Electric charging station

Abstract

The invention relates to an electric charging station (10) for charging a vehicle traction battery, comprising a station housing (12) wherein a dry chamber (11) is provided within the station housing (12), charging power electronics (34) in the dry chamber (11) of the station housing (12), a cooling system (20) wherein a cooling system housing (22) is provided within the station housing (12) which hermetically isolates an air-conducting part of the cooling system (20) from the dry chamber (11), a separate Peltier dehumidifier (40) in the dry chamber (11) of the station housing (12) which has a Peltier element (44) with a hot side (44") and a cold side (44'), wherein the hot side (44") is cooled by a cooling element (32) of the cooling system (20), and wherein the cold side (44') has a condensation surface (42'). thermally assigned, to which a condensate collector (48) is assigned,from which the condensate is discharged from the drying chamber (11) of the station housing (12).

Description

[0001] The invention relates to an electric charging station for charging a vehicle traction battery, and in particular to a high-power charging station which is connected to a medium-voltage network for its power supply.

[0002] Charging stations, especially high-performance charging stations, are typically installed outdoors and can therefore be exposed to a wide range of climatic conditions. Charging stations typically have a powerful cooling system to cool the charging power electronics. In addition to cooling, sufficient and permanent dry air within the charging station's housing must be ensured, particularly to prevent corrosion and permanently ensure the electrical insulation of all electrical components.

[0003] WO 2016 / 198 088 A1 discloses an electrical control cabinet that has a Peltier element for dehumidifying the cabinet's interior. Humidity condenses on the cold side of the Peltier element and is then discharged to the outside via a drain line. The warm side of the Peltier element is cooled by a flow of the interior air, so the temperature difference between the interior air and the cold side of the Peltier element may be only a few degrees Kelvin, which limits the dehumidification performance.

[0004] DE 10 2018 103 706 A1 discloses a charging system for charging a vehicle traction battery. Charging power electronics are arranged in a station housing of the charging system. A cooling system serves to cool the charging power electronics. The charging power electronics are arranged in a space of the station housing, which is separated by a partition wall from an area containing a condenser of the cooling system.

[0005] US 5 884 486 A and KR 10 1 932 654 B1 disclose further prior art.

[0006] The object of the invention is to provide an electric charging station for charging a vehicle traction battery which is corrosion-resistant and reliable even under adverse climatic conditions.

[0007] This object is achieved according to the invention by an electric charging station having the features of claim 1.

[0008] The electric charging station for charging a vehicle traction battery comprises a station housing, wherein a dry space is provided within the station housing, in which the charging power electronics are arranged. Essential parts of a high-performance cooling system, which preferably primarily serves to cool the power electronics and the charging cable, are arranged in the station housing. A cooling system housing is provided within the station housing, which hermetically isolates an air-conducting part of the cooling system from the dry space.

[0009] The cooling system is not designed as a pure ventilation system, but rather generates a temperature below the temperature of the interior air within the station housing, especially during charging mode, or the outside air, especially at locations with temperatures above 10°C. The cooling system does not utilize the Peltier effect.

[0010] The charging station features a separate Peltier dehumidifier within the drying chamber of the station housing. It consists of a Peltier element with a warm side and a cold side. The Peltier element's warm side is actively cooled by a cooling element of the cooling system, so that the Peltier element's warm side is cooled to a temperature below the temperature of the interior air.

[0011] A condensation surface is thermally associated with the cold side of the Peltier element, where the humidity of the indoor air condenses. A condensate collector is spatially associated with the condensation surface in such a way that the condensate forming on the condensation surface collects in the condensate collector, from which the collected condensate is discharged from the dry space of the station housing.

[0012] The condensation surface can be a surface of the Peltier element itself, but can alternatively also be a separate, particularly flat, condensation plate made of a material with good thermal conductivity, which is thermally connected or coupled to the Peltier element's cold side. The condensation plate can, in particular, be designed with a larger surface area than the Peltier element's cold side, thereby improving the drying efficiency of the Peltier dehumidifier.

[0013] The condensation surface cooled by the Peltier element can be cooled to a temperature well below the interior air temperature, thus providing a relatively high dehumidification performance both in the short term and continuously. This allows the charging station to be operated even in unfavorable climatic environments with warm and humid outside air. Furthermore, the charging station can also compensate for a sudden increase in the humidity of the interior air, for example, after opening the station housing, and relatively quickly reduce the humid interior air within the station housing back to the desired humidity level.

[0014] A Peltier dehumidifier contains no mechanical components, ensuring high long-term reliability. Furthermore, a Peltier dehumidifier contains no liquid or gaseous medium that could leak into the interior in the event of a malfunction, thus preventing damage to other parts of the charging station in the event of a Peltier dehumidifier failure.

[0015] The charging station features a hermetically sealed drying chamber containing the charging electronics and the Peltier dehumidifier. The drying chamber is therefore not ventilated with outside air, so the moisture ingress into it is usually low. The average dehumidification capacity required by the dehumidifier during operation is therefore relatively low, meaning that dehumidification can easily be achieved using a Peltier dehumidifier, which, for physical reasons, provides significantly lower cooling capacity than a refrigeration unit.

[0016] The separate cooling system is preferably designed as a gas-conducting refrigeration unit based on a thermodynamic cycle. This makes the cooling system particularly capable of supplying or cooling the charging power electronics and, if necessary, other parts of the charging station, such as a charging cable, buffer batteries, or storage batteries, with a high cooling capacity. Since the refrigeration unit is provided separately from the dehumidifier, the refrigeration unit can essentially be positioned where it cannot cause damage to other parts of the charging station, even in the event of a leak caused by escaping fluid.

[0017] According to a preferred embodiment, the condensation surface is substantially vertical, so that the condensate collecting on the condensation surface drains downwards, where it is collected in the condensate collector. The condensate collector can, for example, be designed as a channel slightly inclined to the horizontal, which is arranged vertically exactly below the condensation surface.

[0018] In principle, pure gravity can be used to drain the condensate. Preferably, a condensate pump is provided upstream of the condensate collector to pump the condensate out of the condensate collector.

[0019] In principle, the condensate from the condensate collector can be drained through a simple pipe into the ground below the charging station.

[0020] The cooling system preferably has an exhaust air duct through which the heated exhaust air coming from a heat exchanger of the cooling system is guided out of the charging station. Particularly preferably, a condensate line is provided between the condensate collector and the exhaust air duct, through which the condensate liquid is introduced into the warm exhaust air of the cooling system, so that the condensate liquid is entrained by the exhaust air flow and, if necessary, immediately absorbed as humidity.

[0021] An exemplary embodiment of the invention is explained in more detail below with reference to the drawings. They show: Fig. 1 schematically shows an electric charging station with a charging power electronics, a cooling system and a Peltier dehumidifier, and Fig. 2 a detailed schematic representation of the Peltier dehumidifier of the Fig. 1.

[0022] In the Fig. Figure 1 schematically shows an electric charging station 10 for charging a vehicle traction battery. The charging station 10 is located outdoors and exposed to the elements. The charging station 10 is a high-performance charging station and can be connected to a medium-voltage or low-voltage power grid in conjunction with buffer or storage batteries. Alternatively or additionally, the charging station 10 can include batteries. The charging station 10 is preferably used for rapid charging of the traction battery.

[0023] The electric charging station 10 essentially comprises, within a station housing 12, a charging power electronics unit 34, a cooling system 20, and a Peltier dehumidifier 40 designed separately from the cooling system 20. The cooling system 20 is designed as a gas-conducting refrigeration machine. A cooling system housing 22 is provided within the station housing 12, which essentially hermetically insulates the air-conducting part of the cooling system 20 from a dry chamber 11 within the station housing 12, which is largely fluidically insulated from the environment, so that essentially no air exchange occurs between the dry chamber 11 and the environment.

[0024] Within the cooling system housing 22, there is essentially an air conditioning compressor 30, an air-cooled heat exchanger 26 arranged downstream of the compressor 30 with respect to the refrigerant circuit, and a throttle element 28 arranged downstream of the heat exchanger 26. Furthermore, within the cooling system housing 22 and, with respect to cooling air flowing in from the outside, downstream of the heat exchanger 26, an exhaust air duct 23 with one or more exhaust air fans 24 is provided therein.

[0025] Downstream of the throttle element 28, outside the cooling system housing 22 and within the dry chamber 11, a cooling element 32 of the coolant circuit in the form of an evaporator or a cooling plate is arranged, which directly cools the power electronics 34 and a Peltier dehumidifier 40 formed separately from the cooling system 20. The entire cooling system can be formed separately in the cooling system housing 22 and cool a cold tank. The liquid from the cold tank is pumped through a cooling plate in the dry chamber.

[0026] The Peltier dehumidifier 40 is in the Fig. 2 in detail. The component of the Peltier dehumidifier 40 that performs the cooling work is a plate-like Peltier element 44, which is arranged vertically and has a cold side 44' and, opposite, a warm side 44". The Peltier element 44 is electrically supplied with electrical energy by an electronic dehumidification controller 60. A metallic and highly thermally conductive condensation plate 42 is applied to the cold side 44' of the Peltier element 44, which is approximately vertical with its base plane and has a larger surface area than the Peltier element 44. The uncovered distal side of the condensation plate 42 forms a free condensation surface 42', on which the humidity of the drying room air condenses. The Peltier element 44 is not directly coupled to the cooling element 32, but is indirectly thermally connected to the cooling element 32 over a large area via a heat coupling plate 46.The warm side 44" of the Peltier element 44 is thus indirectly cooled by the cooling element 32 via the heat coupling plate 46. In this way, the condensation surface 42' can be cooled to a temperature well below the drying room air temperature.

[0027] The peripheral edge of the Peltier element 44 is surrounded by a frame-shaped and heat-insulating insulation body 45.

[0028] Vertically below the condensation surface 42', which is approximately in a vertical plane, there is a condensate collector 48, which is designed as a collecting channel slightly inclined to the horizontal. According to a first embodiment, which is shown in Fig. 1, the liquid condensate 60 collected in the condensate collector 48 flows downwards through a corresponding line into a condensate drain 49, from where the liquid condensate 60 is introduced into the ground below the charging station 10 and seeps in.

[0029] According to a second embodiment described in the Fig. 2, the liquid condensate 60 is pumped from the condensate collector 48 by a condensate pump 50 and via a condensate line 51 to a condensate inlet opening 52 in the upper region of the exhaust air duct 23, so that the liquid condensate is entrained by the warm air flow of the exhaust air duct 23 and transported outside the charging station 10.

Claims

[1] Electric charging station (10) for charging a vehicle traction battery, with a station housing (12), wherein a drying chamber (11) is provided within the station housing (12), with a charging power electronics (34) in the drying chamber (11) of the station housing (12), with a cooling system (20), wherein a cooling system housing (22) is provided within the station housing (12), which hermetically insulates an air-conducting part of the cooling system (20) from the drying room (11), with a separate Peltier dehumidifier (40) in the drying chamber (11) of the station housing (12), which has a Peltier element (44) with a warm side (44") and a cold side (44'), wherein the warm side (44") is cooled by a cooling element (32) of the cooling system (20), wherein the cold side (44') is thermally assigned a condensation surface (42'), to which a condensate collector (48) is assigned, from which the condensate is led out of the drying space (11) of the station housing (12). [2] Electric charging station (10) according to claim 1, wherein the cooling system (20) is designed as a gas-conducting refrigeration machine. [3] Electric charging station (10) according to one of the preceding claims, wherein the condensation surface (42') is substantially vertical. [4] Electric charging station (10) according to one of the preceding claims, wherein a condensate pump (50) is provided upstream of the condensate collector (48) to pump the condensate out of the condensate collector (48). [5] Electric charging station (10) according to one of the preceding claims, wherein the cooling system (20) has an exhaust air duct (23) and a condensate line (51) connected to the condensate collector (48) opens into the exhaust air duct (23).

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