Vehicle-mounted electric energy router and charging method thereof

Abstract

The application discloses a novel vehicle-mounted electric energy router and a charging method thereof. The router comprises a photovoltaic module, a first converter, a second converter, a third converter, a first controller, a second controller and a third controller. The first controller is used for starting the photovoltaic module or the first converter to perform photovoltaic charging or normal charging according to a router working mode. The second controller is used for controlling the energy flow direction of the first converter and the second converter according to the router working mode. The third controller is used for sending a square wave control signal to the third converter according to a target battery identification signal. The third converter is used for converting the output voltage of the second converter into a target battery standard voltage according to the square wave control signal. The application improves the adaptability of the electric energy router, has universality, openness and compatibility, can provide different levels of voltages suitable for different application scenarios, and can be widely applied to the technical field of vehicle-mounted routing equipment.

Description

Technical Field

[0001] This invention relates to the field of vehicle-mounted routing equipment technology, and in particular to a vehicle-mounted electric router and its charging method. Background Technology

[0002] The global energy shortage and people's increasing demands for quality of life have provided an excellent opportunity for the development of electric vehicles. Motor vehicles powered by fossil fuels emit large amounts of toxic and harmful exhaust gases and greenhouse gases during the combustion and consumption of these fuels, causing significant environmental pollution. In contrast, electric vehicles have advantages such as low noise, high energy efficiency, and lower emissions of greenhouse gases and harmful gases. With the promotion and popularization of electric vehicles, research on bidirectional charging stations has gradually become a hot topic, and the requirements for their performance indicators, such as power density, efficiency, and voltage gain range, are becoming increasingly stringent.

[0003] Adopting a one-charger-per-vehicle model would result in significant resource waste, while developing centralized photovoltaic power generation and constructing centralized electric vehicle charging stations would occupy substantial land resources, failing to meet development requirements. Therefore, vehicle-mounted power routers have emerged; the requirements for their performance indicators, such as power density, efficiency, and voltage gain range, are becoming increasingly stringent. However, existing charging piles lack universality, openness, and compatibility, and cannot provide different voltage levels, necessitating specialized design for different application scenarios. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an in-vehicle power router and its charging method, which improves the adaptability of the power router and has universality, openness and compatibility.

[0005] In a first aspect, embodiments of the present invention provide an in-vehicle power router, 1. comprising a photovoltaic module, a first converter, a second converter, a third converter, a first controller, a second controller, and a third controller; The first controller is used to start the photovoltaic module or the first converter according to the router's operating mode; the router's operating mode includes a normal charging mode and a photovoltaic charging mode; The photovoltaic module is used to perform photovoltaic charging in response to the start command of the first controller; The first converter is configured to perform normal charging in response to the start command of the first controller; The second controller is used to control the energy flow direction of the first converter and the second converter according to the router's operating mode; The second converter is connected to the first controller and the third converter to isolate the photovoltaic module and the first converter from the high-voltage side and the low-voltage side of the third converter; The third controller is used to send a square wave control signal to the third converter based on the target battery identification signal; The third converter is used to convert the output voltage of the second converter to the target battery standard voltage according to the square wave control signal.

[0006] Optionally, the photovoltaic module includes a photovoltaic panel, an MPPT module, a disturbance resistor, and a first MOSFET; The photovoltaic panel is used for photoelectric conversion to output electrical energy; The disturbance resistor is connected in series with the first MOSFET to control the incremental increase of the output power of the photovoltaic panel. The MPPT module is used to track the target output power of the photovoltaic panel.

[0007] Optionally, the first converter is a bidirectional AC-DC converter, and the first converter adopts a single-phase full-bridge topology.

[0008] Optionally, the first converter uses the single-phase full-bridge topology and a second MOSFET as the switching transistor to perform high-frequency modulation and switching between rectification and inversion.

[0009] Optionally, the second converter is a bidirectional LLC converter, and the second converter adopts a half-bridge topology.

[0010] Optionally, the second converter isolates the high-voltage side and the low-voltage side through the half-bridge topology and the high-frequency transformer.

[0011] Secondly, embodiments of the present invention provide a charging method using an in-vehicle power router as described in the first aspect of the present invention, comprising: Acquire the router's operating mode and the target battery identification signal; the router's operating mode includes normal charging mode and photovoltaic charging mode; The first controller activates the photovoltaic module for photovoltaic charging or activates the first converter for normal charging according to the router's operating mode. The second controller controls the energy flow direction of the first and second converters according to the router's operating mode, thereby performing feedback control of the router's operating mode. The third controller sends a square wave control signal based on the target battery identification signal, and controls the third converter to convert the output voltage of the second converter to the standard voltage of the target battery based on the square wave control signal.

[0012] The beneficial effects of this invention are as follows: The vehicle-mounted power router of this invention includes a photovoltaic module, a first converter, a second converter, a third converter, a first controller, a second controller, and a third controller; the first controller is used to start the photovoltaic module or the first converter according to the router's operating mode; the router's operating mode includes a normal charging mode and a photovoltaic charging mode; the photovoltaic module is used to perform photovoltaic charging in response to the start command of the first controller; the first converter is used to perform normal charging in response to the start command of the first controller; the second controller is used to control the energy flow direction of the first converter and the second converter according to the router's operating mode; the second converter is connected to the first controller and the third converter to isolate the high-voltage side and low-voltage side of the photovoltaic module and the first converter from the third converter; the third controller is used to send a square wave control signal to the third converter according to a target battery identification signal; the third converter is used to convert the output voltage of the second converter to the target battery's standard voltage according to the square wave control signal. This invention improves the adaptability of the power router, possessing universality, openness, and compatibility, and can provide different voltage levels to adapt to different application scenarios. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic diagram of the topology of an in-vehicle power router provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the BUCK-BOOT converter provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the high-voltage side gate drive structure of the MOSFET driving circuit provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the sampling circuit provided in an embodiment of the present invention; Figure 6 A schematic diagram of the interrupt service routine workflow provided in an embodiment of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] In a first aspect, embodiments of the present invention provide an in-vehicle power router, 1. comprising a photovoltaic module, a first converter, a second converter, a third converter, a first controller, a second controller, and a third controller; The first controller is used to start the photovoltaic module or the first converter according to the router's operating mode; the router's operating mode includes a normal charging mode and a photovoltaic charging mode; The photovoltaic module is used to perform photovoltaic charging in response to the start command of the first controller; The first converter is configured to perform normal charging in response to the start command of the first controller; The second controller is used to control the energy flow direction of the first converter and the second converter according to the router's operating mode; The second converter is connected to the first controller and the third converter to isolate the photovoltaic module and the first converter from the high-voltage side and the low-voltage side of the third converter; The third controller is used to send a square wave control signal to the third converter based on the target battery identification signal; The third converter is used to convert the output voltage of the second converter to the target battery standard voltage according to the square wave control signal.

[0017] Optionally, the photovoltaic module includes a photovoltaic panel, an MPPT module, a disturbance resistor, and a first MOSFET; The photovoltaic panel is used for photoelectric conversion to output electrical energy; The disturbance resistor is connected in series with the first MOSFET to control the incremental increase of the output power of the photovoltaic panel. The MPPT module is used to track the target output power of the photovoltaic panel.

[0018] Optionally, the first converter is a bidirectional AC-DC converter, and the first converter adopts a single-phase full-bridge topology.

[0019] Optionally, the first converter uses the single-phase full-bridge topology and a second MOSFET as the switching transistor to perform high-frequency modulation and switching between rectification and inversion.

[0020] Optionally, the second converter is a bidirectional LLC converter, and the second converter adopts a half-bridge topology.

[0021] Optionally, the second converter isolates the high-voltage side and the low-voltage side through the half-bridge topology and the high-frequency transformer.

[0022] Secondly, embodiments of the present invention provide a charging method using an in-vehicle power router as described in the first aspect of the present invention, comprising: Acquire the router's operating mode and the target battery identification signal; the router's operating mode includes normal charging mode and photovoltaic charging mode; The first controller activates the photovoltaic module for photovoltaic charging or activates the first converter for normal charging according to the router's operating mode. The second controller controls the energy flow direction of the first and second converters according to the router's operating mode, thereby performing feedback control of the router's operating mode. The third controller sends a square wave control signal based on the target battery identification signal, and controls the third converter to convert the output voltage of the second converter to the standard voltage of the target battery based on the square wave control signal.

[0023] The implementation principle of the present invention will be further described in detail below with reference to some specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] First, it should be noted that an electric power router is a device that enables the utilization and conversion of different forms of electric energy. Its integration with information technology gives it communication and intelligent decision-making capabilities, allowing it to proactively manage the energy flow of the power network based on the network's operating status and instructions from users and the control center.

[0025] It can be charged by connecting to multiple parallel ports on the DC side of the power router via the electric vehicle interface, featuring versatility, openness, and compatibility, and can provide different voltage levels to adapt to different application scenarios. When there is sufficient sunlight, the on-board power router uses photovoltaic power generation modules to convert solar energy into a large amount of electrical energy to charge the electric vehicle battery. When connected to AC or photovoltaic power sources, it can charge multiple batteries. When there is no power input, it can use one battery as a power source to charge other batteries, prioritizing the normal power supply of critical equipment. When AC output is required, it can convert DC to AC, improving the adaptability of the power router.

[0026] The objective of this invention is to provide an energy router adapted to electric vehicle in-vehicle use, so as to realize a universal, open and compatible charging system suitable for new energy electric vehicles.

[0027] The router topology of this embodiment of the invention is as follows: Figure 1 As shown, it consists of four parts: a photovoltaic charging module, a bidirectional AC-DC converter, a bidirectional LLC converter, and a BUCK-BOOT converter. Figure 2 As shown, the photovoltaic charging module consists of a photovoltaic panel DC / DC converter, an inverter, and a maximum power point tracking (MPPT) module. The core component of a photovoltaic power generation system is the photovoltaic module, which is composed of photovoltaic cells connected in series and parallel and packaged. It directly converts solar energy into electrical energy, which can be used immediately or converted into alternating current by a photovoltaic inverter. From another perspective, the electrical energy generated by the photovoltaic system can be used immediately or stored in energy storage devices such as batteries and released as needed. The disturbance resistor R and MOSFET connected in series, when the output voltage is basically stable, change the average current through the resistor by changing the duty cycle of the MOSFET, thus generating a current disturbance. This also affects the output current and voltage of the photovoltaic cell. By measuring the changes at this time, the direction of the disturbance in the next cycle is determined. If the disturbance direction is correct, the output power of the solar panel increases, and the disturbance continues in the same direction in the next cycle; otherwise, the disturbance is in the opposite direction, and so on, until the solar photovoltaic panel outputs its maximum power point. The bidirectional AC / DC power supply uses the Cosel AC / DC power supply model CHS4004812H-U; the bidirectional LLC converter uses the FAN7688SJX FAN7688 SOP16 LLC resonant converter. The bidirectional AC-DC converter adopts a single-phase full-bridge topology. Figure 3 The switching transistor uses MOSFETs for high-frequency modulation, which enables excellent dynamic response speed of the control system and achieves rapid switching between rectification and inversion; (Refer to...) Figure 4 The bidirectional LLC converter consists of a switching network, resonant capacitor, resonant inductor, transformer magnetizing inductor, transformer, and rectifier. The magnetizing inductance of the transformer is controlled so that the resonant unit of the converter includes the magnetizing inductor. When the converter operates in the forward direction, it can be in a boost state with a large voltage gain range, and the switching transistors can achieve soft switching across the entire power output range. High-frequency transformer isolation within the LLC converter achieves isolation between the high-voltage and low-voltage sides, increasing the safety of the power router. The higher voltage output from the LLC converter is converted into the standard battery charging voltage to meet the needs of various applications. The photovoltaic charging module converts solar energy into electrical energy in operating mode, which is then used to charge electric vehicles via the LLC converter and buck-boost circuit.

[0028] The control method includes: Controller 1 determines whether the vehicle-mounted power router is operating in normal home charging mode or photovoltaic charging mode. If it is determined that the vehicle-mounted power router is operating in normal mode, it controls the AC-DC conversion module to be in operation. If it is determined that the vehicle-mounted power router is operating in photovoltaic charging mode, it controls the photovoltaic module to be in operation. Controller 2 selects the energy flow direction of the bidirectional AC-DC converter and the bidirectional LLC converter by determining the operating mode of the power router, thereby controlling the operating mode of the power router. Controller 3 identifies the battery type through the signal input from the sensor, and then sends a PWM square wave to control the switching of the two MOSFETs of BUCK-BOOST to generate a charging voltage matching the connected electric vehicle battery. After filtering by a low-pass filter composed of an inductor and a capacitor, the voltage is fed into the battery for charging. The control chip identifies the battery type through the signal input from the sensor, and then sends a PWM square wave to control the switching of the two MOSFETs of BUCK-BOOST to generate a charging voltage matching the connected battery. After filtering by a low-pass filter composed of an inductor and a capacitor, the voltage is fed into the battery for charging. When connected to photovoltaic or other DC power sources, the voltage is first boosted to 45V via BUCK-BOOST to supply power to the low-voltage DC bus, and then used to charge the connected battery. The LLC converter's switching transistors alternately conduct to generate square waves with equal duty cycles. Frequency conversion control is used to stabilize the output voltage at 380V. The bidirectional AC-DC converter uses unipolar modulation to convert DC to AC, thereby supplying power to AC loads.

[0029] Hardware selection: STM32F107 controller chip selected; MOSFET drive circuit high-voltage side gate drive ( Figure 4 This circuit requires electrical isolation from the main circuit. The driver used is optocoupler isolation plus a bootstrap circuit, typically a transformer driver, and sometimes for safety isolation. R1 is used to suppress LC oscillations between the parasitic inductance on the PCB and C1. Its design aims to isolate DC while allowing AC transmission, and to prevent core saturation. The sampling circuit and digital-to-analog converter module use the integrated sampling channel of the STM32. Figure 5The sampling circuit samples the voltage and current in the circuit to ensure the normal operation of the system. The digital-to-analog converter (DAC) is a 12-bit digital input, voltage output digital-to-analog converter. The DAC can be configured in 8-bit or 12-bit mode and can also be used in conjunction with a DMA controller. When the DAC operates in 12-bit mode, the data can be set to left-aligned or right-aligned. The DAC module has two output channels, each with an independent converter. In dual-DAC mode, the two channels can convert independently or simultaneously and update the output of both channels synchronously. The DAC can obtain more accurate conversion results by inputting a reference voltage VREF+ through a pin. Since the power router can operate bidirectionally, the conduction current will change direction. Therefore, a Hall sensor with output voltage offset is used for measurement. This invention selects the CrossChip CC6904SO-10A current sensor, which is a high-performance single-ended output linear current sensor that can effectively measure AC and DC. Therefore, the current reverse sensor outputs a positive voltage, eliminating the need for additional voltage biasing circuitry.

[0030] Software design includes system initialization, system self-test, and fault detection. It employs an active disturbance rejection control loop to ensure correct and stable voltage and current output. Furthermore, it designs interrupt service routines to guarantee normal system operation. Software interrupt services include... Figure 6 As shown, the control method includes: controller 1 determines whether the vehicle-mounted power router is operating in normal home charging mode or photovoltaic charging mode. If it is determined that the vehicle-mounted power router is operating in normal mode, the AC-DC conversion module is controlled to be in operation. If it is determined that the vehicle-mounted power router is operating in photovoltaic charging mode, the photovoltaic module is controlled to be in operation. Controller 2 selects the energy flow direction of the bidirectional AC-DC converter and the bidirectional LLC converter by determining the operating mode of the power router, thereby controlling the operating mode of the power router; controller 3 identifies the battery type through the signal input from the sensor, and then sends a PWM square wave to control the switching of the two MOSFETs of BUCK-BOOST to generate a charging voltage that matches the connected electric vehicle battery. After being filtered by a low-pass filter composed of an inductor and a capacitor, the voltage is fed to the battery for charging.

[0031] In summary, the vehicle-mounted power router provided by this invention fulfills the essential need for charging stations and photovoltaic energy-saving charging for electric vehicles, thus meeting application requirements. By employing a suitable sampling circuit, voltage and current detection of the main circuit of the power router is achieved, ensuring that the control chip can adjust in real time, making the system more reliable and stable. A DSP is used to control the system's operation and data processing, identify different types of access, and program the mutual conversion of electrical energy. Through hardware and software design, the system possesses rich functionality and has significant practical value.

[0032] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is altered and sub-operations described as part of a larger operation are executed independently.

[0033] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the described functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0034] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0035] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution means, apparatus, or device (such as a computer-based device, a processor-including device, or other means that can fetch and execute instructions from, or in conjunction with, an instruction execution means, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution means, apparatus, or device.

[0036] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0037] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution device. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic current having logic gate currents for implementing logical functions on data signals, dedicated integrated current having suitable combinational logic gate currents, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0038] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0040] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A vehicle-mounted power router, characterized in that, It includes a photovoltaic module, a first converter, a second converter, a third converter, a first controller, a second controller, and a third controller; The first controller is used to start the photovoltaic module or the first converter according to the router's operating mode; the router's operating mode includes a normal charging mode and a photovoltaic charging mode; The photovoltaic module is used to perform photovoltaic charging in response to the start command of the first controller; The first converter is configured to perform normal charging in response to the start command of the first controller; The second controller is used to control the energy flow direction of the first converter and the second converter according to the router's operating mode; The second converter is connected to the first controller and the third converter to isolate the photovoltaic module and the first converter from the high-voltage side and the low-voltage side of the third converter; The third controller is used to send a square wave control signal to the third converter based on the target battery identification signal; The third converter is used to convert the output voltage of the second converter to the target battery standard voltage according to the square wave control signal; The third controller identifies the battery type through sensor input signals and then sends a PWM square wave to control the switching of two MOSFETs in the third converter. The third converter is a BUCK-BOOST converter, which generates a charging voltage matching the connected electric vehicle battery under PWM square wave control. After being filtered by a low-pass filter composed of an inductor and a capacitor, the voltage is fed to the battery. When connected to photovoltaic or other DC power sources, the voltage is first boosted to 45V by the third converter to supply power to the low-voltage DC bus, and then the connected battery is charged. The switching transistors of the second converter alternately conduct to generate square waves with equal duty cycles, and frequency conversion control is used to stabilize the output voltage at 380V. The first converter uses unipolar modulation to convert DC to AC, thereby supplying power to AC loads.

2. The vehicle-mounted power router according to claim 1, characterized in that, The photovoltaic module includes a photovoltaic panel, an MPPT module, a perturbation resistor, and a first MOSFET; The photovoltaic panel is used for photoelectric conversion to output electrical energy; The disturbance resistor is connected in series with the first MOSFET to control the incremental increase of the output power of the photovoltaic panel. The MPPT module is used to track the target output power of the photovoltaic panel.

3. The vehicle-mounted power router according to claim 1, characterized in that, The first converter is a bidirectional AC-DC converter, and the first converter adopts a single-phase full-bridge topology.

4. A vehicle-mounted power router according to claim 3, characterized in that, The first converter uses the single-phase full-bridge topology and a second MOSFET as the switching transistor to perform high-frequency modulation and switching between rectification and inversion.

5. A vehicle-mounted power router according to claim 1, characterized in that, The second converter is a bidirectional LLC converter, and the second converter adopts a half-bridge topology.

6. A vehicle-mounted power router according to claim 5, characterized in that, The second converter isolates the high-voltage side from the low-voltage side through the half-bridge topology and the high-frequency transformer.

7. The charging method of the vehicle-mounted power router as described in any one of claims 1 to 6, characterized in that, include: Acquire the router's operating mode and the target battery identification signal; the router's operating mode includes normal charging mode and photovoltaic charging mode; The first controller activates the photovoltaic module for photovoltaic charging or activates the first converter for normal charging according to the router's operating mode. The second controller controls the energy flow direction of the first and second converters according to the router's operating mode, thereby performing feedback control of the router's operating mode. The third controller sends a square wave control signal based on the target battery identification signal, and controls the third converter to convert the output voltage of the second converter to the standard voltage of the target battery based on the square wave control signal. The third controller identifies the battery type through sensor input signals and then sends a PWM square wave to control the switching of two MOSFETs in the third converter. The third converter is a BUCK-BOOST converter, which generates a charging voltage matching the connected electric vehicle battery under PWM square wave control. After being filtered by a low-pass filter composed of an inductor and a capacitor, the voltage is fed to the battery. When connected to photovoltaic or other DC power sources, the voltage is first boosted to 45V by the third converter to supply power to the low-voltage DC bus, and then the connected battery is charged. The switching transistors of the second converter alternately conduct to generate square waves with equal duty cycles, and frequency conversion control is used to stabilize the output voltage at 380V. The first converter uses unipolar modulation to convert DC to AC, thereby supplying power to AC loads.

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