Charging cable unit for a charging station of an electric vehicle charging station and use of such a unit

Abstract

Charging cable unit (40) for a charging station (30) of an electric vehicle charging station, characterized by the following features: - the charging cable unit (40) includes a cooling unit (10) and a charging cable (17), - the charging cable (17) has a secondary coolant circuit, - the cooling unit (10) includes a heat exchanger (20) with first connections (11, 13) and second connections (15, 16), - the second connections (15, 16) are fluidically connected to the secondary coolant circuit and - the cooling unit (10) is designed to cool the secondary coolant circuit when the first connections (11, 13) are fluidically connected to a common primary coolant circuit of the electric vehicle charging station.

Description

[0001] The present invention relates to a charging cable unit for a charging station of an electric vehicle charging station. The present invention further relates to a use of such a charging cable unit. State of the art

[0002] In electrical engineering, a charging station is any stationary device or electrical system that serves to supply energy to mobile battery-powered devices, machines, or motor vehicles simply by placing them on or plugging them in, without having to remove the energy storage device—such as the traction battery of an electric car. Charging stations for electric cars are also colloquially referred to as "electric vehicle charging stations" and can include multiple charging points, which, depending on their design, are characterized as "charging columns."

[0003] Particularly well-known here are high-performance DC fast charging (HPC) systems, such as the combined charging system (CCS) widely used in Europe. In standard DC charging, direct current from the charging station is fed directly into the vehicle. This is achieved by a high-performance rectifier supplied by the power grid or, at solar charging stations, by large buffer batteries. The vehicle contains a battery management system that communicates with the charging station to adjust the current or to terminate the charging process when a capacity limit is reached.

[0004] The necessary power electronics are typically integrated into the charging station according to current technology and can handle loads up to a power limit of 50 kW. Since the DC connections of the charging station are directly connected to corresponding connections of the traction battery, high charging currents can be transmitted with minimal loss, enabling short charging times, but also resulting in heat generation.

[0005] To minimize the weight and flexibility of the charging cable for the user, cable cooling systems with liquid-cooled charging cables are described in the literature. Such systems sometimes present problems during installation, commissioning, and maintenance. The charging cable, in particular, is subject to high wear and tear due to regular use, weather conditions, or improper handling. However, replacing and installing the cable generally requires mounting the cooling system components or connecting the cable cooling circuit to the charging station's cooling system. This necessitates adding coolant and bleeding the cooling circuit to ensure trouble-free operation. These tasks are time-consuming, prone to errors, and tie up maintenance teams on-site at the charging stations.

[0006] Alternatives with leak-free or even dead-volume-free connectors, which could eliminate the need for filling or venting, are disproportionately expensive and sensitive. For example, DE 10 2007 041 110 B4 discloses an electrical connection with a connecting cable and connector, each of which has a cavity for coolant. The connector also has a valve that closes a first opening of the cavity when the connection point of the connecting cable is disconnected from the connector; the connection point has a corresponding valve that closes a second opening of the cavity when the connection point is disconnected from the connector.

[0007] EP 0 800 234 B1 relates to a plug-in coupling for supply or monitoring and control lines with socket and plug, which forms three coupling points consisting of coupling pins on the one hand and coupling sleeves on the other, wherein in addition to the coupling points for electrical lines a coupling point for the pressure medium line is provided and the coupling pin and the coupling sleeve of this coupling point have axial bores and end-end hose connections and a check valve is arranged in the axial bore of the coupling sleeve, which can be pressed open by the coupling pin penetrating into the coupling sleeve.

[0008] EP 2 909 893 A1 concerns another charging cable cooling system.

[0009] CN 1 06 711 549 A reveals a fast charging station with a cooling system and a heating system.

[0010] US 2013 / 0069592A1 discloses a charging system for electric vehicles comprising at least one charging port with an interface for exchanging power with at least one electric vehicle and at least one power converter for converting power from a power source, such as a power grid, into a suitable format for charging the vehicle.

[0011] US 2017 / 0028862A1 discloses a charging station with a charging cable for charging an electrical energy storage device, wherein the charging cable is connected to the charging station at a proximal end and has a first connector at a distal end for connecting to a second connector of a device to be charged which contains an electrical energy storage device, wherein the first connector has first electrical contact elements for electrical connection to second electrical contact elements of the second connector, wherein the charging cable has electrical connecting leads for electrically connecting the first contact elements to a voltage source of the charging station, and wherein the charging cable has a fluid channel for guiding a fluid from the charging station towards the first connector and from the first connector back to the charging station.

[0012] US 2005 / 0 046 387 A1 discloses a highly efficient rapid charger for high-capacity batteries and methods for rapid charging of high-capacity batteries. Disclosure of the invention

[0013] The invention provides a charging cable unit for a charging station of an electric vehicle charging station and a use of such a charging cable unit according to the independent claims.

[0014] One advantage of this solution is that the cooling system can be delivered and installed already filled, without the need to remove any components. This eliminates the need to bleed the cooling circuit on site.

[0015] For charging cable cooling, the charging cable's cooling circuit is simply connected to the charging station's liquid cooling circuit via a heat exchanger, which may use a different cooling medium. All connectors and couplings preferably allow for quick assembly (quick-release couplings, etc.).

[0016] The cooling unit is preferably located at a high point in the charging station. This way, during on-site installation, the cable and cooling unit only need to be lowered into the charging station from above.

[0017] The charging cable is secured only by a few fixings to the sheath (clamping, at the exit from the charging station and possibly in a support arm of the station) and by fixing or suspending the cooling unit inside the charging station.

[0018] Further advantageous embodiments of the invention are specified in the dependent claims. For example, a corresponding arrangement according to the invention allows the charging cable to be threaded into the stationary charging station from the outside. This also allows a bulky element (cooling system, etc.) to be easily inserted at the charging station-side end.

[0019] The solution presented here routes the cable over the roof. Alternatively, however, the solution can be used for any other routing at a charging station without departing from the scope of the invention. Brief description of the drawings

[0020] An embodiment of the invention is shown in the drawings and is described in more detail below. Fig. Figure 1 shows the perspective view of a first charging station. Fig. Figure 2 shows the exploded view of a second charging station. Fig. Figure 3 shows the perspective view of a cooling unit of the second charging station. Fig. Figure 4 shows a partial exploded view of a third charging station. Embodiments of the invention

[0021] Fig. Figure 1 illustrates the basic structure of the proposed charging station (30). As an essential feature of the invention, the charging station (30) includes a cooling unit (10) which cools the closed secondary coolant circuit of the charging station (30) when the charging station (30) is connected fluidically to the common primary coolant circuit of several charging stations of an electric vehicle charging station.

[0022] A summary of the slightly different embodiment according to Fig. 2 with whose in Fig. Figure 3 of the detailed illustration of the cooling unit (10) clarifies this operating principle: The cooling unit (10) is based on a heat exchanger (20) with first connections (11, 13) and second connections (15, 16). While the first connections (11, 13) are connected to the connection points (21) of the primary coolant circuit via two hoses (19) with shut-off valves (18), the second connections (15, 16) supply the secondary coolant circuit via a pump (14) with an expansion tank (12), the heat from which is to be transferred to the primary coolant circuit via the heat exchanger (20). While the primary coolant circuit typically uses a water-glycol mixture, the secondary coolant circuit can be filled with a synthetic fluid such as methoxyhepta- or -nonafluoropropane, hydrofluoroether, fluoroketone or other non-conductive and preferably inert fluid sold under the trade name "Novec".

[0023] The pre-assembled charging cable unit (40) with cooling system can be easily installed in the also in Fig. Lower the internal frame (34) of the charging station (30) shown in Figure 2. The housing of this frame is formed by outer walls (32, 35) with externally attached support plates (31, 36) made of resin mat (sheet molding compound, SMC) and is accessible via a locking mechanism (37) on the left outer wall (32). A top cable holder (33) and a roof (38) with a drip edge are arranged in a form-fitting manner between the upper ends of the support plates (31, 36), as shown in the figure. The cable holder (33) in turn consists of two injection-molded parts, which accommodate the cooled charging cable (17) between them via two complementary shaped recesses.

[0024] This assembly process is now shown using the third design of a charging station (30) according to Fig.4 explained: Preferably the charging cable unit (40) already fits through the illustrated metallic roof frame (39) with round cutout; otherwise, this roof frame (39) is only subsequently inserted via the plug side of the charging cable (17).

[0025] A sealing plate (44), in this case circular and made of plastic, is then slid over the cover. This sealing plate (44) may already be threaded onto the supplied charging cable (17). In this case, it may also be fixed and sealed to the charging cable (17) by gluing, or its seal may be ensured by radial pressure. In the latter case, the inside of the sealing plate (44) is preferably elastic or covered with an elastic material.

[0026] Alternatively, the charging cable unit (40) with cooling system is inserted into the charging station (30) from the front through a door opening, and the charging cable plug (17) is fed through the roof opening. In this assembly step, the sealing plate (44) is already threaded onto the charging cable (17) and, if necessary, secured, as described above. Finally, a roof panel (43) – in this case, rectangular – is attached. Because of the existing sealing plate (44), this panel may have a larger cutout in the center to allow it to be threaded onto the charging cable (17) from the plug side on site.

[0027] The sealing plate (44) is preferably an injection-molded plastic part with a sealing ring. The roof panel (43) can, for example, be an injection-molded plastic or metal part. The illustrated support arm is optional and not essential for carrying out the invention. If it is present, a strain relief (42) at the end of the support arm is advantageous. If it is not present, a corresponding strain relief (42) can be attached to the roof or integrated into the sealing plate (44).

[0028] The strain relief (42) can, for example, consist of a conventional ring made of elastic material such as plastic, nitrile butadiene rubber (NBR), or other rubber around the charging cable (17), as well as at least one plastic enclosure or other locking mechanism that exerts pressure on the elastic ring. The ring can either be pre-threaded or slotted in the charging cable assembly (40) as delivered.

[0029] Alternatively, the strain relief (42), made here of nickel-plated brass, can be threaded onto the charging cable (17) and glued or otherwise fixed in the correct position. Its initial positioning in the correct position eliminates the need for on-site alignment. The chosen position determines the length of the arc from the roof to the end of the support arm and the length of the charging cable (17) from the support arm, which in turn determines whether the charging cable (17) drags on the ground during the intended maneuvers and car charging socket positions or reaches the charging port. The fixed strain relief (42) is positioned radially by the two illustrated plastic half-shells with a screwed-on cable holder (41) and fixed axially – note the negative recesses for the "plate".

Claims

[1] Charging cable unit (40) for a charging station (30) of an electric vehicle charging station, characterized by the following characteristics: - the charging cable unit (40) includes a cooling unit (10) and a charging cable (17), - the charging cable (17) has a secondary coolant circuit, - the cooling unit (10) includes a heat exchanger (20) with first connections (11, 13) and second connections (15, 16), - the second connections (15, 16) are fluidically connected to the secondary coolant circuit and - the cooling unit (10) is designed to cool the secondary coolant circuit when the first connections (11, 13) are fluidically connected to a common primary coolant circuit of the electric vehicle charging station. [2] Charging cable unit (40) according to claim 1, characterized by the following characteristics: - the cooling unit (10) includes a pump (14) and - the pump (14) is fluidically connected to the second connections (15, 16). [3] Charging cable unit (40) according to claim 2, characterized by the following characteristics: - the cooling unit (10) includes an expansion tank (12) and - the expansion tank (12) is fluidically connected to the pump (14). [4] Charging cable unit (40) according to one of claims 1 to 3, characterized by the following characteristics: - the charging cable unit (40) includes hoses (19) for connection to the primary coolant circuit and - the first connections (11, 13) are fluidically connected to the hoses (19). [5] Charging cable unit (40) according to one of claims 1 to 4, characterized by the following characteristic: - The secondary refrigerant circuit is filled with a non-reactive, inert, non-conductive fluid. [6] Charging cable unit (40) according to claim 4 or 5, characterized by the following characteristics: - the hoses (19) have shut-off valves (18) and connection points (21) for connecting the primary coolant circuit and - the shut-off valves (18) are located at the connection points (21). [7] Use of a charging cable unit (40) according to claim 6, characterized by the following characteristics: - one charging station (30) is installed at an electric vehicle charging station with a common primary coolant circuit, - the charging cable unit (40) is placed and mounted below a roof frame (39) in the charging station (30), - the primary coolant circuit is connected to the connection points (21) and - a roof panel (43) is threaded onto the charging cable (17) and placed on the charging station (30). [8] Use according to claim 7, characterized by the following characteristics: - the charging cable unit (40) is lowered from above into the charging station (30) and - a circular sealing plate (44) is pushed over a roof frame (39). [9] Use according to claim 7, characterized by the following characteristics: - the charging cable unit (40) is preferably inserted into the charging station (30) from the front through a door opening and - the charging cable (17) is led upwards out of the charging station (30). [10] Use according to any one of claims 7 to 9, characterized by the following characteristics: - a strain relief (42) is threaded onto the charging cable (17) and - the strain relief (42) is fixed axially to the charging cable (17) with a cable holder (41).

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