A fast charging system for electric vehicles connected to a DC microgrid

Abstract

A fast charging system for electric vehicles connected to a DC microgrid, consisting of: a bidirectional DC-DC converter, wherein the converter is based on gallium nitride (GaN); one or more subsystems for renewable energy sources, including solar and wind energy; a battery energy storage subsystem that is connected to one or more renewable energy source subsystems; a power management module connected to the bidirectional DC-DC converter, wherein the power management module includes a processor configured to perform power management using Discrete Sliding Mode Fuzzy Control (DSMFC); and a charging interface for electric vehicles to facilitate the charging of electric vehicles.

Description

FIELD OF THE INVENTION

[0001] The present disclosure relates to a DC microgrid-connected fast charging system for electric vehicles. More specifically, the invention relates to a highly efficient DC microgrid-connected fast charging system for electric vehicles using a GaN-based bidirectional DC-DC converter and a discrete controller. BACKGROUND OF THE INVENTION

[0002] Chargers used for electric vehicles should possess characteristics such as high efficiency, reliability, power density, compactness, low weight, and low price. Charger performance depends on the circuit topology and control techniques used. The rapidly growing electric vehicle (EV) market faces critical challenges related to charging infrastructure, energy management, and grid stability. Existing EV charging solutions struggle with several limitations: low efficiency, complex control systems, poor power quality, and significant grid disturbances. Conventional charging methods using analog or digital controllers such as digital signal processors and microcontrollers result in complexity, higher costs, and suboptimal power conversion.

[0003] The urgent need for sustainable transportation, driven by fossil fuel depletion and rising carbon emissions, requires innovative charging technology. However, several key challenges exist, including minimizing power consumption from power sources, reducing harmonic distortion, maintaining a high power factor, avoiding grid voltage and frequency fluctuations, and ensuring compact, efficient, and reliable charging solutions.

[0004] The introduction of wide-bandgap semiconductor technologies, particularly gallium nitride (GaN), represents a groundbreaking solution. These advanced materials enable power electronics converters that are highly efficient, faster in operation, more compact, and capable of superior power management.

[0005] To address the above challenges, the present invention provides a DC microgrid-connected electric vehicle fast charging system powered by a novel bidirectional GaN-based DC-DC converter with discrete sliding-mode fuzzy control (DSMFC). The proposed system provides a comprehensive solution to the limitations of electric vehicle charging infrastructure and promises improved grid stability, improved power quality, and more efficient energy management. SUMMARY OF THE INVENTION

[0006] The present disclosure relates to a DC microgrid-connected fast charging system for electric vehicles. The invention is a sophisticated electric vehicle (EV) charging system that integrates a gallium nitride (GaN)-based bidirectional DC-DC converter with a discrete sliding-mode fuzzy controller (DSMFC) within a DC microgrid infrastructure. The system uniquely combines renewable energy sources (solar and wind), battery storage, and intelligent energy management to create a comprehensive electric vehicle charging solution. The proposed system enables flexible, efficient, and stable charging of electric vehicles across various power sources and is thus adaptable to different energy infrastructures.

[0007] An object of the present disclosure is to provide a fast charging system for electric vehicles connected to a DC microgrid. The system comprises: a bidirectional DC-DC converter, wherein the converter is based on gallium nitride (GaN); one or more renewable energy source subsystems, wherein the sources include solar and wind energy; a battery energy storage subsystem connected to the one or more renewable energy source subsystems; a power management module connected to the bidirectional DC-DC converter, the power management module comprising a processor configured to perform power management using discrete sliding mode fuzzy control (DSMFC); and an electric vehicle charging interface to facilitate charging of electric vehicles.

[0008] An object of the present disclosure is to provide a DC microgrid connected fast charging system for electric vehicles

[0009] Another objective of the present disclosure is to develop a highly efficient and compact EV charging system using advanced GaN semiconductor technology to improve power conversion performance.

[0010] Another objective of this disclosure is to provide a robust energy management solution that ensures grid stability and minimizes voltage and frequency fluctuations during electric vehicle charging.

[0011] Another objective of this disclosure is to enable seamless integration of renewable energy sources into the charging infrastructure for electric vehicles, thus supporting a sustainable transport ecosystem.

[0012] Another objective of the present disclosure is to implement an intelligent control mechanism (DSMFC) that optimizes power flow, reduces harmonic distortion, and maintains a high power factor.

[0013] to provide a versatile and portable charging solution that can be easily deployed in a variety of environments, from home charging to public charging stations.

[0014] To further clarify the advantages and features of the present disclosure, a more detailed description of the invention will be given with reference to specific embodiments thereof illustrated in the accompanying drawings. It should be noted that these drawings represent only typical embodiments of the invention and are therefore not to be considered limiting its scope. The invention will be described and explained in additional detail and in greater detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE CHARACTERS

[0015] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout. Fig. 1 shows a block diagram of an electric vehicle fast charging system connected to a DC microgrid according to an embodiment of the present disclosure. And Fig. 2 shows an operational diagram illustrating the DC microgrid connected electric vehicle fast charging system according to an embodiment of the present disclosure.

[0016] Furthermore, those skilled in the art will appreciate that elements in the drawings are shown for convenience and may not necessarily be drawn to scale. For example, the flowcharts illustrate the method by key steps to enhance understanding of aspects of the present disclosure. Moreover, with respect to device construction, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details relevant to understanding embodiments of the present disclosure in order not to clutter the drawings with details that would be readily apparent to those skilled in the art who would benefit from the description herein. DETAILED DESCRIPTION:

[0017] To facilitate an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and described in specific language. It is to be understood, however, that this is not intended to limit the scope of the invention, as such changes and further modifications to the illustrated system and such further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention pertains.

[0018] It will be understood by one skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting thereof.

[0019] References in this specification to "one aspect," "another aspect," or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, occurrences of the phrase "in one embodiment," "in another embodiment," and similar language throughout this specification may or may not all refer to the same embodiment.

[0020] The terms "comprises," "comprising," or other variations thereof are intended to cover non-exclusive inclusion, such that a process or method comprising a list of steps not only includes those steps, but may also include other steps not expressly listed or inherent in such process or method. Likewise, one or more devices or subsystems or elements or structures or components preceded by "comprises...a" does not preclude, without further limitation, the existence of other devices or other subsystems or other elements or other structures or other components or additional devices or additional subsystems or additional elements or additional structures or additional components.

[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are for illustrative purposes only and should not be considered limiting.

[0022] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0023] Fig. 1 shows a block diagram of a DC microgrid connected electric vehicle fast charging system (100) according to an embodiment of the present disclosure.

[0024] With reference to Fig. 1, the system (100) comprises a bidirectional DC-DC converter (102), wherein the converter (102) is based on gallium nitride (GaN); one or more renewable energy source subsystems (104), wherein the sources include solar and wind; a battery energy storage subsystem (106) connected to the one or more renewable energy source subsystems (104); a power management module (108) connected to the bidirectional DC-DC converter (102), wherein the power management module (108) comprises a processor (108a) configured to perform power management (108) using a discrete sliding mode fuzzy controller (DSMFC); and an electric vehicle charging interface (110) to facilitate charging of electric vehicles.

[0025] In one embodiment, the renewable energy subsystem (104) comprises at least one of the following components: solar photovoltaic systems and wind energy generators.

[0026] In one embodiment, the GaN-based bidirectional DC-DC converter (102) is configured to operate on both the source and load sides of the DC microgrid, wherein the GaN-based bidirectional DC-DC converter (102) provides improved charging efficiency and speed for charging electric vehicles.

[0027] In one embodiment, the system (100) further comprises a maximum power point tracking (MPPT) module (112) configured to optimize power extraction from the renewable energy subsystem.

[0028] In one embodiment, the Discrete Sliding Mode Fuzzy Control (DSMFC) power management module (108) is configured to manage the flow of power between multiple power sources, compare the DC bus voltage to a reference voltage, and ensure system stability.

[0029] In one embodiment, the energy management module (108) implements a control technique for managing energy distribution and maintaining system robustness, and wherein the discrete sliding mode fuzzy controller provides an adaptive control mechanism for managing energy flow between renewable energy sources, battery storage, and electric vehicle charging.

[0030] In one embodiment, the system (100) further comprises a charge controller (114) configured to control current flow to and from the battery by comparing the DC bus voltage to the reference voltage.

[0031] In one embodiment, the electric vehicle charging interface (110) is configured to support portable charging across multiple power input configurations.

[0032] In one embodiment, the GaN-based DC-DC converter (102) enables bidirectional power conversion with improved efficiency compared to conventional silicon-based converters.

[0033] The present invention relates to a highly efficient DC microgrid system for electric vehicle (EV) charging using a gallium nitride (GaN)-based bidirectional DC-DC converter and a discrete controller. This invention proposes a design and implementation of a highly efficient DC microgrid-connected fast charging system for electric vehicles using a GaN-based bidirectional DC-DC converter and a discrete controller. The DC microgrid uses renewable energy sources and batteries; power management is performed using a discrete sliding-mode fuzzy control (DSMFC) to ensure system stability. The charging efficiency and speed are increased by implementing a GaN-based bidirectional DC-DC converter. The robustness and stability of the system are ensured by implementing the DSMFC technique.This charging solution results in portable chargers that are ready for use in all households with available renewable sources and batteries.

[0034] Fig. 2 shows an operational diagram illustrating the DC microgrid connected electric vehicle fast charging system according to an embodiment of the present disclosure.

[0035] In relation to Fig. 2, the invention relates to a highly efficient, DC microgrid-connected fast charging system for electric vehicles, enabled by a GaN-based bidirectional DC-DC converter and a discrete controller. The DC microgrid is powered by renewable energy sources such as solar, wind, and battery storage. To maximize the energy harvested from photovoltaic (PV) systems, the system uses maximum power point tracking (MPPT) technology.

[0036] Energy management between the renewable energy sources and the DC grid is controlled using discrete sliding-mode fuzzy control (DSMFC), which ensures system stability. The charge controller controls the current flow to and from the battery by comparing the DC bus voltage with a reference voltage. Charging efficiency and speed are significantly improved by the use of GaN-based bidirectional DC-DC converters on both the source and load sides. The implementation of DSMFC also ensures system robustness and stability.

[0037] This system provides a charging solution and results in portable chargers that can operate on either AC or DC power and are suitable for use anywhere. These chargers are compatible with renewable energy sources, household AC power supplies, and batteries, thus offering versatility and adaptability. By utilizing renewable energy sources and batteries within the DC microgrid and implementing DSMFC for energy management, the system achieves efficient and stable operation.

[0038] The drawings and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be separated into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of the processes described herein may be changed and are not limited to the manner described herein. Furthermore, the actions of any flowchart need not be implemented in the order shown; nor do all actions necessarily need to be performed. Also, those actions that are not dependent on other actions may be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples.Numerous variations, whether explicitly stated in the specification or not, such as differences in structure, dimensions, and material use, are possible. The scope of the embodiments is at least as broad as indicated in the following claims.

[0039] Advantages, other benefits, and solutions to problems have been described above with reference to specific embodiments. However, the advantages, benefits, solutions to problems, and any components that may cause an advantage or solution to occur or become more apparent are not to be construed as a critical, required, or essential feature or component of any or all of the claims. REFERENCES 100 of a fast charging system for electric vehicles connected to a DC microgrid. 102 Bidirectional DC-DC converter 104 One or more subsystems for renewable energy sources 106 Battery energy storage subsystem 108 Energy management module 108a processor 110 Charging interface for electric vehicles 112 Maximum Power Point Tracking (Mppt) module 114 charge controllers 202 MPPT 204 PV arrays 204a Gan-based DC-DC controller 204b Gan-based DC-DC controller 204c Electric Vehicle 206 Windmill 206a AC and DC converter 206b DC / DC converter 206c AC loads 208 Battery Bank 208a Gan-based DC-DC controller 208b DC-AC converter 208c network 210 charging regulator 212 DC busbar

Claims

[1] A fast charging system for electric vehicles connected to a DC microgrid, consisting of: a bidirectional DC-DC converter, the converter being based on gallium nitride (GaN); one or more subsystems for renewable energy sources, including solar and wind energy; a battery energy storage subsystem connected to the one or more renewable energy source subsystems; a power management module connected to the bidirectional DC-DC converter, the power management module comprising a processor configured to perform power management using Discrete Sliding Mode Fuzzy Control (DSMFC); and an electric vehicle charging interface to facilitate the charging of electric vehicles. [2] The system of claim 1, wherein the renewable energy subsystem comprises at least one of the following components: solar photovoltaic systems and wind energy generators. [3] The system of claim 1, wherein the GaN-based bidirectional DC-DC converter is configured to operate on both the source and load sides of the DC microgrid, wherein the GaN-based bidirectional DC-DC converter provides improved charging efficiency and speed for charging electric vehicles. [4] The system of claim 1, further comprising a Maximum Power Point Tracking (MPPT) module configured to optimize power extraction from the renewable energy source subsystem. [5] The system of claim 1, wherein the Discrete Sliding Mode Fuzzy Control (DSMFC) power management module is configured as follows: manage the flow of energy between multiple energy sources; Compare the DC bus voltage to a reference voltage. Ensuring system stability. [6] The system of claims 1 and 5, wherein the energy management module implements a control technique for managing energy distribution and maintaining system robustness, and wherein the discrete sliding mode fuzzy controller provides an adaptive control mechanism for managing energy flow between renewable energy sources, battery storage, and electric vehicle charging. [7] The system of claim 1, further comprising a charge controller configured to control current flow to and from the battery by comparing the DC bus voltage to the reference voltage. [8] The system of claim 1, wherein the electric vehicle charging interface is configured to support portable charging across multiple power input configurations. [9] The system of claim 1, wherein the GaN-based DC-DC converter provides bidirectional power conversion with improved efficiency compared to conventional silicon-based converters.

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