isolation of the DC / DC converter 13 sends a shutdown signal to a driver stage of the output side 23 of the DC / DC converter 13, which shuts down in response to the shutdown signal. Here, the DC / DC driver stage 40 is responsible for the input side 47 and the output side 23 of the DC / DC converter 13 and is galvanically isolated to at least one, here both, side. Separate driver stages that communicate in a galvanically isolated manner would also be conceivable.

[0046] In response to the shutdown of the output stage 23 of the DC / DC converter 13, here the DC / DC driver stage 40, the monitoring circuit 38 detects an exceedance of the limit value on the input side of the galvanic isolation of the DC / DC converter 13 and generates a shutdown signal. This is due, and preferably occurs, to the fact that the interconnect 19 is not stable when the DC / DC converter 13 is shut down. Therefore, in one embodiment, no signal transmission via galvanic isolation is necessary or provided for shutting down both sides of the galvanic isolation of the DC / DC converter 13. If the monitoring circuit 38 communicates with the respective driver stage via galvanic isolation, no further galvanically isolated communication is necessary or provided for the shutdown process.

[0047] The terms "signal" and "transmit" are to be interpreted broadly; the signal can also be a direct emergency shutdown of a supply voltage. Here, and preferably, at least one monitoring circuit 38 is provided for the voltage on the AC side, at the DC output 48 of the power module 3, and in the connecting circuit 19. Here, and preferably, at least one monitoring circuit 38 is provided for the current on the AC side and at the DC output 48 of the power module 3. The monitoring circuit 38 can include a comparator.

[0048] Another preferred embodiment provides that each power module 3 has at least one monitoring circuit 38 which generates a shutdown signal if a limit value of the output current of the power module 3 is exceeded, and that the sum of the limit values ​​of the monitoring circuits 38 of the power modules 3 is at most 10% above a limit value of a connection point 2. If the connection point 2 is allowed to supply a maximum of 20% more output current than its rated current, the output currents of the power modules 3 are, for example, limited to approximately 3% of their rated current, which in turn is only a fraction of the total rated current, here, for example, one-seventh (in the case of seven power modules 3). Preferably, the sum of the limit values ​​of the power modules 3 is at most the limit value of the connection point 2; more preferably, the sum of the limit values ​​of the power modules 3 is below the limit value of the connection point 2.

[0049] In a further preferred embodiment, the power modules 3 are bidirectionally connectable to each other on the output side. The diode 20 shown is then omitted. It is then possible that, in the event of an emergency shutdown of at least one power module 3, in particular the fast charging station 1, at least one power module 3 discharges an energy storage device 10 of another power module 3 via a discharge circuit 12 of the power module 3, in particular only partially simultaneously with a discharge circuit 12 of the other power module 3. If two power modules 3 are connected in parallel, of which only one is active, the other can assist in the discharge process.

[0050] The switching matrix 4 is preferably controlled such that at least sometimes two power modules 3 supply different amounts of power. Preferably, the switching matrix 4 is controlled such that sometimes one power module 3 supplies no power and is nevertheless connected in parallel to another power module 3 that does supply power. It can therefore be provided that a power module 3 that does not supply power is connected in parallel to another power module 3 that does supply power during a charging process.In the event of a failure of the control unit 15 of the power module 3, which provides the power, which preferably results in an emergency shutdown, in particular through cascading triggering of the monitoring circuits 38 of one or more power modules 3, the discharge circuit 12 of the power module 3, which has not provided any power, together with the discharge circuit 12 of the power module 3, which has provided power, discharges an energy storage device 10 of the power module 3, which has provided power.

[0051] According to a further teaching, a method for operating a proposed fast charging station 1 for electric vehicles is proposed, wherein the fast charging station 1 has a power converter arrangement 9 for converting an alternating voltage as input voltage of the fast charging station 1 into a direct voltage as output voltage of the fast charging station 1, wherein the power converter arrangement 9 has at least one energy storage device 10.

[0052] Essential to this further teaching is that the converter arrangement 9 has a discharge circuit 12 connected to the energy storage device 10 for discharging the energy storage device 10, that the discharge circuit 12 is in a discharged state by default, in which the energy storage device 10 is discharged via the discharge circuit 12, that the discharge circuit 12 is actively brought into an inactive state by a control unit 15 during operation of the converter arrangement 9, in which the discharge circuit 12 does not discharge the energy storage device 10, and that the discharge circuit 12 automatically switches to the discharged state in the event of a failure, in particular an emergency shutdown, of the control unit 15.

[0053] Reference may be made to all statements regarding the proposed fast charging station 1. List of reference symbols 1 fast charging station 2 connection point 3 Power module 4 switching matrix 5 DC rail 6 switches 7 output switches 8 Exit fuse 9 Power converter arrangement 10 Energy storage 11 DC connection 12 Discharge circuit 13 DC / DC converters 14 AC / DC converters 15 Control unit 16 NC switching element 17 Short-circuit branch 18 PTC heating elements 19 Connecting Circle 20 diode 21 Switching element 22 Transformer 23 Home page 24 DC+ connection 25 DC connection 26 first circuit branch 27 semiconductor switching elements 28 first output-side connection 29 second circuit branch 30 Semiconductor components 31 second output-side connection 32 Connecting branch 33 third circuit branch 34 Neutral point 35 Neutral point connection 36 Coupling capacitor 37 Connecting circuit capacitor 38 Monitoring circuit 39 AC / DC driver stage 40 DC / DC driver stage 41 Power module control unit 42 Auxiliary voltage input 43 CAN connector 44 AC input 45 Input filter stage 46 Output filter stage 47 Entrance page 48 DC output QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] EP 4 109 724 A1

[0037]

Claims

[1] Fast charging station for electric vehicles, wherein the fast charging station (1) has a power converter arrangement (9) for converting an alternating voltage as the input voltage of the fast charging station (1) into a direct voltage as the output voltage of the fast charging station (1), wherein the power converter arrangement (9) has at least one energy storage device (10), characterized bythat the power converter arrangement (9) has a discharge circuit (12) connected to the energy store (10) for discharging the energy store (10), that the discharge circuit (12) is in a discharging state by default, in which the energy store (10) is discharged via the discharge circuit (12), that the discharge circuit (12) is actively brought into an inactive state by a control unit (15) during operation of the power converter arrangement (9), in which state the discharge circuit (12) does not discharge the energy store (10), and that the discharge circuit (12) automatically changes to the discharging state in the event of a failure, in particular an emergency shutdown, of the control unit (15). [2] Fast charging station according to claim 1, characterized by that the discharge circuit (12) is not programmable, and / or that the discharge circuit (12) does not require and uses a supply voltage to transition from the inactive state to the discharging state. [3] Fast charging station according to claim 1 or 2, characterized by that the discharge circuit (12) has a normally closed (NC) switching element (16) which is arranged in a short-circuit branch (17) via which the energy store (10) is discharged. [4] Fast charging station according to claim 3, characterized by that a positive temperature coefficient (PTC) heating element (18) is arranged in the short-circuit branch (17), which heating element limits a discharge current of the energy store (10) by a temperature-dependent increase in the electrical resistance of the short-circuit branch (17). [5] Fast charging station according to one of the preceding claims, characterized bythat the power converter arrangement (9) has an AC / DC converter (14), a DC / DC converter (13) and a connecting circuit (19) on the output side of the AC / DC converter (14) and on the input side of the DC / DC converter (13), preferably that the DC / DC converter (13) is galvanically isolated, and / or that a diode (20) is arranged between the power converter arrangement (9) and a connection point (2) of the rapid charging station (1). [6] Fast charging station according to claim 5, characterized by that an energy store (10) with a discharge circuit (12) is arranged on the input side of the galvanic isolation and / or on the output side of the galvanic isolation, in particular in front of the diode (20). [7] Fast charging station according to claim 5 or 6, characterized bythat the control unit (15) discharges the energy store (10) in a shutdown routine by controlling switching elements (21) of the DC / DC converter (13) and / or the AC / DC converter (14), that the control unit (15) does not carry out the shutdown routine in the event of a failure and preferably does not further control the switching elements (21) of the DC / DC converter (13) and / or the AC / DC converter (14), further preferably that the switching elements (21) of the DC / DC converter (13) and / or the AC / DC converter (14) are normally open (NO) switching elements (21). [8] Fast charging station according to one of the preceding claims, characterized bythat the rapid charging station (1) has at least one power module (3) which has the power converter arrangement (9), preferably that the rapid charging station (1) has a plurality of power modules (3) with power converter arrangements (9), further preferably that the power modules (3) can be flexibly distributed between at least two connection points (2) of the rapid charging station (1). [9] Fast charging station according to one of claims 5 to 8, characterized by that the power module (3) has at least one monitoring circuit (38) which in particular monitors a current and / or a voltage and / or a temperature and generates a shutdown signal when a limit value is exceeded, preferably that the shutdown signal leads to an emergency shutdown of the control unit (15) and therefore the discharge circuit (12) automatically goes into the discharging state. [10] Fast charging station according to claim 9, characterized bythat the power module (3) has at least two galvanically isolated monitoring circuits (38), each of which monitors in particular a current and / or a voltage and / or a temperature and generates a shutdown signal when a limit value is exceeded, preferably that each of the shutdown signals leads to an emergency shutdown of the control unit (15) and therefore the discharge circuit (12) automatically goes into the discharging state. [11] Fast charging station according to claim 10, characterized bythat one of the galvanically isolated monitoring circuits (38) is arranged on the input side of the galvanic isolation of the DC / DC converter (13) and one of the galvanically isolated monitoring circuits is arranged on the output side of the galvanic isolation of the DC / DC converter (13), that a switch-off signal of the monitoring circuit (38) arranged on the output side of the galvanic isolation of the DC / DC converter (13) sends a switch-off signal to a driver stage on the output side (23) of the DC / DC converter (13), which switch-off signal switches off in response to the switch-off signal, that in response to the switch-off of the driver stage on the output side (23) of the DC / DC converter (13), the monitoring circuit (38) on the input side of the galvanic isolation of the DC / DC converter (13) detects that the limit value has been exceeded and generates a switch-off signal. [12] Fast charging station according to claim 8 and one of claims 9 to 11, characterized bythat the power modules (3) each have at least one monitoring circuit (38) which generates a shutdown signal when a limit value of the output current of the power module (3) is exceeded, that the limit values of the monitoring circuits (38) of the power modules (3) are in total a maximum of 10% above a limit value of a connection point (2), preferably in total a maximum of the limit value of the connection point (2), more preferably in total are below the limit value of the connection point (2). [13] Fast charging station according to one of claims 8 to 12, characterized bythat the power modules (3) are bidirectionally connectable to one another on the output side, that in the event of an emergency shutdown of at least one power module (3), in particular of the rapid charging station (1), at least one power module (3) discharges an energy store (10) of another power module (3) via a discharge circuit (12) of the power module (3), in particular only partially at the same time as a discharge circuit (12) of the other power module (3). [14] Method for operating a rapid charging station (1) for electric vehicles according to one of the preceding claims, wherein the rapid charging station (1) has a power converter arrangement (9) for converting an alternating voltage as the input voltage of the rapid charging station (1) into a direct voltage as the output voltage of the rapid charging station (1), wherein the power converter arrangement (9) has at least one energy storage device (10), characterized bythat the power converter arrangement (9) has a discharge circuit (12) connected to the energy store (10) for discharging the energy store (10), that the discharge circuit (12) is in a discharging state by default, in which the energy store (10) is discharged via the discharge circuit (12), that the discharge circuit (12) is actively brought into an inactive state by a control unit (15) during operation of the power converter arrangement (9), in which state the discharge circuit (12) does not discharge the energy store (10), and that the discharge circuit (12) automatically changes to the discharging state in the event of a failure, in particular an emergency shutdown, of the control unit (15).

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