Method for operating a charging system for transferring electrical energy to a motor vehicle

Abstract

The invention relates to a method for operating a charging system (1) for transferring electrical energy to a motor vehicle, comprising the following steps: - Use of a cooling device (2) of the charging system to cool a fluid; - Storage of the cooled fluid in a fluid storage unit (3) of the charging system; and - Discharge of the cooled fluid from the fluid storage tank (3) into a district cooling network (4); and / or - Reception of the cooled fluid from the district cooling network (4) in the fluid storage tank (3).

Description

[0001] The present invention relates to a method for operating a charging system for transferring electrical energy to a motor vehicle according to claim 1.

[0002] It is known from the prior art to use the high-performance cooling devices of such charging systems to cool a fluid in a fluid reservoir. From DE 10 2022 127 428 A1, it is known to use such a fluid reservoir to dampen power peaks and / or dips that occur during varying levels of use of the charging system. Furthermore, a fluid reservoir is used to store the fluid for multiple charging devices of the charging system.

[0003] DE 10 2017 219 736 A1 describes a charging station for electric vehicles which, in addition to a charging plug, also includes a media plug through which both cooling and heating media can be exchanged between a vehicle-side temperature control circuit and the charging station. The charging station can be connected to external heat or cooling suppliers and is capable of dissipating or supplying heat independently of the charging process, with temperature-dependent control. Furthermore, a payment interface for the dissipated or supplied heat is provided.

[0004] DE 10 2018 103 706 A1 describes a charging system for electric vehicles comprising a charging station, at least one charging port, a buffer storage unit for energy storage, power electronics for energy supply, and a refrigerant storage unit for cooling the power electronics. The refrigerant can also be used to cool the buffer storage unit, the charging cable, and the charging port, whereby the refrigerant storage unit and / or the buffer storage unit can be located underground. The cooling system can also function as a temperature control system by using the refrigerant for heating.

[0005] DE 10 2020 204 691 A1 describes a charging device for electrical energy storage devices, comprising at least one interface for the transmission of electrical energy and another for the transmission of thermal energy. A thermal storage device is thermally and / or fluidically connected to a temperature control system of the charging device and to at least one further temperature control system of another charging device. The technical solution enables the shared use of a thermal storage device for temperature control of several charging devices.

[0006] DE 10 2017 110 703 A1 describes a cooling device for cooling one or more charging stations in a charging park, wherein each charging station has an internal coolant channel with inlet and outlet connections. The system comprises a coolant circuit with a cooling unit and a pump, the coolant channels of the charging stations being integrated into the circuit. Additionally, one or more thermal storage units are provided in the coolant circuit to buffer thermal energy and optimize cooling performance.

[0007] DE 10 2022 201 609 A1 describes an intelligent charging arrangement for charging traction batteries, in which at least one temporary cooling circuit between the traction battery and the charging device, an external cooling circuit between the charging infrastructure and a building, and at least one internal cooling circuit of the charging infrastructure are thermally interconnected. The aim is to achieve improved overall efficiency and operation without an air cooler by flexibly coupling the various cooling circuits.

[0008] In contrast, the present invention is based on the objective of making better use of the cooling device.

[0009] This problem is solved by a method according to claim 1 and a charging system according to claim 4. Embodiments of the invention are specified in the dependent claims.

[0010] The charging system's cooling device is used to cool a fluid. This fluid could be, for example, water. The cooled fluid is stored in a fluid reservoir within the charging system. This cooled fluid can then be used to cool components of the charging system during the transfer of electrical energy to the vehicle.

[0011] The cooled fluid is discharged from the fluid storage tank into a district cooling network. This preferably occurs when the charging system itself requires little or no cooling. For example, this might be during times when the charging system is not in use or is only lightly used. This is often the case with charging systems at night. The charging system may, for example, include a connection to the district cooling network. The district cooling network could, for example, be a public district cooling network.

[0012] When the cooled fluid is discharged into the district cooling network, uncooled fluid can flow in via an inlet connection of the charging system, thus maintaining a constant fluid mass within the system. This incoming fluid can then be cooled again by the refrigeration unit.

[0013] Alternatively or additionally, the cooled fluid in the fluid storage tank can be received from the district cooling network. This can be advantageous, for example, during peak loads of the charging system's charging capacity and / or at high outside temperatures. Under certain circumstances, the charging system can then be designed to be smaller and / or more cost-effective, while still providing sufficient cooling thanks to the cooling effect received from the district cooling network.

[0014] The cooled fluid is also used to cool components of the charging system during the transfer of electrical energy to the vehicle. For example, after being used to cool the components, it can be cooled again and then fed into the district cooling network.

[0015] Cooling the components has a higher priority than discharging the cooled fluid into the district cooling network. In the context of this description, this means in particular that discharging the cooled fluid into the district cooling network only occurs if the fluid is not needed, or at least not completely needed, for cooling the components.

[0016] According to one embodiment of the invention, only the portion of the cooled fluid not required for cooling the components can be discharged into the district cooling network. For example, this portion can be estimated using computer assistance based on the current utilization of the charging system and / or historical data.

[0017] According to one embodiment of the invention, the cooled fluid can only be discharged into the district cooling network if it is not required for cooling the components. This can mean, in particular, that the cooled fluid is not discharged into the district cooling network if a portion of the fluid is needed for cooling the components.

[0018] The charging system according to claim 6 comprises a fluid storage unit, a cooling device, and a connection to a district cooling network. The charging system is configured to execute a method according to an embodiment of the invention. The dispensing and / or receiving of the cooled fluid takes place via the connection.

[0019] According to one embodiment of the invention, the charging system can comprise several charging devices. Each charging device can be configured to transfer electrical energy to a motor vehicle. Thus, electrical energy can be transferred to several motor vehicles simultaneously. The fluid storage unit can be fluidically connected to the charging devices, so that the cooled fluid can be used to cool the charging devices, particularly during the transfer of electrical energy.

[0020] Further features and advantages of the present invention will become clear from the following description of a preferred embodiment with reference to the accompanying figure. This figure shows Fig. 1 A schematic view of a charging system according to an embodiment of the invention.

[0021] The charging system 1 comprises a cooling device 2 and a fluid storage tank 3. The fluid storage tank 3 is fluidically connected to the cooling device 2, allowing cooled fluid in the cooling device 2 to flow into the fluid storage tank 3. When the charging system 1 is used to transmit electrical energy to a motor vehicle, components of the charging system 1 that heat up considerably during transmission are cooled by the fluid. The heat generated in or by the components during transmission is transported by the fluid to the cooling device 2, where it is dissipated by the cooling device to the surrounding environment of the charging system 1. These surrounding components can be, for example, resistors and components of a voltage converter. When the charging system 1 is not used to transmit electrical energy, the cooled fluid from the fluid storage tank 3 is discharged into a public district cooling network 4 to which the fluid storage tank 3 is connected.Preferably, the district cooling network is a closed loop, so that the mass of the fluid in the charging system 1 remains constant and only the temperature of the fluid changes.

[0022] It is also possible that the charging system 1 receives the cooled fluid from the public district cooling network 4 and stores it in the fluid storage tank 3. In this case, the additional cooling capacity can be used to adequately cool the charging system 1 during peak loads and / or high outside temperatures.

[0023] It is also possible for the fluid to be used simultaneously for cooling the components of charging system 1 and to be supplied to the district cooling network 4. This can be done, for example, if the cooling capacity is much higher than the cooling capacity required to adequately cool the components.

Claims

[1] Method for operating a charging system (1) for transferring electrical energy to a motor vehicle, comprising the following steps: - Use of a cooling device (2) of the charging system to cool a fluid; - Storage of the cooled fluid in a fluid storage unit (3) of the charging system; and - Output of the cooled fluid from the fluid storage (3) into a district cooling network (4), wherein the cooled fluid is also used to cool components of the charging system (1) during the transmission of electrical energy to the motor vehicle, and wherein the cooling of the components has a higher priority than the output of the cooled fluid into the district cooling network (4). [2] Method according to the previous claim, characterized by , that only such proportion of the cooled fluid is discharged into the district cooling network (4) that is not required for cooling the components. [3] Method according to any one of the preceding claims, characterized by, that the cooled fluid is only discharged into the district cooling network (4) when it is not needed for cooling the components. [4] Charging system (1) for transmitting electrical energy to a motor vehicle, comprising a cooling device (2), a fluid storage device (3) and a connection to a district cooling network (4), wherein the charging system (1) is configured to perform a method according to one of the preceding claims, wherein the output and / or reception of the cooled fluid is carried out via the connection. [5] Charging system (1) according to the previous claim, characterized by , that the charging system (1) comprises several charging devices, each of which is designed to transfer electrical energy to a motor vehicle, wherein the fluid storage unit (3) is fluidically connected to the charging devices so that the cooled fluid can be used to cool the charging devices.

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