Smart city solar energy Internet of Things electric vehicle charging module

Abstract

The invention relates to an intelligent city solar energy Internet of Things electric vehicle charging module. The module comprises a solar photovoltaic array, a charging controller, a battery energy storage unit, an inverter, an Internet of Things monitoring unit, an electric vehicle charging port and a power supply protection module. According to the module, solar energy is converted into electric energy through a photovoltaic array, and stable output is achieved through a charging controller and a DC-DC conversion unit (BUCK and BOOST); the energy storage unit and the battery management system work cooperatively to guarantee power supply at night; the inverter supports a grid-connected operation mode and an off-grid operation mode. The Internet of Things monitoring unit realizes real-time monitoring and cloud transmission of parameters such as current, voltage, temperature and SOC based on ESP8266, and has predictive maintenance and data security functions. The system adopts a modular structure, can expand deployment, supports bidirectional energy flow and urban traffic platform linkage, and has the effects of being green, low-carbon, high in reliability and intelligent in management.

Description

Technical Field

[0001] This application relates to the fields of new energy and intelligent transportation, and in particular to a smart city solar-powered Internet of Things electric vehicle charging module. Background Technology

[0002] In recent years, with the intensification of the global energy crisis and the increasing prominence of environmental pollution, the utilization of clean, efficient, and renewable energy has become one of the key directions of global technological development. Electric vehicles (EVs), as an important representative of green transportation, are gradually replacing traditional gasoline-powered vehicles and becoming the main trend of future transportation due to their advantages such as zero emissions, low noise, and high energy efficiency. However, the widespread application of electric vehicles cannot be separated from the support of efficient, convenient, and sustainable charging infrastructure. Currently, electric vehicle charging stations worldwide still largely rely on traditional power grids, which are mainly powered by fossil fuels such as coal and natural gas. Their high carbon emission characteristics, to some extent, offset the environmental advantages brought by electric vehicles.

[0003] To achieve truly green transportation, researchers and engineering companies have begun exploring the integration of renewable energy into charging systems. Among these, solar photovoltaic (PV) power generation, with its renewable, low-carbon, and ubiquitous nature, has emerged as one of the most promising solutions. Solar charging stations directly convert solar energy into electricity through photovoltaic modules, providing charging support for electric vehicles. This not only effectively reduces dependence on fossil fuels but also enables energy self-sufficiency in remote areas or those with insufficient grid coverage. The combination of solar PV technology and electric vehicles has become an important component of smart cities and sustainable transportation systems.

[0004] Currently, the mature application of solar photovoltaic (PV) power generation systems mainly benefits from their low operation and maintenance costs, high energy conversion efficiency, and flexible installation methods. However, the output power of PV systems is highly susceptible to factors such as climate conditions, sunlight intensity, temperature variations, and component aging, leading to large fluctuations in power generation and making it difficult to guarantee the stability and continuity of the charging system. Furthermore, PV power output is typically direct current (DC), while electric vehicle charging equipment requires precise voltage and current control to ensure battery safety and charging efficiency. Therefore, achieving efficient energy management and intelligent scheduling of PV power generation under different environmental conditions has become a core technical challenge for current solar-powered electric vehicle charging systems.

[0005] In addition, traditional electric vehicle charging stations generally have the following problems: (1) Single energy source: Most charging stations still rely on the municipal power grid for power supply, and the high proportion of fossil fuels in the power grid structure indirectly leads to increased carbon dioxide emissions, which weakens the environmental benefits of electric vehicles; (2) Operating costs fluctuate greatly: Electricity prices are significantly affected by market supply and demand and energy policies, especially during peak electricity consumption periods or fast charging periods, when demand for electricity is high, making it difficult for operating companies to predict and control operating costs; (3) Uneven infrastructure layout: At present, the charging network is highly concentrated in the core urban area, while the charging infrastructure in rural areas, transportation arteries and remote areas is seriously insufficient, which restricts the long-distance driving ability of electric vehicles. (4) Insufficient charging reliability: Charging stations frequently experience equipment failures, communication interruptions, or uneven charging performance, resulting in a poor user experience; (5) Lack of data and lagging management: Most traditional charging systems lack real-time monitoring and remote management capabilities, and cannot detect faults or optimize energy consumption in a timely manner.

[0006] Meanwhile, the global energy structure is accelerating its transition to renewable energy. According to data from the International Energy Agency (IEA), China has become the world's largest country in terms of installed photovoltaic capacity, currently possessing over 1.4 terawatts of solar and wind power capacity, and plans to further expand to a total scale of approximately 2.7 terawatts within the next decade. The Chinese government has clearly set goals, which not only require decarbonization in the industrial and building sectors but also urgently demand a green transformation of the transportation system. Against this backdrop, developing an electric vehicle charging module based on solar photovoltaic power supply, integrated energy storage, and intelligent control is of great significance for supporting green transportation, optimizing urban energy structures, and promoting the construction of smart cities.

[0007] In existing technologies, some solar charging stations combine photovoltaic panels with batteries, using DC-DC conversion circuits to achieve voltage regulation and energy storage. However, these systems generally suffer from the following technical limitations: First, the system lacks an efficient energy management strategy and cannot intelligently allocate energy based on real-time lighting conditions and battery state of charge (SOC), resulting in low energy utilization. Secondly, energy storage units are often independently controlled and not linked with the main controller or cloud system, making it impossible to perform remote status monitoring and health management; Third, some systems only support off-grid operation mode, which lacks flexibility in urban power grid access or load dispatch scenarios. Fourth, the lack of communication and interconnection capabilities between devices makes it difficult to achieve Internet of Things (IoT) level management and data analysis of charging station clusters; Finally, traditional charging controllers have poor compatibility with different vehicle models and charging protocols (such as CCS, CHAdeMO, or GB / T standards), which limits the widespread application of charging facilities.

[0008] In recent years, with the rapid development of the Internet of Things (IoT) and cloud computing technologies, smart energy systems have gradually become a research hotspot. IoT-based energy management architectures can achieve multi-point monitoring, real-time data acquisition, remote diagnostics, and predictive maintenance, thereby significantly improving the safety and operational efficiency of charging stations. However, how to deeply integrate solar power generation, energy storage management, and IoT monitoring to build a comprehensive charging module that is both energy self-sufficient and interconnected with urban energy management systems remains a technological bottleneck in current research and application.

[0009] Therefore, there is an urgent need for a solar-powered IoT electric vehicle charging module with high-efficiency energy conversion, intelligent scheduling and control, remote real-time monitoring, and multi-mode operation capabilities. This system should not only fully utilize solar power generation when sunlight is abundant and provide energy storage and power supply when sunlight is insufficient or at night, but also support grid-connected and off-grid switching, bidirectional energy flow, and data cloud interaction to improve energy utilization and system stability. By integrating intelligent sensors and wireless communication modules, real-time acquisition and uploading of key parameters such as voltage, current, temperature, SOC, and power factor can be achieved, thereby enabling fault prediction, energy consumption optimization, and equipment health management.

[0010] In summary, existing solar-powered electric vehicle charging systems still have significant shortcomings in energy management, equipment interconnection, operational reliability, and intelligence. There is an urgent need for a new type of smart city solar-powered IoT electric vehicle charging module. This module would integrate photovoltaic power generation, energy storage control, and IoT technologies to construct a next-generation smart charging infrastructure that is green, low-carbon, sustainable, highly reliable, and offers remote, visualized management capabilities. This invention addresses these technical problems with an improved solution aimed at achieving a truly integrated "green energy + smart mobility" system, providing solid support for the construction of smart city energy systems. Summary of the Invention

[0011] To address the aforementioned technical issues, this application provides a smart city solar-powered IoT electric vehicle charging module.

[0012] The smart city solar-powered IoT electric vehicle charging module provided in this application adopts the following technical solution: A smart city solar-powered IoT electric vehicle charging module, characterized in that: it includes... Solar photovoltaic arrays are used to convert solar energy into direct current (DC) electricity. A charging controller is used to regulate the output voltage and current of the DC power to prevent the battery from being overcharged or over-discharged. A battery energy storage unit is used to store the electrical energy generated by the photovoltaic array to provide power at night or in low light conditions; An inverter is used to convert direct current (DC) power into alternating current (AC) power for charging AC-powered electric vehicles. The Internet of Things (IoT) monitoring unit, including an ESP8266 microcontroller and sensors, is used to collect system operating parameters and upload the data to a cloud server via a wireless communication module. The electric vehicle charging port is a Type 2 interface structure, used to connect to the electric vehicle and transfer energy; The power protection module, including miniature circuit breakers (MCBs), fuses, and surge protectors, is used to provide overload, short circuit, and overvoltage protection.

[0013] By adopting the above technical solution, the module directly converts natural light energy into DC power through a solar photovoltaic array, constructing a clean charging system driven by renewable energy. This reduces dependence on fossil fuels and the mains power grid, lowering carbon emissions and operating costs. The introduction of a charging controller enables the system to adjust output voltage and current in real time, preventing overcharging or over-discharging of the battery and extending the lifespan of the energy storage device and electric vehicle battery. Furthermore, intelligent algorithms achieve maximum power point tracking (MPPT), significantly improving photovoltaic energy conversion efficiency. The battery energy storage unit configuration ensures stable power supply even at night, on cloudy days, or under low light conditions, enhancing the system's continuous operation capability and energy independence. The inverter module achieves efficient DC-AC energy conversion, is compatible with different types of electric vehicle charging needs, and supports both off-grid independent operation and grid-connected modes. The switching mechanism allows for flexible scheduling based on grid conditions, enabling bidirectional energy flow and feedback utilization. The IoT monitoring unit, through the ESP8266 microcontroller and various sensors, collects real-time system operation data, including key parameters such as current, voltage, temperature, and SOC, and uploads the information to the cloud server. This enables remote monitoring, data analysis, and predictive maintenance, significantly improving the intelligence and reliability of system operation and maintenance. The power protection module provides comprehensive electrical safety protection, preventing overload, short circuit, and surge faults, ensuring the charging safety of equipment and vehicles. This module highly integrates photovoltaic power generation, energy storage, inverter, intelligent monitoring, and safety protection, possessing functions such as green energy utilization, high-efficiency output, intelligent operation and maintenance, and modular expansion. It is widely used in the construction of smart city transportation infrastructure, providing technical support for building a low-carbon, safe, and efficient intelligent charging network.

[0014] Optionally, the charging controller integrates a maximum power point tracking (MPPT) algorithm to dynamically adjust the operating point based on changes in light intensity and temperature, thereby achieving the maximum power output of the photovoltaic array.

[0015] By adopting the above technical solution, the maximum power point tracking (MPPT) algorithm integrated in the charging controller dynamically adjusts the operating voltage and current of the photovoltaic array according to the changes in real-time light intensity and ambient temperature, so that it always operates near the maximum power point, significantly improving the solar energy utilization efficiency and maximizing the output power of photovoltaic power generation. This algorithm effectively reduces energy loss, improves the stability and reliability of the system under different climatic conditions, and realizes efficient and intelligent energy management and output control.

[0016] Optionally, the battery energy storage unit includes a lithium-ion battery pack and a battery management system (BMS) for monitoring battery voltage, current, temperature and SOC status, and for performing equalization charging control.

[0017] By adopting the above technical solutions, balanced charging and discharging control is performed based on the detection data to prevent overcharging, over-discharging, and overheating of the battery, thereby extending battery life and improving the safety and stability of the energy storage system. At the same time, the BMS realizes energy balancing and state optimization of multiple battery groups, improving the working efficiency and overall energy utilization of the entire energy storage unit.

[0018] Optionally, the inverter supports two modes: grid-connected operation and off-grid independent power supply. In off-grid mode, it is powered independently by the energy storage unit, while in grid-connected mode, it operates synchronously with the mains power grid to achieve energy feedback.

[0019] By adopting the above technical solutions, the inverter has dual-mode operation functions of grid-connected and off-grid. It can automatically switch the working state according to the power supply environment. In off-grid mode, the system can be independently powered by the energy storage unit, ensuring that it can still stably charge electric vehicles in the event of a mains power outage or in remote areas without a power grid. In grid-connected mode, the inverter operates synchronously with the mains power grid, realizing the feedback and sharing of excess power, improving the system's energy utilization rate and economy, and supporting distributed energy grid connection and smart grid construction.

[0020] Optionally, the IoT monitoring unit further includes: current, voltage, and temperature sensors; an ESP8266 microcontroller; and a cloud communication interface (MQTT or HTTP protocol) for real-time monitoring and cloud uploading of charging power, battery SOC, system temperature, and fault alarms. The power protection module further includes an over-temperature protection circuit for detecting the temperature of the charging connector and cable, and automatically disconnecting the output when the temperature exceeds the threshold to prevent overheating damage.

[0021] By adopting the above technical solutions, the collaborative design of the IoT monitoring unit and the power protection module enables the system to achieve comprehensive intelligent monitoring and safety protection functions. The IoT monitoring unit integrates current, voltage, and temperature sensors and an ESP8266 microcontroller to collect key operating parameters such as charging power, battery SOC, system temperature, and fault status in real time. It also uses MQTT or HTTP communication protocols to upload the data to the cloud platform, enabling remote monitoring, data recording, and operational status analysis. Through cloud data management, maintenance personnel can monitor the health status of equipment in real time, perform timely fault diagnosis and predictive maintenance, and improve the reliability and availability of the system. The over-temperature protection circuit in the power protection module can monitor the temperature of the charging connector and cable. When the temperature exceeds the set threshold, the system automatically cuts off the output current, effectively preventing component damage or fire risks caused by overheating. This achieves deep integration of information technology and safety control, possessing comprehensive technical functions of high reliability, high security, and remote intelligent operation and maintenance, providing stable and efficient operation guarantees for smart city charging infrastructure.

[0022] Optionally, a blocking diode and a bypass diode are connected in series between the solar photovoltaic array and the charging controller to prevent reverse current flow and hot spot effects at night or under partial shading conditions.

[0023] By adopting the above technical solution, the blocking diode and bypass diode connected in series between the solar photovoltaic array and the charging controller can effectively prevent the reverse flow of current at night or when there is partial shading, avoid energy loss of photovoltaic modules due to current backflow, and the bypass diode can prevent the hot spot effect caused by partial shading of photovoltaic units, reduce the damage of local overheating to the modules, improve the safety, reliability and overall power generation efficiency of the photovoltaic array, and ensure the stable operation of the charging system under various light conditions.

[0024] Optionally, the charging controller includes a DC-DC conversion unit, which consists of a BUCK buck converter and a BOOST boost converter, used to automatically adjust the output voltage to a stable value according to the input voltage, wherein: The BUCK module has an input voltage of 36V and an output voltage of 12V. The BOOST module has an input voltage of 12V and an output voltage of 20V. The switching frequency is 40kHz, and the inductors and capacitors are optimized based on the output ripple and volatility.

[0025] By adopting the above technical solution, the DC-DC conversion unit in the charging controller integrates a BUCK buck converter and a BOOST boost converter, realizing intelligent adjustment and stable output of the input voltage. The BUCK module can efficiently step down the 36V input voltage to 12V to meet the needs of low-voltage loads, while the BOOST module can boost the 12V input voltage to 20V to meet the needs of high-voltage output, ensuring the stability of the system output voltage under different operating conditions. The 40kHz switching frequency, combined with precisely optimized inductor and capacitor parameters, effectively suppresses output voltage ripple and current fluctuations, improving energy conversion efficiency and system reliability. The DC-DC conversion unit can dynamically respond to changes in input voltage, realizing continuous and smooth power regulation, ensuring coordinated power distribution between photovoltaic power generation, energy storage units, and electric vehicle loads, improving the energy management efficiency and safety of the entire charging module, and providing efficient, stable, and adjustable power output for smart city solar electric vehicle charging.

[0026] Optionally, the parameters of the DC-DC converter unit are optimized through Simulink simulation and physical verification to ensure that the output voltage fluctuation rate does not exceed 1% and the current ripple does not exceed 10%.

[0027] By adopting the above technical solutions, high-precision voltage and current regulation is achieved, which improves the stability and reliability of power conversion, effectively protects electric vehicle batteries and energy storage units from voltage fluctuations and current spikes, and improves charging efficiency and overall system operation safety, providing high-performance and controllable power output guarantee for smart city solar charging modules.

[0028] Optionally, the system is equipped with an amorphous silicon relay to provide electrical isolation between the controller and the power supply, thereby improving the safety and anti-interference capability between the control signal and the main power circuit. The cloud platform includes data encryption and authentication mechanisms to ensure the security of charging data transmission and the protection of user privacy.

[0029] By adopting the above technical solutions, the amorphous silicon relay provides electrical isolation between the controller and the power supply, effectively improving the safety and anti-interference capability between the control signal and the main power circuit, preventing electrical faults from affecting the control system. The cloud platform ensures the security of charging data during transmission through data encryption and authentication mechanisms, protects user privacy, and ensures the reliable execution of remote monitoring, operation analysis, and predictive maintenance functions, thus achieving an effective integration of system operation security, data integrity, and intelligent management.

[0030] Optionally, the module has a predictive maintenance function, which analyzes the operating data uploaded to the cloud to identify abnormal states in advance and issue maintenance warnings, thereby reducing downtime. The IoT monitoring unit can communicate with the urban traffic management platform to realize real-time updates of charging pile location, occupancy status and traffic congestion. The module adopts a modular structure design, and each module includes an independent photovoltaic unit, energy storage unit, control unit and communication unit, which can be connected in parallel to expand according to charging needs; The system supports bidirectional energy flow. When the vehicle battery SOC is higher than a set value, it can feed excess electrical energy back to the energy storage system or connect it to the grid for output, thereby realizing energy reuse.

[0031] By adopting the above technical solutions, the module has predictive maintenance capabilities. It can identify anomalies in advance and issue maintenance warnings by analyzing the operating data uploaded to the cloud, thereby reducing downtime and improving system reliability. At the same time, the IoT monitoring unit is linked with the urban traffic management platform to realize real-time updates on the location, occupancy status, and traffic congestion of charging piles. The modular structure design supports the parallel expansion of photovoltaic units, energy storage units, control units, and communication units to meet different charging needs. It also enables the feedback of excess power to the energy storage system or the power grid through bidirectional energy flow, thereby improving energy utilization efficiency and system flexibility.

[0032] In summary, this application includes at least one of the following beneficial technical effects: 1. By directly converting natural sunlight into DC power through solar photovoltaic arrays, clean charging driven by renewable energy can be achieved, reducing dependence on fossil fuels and grid electricity, and lowering carbon emissions and operating costs; 2. The charging controller can adjust the output voltage and current in real time to prevent overcharging or over-discharging of the battery, extend the service life of the energy storage unit and electric vehicle battery, and dynamically optimize the power output of the photovoltaic array through the MPPT algorithm to improve energy conversion efficiency; 3. Equipped with a lithium-ion battery energy storage unit and BMS, it realizes the monitoring and equalization charging control of battery voltage, current, temperature and SOC, ensuring stable power supply at night or under low light conditions, and improving the system's continuous operation capability and energy independence; 4. The inverter supports both grid-connected and off-grid operation, enabling independent power supply for energy storage and feedback of excess energy to the grid, thereby improving energy utilization and economy, and ensuring continuous charging capability in remote areas and in the event of power outages. 5. The IoT monitoring unit combines multiple sensors and cloud communication interfaces to achieve real-time data acquisition, remote monitoring, data analysis, and predictive maintenance, thereby improving the system's intelligent operation and maintenance level and reliability; 6. The power protection module provides overload, short circuit, surge and over-temperature protection to ensure the charging safety of equipment and vehicles; 7. Blocking diodes and bypass diodes are configured between the photovoltaic array and the charging controller to prevent reverse current flow and hot spot effect caused by nighttime or partial shading, thereby improving the safety and power generation efficiency of the photovoltaic module. 8. The DC-DC converter unit integrates BUCK buck and BOOST converters to achieve automatic input voltage adjustment and stable output, optimize voltage fluctuation rate and current ripple, and improve energy conversion efficiency and system reliability; 9. Amorphous silicon relays provide electrical isolation between control signals and the main power circuit, while the cloud platform ensures charging data security and user privacy through data encryption and authentication mechanisms; 10. The modular structure design supports the parallel expansion of photovoltaic units, energy storage units, control units and communication units. The system supports bidirectional energy flow, realizes the feedback and utilization of excess power, and provides real-time location, occupancy and traffic status information through linkage with the urban traffic management platform, realizing the construction of intelligent, scalable, green and efficient charging infrastructure. Attached Figure Description

[0033] Figure 1 This is a system framework diagram of an embodiment of this application.

[0034] Figure 2 This is a system simulation diagram of an embodiment of this system.

[0035] Figure 3 This is a circuit diagram of a BUCK converter according to an embodiment of this application.

[0036] Figure 4 This is a circuit diagram of a BOOST converter according to an embodiment of this application.

[0037] Figure 5 This is a flowchart of the proposed system in an embodiment of this application.

[0038] Figure 6 This is a schematic diagram of photovoltaic voltage characteristics on different dates in the embodiments of this application. Figure 1 .

[0039] Figure 7 This is a schematic diagram of photovoltaic voltage characteristics on different dates in the embodiments of this application. Figure 2 .

[0040] Figure 8 This is a schematic diagram of photovoltaic voltage characteristics on different dates in the embodiments of this application. Figure 3 .

[0041] Figure 9 This is a schematic diagram of the output voltage characteristics on different dates in the embodiments of this application. Figure 1 .

[0042] Figure 10 This application's embodiments illustrate the output voltage characteristics on different dates. Figure 2 .

[0043] Figure 11 This is a schematic diagram of the output voltage when no load is connected in the embodiments of this application. Figure 1 .

[0044] Figure 12 This is a schematic diagram of the output voltage when no load is connected in the embodiments of this application. Figure 2 . Detailed Implementation

[0045] The following is in conjunction with the appendix Figure 1-12 This application will be described in further detail.

[0046] This application discloses a smart city solar-powered IoT electric vehicle charging module. (Refer to...) Figure 1 , Figure 2 It includes solar photovoltaic arrays, charging controllers, battery energy storage units, inverters, IoT monitoring units, electric vehicle charging ports, and power protection modules; Solar photovoltaic arrays are used to convert solar energy into direct current (DC) electricity. The charging controller is used to regulate the output voltage and current of the DC power to prevent the battery from being overcharged or over-discharged. The battery energy storage unit is used to store the electrical energy generated by the photovoltaic array to provide power at night or in low light conditions; Inverters are used to convert direct current (DC) power into alternating current (AC) power for charging AC-powered electric vehicles. The IoT monitoring unit includes an ESP8266 microcontroller and sensors, which are used to collect system operating parameters and upload the data to the cloud server via a wireless communication module; The electric vehicle charging port is a Type 2 interface structure, used to connect to the electric vehicle and transfer energy; The power protection module includes miniature circuit breakers (MCBs), fuses, and surge protectors to provide overload, short circuit, and overvoltage protection. Solar photovoltaic power generates DC power → the charging controller optimizes voltage / current → the battery stores excess energy → the inverter / DC power supply powers the electric vehicle through the charging port → the IoT system updates the charging status, battery SOC and fault alarms to the cloud in real time.

[0047] Reference Figure 3 The BUCK converter and related mathematical formulas are integrated into the Simulink model. Rated power = 220 W Open circuit voltage = 36.06V Input voltage = 36V Output voltage = 12V Current ripple level = 10% Voltage fluctuation = 1% Figure 3 The arrangement of the BUCK converter used for simulation in the SIMULINK model is shown.

[0048] Now (1) (2) (3) We can obtain the value of the series inductance from the formula. (4) (5) Similarly, we can find the value of the shunt capacitor. (6) Reference Figure 4 The BOOST converter and related mathematical formulas are integrated into the Simulink model. Input voltage = 12V Output voltage = 20V Load resistance (R) = 4 ohms Volatility (r) = 5% Switching frequency = 40 kHz = 40000 Hz Duty cycle calculation, Calculation of minimum inductance Set the inductance value to be 25% larger than the minimum inductance value. Similarly, the calculation of the minimum capacitance... When designing a DC-DC converter, it is necessary to meet practical needs while also taking into account ease of operation. Basic parameter calculations are performed, and several key indicators are determined to ensure that the equipment can output ideal signals under different operating conditions. Specifically, it is necessary to calculate the series inductance value required for boosting and determine the parallel capacitor parameters that are crucial for filtering out stray noise. This not only results in a cleaner DC output but also keeps the voltage across the load stable.

[0049] In the real-time hardware model of this system, a design prototype was used to conduct performance tests on the integrated electric vehicle charging module of the smart city solar power grid. This technical solution successfully verified the parameter settings, performance, and technical functions through the developed device prototype. On the prototype, the performance of the solar photovoltaic array, DC-DC boost converter, and electric vehicle load were all verified. System components include: a solar photovoltaic array, a DC-DC boost converter, an inverter, a rectifier, LED bulbs as load devices, and an Arduino Uno controller (AT mega 328) and an ESP 8266 microcontroller. Strong isolation was achieved between the controller and the power supply through the use of amorphous silicon relays.

[0050] Example 1 The overall system structure is as follows Figures 1-12 As shown, an intelligent electric vehicle charging system based on a solar photovoltaic array includes a photovoltaic power generation module, a charging controller module, a battery energy storage module, an inverter module, an IoT monitoring module, and a power protection module. The photovoltaic power generation module consists of several monocrystalline or polycrystalline silicon solar panels, each with a power output of 200–400W, connected in series and parallel to form a photovoltaic array with a total power output of 2kW–20kW. The photovoltaic array is installed on the roof of a building or the top of a parking shed, with a south-facing tilt to improve sunlight utilization. Each group of photovoltaic modules is combined through a combiner box and then connected to the charging controller module via blocking diodes and bypass diodes to prevent reverse current flow and hotspot effects, ensuring stable system operation. The charging controller module internally includes a Maximum Power Point Tracking (MPPT) control unit, a DC-DC converter unit, and a logic control unit. The MPPT unit calculates the optimal operating point in real time by detecting the voltage and current of the photovoltaic array, ensuring that the photovoltaic output power is always at its maximum. The DC-DC converter unit consists of a buck module and a boost module. When the input voltage is higher than the target voltage, a buck mode is used; when the input voltage is insufficient, a boost mode is used to ensure that the output voltage is stable at the set value. The buck module has an input voltage of 36V and an output of 12V; the boost module has an input of 12V and an output of 20V. The switching frequency is 40kHz. The inductor and capacitor parameters are optimized through simulation to reduce ripple. Through Simulink simulation verification and physical testing, the system output voltage fluctuation rate does not exceed 1%, and the current ripple does not exceed 10%. The battery energy storage module uses a high-energy-density lithium iron phosphate battery pack with a nominal voltage of 3.2V per cell. These cells are connected in series and parallel to form energy storage units with voltage levels of 48V or 96V. The energy storage system has a built-in BMS battery management system, which monitors the voltage, temperature and SOC (state of charge) of each cell in real time. It also has equalization charging and discharging and protection functions. When there is sufficient sunlight, the system stores excess energy and supplies power to the inverter or charging terminal from the battery at night or on cloudy days, ensuring continuous power supply. The inverter module is connected to the energy storage DC bus and uses an SPWM control strategy to achieve efficient DC-AC conversion. The module supports two modes: grid-connected operation and off-grid independent power supply. In off-grid mode, the energy storage unit supplies power independently. In grid-connected mode, the inverter output operates synchronously with the mains power grid, enabling energy feedback and bidirectional power flow. The inverter has output voltage regulation, power factor correction, and harmonic suppression functions, and the conversion efficiency can reach over 95%. The power protection module is located at the system input, energy storage and output ends, including overvoltage, undervoltage, short circuit, overcurrent, reverse connection and surge protection circuits. The module is equipped with an over-temperature protection circuit, which can detect the temperature of connectors and cables in real time and automatically disconnect the output when the set threshold is exceeded to prevent overheating damage. The IoT monitoring module is based on the ESP8266 microcontroller and integrates current, voltage, temperature and light sensors. It is also equipped with a cloud communication interface (supporting MQTT or HTTP protocols) to monitor charging power, battery SOC, system temperature and fault alarm status in real time. The data is then uploaded to the cloud server. The cloud platform has data encryption and identity authentication mechanisms to ensure data transmission security and user privacy protection.

[0051] Example 2 Grid-connected operation as follows Figures 1-12As shown, when the output power of the photovoltaic array exceeds the charging and energy storage needs of electric vehicles, the system automatically enters grid-connected mode. The energy dispatch control unit monitors grid parameters in real time and feeds excess power back to the grid through the grid-connected interface at the inverter output, realizing a "self-generation and self-consumption, surplus power to the grid" operation mode; In grid-connected mode, the controller adopts a dual closed-loop control structure: the outer loop voltage control loop is used to maintain the output voltage stability, and the inner loop current control loop is used to adjust the grid-connected current waveform to make it in phase and frequency with the grid voltage, ensuring that the output power factor is close to 1. The system has an islanding detection function. When a grid power failure or frequency abnormality is detected, the grid-connected output is immediately cut off to ensure the safety of personnel and equipment. Through this embodiment, the system can effectively balance local electricity consumption and grid energy exchange, improve the utilization rate of photovoltaic power generation, and also has the functions of power feedback and peak shaving and valley filling, providing stable power support for regional distributed energy networks.

[0052] Example 3 Off-grid independent operation mode such as Figures 1-12 As shown, under the condition of power grid failure or no grid connection, the system can automatically switch to off-grid operation mode. The off-grid switching control module achieves electrical isolation through amorphous silicon relays and completes mode switching in milliseconds to avoid output interruption. At this time, the system is independently powered by the battery energy storage module. The inverter outputs a stable AC voltage to power the charging pile or AC load. The controller dynamically adjusts the output voltage and frequency according to the battery SOC and load power to ensure the stability and reliability of off-grid power supply. Off-grid mode is particularly suitable for remote areas, temporary parking lots, emergency rescue sites and other areas without grid access. The energy storage battery pack is kept in a high-efficiency charging state through MPPT control strategy, ensuring self-circulation energy supply by charging during the day and discharging at night, realizing a truly independent green energy system.

[0053] Example 4 Smart IoT monitoring and predictive maintenance, such as Figures 1-12As shown, this embodiment further introduces an IoT cloud monitoring platform on the basis of the above, realizing remote control and intelligent maintenance functions. The IoT module uploads the collected data (voltage, current, temperature, power, SOC, alarm signals, etc.) to the cloud database in real time through the ESP8266. The platform analyzes the long-term operating characteristic curves through big data algorithms, predicts equipment aging, abnormal temperature and energy efficiency decline, and issues maintenance warning signals in advance, significantly reducing downtime due to failure. In addition, the IoT module can be connected to the urban traffic management platform to realize the synchronous update of charging pile geographical location, occupancy status and traffic congestion information, providing dynamic energy data support for intelligent transportation systems. The cloud control platform supports remote parameter adjustment, firmware upgrade and data visualization. Users can view the charging status and energy distribution through a mobile APP, thereby realizing comprehensive visualized operation and maintenance management.

[0054] Example 5 Modular expansion and bidirectional energy flow: To meet different power requirements, the system adopts a modular design. Each module contains an independent photovoltaic unit, energy storage unit, control unit, and communication unit. Multiple modules can be connected in parallel to expand and build a high-power charging system. When expanding, there is no need to change the main control architecture. Data interaction and power sharing control between modules can be achieved simply through CAN bus or RS485 interface. The system supports bidirectional energy flow. When the SOC of the electric vehicle battery is higher than the set threshold and is in grid-connected state, the system can feed excess power back to the energy storage system or output it to the grid, realizing energy reuse and power balance regulation. Through the above structure, the system has high flexibility and scalability, and can realize multi-level energy dispatch according to the scale of the site, the number of vehicles, and the lighting conditions, significantly improving energy management efficiency and renewable energy penetration rate.

[0055] In the above embodiments, the photovoltaic voltage characteristics on different dates are as follows: Figures 5-8 As shown, the output voltage characteristics on different dates are as follows: Figures 9-10 As shown, the output voltage when no load is connected is as follows: Figure 11 As shown in Figure 12, the output voltage during loading is as shown in Figure 12.

[0056] In summary, this technical solution, through the organic integration of photovoltaic arrays, energy storage units, inverters, and intelligent monitoring and safety protection modules, constructs a renewable energy-driven intelligent charging system. The system not only possesses high energy efficiency and low-carbon environmental protection characteristics, but also enables free switching between off-grid and grid-connected operation, bidirectional energy flow, and cloud-based intelligent monitoring. Compared with traditional AC charging piles or fixed power supply charging systems, this technical solution significantly reduces operating costs and energy consumption, while simultaneously improving the system's safety, stability, and intelligence level. It is widely applicable to scenarios such as urban smart transportation, distributed energy in residential areas, public parking lots, and new energy demonstration projects.

[0057] This technical solution has the following technical effects: 1. 100% renewable electric vehicle charging reduces carbon footprint.

[0058] IoT monitoring improves reliability, reduces downtime, and enables preventative maintenance.

[0059] Energy storage ensures uninterrupted availability of charging.

[0060] Modular design allows for larger-scale smart city deployments.

[0061] This project aims to develop a solar-powered IoT smart electric vehicle charging module, which will play an important role in the field of modern electric transportation.

[0062] The voltage of a substation can be monitored using IoT technology when the load is connected and when the load is not connected.

[0063] To establish smart city infrastructure in India, this project aims to meet the topology requirements of fast smart charging solutions and enable bidirectional communication with the power grid infrastructure.

[0064] Increased demand for electric vehicle charging could overload the power grid, especially during peak electricity demand periods.

[0065] 9. The lack of accessible charging infrastructure in remote or off-grid areas hinders the widespread adoption of electric vehicles.

[0066] The key technical features of this technical solution are: 1. This technical solution aims to develop a solar-powered IoT smart electric vehicle charging module, which plays an important role in the field of modern electric transportation.

[0067] 2. This technical solution, through IoT integration technology, can monitor charging parameters in real time, thereby bringing convenience to a large number of electric vehicle owners and engineers in related fields.

[0068] 3. This technical solution aims to meet the topology requirements of fast smart charging solutions in the establishment of smart city infrastructure and to achieve bidirectional communication with the power grid infrastructure.

[0069] 4. With the help of the Internet of Things, this technical solution can solve the traffic congestion problem at charging stations and allow users to view the current traffic conditions at each charging point.

[0070] The implementation principle of a smart city solar IoT electric vehicle charging module in this application embodiment is as follows: The primary energy source of this technical solution is a solar photovoltaic array. The photovoltaic cells convert solar radiation energy into DC power through the photovoltaic effect. Under different irradiance and temperature conditions, the IV characteristic curve of the photovoltaic array has a significant nonlinear relationship. In order to keep the system output power at its maximum value, this application has built a maximum power point tracking (MPPT) algorithm module into the charging controller. The MPPT module collects the photovoltaic voltage Vpv and current Ipv in real time. Through the power calculation formula: Ppv=Vpv×Ipv, and using the perturbation observation method (P&O) or incremental conductance method (INC), the relationship between the power change rate and the voltage change rate is calculated. This dynamically adjusts the duty cycle D of the DC-DC converter so that the maximum power point Pmpp is obtained when dP and dP / dV=0. The operating point of the photovoltaic array is automatically adjusted under different weather conditions to achieve adaptive power adjustment and improve the energy conversion efficiency by more than 10%. The core of this energy regulation solution is a DC-DC converter unit, comprising two-stage topologies: BUCK (step-down) and BOOST (boost). The BUCK principle works as follows: when the photovoltaic array output voltage is higher than the voltage required by the energy storage unit, the controller activates the BUCK module. This module periodically turns the MOSFET on and off, reducing the input voltage to the target value according to the duty cycle. The basic voltage relationship is: Vo = D × Vin, where D is the duty cycle. To suppress ripple and maintain stable output, the system design incorporates an inductor L and a filter capacitor C, selected based on load power and ripple requirements: L > (1−D)R / 2f, C > D(1−D) / 8Lf²r. Through Simulink simulation and hardware verification, the BUCK stage output voltage fluctuation is less than 1%, and the current ripple is less than 10%. The BOOST principle works as follows: when the photovoltaic input voltage is insufficient to drive the charging load, the system automatically switches to BOOST mode. The output voltage relationship is: the BOOST module utilizes the inductor energy storage effect during MOSFET off-peak periods to boost the voltage. The process is controlled by a PWM signal. The system adjusts the duty cycle in real time to ensure stable output. The output voltage stability error does not exceed ±1.5%. Both stages of DC-DC conversion are controlled by the closed-loop controller to achieve automatic switching and bidirectional energy flow, so that the system can maintain stable power supply under multiple operating conditions. The energy storage module uses lithium iron phosphate battery packs and is monitored for all parameters through a BMS battery management system. The BMS dynamically manages the charging and discharging status by collecting voltage, temperature, and SOC data: when photovoltaic power generation is sufficient, the BMS prioritizes charging the energy storage unit and automatically adjusts the charging current according to the MPPT output power; when the battery SOC is detected to reach a threshold (e.g., 95%), the system enters float charging mode; when there is insufficient sunlight or during nighttime operation, the energy storage module discharges to the inverter or DC load; if the battery voltage is lower than the protection threshold (e.g., 2.5V / cell), the system automatically cuts off the discharge. This logic enables closed-loop energy management and battery life protection.

[0071] The inverter module converts DC power to AC power using an SPWM control strategy, outputting a standard 220V / 50Hz AC voltage. The SPWM signal is generated in real time by a microcontroller. The PWM pulse is obtained by comparing a triangular carrier wave with a sinusoidal reference wave, and the conduction timing of the MOSFETs or IGBTs is adjusted to achieve waveform modulation. When the inverter detects the presence of the grid and the voltage frequency is stable, it automatically enters the grid-connected mode. The control system adopts a dual closed-loop structure: the voltage outer loop is used to maintain the inverter output amplitude; the current inner loop is used to ensure that the output current is in phase and frequency with the grid voltage. In this mode, the system can not only charge the vehicle, but also feed excess energy back to the grid to achieve energy sharing. If an islanding effect (grid disconnection) is detected, the inverter immediately cuts off the output to ensure safety. The IoT monitoring unit, based on the ESP8266, integrates current, voltage, light, and temperature sensors. The microcontroller collects real-time data via serial port, filters and extracts features, and then uploads it to the cloud server via a Wi-Fi module. The data interaction protocol uses a lightweight MQTT communication architecture, characterized by low latency and high reliability. Each device has a unique ID number, and the cloud uses TLS / SSL encryption for two-way authentication. The cloud platform uses a distributed database to store historical operating data and employs machine learning algorithms to achieve the following functions: fault prediction and alarm, intelligent matching of light intensity and load power, remote charging strategy optimization and dynamic scheduling, and device health status analysis and maintenance suggestions. Users can view charging power, SOC, energy revenue, and carbon emission reductions in real time via a mobile app or web browser, achieving intelligent and visualized operation and maintenance. The system is equipped with protection modules at the power inlet, DC bus and AC output. The protection logic includes an MCB circuit breaker that quickly disconnects when the detected current exceeds 1.5 times the rated value; an SPD to absorb high voltage spikes caused by lightning strikes or sudden changes; and a temperature sensor to automatically disconnect when the temperature of the terminal and cable exceeds the threshold. With the above multi-layer safety protection, the system can operate stably in complex outdoor environments for a long time. The overall operation process of the system is as follows: the photovoltaic array receives solar energy and outputs DC power; the MPPT algorithm adjusts the duty cycle to achieve maximum power point operation; the DC-DC converter stabilizes the output voltage and charges the energy storage battery; when the vehicle is connected, the system determines the operating mode (off-grid or grid-connected); the inverter outputs AC power or the DC port directly supplies power; the ESP8266 module collects operating data and uploads it to the cloud; the cloud platform analyzes the data and provides feedback on the scheduling strategy; the controller performs dynamic adjustments to achieve closed-loop optimization. This technical solution enables intelligent control of the entire energy collection, conversion, transmission, storage and information feedback chain, which significantly improves charging efficiency, stability and safety.

[0072] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A smart city solar-powered IoT electric vehicle charging module, characterized in that: include Solar photovoltaic arrays are used to convert solar energy into direct current (DC) electricity. A charging controller is used to regulate the output voltage and current of the DC power to prevent the battery from being overcharged or over-discharged. A battery energy storage unit is used to store the electrical energy generated by the photovoltaic array to provide power at night or in low light conditions; An inverter is used to convert direct current (DC) power into alternating current (AC) power for charging AC-powered electric vehicles. The Internet of Things (IoT) monitoring unit, including an ESP8266 microcontroller and sensors, is used to collect system operating parameters and upload the data to a cloud server via a wireless communication module. The electric vehicle charging port is a Type 2 interface structure, used to connect to the electric vehicle and transfer energy; The power protection module, including miniature circuit breakers (MCBs), fuses, and surge protectors, is used to provide overload, short circuit, and overvoltage protection.

2. The smart city solar-powered IoT electric vehicle charging module according to claim 1, Its features are, The charging controller integrates a maximum power point tracking (MPPT) algorithm, which dynamically adjusts the operating point based on changes in light intensity and temperature to achieve the maximum power output of the photovoltaic array.

3. The charging module according to claim 1 or 2, characterized in that, The battery energy storage unit includes a lithium-ion battery pack and a battery management system (BMS) for monitoring battery voltage, current, temperature and SOC status, and for performing equalization charging control.

4. The charging module according to any one of the preceding claims, characterized in that, The inverter supports two modes: grid-connected operation and off-grid independent power supply. In off-grid mode, it is powered independently by the energy storage unit, while in grid-connected mode, it operates synchronously with the mains power grid to achieve energy feedback.

5. The charging module according to claim 1, characterized in that, The IoT monitoring unit further includes: current, voltage, and temperature sensors; an ESP8266 microcontroller; and a cloud communication interface (MQTT or HTTP protocol) for real-time monitoring and cloud uploading of charging power, battery SOC, system temperature, and fault alarms. The power protection module further includes an over-temperature protection circuit for detecting the temperature of the charging connector and cable, and automatically disconnecting the output when the temperature exceeds the threshold to prevent overheating damage.

6. The charging module according to any one of the preceding claims, characterized in that, A blocking diode and a bypass diode are connected in series between the solar photovoltaic array and the charging controller to prevent reverse current flow and hot spot effect at night or under partial shading conditions.

7. The charging module according to claim 1, characterized in that, The charging controller includes a DC-DC converter unit, which consists of a buck converter and a boost converter, used to automatically adjust the output voltage to a stable value according to the input voltage, wherein: The BUCK module has an input voltage of 36V and an output voltage of 12V. The BOOST module has an input voltage of 12V and an output voltage of 20V. The switching frequency is 40kHz, and the inductors and capacitors are optimized based on the output ripple and volatility.

8. The charging module according to claim 7, characterized in that, The parameters of the DC-DC converter unit were optimized through Simulink simulation and physical verification to ensure that the output voltage fluctuation rate does not exceed 1% and the current ripple does not exceed 10%.

9. The charging module according to any one of the preceding claims, characterized in that, The system is equipped with amorphous silicon relays to provide electrical isolation between the controller and the power supply, thereby improving the safety and anti-interference of the control signal and the main power circuit. The cloud platform includes data encryption and authentication mechanisms to ensure the security of charging data transmission and the protection of user privacy.

10. The charging module according to claim 1, characterized in that, The module has a predictive maintenance function. By analyzing the operating data uploaded to the cloud, it can identify abnormal states in advance and issue maintenance warnings, thereby reducing downtime. The IoT monitoring unit can communicate with the urban traffic management platform to realize real-time updates of charging pile location, occupancy status and traffic congestion. The module adopts a modular structure design, and each module includes an independent photovoltaic unit, energy storage unit, control unit and communication unit, which can be connected in parallel to expand according to charging needs; The system supports bidirectional energy flow. When the vehicle battery SOC is higher than a set value, it can feed excess electrical energy back to the energy storage system or connect it to the grid for output, thereby realizing energy reuse.

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