Automatic conversion device for charging in parking, charging system and control method

Abstract

The application discloses a kind of parking charging automatic conversion device, charging system and control method, belong to new energy vehicle intelligent charging field.Device includes photovoltaic interface, external power supply interface, output interface, automatic identification switching module and manual physical master switch, and two power supply hardware interlock protection is built by input identification, switching control and relay two-way interlocking.Conventional hardware can be adapted to alternating current mains or high-voltage direct current fast charging alternatively.Integrated EMC filtering and transient suppression, compatible high-voltage interlock signal, meet charging safety standard.Set hierarchical authority and 500ms hardware anti-shake, with physical master switch as the highest authority, fusion local automatic and remote control.Do not change vehicle BMS, charging handshake and closed loop are realized by original vehicle BMS, device focuses on power supply path safety switching, solve the problem of poor adaptability, easy to touch, weak protection, low intelligentization of traditional equipment, realize unattended high-precision high-safety general intelligent switching.

Description

Technical Field

[0001] This invention relates to the field of intelligent charging control technology for new energy vehicles, specifically to an automatic switching device for parking charging, a charging system, and a control method. It is applicable to parking conditions of new energy passenger cars, RVs, and commercial vehicles, and can realize universal adaptive switching, safety protection, and remote intelligent management between the on-board photovoltaic system and the vehicle's independent AC mains charging system and independent high-voltage DC fast charging system. Background Technology

[0002] Existing onboard dual-source charging switching equipment suffers from several core technological shortcomings, making it difficult to adapt to the parking charging needs of modern new energy vehicles. Firstly, its application is limited; traditional equipment only supports switching between photovoltaic and AC mains power, failing to adapt to onboard high-voltage DC fast charging parking scenarios. This severely limits its versatility and makes it difficult to cover the parking charging needs of multiple vehicle models and modes. Secondly, its operational stability is poor; traditional equipment lacks hardware anti-shake control logic, making it highly susceptible to instantaneous voltage fluctuations and power supply plug-and-play jitter, frequently resulting in incorrect or erratic switching, severely impacting the continuity and stability of parking charging. Thirdly, its safety protection system is incomplete; it relies solely on a single software-based electronic control logic for circuit on / off control, lacking hardware fallback protection and tiered access control mechanisms. When the electronic control program malfunctions or the equipment fails, it cannot effectively cut off power, posing significant safety hazards during equipment maintenance and vehicle charging. Fourthly, its level of intelligence is low; it only supports local manual operation and cannot achieve unattended automatic switching or remote intelligent management, resulting in poor intelligent adaptability. It should be noted that the pre-converter structure for AC charging and the high-voltage adapter structure for DC charging are well-known and common technologies in the industry, and are not within the scope of this invention. The core innovation of this invention lies in the optimization and upgrading of the device's general hardware architecture, the all-dimensional safety protection system, and the intelligent adaptive switching control method. This invention does not alter the original BMS charging logic of the vehicle; the vehicle's charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS. This device focuses on solving the problem of safe switching and protection of the power path. Summary of the Invention

[0003] Purpose of the invention The purpose of this invention is to provide an automatic switching device, charging system, and control method for parking charging, solving the technical problems of poor versatility, weak switching stability, lack of safety protection, and low level of intelligence in existing on-board charging switching devices. This invention, through a universal hardware architecture, coupled with original hierarchical permission control, hardware anti-shake adaptation, and remote collaborative control logic, enables a single device to adapt to two mainstream on-board charging systems. This invention does not modify the vehicle's original BMS charging logic; the vehicle charging handshake and charge / discharge closed-loop control are still implemented by the original vehicle BMS. This device focuses on solving the safety switching and protection of the power path, comprehensively improving the versatility, operational stability, safety, and intelligence level of parking charging for new energy vehicles.

[0004] Technical solution An automatic switching device for parking charging includes a photovoltaic input interface (1), an external power input interface (2), an output interface (3), an automatic identification and switching module (4), and a manual physical master switch (8); the photovoltaic input interface (1), the external power input interface (2), and the output interface (3) are electrically connected to the automatic identification and switching module (4); the manual physical master switch (8) is connected in series in the device's main power supply circuit and is an independent mechanical circuit breaker hardware structure. The hardware interlocking priority is higher than all electrical control and automatic control logic, and it is used to realize the device hardware-level forced power-off interlocking. The photovoltaic input interface (1) is used to connect to the power output terminal of the vehicle photovoltaic system; the external power input interface (2) is a platform universal interface, which is configured to adapt to an external 220V AC mains charging gun or to adapt to an external high-voltage DC fast charging gun; the output interface (3) matches the configuration of the external power input interface (2): when the external power input interface (2) is configured to adapt to an AC mains charging gun, the output interface (3) is used to connect to the vehicle OBC on-board charger; when the external power input interface (2) is configured to adapt to a DC fast charging gun, the output interface (3) is used to connect to the vehicle DC fast charging module; the same physical unit can only use one configuration at a time, and cannot be compatible with both AC and DC charging guns at the same time. This device does not change the original BMS charging logic of the vehicle. The vehicle charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS. This device focuses on solving the power path safety switching and protection. The automatic identification and switching module (4) integrates an input identification unit (41), a switching control unit (42), and a relay dual-channel interlock (43). The relay dual-channel interlock (43) includes a first relay and a second relay. The normally closed auxiliary contact of the first relay is connected in series to the coil power supply circuit of the second relay, and the normally closed auxiliary contact of the second relay is connected in series to the coil power supply circuit of the first relay. The output terminal of the switching control unit (42) is connected to the coil control terminals of the first relay and the second relay respectively. The input identification unit (41) is used to collect and identify the voltage parameters and on / off status of the photovoltaic input power supply and the external input power supply in real time. The switching control unit (42) and the relay dual-channel interlock (43) cooperate to form a hardware electrical interlock structure, so that the photovoltaic input path and the external power supply input path cannot be connected to the output interface (3) at the same time, thus completely eliminating the risk of short circuit in parallel connection of dual power supplies from the hardware level. Furthermore, the device is entirely encapsulated in a one-piece sealed dustproof and waterproof housing, and all interfaces adopt a vehicle-standard quick-connect interface structure, which does not require modification of the vehicle's original on-board circuit, enabling non-destructive and rapid assembly, and is suitable for the vehicle's small installation space and complex on-board conditions such as vibration and temperature difference. Furthermore, the dual-channel interlocking relay (43) is selected according to the factory configuration of the device, using an electromagnetic relay or DC contactor with an AC 250V or DC 750V and above voltage level to carry the rated operating current under different charging conditions and ensure that the equipment is compatible with different power parking charging scenarios. Preferably, the power input terminal of the automatic identification switching module (4) is provided with an EMC filter circuit and a transient voltage suppression circuit; the EMC filter circuit includes an X capacitor, a Y capacitor and a common-mode inductor, which are used to effectively suppress conducted interference and radiated interference on the power line; the transient voltage suppression circuit includes a TVS diode and a reverse connection protection diode, which are used to absorb transient pulse interference on the vehicle power line and ensure stable operation of the switching control unit (42) in a complex vehicle electromagnetic environment. In the relay dual-channel interlock (43), each relay coil is connected in parallel with a freewheeling diode or an RC absorption circuit, which are used to suppress the reverse induced electromotive force and spark interference generated when the relay is switched on and off, reduce the electromagnetic radiation of the equipment, and improve the overall electromagnetic compatibility of the equipment. Furthermore, the external power input interface (2) is compatible with the high voltage interlock (HVIL) signal terminal, which transmits the HVIL signal to the vehicle BMS. The switching control unit (42) collects the HVIL circuit status in real time. When the HVIL circuit is abnormally disconnected, the switching control unit (42) prevents the relay or contactor coil from being energized and immediately cuts off the high voltage power circuit. When adapting to DC fast charging scenarios, the device performs a hardware-level safety handshake with the vehicle battery management system (BMS) through the HVIL signal to ensure that the charging gun connection is reliable and the circuit is normal before the high voltage circuit can be turned on. The device housing is equipped with a dedicated grounding terminal (PE). The insulation resistance between the high voltage circuit inside the device and the grounding terminal is not less than 1MΩ (DC 750V condition). The housing and the vehicle body are equipotentially connected, which fully meets the vehicle's high voltage safety protection requirements. Furthermore, the device housing has a protection rating of no less than IP67 and an operating temperature range of -40℃ to +85℃, making it stable and adaptable to complex operating conditions such as outdoor parking and driving vibrations of vehicles, and conforming to the GB / T 28046 series of vehicle electronic equipment environmental standards. A parking charging system includes an on-board photovoltaic system, a photovoltaic controller, the aforementioned parking charging automatic conversion device, a vehicle-side charging module, and an external power gun; the photovoltaic controller is connected in series between the on-board photovoltaic system and the photovoltaic input interface (1) to regulate the photovoltaic output power and ensure stable output of photovoltaic power supply voltage and current. The vehicle-side charging module is either an OBC (On-Board Charger) or a DC fast charging module. When the external power gun is an AC mains charging gun, the vehicle-side charging module corresponds to an OBC; when the external power gun is a DC fast charging gun, the vehicle-side charging module corresponds to a DC fast charging module. The conversion device is a universal integrated hardware unit that completes the corresponding configuration according to the target vehicle's charging interface type. Each application only adapts to one charging architecture. This conversion device does not change the vehicle's original BMS charging logic. The vehicle charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS. This device focuses on solving the safety switching and protection of the power path. An automatic switching control method for parking charging, applied to the aforementioned parking charging system, includes the following steps: S1. The device is powered on and initialized. The system enters the normal monitoring state. The input identification unit (41) collects the on / off status and voltage parameters of the photovoltaic input power supply and the external input power supply in real time. S2. The system prioritizes determining the working status of the manual physical main switch (8). If the manual physical main switch (8) is in the open state, the entire machine hardware is immediately locked, blocking all automatic switching, local manual operation, and remote control commands, and the entire machine has no power output. If the manual physical main switch (8) is in the closed state, the equipment enters the normal intelligent control workflow. S3. When the equipment is working normally, the input identification unit (41) adaptively identifies the currently connected AC mains signal or high voltage DC fast charging signal and executes the local adaptive switching logic: when a valid external power supply is detected to be stably connected, after 500ms hardware delay anti-shake calibration, the photovoltaic power supply path is automatically cut off and the external power supply path is connected; when the external power supply is detected to be stably disconnected, after 500ms hardware delay anti-shake calibration, the photovoltaic power supply path is automatically restored. S4. The device periodically collects its own working status, current power supply mode, and power parameters, and uploads them to the terminal application (APP) via the wireless communication module, while continuously listening for remote control commands in real time. S5. When the terminal APP sends a remote command, the system first checks the lockout status of the manual physical main switch (8). If the hardware is not locked, the system performs the remote switching of photovoltaic power supply mode, the remote switching of external power supply mode, and the remote emergency power cut-off operation. S6. After all switching commands are executed, the device synchronously updates its working status and sends the execution results back to the terminal APP. It continuously cycles through monitoring, switching, and data uploading tasks to achieve unattended, routine operation. It should be noted that this control method only completes the switching and protection of the power path and does not change the original BMS charging logic of the vehicle. The vehicle charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS. Furthermore, the system sets three levels of control permission priority, from high to low: manual physical master switch (8) hardware lockout, remote emergency control / local manual emergency control, and local automatic identification switching control. Through multi-level permission protection, the system comprehensively ensures the safe operation of the equipment.

[0005] Beneficial effects 1. Comprehensive Upgrade in Versatility: This invention breaks through the limitations of traditional devices in a single charging scenario through a universal hardware architecture and adaptive identification control logic. It can automatically adapt to two mainstream parking charging scenarios: AC mains power and high-voltage DC fast charging, and is compatible with all types of new energy vehicles, greatly expanding the scope of application of the device. The device does not make any modifications to the original vehicle BMS. The vehicle charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS, which is only responsible for the safe switching and protection of the power path, without damaging the original vehicle charging control system. 2. Extremely high operational stability: This invention features a unique 500ms hardware delay anti-shake control logic, which can effectively filter interference caused by vehicle voltage fluctuations and instantaneous jitter during power plugging and unplugging, completely eliminating equipment switching errors and frequent switching faults, and ensuring continuous stability during the parking charging process. 3. Comprehensive safety protection system: This invention constructs a three-level hierarchical access control system, with a manual physical master switch as the highest level of hardware backup protection, combined with hardware dual-path interlocking and software intelligent control mechanism, forming a dual-redundant safety architecture of hardware and software, completely avoiding various safety risks such as power short circuit, leakage, and misoperation. 4. Excellent electromagnetic compatibility and vehicle reliability: The device input is equipped with EMC filtering and transient suppression circuits, and the relay coil is equipped with a freewheeling / absorption circuit, which can effectively suppress transient electromagnetic interference during switching and fully meet the requirements of GB / T 18655-2018 and GB / T 21437.2-2021 vehicle EMC standards; with IP67 high protection level and wide temperature operating range, it can perfectly adapt to the complex electromagnetic environment of vehicles and outdoor high and low temperature and vibration conditions. 5. Comprehensive vehicle compliance: The device is compatible with high voltage interlock (HVIL) signals, equipped with a dedicated grounding terminal, and has an insulation resistance ≥1MΩ under high voltage conditions, fully complying with mandatory national standards for electric vehicle charging safety and vehicle safety such as GB / T 18487.1-2015 and GB 18384-2020; the device does not intervene in the original vehicle BMS control, retains the original vehicle's complete charging safety logic, and reduces the risk of modification compliance. 6. High level of intelligence: It integrates local automatic adaptation and switching with remote APP intelligent management and control functions, without the need for manual on-site intervention. It can realize unattended adaptive charging switching, and also supports remote status query, working condition switching and emergency power cut-off operation, accurately adapting to the needs of modern intelligent parking and charging. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the overall module connection of the device of the present invention; Figure 2 This is a diagram showing the overall architecture of the parking charging system of the present invention; Figure 3 This is a block diagram of the internal hardware composition of the automatic identification and switching module of the present invention; Figure 4 This is a flowchart of the automatic switching control method for parking charging according to the present invention.

[0007] Explanation of reference numerals in the attached figures 1-Photovoltaic input interface; 2-External power input interface; 3-Output interface; 4-Automatic identification and switching module; 41-Input identification unit; 42-Switching control unit; 43-Relay dual-channel interlock; 8-Manual physical main switch. Detailed Implementation

[0008] Example 1 (AC mains adaptive switching mode) This embodiment is adapted to the AC parking charging scenario of vehicles. The hardware connection method is as follows: the photovoltaic input interface (1) is connected to the vehicle photovoltaic system through the photovoltaic controller, the external power input interface (2) is connected to the 220V AC mains charging gun, and the output interface (3) is connected to the vehicle OBC on-board charger. The relay dual-channel interlock (43) uses an electromagnetic relay adapted to AC 250V / 16A, with an RC absorption circuit (resistor 100Ω / capacitor 0.1μF) connected in parallel at both ends of its coil to effectively suppress spark interference and reverse electromotive force during the switching process. The device power input terminal is equipped with an EMI filter circuit (including X capacitor 0.47μF, Y capacitor 2.2nF, common mode inductor 10mH) and a TVS tube (SMCJ58A). The measured radiated interference of the device meets the GB / T 18655-2018 level 3 limit, and the conducted immunity successfully passes the GB / T 21437.2-2021 pulse 1 / 2a / 3a / 3b test. In this embodiment, the device does not modify the original BMS charging logic of the vehicle. The vehicle charging handshake and charging / discharging closed-loop control are still implemented by the original vehicle BMS. This device focuses on solving the safe switching and protection of the power path. After the device is powered on and initialized, the input identification unit (41) monitors the on / off status and voltage parameters of the photovoltaic power supply and the external mains power supply in real time. After the manual physical main switch (8) is closed, the device enters the normal intelligent working mode; when a stable AC mains power is detected, after 500ms hardware anti-shake calibration, the system automatically cuts off the photovoltaic power supply path and switches to the mains power supply mode; when the mains power is disconnected, the photovoltaic power supply is automatically restored after the delay anti-shake calibration is completed. The device uploads the charging status, power parameters and device operating status to the terminal APP in real time, supports remote working status switching and emergency power-off operation, and realizes unattended automatic operation throughout the process, which is suitable for the daily parking charging scenario of household new energy passenger vehicles. If the manual physical main switch (8) is manually disconnected, all electrical control logic and remote control commands will be invalidated, and the device will be forcibly powered off and locked, which will completely ensure the safety of equipment maintenance operations.

[0009] Example 2 (Adaptive switching mode for DC fast charging) This embodiment uses the same universal device body as Embodiment 1, and only adjusts the hardware configuration selection to adapt to the vehicle's high-voltage DC fast charging architecture. In this embodiment, the external power input interface (2) is connected to the high-voltage DC fast charging gun. This interface integrates a high-voltage interlock (HVIL) signal terminal, and the HVIL signal can be completely transmitted to the vehicle BMS. The switching control unit collects the working status of the HVIL circuit in real time. When the HVIL circuit is abnormally disconnected, or the charging gun is loose or detached, the switching control unit immediately prohibits the contactor coil from being energized and cuts off the high-voltage power circuit. Only after the charging gun is reliably connected and the HVIL circuit is normally conducting can the high-voltage circuit be allowed to work, thus realizing hardware-level safety handshake protection. The output interface (3) is connected to the vehicle DC fast charging module. The connection structure between the photovoltaic input interface (1) and the vehicle photovoltaic system remains unchanged. The relay dual-channel interlock (43) uses a DC contactor adapted to DC 750V / 100A. A freewheeling diode with a reverse withstand voltage of 1000V / 3A is connected in parallel across the coil to suppress the reverse electromotive force and electromagnetic interference generated by the high-voltage switching. For this embodiment to function normally, the following prerequisites must be met: the DC voltage output from the onboard photovoltaic system after being regulated by the photovoltaic controller's MPPT must fall within the allowable input voltage range of the vehicle's DC fast charging interface; and the vehicle's BMS and fast charging hardware circuit must support low-current DC input charging conditions. This device is only responsible for the hardware safety switching and interlocking protection of the power path and does not modify the original vehicle BMS charging control logic. The voltage and current output from the photovoltaic side are regulated by the front-end photovoltaic controller in a closed loop, while the vehicle-side charging handshake and precise voltage and current control are still completed by the vehicle's BMS. When the photovoltaic output power cannot meet the minimum operating conditions of the vehicle's fast charging circuit, the BMS will automatically reject the charging process, and the circuit cannot be established. This is within the normal operating boundary of the system and is not a defect of the device. The system's operating logic is completely consistent with the AC charging scenario. The input identification unit (41) can adaptively identify high-voltage DC power signals. It avoids interference from instantaneous voltage fluctuations and plug-and-play jitter during high-voltage power connection through 500ms hardware anti-shake logic. It also achieves conflict-free and safe switching between the photovoltaic path and the DC fast charging path with the help of the relay dual-channel interlock (43). The manual physical master switch (8) maintains the highest hardware interlock priority and can forcibly cut off the high-voltage power supply of the whole machine at any time to eliminate high-voltage safety hazards. The device housing is equipped with M6 dedicated grounding bolts, which are reliably grounded to the vehicle body. The insulation resistance under DC 750V conditions is ≥2MΩ, which fully meets the vehicle potential balance and high-voltage safety requirements of GB 18384-2020. This embodiment is suitable for high-power parking fast charging scenarios of RVs and commercial new energy vehicles. It is safe, stable and reliable in operation.

[0010] Example 3 (Remote Intelligent Control Emergency Response) In the normal parking operation state of the equipment, the manual physical main switch (8) remains closed, and the equipment defaults to the photovoltaic power supply mode. Users can send remote operating condition switching commands through the terminal APP. After the system verifies that the manual physical main switch (8) is not hardware locked, it will automatically switch the power supply mode to external power supply. In case of emergency conditions such as circuit abnormalities, equipment failures, and power grid fluctuations, users can send remote emergency power cut-off commands through the APP. The equipment will immediately cut off all power supply paths to achieve remote emergency protection. If the manual physical main switch (8) is manually disconnected during the emergency, the local automatic control logic and all remote control commands will immediately become invalid, and the equipment will be forcibly locked and powered off. Through multiple protection mechanisms, the operation safety of unattended parking charging is thoroughly guaranteed, and it is adapted to the intelligent emergency management and control needs of various scenarios. In this embodiment, the device still does not intervene in the original vehicle BMS internal logic. The charging handshake and charging and discharging closed-loop control are completely completed by the original vehicle BMS.

[0011] Vehicle Compliance Design Specifications This device is designed and developed in strict accordance with GB / T 18487.1-2015 "General Requirements for Conductive Charging Systems of Electric Vehicles", GB18384-2020 "Safety Requirements for Electric Vehicles", GB / T 20234.1-2015 "General Requirements for Connecting Devices for Conductive Charging of Electric Vehicles", and the GB / T 28046 series of environmental standards for on-board electronic equipment. The device's housing protection rating is no lower than IP67, and its operating temperature range is -40℃ to +85℃, allowing it to withstand high and low temperature environments in vehicles, as well as parking and driving vibration conditions. Input EMC filtering and transient suppression circuits ensure that both radiated and conducted interference meet national standard limits, and its immunity has passed the full set of tests in GB / T 21437.2-2021. In DC charging adaptation scenarios, the device is compatible with HVIL high-voltage interlock signals, enabling a safe handshake with the vehicle's BMS and eliminating the risk of high-voltage connection issues. The device has a high-voltage circuit insulation resistance of ≥1MΩ (DC 750V) and is equipped with a dedicated grounding terminal, resulting in excellent vehicle potential balance performance. The device does not alter the original vehicle BMS charging logic, fully preserving the original vehicle charging safety management system, further improving the compliance of the modified vehicle, and fully meeting the compliance requirements of on-board equipment for new energy vehicles.

Claims

1. A parking charging automatic switching device, characterized in that, include: Photovoltaic input interface (1) is used to connect the power output terminal of the vehicle photovoltaic system; External power input interface (2), the external power input interface (2) is configured to be compatible with an external AC mains charging gun, or is configured to be compatible with an external DC fast charging gun; Output interface (3), the configuration of which is matched with that of the external power input interface (2): when the external power input interface (2) is configured to be compatible with AC mains charging gun, the output interface (3) is used to connect to the vehicle OBC on-board charger; when the external power input interface (2) is configured to be compatible with DC fast charging gun, the output interface (3) is used to connect to the vehicle DC fast charging module. The automatic identification and switching module (4) is electrically connected to the photovoltaic input interface (1), the external power input interface (2) and the output interface (3) respectively; The manual physical main switch (8) is connected in series with the device's main power supply circuit. It is an independent mechanical circuit breaker structure, and the hardware interlocking priority is higher than the electrical control logic. The automatic identification and switching module (4) includes an input identification unit (41), a switching control unit (42), and a relay dual-channel interlock (43). The switching control unit (42) and the relay dual-channel interlock (43) form a dual-channel hardware interlock structure, so that the photovoltaic input interface (1) and the external power input interface (2) are not simultaneously connected to the output interface (3). The device only realizes the safe switching and protection of the power path, without changing the original BMS charging logic of the vehicle. The vehicle charging handshake and charging and discharging closed-loop control are completed by the original vehicle BMS.

2. The automatic parking charging conversion device according to claim 1, characterized in that: The power input terminal of the automatic identification switching module (4) is equipped with an EMC filter circuit and a transient voltage suppression circuit. In the relay dual-channel interlock (43), each relay coil is connected in parallel with a freewheeling diode or an RC absorption circuit.

3. A parking charging system, characterized in that: It includes an on-board photovoltaic system, a photovoltaic controller, the conversion device as described in claim 1 or 2, a vehicle-side charging module, and an external power gun; the vehicle-side charging module is selected as either an OBC on-board charger or a DC fast charging module, and the external power gun is selected as either an AC mains charging gun or a DC fast charging gun; the conversion device only completes the safe switching and protection of the power path, without changing the original BMS charging logic of the vehicle, and the vehicle charging handshake and charging / discharging closed-loop control are implemented by the original vehicle BMS.

4. A parking charging automatic switching control method, applied to the parking charging system of claim 3, characterized in that, Includes the following steps: S1. The device is powered on and initialized. The input identification unit (41) monitors the status of the external power supply and the photovoltaic power supply in real time. S2. Prioritize detecting the status of the manual physical master switch (8). If the switch is open, the entire machine hardware is locked, and all control commands are blocked. If the switch is closed, the normal working process begins. S3. During normal operation, the system identifies the currently compatible AC mains power or DC fast charging external power supply signal and automatically switches between the photovoltaic power supply path and the external power supply path after a 500ms delay anti-shake processing. This method only performs power path switching and protection and does not change the original BMS charging logic of the vehicle. The vehicle charging handshake and charging / discharging closed-loop control are implemented by the original vehicle BMS. S4. Upload the device's operating status to the terminal APP in real time and continuously listen for remote control commands; S5 responds to remote switching and remote power-off commands, completes the switching of operating conditions and sends back the execution results, and runs continuously in a loop.

5. The automatic switching control method for parking charging according to claim 4, characterized in that: The system control permissions are prioritized from highest to lowest as follows: manual physical master switch (8) hardware interlock, remote emergency control, and local automatic identification and switching control.

6. The automatic switching control method for parking charging according to claim 4, characterized in that: The connection and disconnection of the external power supply are performed after a 500ms hardware delay for debouncing, avoiding erroneous switching caused by voltage fluctuations and plug-in / plug-out jitter.

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