Methods and apparatus for a residential fast electric vehicle DC charger and energy management

Abstract

An electric vehicle charging system is disclosed, including a bidirectional DC charger and an internal DC bus in electrical connection with the bidirectional DC charger. A transformerless split inverter is in electric connection to a home's AC power grid to charge one or more electric vehicles.

Description

APPLICATIONFORUNITED STATES LETTERS PATENTMETHODS AND APPARATUS FOR A RESIDENTIAL FAST ELECTRIC VEHICLE DC CHARGER AND ENERGY MANAGEMENTTECHNICAL FIELD

[0001] The embodiments generally relate to electric vehicle charging systems and more particularly to a method and apparatus for residential fast electric vehicle (EV) chargers and energy management 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 current residential DC or AC electric vehicle chargers are supplied energy from the AC power grid. AC EV chargers have an AC connection to the vehicle’s embedded on-board charger (OBC) that is an AC / DC converter included in the vehicle to transform the AC to DC required by the battery. The DC fast charger is an external AC / DC converter connected to the AC power grid that delivers DC directly to the battery in the vehicle. Consequently, energy generated by renewable resources or saved in energy storage systems must be converted to AC and back to DC to support the charging of the electric vehicle, causing inefficiencies due to losses in the energy exchange process.SUMMARY OF THE INVENTION

[0003] 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.

[0004] The embodiments provided herein relate to an electric vehicle charging system, including a bidirectional DC charger and an internal DC bus in electrical communication with the bidirectional DC charger. A transformerless split inverter has a bidirectional electric power connection to a home’s AC power grid to charge one or more electric vehicles. The system may be utilized as a home energy management system because other sources of DC energy such as PV solar panel or battery energy storage can be connected to the DC in other to exchange energy

[0005] In one aspect, the electric vehicle charging system is in communication with the Internet. The system receives historical, current, or future weather information to provide a predictive model of energy consumption and energy generation to allow the DC charger controller to decide which energy source should be used to charge the vehicle or use for other purposes at home.

[0006] In one aspect, the DC charger provides efficient management of the energy among different sources of energy and the load of a home.

[0007] In one aspect, the electric vehicle charging system is compatible with the home’ s AC power grid.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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:

[0010] FIG. 1 illustrates a schematic of the electric vehicle solar charging system, according to some embodiments;

[0011] FIG. 2 illustrates a schematic of the electric vehicle solar charging system including an AC converter, according to some embodiments;

[0012] FIG. 3 illustrates a schematic of the DC charger architecture, according to some embodiments; and

[0013] FIG. 4 illustrates a schematic of the transformerless inverter, according to some embodiments.DETAILED DESCRIPTION

[0014] 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.

[0015] 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.

[0016] 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.

[0017] In general, the embodiments provided herein relate to an electric vehicle charging system. A DC charger includes an internal DC bus for efficient energy exchange among the renewable source of energy and storage system. The DC bus includes an extension for an auxiliary system resulting in a highly efficient energy exchange. The DC charger becomes a master energy converter at a residence with bidirectional capabilities providing a transformerless and splitconnection (240V / 120V) to the AC power grid. Because EV DC chargers may become the largest energy converters in a home, they may become the home energy management system. The system will include a DC bus for efficient energy exchange. The system will include a seamless connection for versatility and reliability in the present architecture.

[0018] FIG. 1 and FIG. 2 illustrates a schematic of the electric vehicle solar charging system wherein the AC converter to is eliminated to push the AC of the DC charging to the AC side. An internal DC bus is created to provide more efficient energy exchange. FIG. 2 illustrates the DC bus utilized as an AC converter to eliminate the need for a split transformer. The system will accommodate any AC load or source to supply the EV with sufficient energy for fast charging.

[0019] FIG. 3 illustrates a schematic of the DC charger architecture for the energy management system. FIG. 4 illustrates the transformerless inverter. The DC charger is in operable communication with the AC power grid and / or solar panel(s) to provide power to the EV. The DC charger becomes the master energy converter at a residence with bidirectional capabilities. The transformerless inverter for the split system (240V / 120V). The system is retrofittable and compatible with the AC residential power supply infrastructure and is fully connected to the AC power grid. This removes the need for additional equipment and switches. The DC charger will provide an energy management of the energy source and the energy load when the home is in an islanding mode (i.e., when the home is not connected to the grid).

[0020] In some embodiments, the DC charger has direct communication with the Internet via a network to permit the system to receive information such as weather forecasts. This may allow for predictive controlling of the energy source, energy distribution, and / or energy storageaccording to historical, current, and / or future energy generation resources and consumption patterns.

[0021] The system provides a cost-effective solution to upgrade a current system to a bidirectional system. The system removes the need to for additional inverters in the home, including eliminating the need for solar inverters or inverters in communication with the EV battery.

[0022] In some embodiments, the system is retrofittable to the user’s current system and is compatible with current AC residential systems.

[0023] 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.

[0024] 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.

[0025] 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.

Claims

What is claimed is:

1. An electric vehicle charging system, comprising; a bidirectional DC charger; an internal DC bus in electrical connection with the bidirectional DC charger; and a transformerless split inverter in with bidirectional electrical connection to a home’s AC power grid to charge one or more electric vehicles.

2. The electric vehicle charging system of Claim 1, wherein the electric vehicle charging system is in communication with the Internet.

3. The electric vehicle charging system of Claim 2, wherein the electric vehicle charging system receives historical, current, or future weather information to provide a predictive model of energy consumption and energy generation.

4. The electric vehicle charging system of Claim 1, wherein the DC charger provides management of the energy source and the energy load of a home with the capability of deciding at every time which energy source is to be used to charge the vehicle and when to charge the vehicle based on smart control that considers tariffs’ rate at the specific time of the day, weather conditions and prediction, and / or user commands.

5. The electric vehicle charging system of Claim 4, wherein the electric vehicle charging system is compatible with the home’s AC power grid.

Images