WO2024061461A1

WO2024061461A1 - Off grid self sufficient electric vehicle charging station

Info

Publication number: WO2024061461A1
Application number: PCT/EP2022/076277
Authority: WO
Inventors: Ralph Max HOFMEIER; Irma VELAZQUEZ DIAZ
Original assignee: Energy And Water Development Corp
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2024-03-28

Abstract

The invention relates to an off-grid self-sufficient charging station for electric trucks while generating the required energy for its function and a method to control the charging. The charging station according to the invention is an off-grid system and has its own micro grid, which electrically connects the different components of the system. The system comprises at least one energy generation device, at least one charging point for charging at least one battery in an electric heavy vehicle and at least one electric storage unit for storing electric energy and at least one energy management systemThe charging station is preferably used for charging trucks.

Description

Off Grid Self Sufficient Electric Vehicle Charging Station

The invention relates to an off-grid self-sufficient charging station for electric trucks while generating the required energy for its function and a method to control the charging.

Electric vehicles have become popular to reduce the consumption of fossil fuel and to reduce the carbon footprint when using such vehicles. Like vehicles with a combustion engine electric vehicles do not produce the energy they consume and need to be charge on a regular basis. While charging stations for electric cars are becoming increasingly common, there is virtually no public infrastructure for charging electric trucks. At the same time, the public charging infrastructure for cars continues to grow, and there are already concerns about the capacity of the power grids. The charging of electric trucks may lead to an overuse of power grids and there are concern that the public grid needs improvement with preparing and expanding the networks to meet the requirements for truck charging on a wide basis.

Both sectors use the same Combined Charging System, such as CCS2, standard for charging up to 350 kilowatts (kW). However, as trucks have considerably higher battery capacities, it is unpractical to charge them with lower power chargers. Hence, high charging powers of e.g. over 80kW are typically used.). As is already know from petrol stations special areas for trucks are necessary to be usable for trucks their dimensions, especially lengths and height.

DE 10 2018 203 387 A1 describes a charging station for electric cars. In comparison to charging stations that are state of the art this charging stations allows to charge two vehicles. The charging system has a first and a second plug device and an electrical charging system with a switching mode which prevents an output of the first electrical current to the first plug device if the second electrical current is flowing through the second plug device.

Thus, the technical object may be providing a charging station navigable by electric trucks, an improved charging system that does not overuse the public grid and provides a secure energy supply while enabling the charging of several trucks at the same time, and preventing carbon footprint.

Claims 1 and 12 indicate the main features of the invention. Features of embodiments of the invention are subject of claims 2 to 11 and 13 to 14 or describes below.

Subject of the invention is a self-sufficient truck charging station for electric heavy vehicles, preferably electric trucks, comprising

- at least one energy generation device,

- at least one charging point for charging at least one battery in an electric heavy vehicle,

- at least one electric storage unit for storing electric energy and

- at least one energy management system, which controls the energy consumption and energy distribution of the charging station.

The at least one energy generation device comprises at least one solar glass component for generating energy, preferably a plurality of solar glass components, and a base structure on which the solar glass components are mounted. The at least one energy generation device is electrically connected to at least one charging point and/or at least one electric storage unit. The charging station is an off-grid system. The term solar glass component may refer more broadly to solar panels or it may specifically refer to improved versions of solar panels, which show better characteristics, in particular higher electricity generation, than solar panels, especially in adverse weather and shading conditions.

The charging station according to the invention is an off-grid system. An Off-Grid system, also called stand-alone system, is a solar cell system that is operated independently of the public grid, i.e. autonomously. Accordingly, the off-grid system has no connection to the public power grid. Such systems are used where connection to the public grid is impossible or uneconomical. In order for such an off-grid PV system to operate optimally, the electricity generated with it can be temporarily stored in an energy storage device. The Off-Grid system is not connected to the public power grid but is independent of the public grid and isolated from the public grid. The charging station has its own micro grid, which electrically connects the different components of the system.

Electric heavy vehicles are for example electric trucks, electric busses and electric special purpose vehicle. The charging station is preferably used for charging trucks. The charging station can be used to charge any other electric vehicle since as it can have the most common and standard connectors or adapters.

Preferably at least one charging point provides at least 100 kilowatts (kW) power for charging, preferably 100 kW, more preferably 200 kW (DC) and optionally between 300 kW up to 400 kW for hyper charging. The charging point has at least one connector or adapter which can be connected to an electric heavy vehicle.

In one embodiment the charging point has at least two charging posts, preferably two charging posts with at least 100 kW and 50 kWp (kW peak) for simultaneous charging. Some typical charging times of different vehicles at the charging station are provided in Table 1 . Generally, the charging time depends on the size of the battery and the maximum charging power that the vehicle can take. The size of the battery and the maximum charging power input being the most significant parameters, small and medium vehicles rarely exhibit maximum charging power over 50kW and very rarely over 80 kW. However, maximum charging power of trucks or other heavy vehicles can be up to 400 kW. The maximum charging power of small and medium vehicles may range from 7 kW to 80 kW, whereas maximum charging power of trucks and other heavy equipment can range from 50 kW to 400 kW. Typically, small and medium size cars and vans have similar maximum ranges when fully loaded.

Table 1 Examples of Charging capacity and charging time.

The invention provides an Off-grid charging station, which uses solar energy as energy source for the charging points. The charging station has at least one energy storage device, preferably at least one battery, for storing energy. Highly efficient battery systems and energy management systems may be employed. Possible batteries include LiFePO4 (lithium iron phosphate), LTO (lithium titanate batteries), NMC and NCA batteries which includes cobalt. All of the batteries may be lithium-ion batteries. However, a preferred embodiment comprises LiFePO4 batteries, as they are the most common and most cost-effective type of batteries.

Particularly, if the energy generation device produces a higher amount of energy than required for the operation of the charging points, the excess energy being produced may be stored in the energy storage device. Furthermore, if the solar glass component does not produce enough energy for the operation of the charging points, the energy storage system may provide energy to the charging points.

The energy storage device may for example be a Lithium Iron Phosphate battery (LiFePO4-bat- tery). However, the energy storage device may also be a lithium-ion battery, a lithium iron polonium battery, or another kind of energy storage. The energy storage device may have a weight of 100 kg to 1000 kg, preferably, 200 kg to 500 kg, preferably around 400 kg.

The charging station can further comprise an inverter which converts the energy coming from the solar glass components in the form of DC voltage. The inverter charger converts the energy from for example solar panels and optionally a MPPT device in the form of DC voltage to charge the batteries and to provide the energy required by the load in the form of for example a 3 Phase 3P+N+E 400VAC voltage. The inverter must be at least 50 kW peak and the charger also 50 kW peak.

The charging station can have at least one DC/DC Converter and/or or at least one MPPT device. The DC/DC converter controls converting all the energy coming from the solar glass component and combiner boxes to a stable voltage connection to the inverter/chargers and then to energy storage units and charging points (load). The MPPT device must be configured to handle at least 250VDC and a minimum Power of 50 kWp solar. It must be able to deliver at least a minimum of 48V DC and reverse current protection. The MPPT device measures the cell output and applies the proper resistance (load) to obtain maximum power.

The charging station preferably has a grounding system. The DC system will be connected to ground. All the metal elements of the electrical system must be properly grounded. Depending on the soil resistivity, more ground rods may be required. The grounding system can include hot galvanized metal rods or copper clad metal rods connected in series and bonded together and to the structure with, for example, aluminium bare wire or copper bare/stranded equivalent. The bonding of the internal connections of the base structure can be cable, for example copper cable and the rest of the electrical elements can be connected with cable +90°C of yellow and green colours denoting the grounding cables. For example the grounding can be installed using at least 3.0 m long 16 mm diameter hot galvanized metal rod or 2.4 m long copper clad 3/8 inches diameter connected in series and bonded together and to the structure with 8mm diameter aluminium bare wire or copper bare/stranded equivalent.

The different elements of the charging station such as the at least one energy generation device, the at least one charging point, the at least one electric storage unit, the at least one energy management system, the DC/DC Converter(s), the MPPT device(s) and the in- verter/charger are electronically connected, preferably by electric lines. The electric lines connecting the different elements of the charging station form a micro grid which is independent of the public grid.

The energy generation device comprises at least one solar glass component for generating energy. The solar glass component can be a solar glass panel. The solar glass panels can be connected using a 4 mm² copper conductor with -20°C to +90°C insulation and connected with MC4 IP64 1000V solar connectors. Each orientation will be combined in the combiner boxes with the respective protection, disconnect and fuses, the solar panels have their own bypass diodes and fuses.

The base structure of the energy generation device can be a skeleton support structure building a housing and the surface of the housing can at least partially be covered by the solar glass components. Preferably, the skeleton support structure is a metallic structure built from metallic struts and/or bars. The housing can be used to house other components of the charging station. It provides a centrepiece of the charging station, which is capable to withstand the harshest weather conditions, and can protect other components such as the energy storage unit form the surrounding. The electric storage unit and optionally the energy management system can be installed inside the housing.

The at least one solar glass component is attached to the skeleton support structure, the solar glass components preferably forming a wall and/or a roof section of the housing.

In a preferred embodiment, the housing has a pyramid shape or a castle shape.

The pyramid shape and the castle shape provide a plurality of outer surfaces, which may comprise solar glass components. Thus, the solar energy in the region around the system may be collected and used for the energy generation.

In another example, the system may comprise a plurality of solar glass components. The plurality of solar glass components may for example cover most of or the complete outer surface of the system. Thus, the potential energy generation may be maximized.

The skeleton support structure preferably comprises at least one diagonal strut being connected to the skeleton support structure with a first end section and a second end section, the at least one diagonal strut having a flat side surface extending between the first end section and the second end section.

The energy generation device preferably comprises a plurality of solar glass components. The presently described solar glass components tolerate greater temperature ranges than conventional photovoltaic systems. This enables the solar cells to work more efficiently, reducing high losses at high temperature conditions. Furthermore, solar glass components are better protected in harsh conditions.

The energy generation device can comprise a plurality of solar panels and solar glass panels as solar glass components. Preferably the energy generation device has at least 500 solar components, more preferably at least 750 solar glass components, mounted on the base structure.

The energy generation device comprises at least one solar glass component having a solar cell layer. That solar cell layer may be connected to the charging points and/or the energy storage unit (battery). Furthermore, the energy generation system may comprise a plurality of solar glass components each having a solar cell layer. The number of the solar glass components is not limited. All solar cell layers are connectable to the charging points or batteries depending on the electrical system configuration. In operation of the system, the solar cell layers are connected to the charging points. At night, the solar cell layer may for example be turn off from the electrical system configuration leaving the batteries be the energy source powering the charging points.

The energy generation device has at least one solar glass component. The solar glass component preferably comprises a layered structure. At least one of the layers of the layered structure is a solar cell layer/solar glass panel layer. The solar cell layer/solar glass panel layer is configured to generate electrical energy from light that falls on the solar layer. The electrical connection of the energy generation device to one of the other components can be performed by electrically connecting the solar cell layer to those components. For example, the solar cell layer is electrically connected to an electrical line which leads to one of the other components. The charging station can further comprise at least one atmospheric water generator which generates water from air by cooling down the air, wherein the energy generation device is electrically connected to the atmospheric water generator and provides energy for the atmospheric water generator. The atmospheric water generator may comprise at least one compressor for cooling down air, at least one air inlet, at least one air outlet and at least one water condenser. The atmospheric water generator may provide water for the charging station, especially water using facilities of the charging station such as toilets, showers, water taps in sanitary areas or kitchens or car wash units or workshops. The water can be heated using at least one solar heater. The charging station may also have at least one water tank for storing water. The at least one atmospheric water generator may condense water from the atmosphere by cooling down air. After condensing water from the cooled down air, the (dry) cooled air may be guided to the at least one energy storage device to cool the energy storage device.

The energy management system may connect and disconnect the solar cell layer from energy storage device. Furthermore, the energy management system may connect and disconnect the energy generation device from the charging points. Thus, the energy management system may control the energy source being used to load the charging points. Furthermore, the energy management system may control the storing of the excess energy from the energy generation device.

The energy management system controls the energy consumption and energy distribution of the charging station. It can be connected to sensors and communication devices to get information about the actual energy consumption at the charging points, the level of energy generation in the energy generating device and the charge level of the energy storage unit. The energy management system is configured to ensure the energy storage unit, the inverter/ charger and the MPPT controller work efficiently together. The energy management system may control the energy flow between the components. The energy management system may further control whether the energy storage device can store further energy if the energy generation device produces excess energy. If the energy storage device cannot store any more energy, the energy management system may switch off or disconnect the solar glass components.

The charging station according to the invention is a fully sustainable off-grid electric truck and vehicle charging station with a solar energy device and a battery energy storage unit.

In one embodiment the charging station comprises an energy generation device, having a base structure which is a metallic structure and solar glass components attached to the metallic structure, at least one DC/DC converters or MPPT device ((Max Power Point Tracking), at least one inverter, at least one battery as energy storage unit and at least one charging point (load). Optionally the charging station also has a grounding system.

In an exemplary embodiment the charging station has the following components:

A housing having a skeleton structure with solar glass panels mounted on the outside, preferably the walls and optionally the roof, which houses at least the energy storage units and the energy management system. The housing is equipped with at least 600 solar panels, preferably approximately 900 solar panels and solar glass panels installed adding a capacity of more than 250 kWp. This energy generating device generates at least 1000 kWh of solar energy per day. The energy storage units are batteries. More than 1000 kWh of energy storage capacity can be used in lithium battery systems (LFP) to ensure continuous use and availability of energy. The charging stations have at least 2, preferably 4 charging points which two chargers for simultaneously charging electric heavy vehicles.

The system can be low voltage AC coupled, which will ensure easy integration and expansion of the system in the future. The different elements form a micro grid isolated from the public system. It has a capacity of preferably up to 250 KW of instant and continuous power.

The charging points can be 200 kW of power, with the capacity to charge 2 trucks simultaneously of 100 kW each, and of course can also be able to charge any other electric vehicle since it has the most common and standard connections/adapters.

If the energy output value is sufficient, in a further step, the energy management system electrically connects the solar cell layers of the solar glass components of the energy generation device to the energy storage and this to the atmospheric water generators.

Preferably, the off-grid charging station has at least one energy generation device, at least one energy management system, at least one charging point and at least one energy storage device. The energy management system controls the energy generation, storage and consumption preferably using the following steps.

In a first step, the energy output of the energy generation device is determined. An energy output value comprises the information about the determined energy output. The energy output value is compared to a first threshold value to assess whether the energy generation device produces enough energy to operate at least one charging point. A sufficient energy production can be assessed if the energy output value is higher than the first threshold value. However, if, for example, the energy output value is defined to be negative, then a sufficient energy production can be assessed if the energy output value is lower than the first threshold. This may apply to all threshold values discussed in this specification. In a further step, it is assessed whether the energy generation device generates excess energy that is not required for operating the charging points. The energy output value is compared to a second threshold value. If the energy output value is higher than a second threshold value, the energy management system electrically connects or disconnects the solar cell layers to the energy storage devices. The excess energy may then be used to charge the energy storage devices.

In a further step, if the energy output value is lower than the first threshold value, the energy management device may electrically connect the energy storage device to the charging points. The solar cell layers may still be electrically connected to energy storage device, such that both, the solar cell layers and the energy storage devices may power the charging point.

Furthermore, the method may comprise the following optional step. In optional step, the charge of the energy storage device is determined. The charge is represented by a charge value. If the charge value is higher than the third threshold value, it means that the energy storage device is fully charged and cannot store more energy. If, furthermore, the energy generation device produces excess energy, then the energy management system may switch off or disconnect the solar cell layers.

Further features, details and advantages of the invention result from the wording of the claims as well as from the following description of exemplary embodiments based on the drawings. The figures show:

Fig. 1 a schematic drawing of the off-grid charging station;

Fig. 2 a schematic drawing of the components of the charging station and their connection;

Fig. 3 a schematic drawing of examples of the energy generating system;

Fig. 4a-c a schematic drawing of a support structure of the energy generating system;

Fig. 5a, b a schematic cross-sectional drawing of a strut; and

Fig. 6 a schematic drawing of the framework and a solar glass component with horizontal profiles; and Figure 1 shows a schematic drawing of an exemplary embodiment of the off-grid charging station. The charging station has an energy generation device 12. The energy generation device has a plurality of solar glass components 16. The solar glass components 16 cover the side wall of the energy generation device. Additional solar glass components 16 are placed on the roof of the energy generation device as indicated by an arrow. Inside the housing of the energy generation device an energy storage unit 20 is allocated as indicated by an arrow. The energy generation device 12 is electrically connected to electric line 24. Electric line 24 leads to two charging points 10. The charging points 10 are electrically connected to the electric line 24. Each charging point 10 is electrically connected to an electric line 26 which leads to a charger 72. The charger 72 is connected to an electric truck 70 to charge the battery of the truck 70.

Figure 2 shows a schematic drawing of the components of the charging station and the connection between them. Solar glass panels 18 are electrically connected to a combiner box 56with DC power flowing from the solar glass panels 18. The combiner box 56 collects data about the DC current and sends them to at least one of the following components the DC/DC converter 58, MPPT device 58, energy management system 22, inverter 60. The combiner box 56 is electrically connected to the DC/DC converter 58 and/or the MPPT device 58 and the DC current flows from the combiner box 56 to the converter. The energy management system 22 directs the current to the inverter 60. In the inverter 60 the current is inverted from DC to AC. The inverter also charges the battery 20 which has a battery management system 30 with protection and sensors. The battery management system and the battery storage system may include various types of sensors 62, such as temperature, alarm and smoke detector sensors as wells as sensors for determining the charging points. The battery systems may further comprise various components for battery protection, such as ground fault protection, overcurrent protection, emergency stops, fuses etc.

A power control unit 32 controls and distributes the AC current to the electric vehicle charging point 10 and other AC auxiliary loads 74 such as cooling devices, ventilators, air extractors, light, external cameras, Wi-Fi, normal 230V 50 Hz supply, computers, routers/modems for communication. Power can be provided to any sub-device that is not part of the energy generationtransformation process but requires electrical energy. Furthermore, all the elements that complements the monitoring, sensing, and protection of the energy conversion process may be supplied by the power control unit 32The charging point 10 may be connected to above mentioned sensors 62. If more power is needed the charging station can have an add on expansion 64 with more solar panels. This can be switch on if additional power is needed and can be dormant if the main energy generation device produces enough energy. The ADD ON expansion 64 may have external solar panels 18 either DC coupled or AC coupled. It also may contain both. It can have at least one combiner box 56, at least one DC/DC converter 58, at least one MPPT and/or at least one inverter 60. Figure 2 also shows which components are electrically connected either with a DC or an AC and which components exchanges data.

Fig. 3 shows an exemplary embodiment of the energy generation device 12. The energy generation device 12 may have a housing 54 that is shaped as a castle. The housing 54 has wall elements wherein at least some of the wall elements are the solar glass components 16. Thus, the solar glass components 16 form a portion of the outer surface of the housing 54, i.e. the energy generating device 12. The housing 54 may further comprise a base structure 34 for holding the solar glass components 16 of the energy generation device 12. The energy storage device 20, the energy management device 22 and optionally the atmospheric water generator 14 may be arranged inside the housing 54.

A portion of the wall in the lowest level 56 may be a door structure, such that maintenance staff may enter the housing.

The support structure 34 may be a skeleton support structure made of a castle-shaped frame30 work as shown in figure 4a to 4c. Figure 4a shows an isometric view of the framework. Figure 4b shows a side view and figure 4c shows a top view of the framework.

The energy storage device 20 and the energy management device 22 may be arranged below the tower-like structures of the framework as ballast for stabilizing the framework. If an atmospheric water generator 14 is used this may also be arranged below the tower-like structures.

The framework may comprise vertical bars 38 and horizontal bars 40. Diagonal struts 36 connect to the vertical bars 38 and the horizontal bars 40 to stiffen the support structure 34. A first end section 48 and a second end section 50 of the diagonal struts 36 connect to the bars 38, 40, wherein the diagonal struts 36 extend between the end sections 48, 50.

The bottom if the housing 54 may comprise a floor 42 made from bars or profiles.

The roof (or top) of the housing may comprises a as well bars or profiles to hold the solar glass component. A fagade may have for example five modules joints in width, to hold the roof (joint minimally small, slight angle of inclination of the modules). The diagonal struts 36 may further comprise a flat side surface 52 extending between the first end section 48 and the second end section 50. Figures 5a and 5b show exemplary cross sections for the diagonal struts 36, wherein the cross sections extends transverse to the direction from the first end section 48 to the second end section 50.

The flat side surface 52 faces the solar glass component 16 that covers the diagonal strut 36.

The framework may further comprise horizontal profiles 44, 46 for hanging on the solar glass panels 16 as shown in Fig. 6. The horizontal profiles 44, 46 are attached to the vertical bars 38 of the support structure 34. Furthermore, those horizontal profiles 44, 46 may abut to the flat side surface 52. The framework may further comprise vertical profiles for holding on the solar glass panels 16.

The invention is not limited to one of the afore mentioned embodiments. It can be modified in many ways.

All features and advantages resulting from the claims, the description, and the drawing, including constructive details, spatial arrangements, and procedural steps, may be essential for the invention both in themselves and in various combinations.

Reference Sig ns charging point energy generation device atmospheric water generator solar glass component solar glass panels energy storage unit energy management system electrical line electrical line electrical line battery management system power control unit base structure diagonal strut vertical bars horizontal bar floor horizontal profile horizontal profile first end section second end section side surface housing combiner box

DC/DC converter or MPPT device solar inverter sensor

ADD ON expansion electric heavy vehicle charger

AC auxiliary load

Claims

Clai ms Self-sufficient truck charging station for charging electric heavy vehicles comprising

- at least one energy generation device (12), wherein the at least one energy generation device (12) comprises at least one solar glass component (16) for generating energy, preferably a plurality of solar glass components (16), and a base structure (34) on which the solar glass components (16) are mounted,

- at least one charging point (10) for charging at least one battery in an electric heavy vehicle (70),

- at least one electric storage unit (20) for storing electric energy and

- at least one energy management system (22), which controls the energy consumption and energy distribution of the charging station, wherein the at least one energy generation device (12) is electrically connected to at least one charging point (10) and/or at least one electric storage unit (20) and the charging station is an off-grid system. Charging station according to any of the proceeding claims wherein the charging point (10) provides at least 100 kW power for charging, preferably 100 kW, more preferably 200 kW (DC) and optionally between 300 kW up to 400 kW for hyper charging. Charging station according to any of the proceeding claims wherein the charging point (10) has at least two charging posts, preferably two charging posts with at least 100 kW and 50 kWp (kW peak), for simultaneous charging. Charging station according to any of the proceeding claims wherein the charging station further comprises an inverter (60) which converts the energy coming from the solar glass components in the form of DC voltage. Charging station according to anyone of the preceding claims, wherein the base structure (34) of the energy generation device (12) is a skeleton support structure building a housing (54) and wherein the surface of the housing (54) is at least partially covered by the solar glass components (16). Charging station according to claim 5 wherein the electric storage unit (20) and optionally the energy management system (22) is installed inside the housing (54). Charging station according to claim 5 or 6 wherein the skeleton support structure (34) comprises at least one diagonal strut (36) being connected to the skeleton support structure (34) with a first end section (48) and a second end section (50), the at least one diagonal strut (36) having a flat side surface (52) extending between the first end section (48) and the second end section (50). Charging station according to claim 7, wherein the at least one solar glass component () is attached to the skeleton support structure (34), the solar glass components (16) forming a wall and/or a roof section of the housing (54). Charging station according to claim 7 or 8, wherein the housing (54) has a pyramid shape or a castle shape. Charging station according to anyone of the preceding claims, wherein the energy generation device (12) comprises a plurality of solar glass components (16). Charging station according to any of the proceeding claims wherein the charging station further comprises at least one atmospheric water generator (14) and the at least one energy generating device (12) is electrically connected to the at least one atmospheric water generator (14) and provides energy for the atmospheric water generator (14).