[0001] The embodiments generally relate to electric vehicle charging systems and more particularly relate to solar-powered electric vehicle charging systems.

BACKGROUND

[0002] Electric vehicles (EVs) must be charged regularly to ensure their battery packs have sufficient energy to power the vehicle. EV chargers are devices that supply electric energy for the recharging of plug-in electrical vehicles, neighborhood electric vehicles, and plug-in hybrids. The battery pack in the EV charges and discharges direct current (DC) electricity. Some EV chargers supply standard alternating current (AC) electricity to the EV, which first flows through an onboard AC/DC converter before entering the battery management system of the battery pack to charge the battery cells. Others use high-capacity charging stations that provide electrical conversion, monitoring, and safety functionalities. These stations can support faster charging than residential charging stations by using direct current (DC) at higher voltages directly to the onboard battery management system of the battery pack, avoiding the onboard AC/DC converter.

[0003] Solar arrays may be used to supply power to electric vehicles. When EV charging is concurrent with solar generation, the solar array transmits direct current (DC) electricity to a solar inverter, which inverts the electricity to alternative current (AC). While some of this electricity may be supplied to the power grid or an AC -based energy storage system (electro-chemical batteries, kinetic storage, gravitational storage, etc.), while some is transmitted to the EV having an onboard converter and battery. The AC/DC converter onboard the EV converts the electricity back to DC to charge the battery pack. Alternatively, fast high-voltage DC charging involves the same converted solar power supplied to an AC/DC converter in the EV charging device which converts the AC to high-voltage DC and sends it to the EV’s battery pack, avoiding the EV’s onboard AC/DC converter. Traditional EV chargers using electricity from solar arrays first use inverters.

SUMMARY OF THE INVENTION

[0004] This summary is provided to introduce a variety of concepts in a simplified form that is further disclosed in the detailed description of the embodiments. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

[0005] The embodiments provided herein relate to an electric vehicle (EV) solar charging system, comprising a photovoltaic system to transmit power either directly or round-trip through energy /battery storage, or a combination of both, to an electric vehicle via a DC/DC converter. The voltages of the direct solar electricity and of the power storage system are adjusted to a matched constant voltage (for example, between 420 and 380 Vdc) through DC/DC converters, increasing or lowering the voltage as necessary, depending on the origin voltage of each. This output can be further adjusted to match the desired voltage communicated by the battery management system of the EV’s onboard battery pack, which may be different for different EVs. This adjustment may be performed at the initial DC/DC conversion stage at input, or by an inline DC-DC converter at output, which also may be bi-directional to also return power from the EV battery pack into the house load if desired (eg. for emergency power use during a grid outage, or for peak grid-management by the power utility). The DC output circuit feeds directly to the EV’s battery back through the DC charging ports of the EV, which may be EV charging plug ports. In periods of low light or lack of stored solar energy, or to increase the charge rate of DC alone, an AC power source can be converted to high voltage DC, added to the DC/DC modified DC output of the solar generation stream, and sent to the DC charging ports of the EV either directly or through the bi-directional DC-DC converter if necessary. Alternatively, when insufficient solar generated or stored electricity is available, a standard AC power source can provide power to the electric vehicle’s battery charger through the EV’s onboard AC/DC converter through the AC charging ports of the EV, which may be an EV charging plug.

[0006] The system may use DC power provided by the photovoltaic system In one aspect, the system uses the DC power supplied from solar energy which can be directly used to charge the batteries of the electric vehicle. The DC power from the photovoltaic (PV) system supplies power to isolated DC/DC converter to create the appropriate voltage for the electric vehicle. For example, the appropriate voltage may be between 100V to 450V. The output power is proportional to the available solar power, such as 15KW. The DC power is provided to the EV battery pack through the DC ports of the EV charging plug.

[0007] The system may use other clean-tech generation other than, or in addition to, PV solar generation, as the source of on-site generated electricity, especially as DC electricity. Solar PV generation can be considered to be used interchangeably with any on-site electrical generation technology; that is, electricity supplied other than from the grid.

[0008] The system may be operable in low light conditions which decrease or eliminate solar power provided by the photovoltaic system. DC electricity can be provided by building battery storage or other types of energy storage (kinetic energy storage, pumped energy storage or others). The DC power from the energy system supplies power to an isolated DC/DC converter to create the appropriate voltage for the electric vehicle. For example, the appropriate voltage may be between lOOVdc to 450Vdc. The output power is proportional to the available discharge capacity of the energy storage system. The DC power is provided to the EV battery pack through the DC ports of the EV charging plug. [0009] The system may be operable in low light conditions which decrease or eliminate solar power provided by the photovoltaic system. Standard AC electricity can be provided and converted to DC with an AC/DC converter to create the appropriate voltage for the electric vehicle. For example, the appropriate voltage may be between lOOVdc to 450Vdc. The output power is proportional to the available supplied AC power, such as 9.6 KW for a 240V 40A AC supply. The DC power is provided to the EV battery pack through the DC ports of the EV charging plug.

[0010] The system may increase its charge rate by combining two or more of the PV solar, building energy storage and standard AC converted to DC sources. The voltages of the two or three of the sources are matched and combined to achieve a faster charge rate than provided by any one individually. The aggregation of these streams into a single DC output occurs prior to the DC ports of the EV charging plug.

[0011] In one aspect, the DC output can be fed through a bi-directional DC-DC converter prior to the charge ports, which can both dynamically match the voltage desired the EV’s battery management system and return electricity from the EV battery pack back into the house load for emergency use or peak leveling situations. The bi-directional DC-DC converter takes the combined DC inputs prior the DC ports of the EV charging plug.

[0012] The system may be operable in low light conditions which decrease or eliminate solar power provided by the photovoltaic system. When little or no DC electricity is available, the system switches to standard AC electricity provided directly through to the AC ports of the of the EV charging plug, which is then converted to DC by the on-board EV AC/DC converter to create the appropriate voltage for the electric vehicle. The output power is proportional to the available power from the building breaker panel. This option is available when the EV charging plug and EV charging control allows for both AC and DC port connections in the same charging plug.

[0013] Additionally, the AC input can be dynamically switched to the AC charging inputs of a second EV, which may be an AC charging EV port plug, and used to charge a second EV through its on-board AC/DC converter. This charging can be concurrent with charging of the other vehicle through the DC ports of its EV charging plug.

[0014] In one aspect, a controller is provided to permit the system to automatically control the power source(s) based on power input from the photovoltaic system, building battery storage, DC supplied directly to EV battery pack converted from standard AC and AC supplied directly to the EV’s onboard AC/DC converter. Alternatively, the user may manually alter the power source based on power demands and availability.

[0015] In one aspect, the electric vehicle includes an onboard charger.

[0016] In one aspect, the photovoltaic system includes a rapid shutdown optimizer to optimize power and ensure proper bounded voltage is transmitted to the inverter from panels which may have varying voltage outputs due to dynamic shadowing, mixed loads, soiling, debris, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A complete understanding of the present embodiments and the advantages and features thereof will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0019] FIG. 1 illustrates a schematic of the electric vehicle solar charging system, according to some embodiments.

[0020] FIG 2. illustrates a schematic of an electrical vehicle solar charging system which can charge two electric vehicles simultaneously, where the second is charged from an AC electricity source, like the grid.

DETAILED DESCRIPTION

[0021] The specific details of the single embodiment or variety of embodiments described herein are to the described apparatus. Any specific details of the embodiments are used for demonstration purposes only, and no unnecessary limitations or inferences are to be understood therefrom.

[0022] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of components and procedures related to the apparatus. Accordingly, the apparatus components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0023] The specific details of the single embodiment or variety of embodiments described herein are set forth in this application. Any specific details of the embodiments are used for demonstration purposes only, and no unnecessary limitation or inferences are to be understood therefrom. Furthermore, as used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship, or order between such entities or elements.

[0024] In general, the embodiments provided herein relate to an electric vehicle charging system which uses energy provided by a photovoltaic systems designed to supply usable power to the electric vehicle. The system uses the DC power supplied from solar energy which can be directly used to charge the batteries of the electric vehicle. The DC power from the photovoltaic system to supply power to an isolated DC/DC converter as necessary to create the appropriate voltage for the electric vehicle. For example, the appropriate voltage may be between 100V to 450V. The output power is proportional to the available solar power, such as 15KW.

[0025] FIG. 1 illustrates the electric vehicle solar charging system 100, including a photovoltaic system 101 to transmit power either directly or round-trip through energy /battery storage 103, or a combination of both, to an electric vehicle 105 via DC/DC converters 106 and 107 as necessary to achieve the desired output voltage. The voltages of the direct solar electricity and of the power storage system are adjusted to a matched constant voltage (for example, between 420 and 380 Vdc) through their respective DC/DC converters 106 and 107, as necessary, depending on the origin voltage of each. The output of the DC/DC converters may be adjusted to match the desired voltage communicated by the battery management system 109 of the EV’s onboard battery pack 111, which may be different for different EVs. This adjustment may be performed at the DC/DC conversions 106 and 107 at the input stage, or by an inline DC-DC converter 117 at the output stage, which also may be bi-directional to also return power from the EV battery pack into the house load if desired (e.g., for emergency power use during a grid outage, or for peak grid- management by the power utility). The DC output circuit feeds directly to the EV’s battery pack 111 through the DC charging ports of the EV, which may be EV charging plug ports 113.

[0026] During periods of low light or lack of stored solar energy, or to increase the EV charge rate, an AC power source can be converted to high voltage DC 124, added to the modified DC output of the solar generation stream, and sent to the DC charging ports of the EV 105 either directly or through the bi-directional DC-DC converter 117 if necessary.

[0027] In some embodiments, when insufficient solar generated 101 or stored electricity 103 is available, a standard AC power source alternatively can provide power to the electric vehicle’s battery charger through the EV’s onboard AC/DC converter 115 through the AC charging ports of the EV.

[0028] The system may use DC power provided by the photovoltaic system, both directly 101 and stored 103. DC electricity and building energy storage systems simultaneously to improve the rate of EV charging. The DC power from each is supplied to an isolated DC/DC converter as necessary to create the appropriate voltage for the electric vehicle. For example, the appropriate voltage may be between 100V to 450V. The output power is proportional to the available solar power, such as 15KW. The DC power is provided to the EV battery pack through the DC ports of the EV charging plug 113.

[0029] The battery 103 may also be charged directly from the grid, prior to sending to the DC/DC converter 107.

[0030] In some embodiments, the system may increase its charge rate by combining two or more of the PV solar 101, building energy storage 103 and standard AC converted to DC sources 124. The voltages of the two or three of the sources are matched and combined to achieve a faster charge rate than provided by any one individually. The aggregation of these streams into a single DC output occurs prior to the DC ports of the EV charging plug 113.

[0031] In one aspect, the DC output can be fed through a bi-directional DC-DC converter 117, which can both dynamically match the voltage desired the EV’s battery management system 109 and return electricity from the EV battery pack back into the house load for emergency use or peak leveling situations. The bi-directional DC-DC converter 117 takes the combined DC inputs prior the DC ports of the EV charging plug 113. [0032] In some embodiments, the system includes a controller 119 to permit the system to automatically control the power source(s) based on power input from the photovoltaic system, building battery storage, DC supplied directly to EV battery pack converted from standard AC and AC supplied directly to the EV’s onboard AC/DC converter. Alternatively, the user may manually alter the power source based on power demands and availability.

[0033] In some embodiments, the system includes a second output which charges a second EV 205 through a separate AC port plug 213, which charges its battery pack 211 through its on-board AC/DC converter 215 via is battery management system 209. This power is sourced from the same AC source 203 used to supply the other EV through its AC ports of its charging plug 113 to its onboard AC/DC converter 115 when that AC source 203 is not being used to charge the first EV 105. Alternatively, the AC source can be the same 201 as is connected to the AC/DC converter 124 which converts to high voltage DC and supplies the DC EV charging plug ports 113 when this power is not being used to charge EV1 105. The controller 119 dynamically directs this AC source to EV1 105 or EV2 205 to either maximize charging to the first EV 105 or concurrently charge both EVs 105 and 205, which can be done autonomously or through manual user control.

[0034] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. [0035] An equivalent substitution of two or more elements can be made for any one of the elements in the claims below or that a single element can be substituted for two or more elements in a claim. Although elements can be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination can be directed to a subcombination or variation of a subcombination.

[0036] It will be appreciated by persons skilled in the art that the present embodiment is not limited to what has been particularly shown and described hereinabove. A variety of modifications and variations are possible in light of the above teachings without departing from the following claims.