Linkage multi-source grid-connected switching method and grid-connected cabinet

Abstract

The invention discloses a linkage multi-source grid-connected switching method, which comprises the following steps of: controlling a plurality of circuit breakers to be closed, and pressing a mode button to select a control mode; if a grid-connected button is pressed down, it is determined that power supply of the power grid is normal, the energy manager sequentially controls the main contactor and the branch contactors to be closed, and the photovoltaic array, the battery pack and the power grid are dispatched in real time to supply power to the load; if the off-grid button is pressed, it is determined that power supply of the power grid is not needed, the energy manager controls the sub-contactors to be closed, and the photovoltaic array and the battery pack are dispatched in real time to supply power to the load; if the automatic switching button is pressed down, whether the main circuit breaker is closed is judged, if yes, it is determined that the power grid supplies power normally, the energy manager controls the main contactor and the branch contactor to be closed, and the photovoltaic array, the battery pack and the power grid are dispatched in real time to supply power to the load; if the main circuit breaker is under-voltage tripped, power supply of the power grid side is determined to be abnormal, the energy manager controls the sub-contactor to be closed, and the photovoltaic array and the battery pack are dispatched in real time to supply power to the load.

Description

Technical Field

[0001] This invention relates to the field of power supply technology, and in particular to a method for switching between multiple sources in a grid and a grid-connected cabinet. Background Technology

[0002] In a multi-source power supply system, the grid, energy storage system, photovoltaic system and load need to be connected through a grid-connected cabinet. The grid-connected cabinet coordinates and switches the power from the grid, energy storage system and photovoltaic system to supply power to the load.

[0003] The switching of existing grid-connected cabinets is mostly triggered by a single condition (such as abnormal grid voltage), which does not cover the complex scenarios of multi-source systems. Furthermore, the switching process has safety and stability risks, and it is difficult to coordinate the intermittency of photovoltaics, the limited capacity of energy storage, and the stability of the grid, resulting in low energy utilization efficiency and chaotic switching logic.

[0004] In view of the shortcomings of the existing technologies, there is an urgent need for a multi-source grid-connected switching method and grid-connected cabinet that is highly adaptable to the power grid, efficient in energy dispatch, and highly secure. Summary of the Invention

[0005] This invention addresses the problems and shortcomings of existing technologies by providing a novel method for multi-source grid-connected switching and a grid-connected cabinet.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] This invention provides a method for coordinated multi-source grid-connected switching, including a grid-connected cabinet, an energy storage module, a photovoltaic module, and a load. The grid-connected cabinet includes a combiner and distribution component, a control component, and multiple mode control buttons. The mode control buttons include a grid-connected button, an off-grid button, and an automatic switching button. The energy storage module includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack disposed within the energy storage cabinet. The photovoltaic module includes a photovoltaic array and a photovoltaic inverter.

[0008] The power distribution assembly includes multiple circuit breakers, multiple contactors, and an AC coupling bus. The circuit breakers include main circuit breakers and multiple branch circuit breakers. The contactors include main contactors and branch contactors. The AC coupling bus is connected to the power grid via the main contactors and main circuit breakers. The AC coupling bus is connected to energy storage modules via the branch circuit breakers. The AC coupling bus is connected to parallel loads and photovoltaic modules via the branch circuit breakers and branch contactors.

[0009] The control components include a switch, a serial server, and an I / O module. The energy manager interacts with the serial server and the I / O module via the switch. The input node of the I / O module is connected to the mode control button to obtain its status, and the input node of the I / O module is connected to the auxiliary contact of the circuit breaker to obtain its status. The output node of the I / O module is connected to and controls the circuit breaker and the contactor. The switching method includes the following steps:

[0010] Control the closure of multiple circuit breakers; press the mode button to select the control mode.

[0011] If the grid connection button is pressed, it is assumed that the power supply from the grid is normal. The energy manager controls the main contactor and the branch contactor to close sequentially through the IO module. Based on the load, the power generation of the photovoltaic array, and the status of the battery pack, the power of the photovoltaic array, the power of the battery pack, and the power of the grid are scheduled to supply power to the load in real time.

[0012] If the off-grid button is pressed, it is determined that no grid power supply is needed. The energy manager controls the closing of the sub-contaminant through the IO module, and schedules the power of the photovoltaic array and the power of the battery pack to supply power to the load in real time according to the load, the power generation of the photovoltaic array and the status of the battery pack.

[0013] If the automatic switching button is pressed, it is determined whether the main circuit breaker is closed. If closed, it is assumed that the power grid is supplying power normally. The energy manager controls the main contactor and branch contactor to close sequentially through the IO module. Based on the load, photovoltaic array power generation, and battery pack status, it schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time. If the main circuit breaker trips due to undervoltage, it is assumed that the power grid supply is abnormal. The energy manager controls the branch contactor to close through the IO module and schedules the photovoltaic array power and battery pack power to supply power to the load in real time. When the power grid supply returns to normal, the main circuit breaker automatically recovers from undervoltage tripping. The energy manager controls the main contactor to close through the IO module and schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time.

[0014] Preferably, the power distribution assembly further includes multiple electricity meters, which are correspondingly installed at the input terminals of multiple circuit breakers to measure the voltage, current, and power flowing through the corresponding circuit breaker; the multiple electricity meters are respectively connected to the serial port server to send the measured data, and according to the load conditions, photovoltaic array power generation status, and battery pack status, the photovoltaic array power, battery pack power, and grid power are scheduled in real time to supply power to the load, including the following steps:

[0015] Obtain load power and photovoltaic array power generation status, and control photovoltaic inverter and energy storage converter according to load and photovoltaic array power generation status;

[0016] If the power output of the photovoltaic array is greater than the load power, the power output of the photovoltaic array is converted from DC to AC by the photovoltaic inverter to supply power to the load, and the excess power is converted from AC to DC by the energy storage converter to charge the battery pack.

[0017] If the photovoltaic array's power output is less than the load power, the photovoltaic array's power output is converted from DC to AC by the photovoltaic inverter to supply power to the load; the energy storage converter switches to VSG mode, and the portion of the load power that is insufficient is supplied by the battery pack through the energy storage converter after DC to AC conversion; if the load power is still insufficient, it is supplied by the grid.

[0018] If the photovoltaic array is not generating electricity, it is in standby mode. During periods of low electricity demand, the grid charges the battery pack via AC-DC conversion through the energy storage converter, and then supplies power to the load. During periods of high electricity demand, the energy storage converter switches to VSG mode, and the battery pack supplies power to the load via DC-AC conversion through the energy storage converter. If the load power is still insufficient, the grid supplies power again.

[0019] Preferably, the photovoltaic array power and battery pack power are scheduled to supply power to the load in real time according to the load conditions, photovoltaic array power generation, and battery pack status, including the following steps:

[0020] Obtain load power and photovoltaic array power generation status, and control photovoltaic inverter and energy storage converter according to load and photovoltaic array power generation status;

[0021] If the power output of the photovoltaic array is greater than the load power, the power output of the photovoltaic array is converted from DC to AC by the photovoltaic inverter to supply power to the load, and the excess power is converted from AC to DC by the energy storage converter to charge the battery pack.

[0022] If the power output of the photovoltaic array is less than the load power, the power output of the photovoltaic array is supplied to the load after DC-AC conversion by the photovoltaic inverter; the energy storage converter switches to VSG mode, and the part of the load power that is insufficient is supplied to the load by the battery pack after DC-AC conversion by the energy storage converter.

[0023] If the photovoltaic array is not generating electricity, it is in standby mode; the energy storage converter switches to VSG mode, and the battery pack supplies power to the load after DC-AC conversion through the energy storage converter.

[0024] Preferably, the method further includes the following steps:

[0025] When the remaining charge of the battery pack is less than or equal to the set discharge threshold, the energy storage converter is controlled to stop supplying power to the load.

[0026] When the remaining charge of the battery pack is greater than or equal to the set full charge threshold, the control energy storage converter stops charging the battery pack.

[0027] Based on the same concept, the present invention also provides a grid-connected cabinet applied to the above-mentioned multi-source grid-connected switching method, comprising a cabinet body, a busbar distribution component disposed in the cabinet body, a control component, and multiple mode control buttons disposed on the cabinet body.

[0028] The power distribution assembly includes multiple circuit breakers, multiple contactors, and an AC coupling bus. The circuit breakers include main circuit breakers and multiple branch circuit breakers. The contactors include main contactors and branch contactors. The AC coupling bus is connected to the power grid via the main contactors and main circuit breakers. The AC coupling bus is connected to energy storage modules via the branch circuit breakers. The AC coupling bus is connected to parallel loads and photovoltaic modules via the branch circuit breakers and branch contactors.

[0029] The energy storage module includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack installed in the energy storage cabinet; the photovoltaic module includes a photovoltaic array and a photovoltaic inverter;

[0030] The control components include a switch, a serial server, and an I / O module. The energy manager connects to the serial server and the I / O module through the switch to exchange data. The input node of the I / O module is connected to the mode control button to obtain the status of the mode control button. The input node of the I / O module is connected to the auxiliary contact of the circuit breaker to obtain the status of the circuit breaker. The output node of the I / O module is connected to and controls the circuit breaker and the contactor.

[0031] The energy manager controls the circuit breaker, the contactor, the photovoltaic inverter, and the energy storage converter to operate based on the status of the mode control button, the load, the photovoltaic array power generation, the battery pack status, and the grid status, and schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time.

[0032] Preferably, the power distribution assembly further includes multiple meters, which are correspondingly installed at the input terminals of multiple circuit breakers to measure the voltage, current, and power flowing through the corresponding circuit breaker; the multiple meters are respectively connected to the serial port server to send the measured data.

[0033] Preferably, the energy storage module includes multiple energy storage cabinets, and the energy manager in one of the energy storage cabinets controls the circuit breaker, the contactor, the photovoltaic inverter and the energy storage converter to work according to the status of the mode control button, the load status, the photovoltaic array power generation status, the battery pack status and the grid status.

[0034] Preferably, the system also includes an industrial router, the switch is connected to the industrial router, and the industrial router is connected to a host computer for data interaction.

[0035] Preferably, it also includes a UPS, which provides backup power to the energy manager.

[0036] The positive and progressive effects of this invention are as follows:

[0037] The multi-source grid-connected switching method and grid-connected cabinet provided by this invention are equipped with grid-connected, off-grid, and automatic switching buttons to enable on-demand switching of control modes. The optimized structure, combined with the VSG mode of the energy storage inverter in automatic switching mode, achieves seamless switching between grid-connected and off-grid modes. This effectively addresses abnormal situations such as grid fluctuations and momentary power outages. In the event of grid power failure, rapid disconnection can be performed to prevent equipment islanding, better protect the energy storage inverter, and enhance safety and reliability. It achieves seamless grid-connected to off-grid switching at the microsecond level, with zero interruption for sensitive loads. Compared to traditional grid-connected systems, it responds to load demands faster, preventing equipment downtime and data loss. In off-grid mode, it can operate independently to meet load demands during grid faults. A complex system architecture can be implemented through an energy manager, supporting two-way switching between the grid and energy storage. It can also connect to photovoltaic and other power sources to improve energy utilization and ensure more reliable load operation. Attached Figure Description

[0038] Figure 1 This is a flowchart of the multi-source grid-connected switching method according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the grid-connected cabinet according to an embodiment of the present invention;

[0040] Figure 3 This is a control topology diagram of the grid-connected cabinet according to an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please see Figures 1-3 This embodiment provides a method for switching between multiple sources in a grid and a grid-connected cabinet.

[0043] Specifically, the multi-source grid-connected switching system includes a grid-connected cabinet 1, an energy storage module 2, a photovoltaic module 3, and a load 4. The grid-connected cabinet 1 includes a combiner and distribution component 12, a control component 13, and multiple mode control buttons (not shown). The mode control buttons include a grid-connected button, an off-grid button, and an automatic switching button. The energy storage module 2 includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack installed in the energy storage cabinet. The photovoltaic module 3 includes a photovoltaic array and a photovoltaic inverter.

[0044] The power distribution assembly 12 includes multiple circuit breakers, multiple contactors, and an AC coupling bus 126. The circuit breakers include a main circuit breaker 121 and multiple branch circuit breakers 122. The contactors include a main contactor 123 and branch contactors 124. The AC coupling bus 126 is connected to the power grid 5 via the main contactor 121 and the main circuit breaker 121. The AC coupling bus 126 is connected to the energy storage module 2 via the branch circuit breaker 122. The AC coupling bus 126 is connected to the parallel load 4 and the photovoltaic module 3 via the branch circuit breaker 122 and the branch contactor 124.

[0045] The control component 13 includes a switch 131, a serial server 132, and an IO module 133. The energy manager connects to the serial server 132 and the IO module 133 through the switch 131 to exchange data. The input node of the IO module 133 is connected to the mode control button to obtain the status of the mode control button. The input node of the IO module 133 is connected to the auxiliary contact of the circuit breaker to obtain the status of the circuit breaker. The output node of the IO module 133 is connected to and controls the circuit breaker and the contactor.

[0046] The switching method includes the following steps:

[0047] S1: Controls the closing of multiple circuit breakers. Press the mode button to select the control mode.

[0048] S2: If the grid connection button is pressed, it is assumed that the power supply of grid 5 is normal. The energy manager controls the main contactor 123 and the branch contactor 124 to close in sequence through IO module 133. According to the load 4, the power generation of photovoltaic array 31 and the status of battery pack, the power of photovoltaic array 31, battery pack and grid 5 are scheduled to supply power to load 4 in real time.

[0049] S3: If the off-grid button is pressed, it is determined that the power supply from the grid 5 is not needed. The energy manager controls the contactor 124 to close through the IO module 133. Based on the load 4, the power generation of the photovoltaic array 31, and the battery pack status, the power of the photovoltaic array 31 and the battery pack are scheduled in real time to supply power to the load 4.

[0050] S4: If the automatic switching button is pressed, determine whether the main circuit breaker 121 is closed. If it is closed, it is determined that the power grid 5 is supplying power normally. The energy manager controls the main contactor 123 and the branch contactor 124 to close sequentially through the IO module 133. Based on the load 4, the power generation of the photovoltaic array 31, and the battery pack status, the energy manager schedules the power of the photovoltaic array, the power of the battery pack, and the power of the grid to supply power to the load in real time. If the main circuit breaker 121 trips due to undervoltage, it is determined that the power supply on the grid 5 side is abnormal. The energy manager controls the branch contactor 124 to close through the IO module 133 and schedules the power of the photovoltaic array 31 and the power of the battery pack to supply power to the load 4 in real time. When the power grid supply returns to normal, the main circuit breaker trips due to undervoltage and automatically recovers. The energy manager controls the main contactor 123 to close through the IO module 133 and schedules the power of the photovoltaic array 31, the power of the battery pack, and the power of the grid 5 to supply power to the load 4 in real time.

[0051] Specifically, a grid-connected button, an off-grid button, and an automatic switching button are provided to allow users to manually switch between grid-connected and off-grid modes as well as to switch between grid-connected and off-grid modes automatically, thus enabling on-demand switching of control modes.

[0052] In some embodiments, the power distribution assembly 12 further includes multiple meters 125, which are correspondingly installed at the input terminals of multiple circuit breakers to measure the voltage, current, and power flowing through the corresponding circuit breakers. The multiple meters 125 are respectively connected to a serial port server 132 to send the measured data. Based on the load 4 status, the photovoltaic array 31 power generation status, and the battery pack status, the power of the photovoltaic array 31, the battery pack, and the grid 5 are real-time scheduled to supply power to the load, including the following steps:

[0053] The power of load 4 and the power generation status of photovoltaic array 31 are obtained, and the photovoltaic inverter 32 and energy storage converter are controlled according to the power generation status of load 4 and photovoltaic array 31.

[0054] If the power output of photovoltaic array 31 is greater than the power output of load 4, the power output of photovoltaic array 31 is converted from DC to AC by photovoltaic inverter 32 to supply power to load 4, and the excess power is converted from AC to DC by energy storage converter to charge the battery pack.

[0055] If the power output of photovoltaic array 31 is less than that of load 4, the power output of photovoltaic array 31 is converted from DC to AC by photovoltaic inverter 32 to supply power to load 4; the energy storage converter switches to VSG (Virtual Synchronous Generator) mode, and the part of the power that load 4 is short of is supplied to load 4 by the battery pack after DC to AC conversion by the energy storage converter; if the power of load 4 is still insufficient, it is supplied by the grid 5.

[0056] If the photovoltaic array 31 is not generating electricity, it is in standby mode. During the off-peak hours of the power grid 5, the battery pack is charged by the power grid 5 through the AC-DC conversion of the energy storage converter, and the power grid 5 supplies power to the load. During the peak hours of the power grid 5, the energy storage converter switches to VSG mode, and the battery pack supplies power to the load through the DC-AC conversion of the energy storage converter. If the power of the load 4 is still insufficient, the power grid 5 supplies power again.

[0057] In some embodiments, the power of the photovoltaic array 31 and the battery pack are real-time dispatched to supply power to the load 4 based on the load 4 status, the power generation status of the photovoltaic array 31, and the battery pack status, including the following steps:

[0058] The power of load 4 and the power generation status of photovoltaic array 31 are obtained, and the photovoltaic inverter 32 and energy storage converter are controlled according to the power generation status of load 4 and photovoltaic array 31.

[0059] If the power output of photovoltaic array 31 is greater than the power output of load 4, the power output of photovoltaic array 31 is converted from DC to AC by photovoltaic inverter 32 to supply power to load 4, and the excess power is converted from AC to DC by energy storage converter to charge the battery pack.

[0060] If the power output of the photovoltaic array 31 is less than the load power, the power output of the photovoltaic array 31 is supplied to the load 4 after DC-AC conversion by the photovoltaic inverter 32; the energy storage converter switches to VSG mode, and the part of the load 4 that is not powered by the battery pack is supplied to the load after DC-AC conversion by the energy storage converter.

[0061] If the photovoltaic array 31 is not generating electricity, the photovoltaic array is in standby mode; the energy storage converter switches to VSG mode, and the battery pack supplies power to the load after DC-AC conversion through the energy storage converter.

[0062] In some embodiments, the following steps are also included:

[0063] When the remaining charge of the battery pack is less than or equal to the set discharge threshold, the energy storage converter is controlled to stop supplying power to the load.

[0064] When the remaining charge of the battery pack is greater than or equal to the set full charge threshold, the control energy storage converter stops charging the battery pack.

[0065] The present invention provides a grid-connected cabinet for use in a multi-source grid-connected switching method, including a cabinet body 11, a busbar distribution component 12 disposed in the cabinet body 11, a control component 13, and multiple mode control buttons disposed on the cabinet body 11.

[0066] The power distribution assembly 12 includes multiple circuit breakers, multiple contactors, and an AC coupling bus 126. The circuit breakers include a main circuit breaker 121 and multiple branch circuit breakers 122. The contactors include a main contactor 123 and branch contactors 124. The AC coupling bus 126 is connected to the power grid 5 via the main contactor 123 and the main circuit breaker 121. The AC coupling bus 126 is connected to the energy storage module 2 via the branch circuit breaker 122. The AC coupling bus 126 is connected to the parallel load 4 and the photovoltaic module 3 via the branch circuit breaker 122 and the branch contactor 124.

[0067] The energy storage module 2 includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack installed in the energy storage cabinet; the photovoltaic module 3 includes a photovoltaic array 31 and a photovoltaic inverter 32.

[0068] The control component 13 includes a switch 131, a serial server 132, and an IO module 133. The energy manager connects to the serial server 132 and the IO module 133 through the switch 131 to exchange data. The input node of the IO module 133 is connected to the mode control button to obtain the status of the mode control button. The input node of the IO module 133 is connected to the auxiliary contact of the circuit breaker to obtain the status of the circuit breaker. The output node of the IO module is connected to and controls the circuit breaker and the contactor.

[0069] The energy manager controls the circuit breaker, contactor, photovoltaic inverter 32 and energy storage converter to operate based on the status of the mode control button, the load 4 status, the power generation status of photovoltaic array 31, the battery pack status and the grid 5 status, and schedules the power of photovoltaic array 31, battery pack and grid 5 to supply power to load 4 in real time.

[0070] Specifically, load 4 and photovoltaic module 3 are connected to grid-connected cabinet 1 via a distribution box. The distribution box is equipped with two distribution circuit breakers. The output terminals of the two distribution circuit breakers are connected to load 4 and photovoltaic module 3 respectively. The input terminals of the two distribution circuit breakers are connected to the distribution meter respectively and then connected in parallel to the output terminal of contactor 124 in grid-connected cabinet 1.

[0071] In some embodiments, the busbar distribution assembly 12 further includes a plurality of meters 125, which are correspondingly disposed at the input terminals of a plurality of circuit breakers to measure the voltage, current and power flowing through the corresponding circuit breaker; the plurality of meters 125 are respectively connected to a serial port server 132 to send the measured data.

[0072] In some embodiments, the energy storage module 2 includes multiple energy storage cabinets, and the energy manager in one of the energy storage cabinets controls the circuit breaker, contactor, photovoltaic inverter 32 and energy storage converter to operate according to the status of the mode control button, the load 4 status, the power generation status of the photovoltaic array 31, the battery pack status and the grid 5 status.

[0073] In some embodiments, the system also includes an industrial router 134, a switch 131 connected to the industrial router 134, and the industrial router 134 connected to a host computer for data interaction.

[0074] In some embodiments, a UPS (Uninterruptible Power Supply) is also included, which provides backup power to the energy manager.

[0075] In summary, the multi-source grid-connected switching method and grid-connected cabinet provided by this invention are designed with grid-connected, off-grid, and automatic switching buttons to enable on-demand switching of control modes. The optimized structure, combined with the VSG mode of the energy storage inverter in automatic switching mode, achieves seamless switching between grid-connected and off-grid modes. This effectively addresses abnormal situations such as grid fluctuations and momentary power outages. When grid 5 loses power, rapid disconnection can be performed to prevent equipment islanding, better protecting the energy storage inverter and enhancing safety and reliability. It achieves seamless grid-connected to off-grid switching at the microsecond level, with zero interruption for sensitive loads. Compared to traditional grid-connected systems, it responds to load demands faster, preventing equipment downtime and data loss. In off-grid mode, it can operate independently, meeting the needs of load 4 during grid 5 failures. The energy manager enables complex system architecture and supports multi-source power supply switching from grid 5, energy storage, and photovoltaic power devices, improving energy utilization and ensuring more reliable operation of load 4.

[0076] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for coordinated multi-source grid-connected switching, characterized in that, The system includes a grid-connected cabinet, an energy storage module, a photovoltaic module, and a load. The grid-connected cabinet includes a combiner and distribution assembly, a control assembly, and multiple mode control buttons. The mode control buttons include a grid-connected button, an off-grid button, and an automatic switching button. The energy storage module includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack installed in the energy storage cabinet. The photovoltaic module includes a photovoltaic array and a photovoltaic inverter. The power distribution assembly includes multiple circuit breakers, multiple contactors, and an AC coupling bus. The circuit breakers include main circuit breakers and multiple branch circuit breakers. The contactors include main contactors and branch contactors. The AC coupling bus is connected to the power grid via the main contactors and main circuit breakers. The AC coupling bus is connected to energy storage modules via the branch circuit breakers. The AC coupling bus is connected to parallel loads and photovoltaic modules via the branch circuit breakers and branch contactors. The control components include a switch, a serial server, and an I / O module. The energy manager interacts with the serial server and the I / O module via the switch. The input node of the I / O module is connected to the mode control button to obtain its status, and the input node of the I / O module is connected to the auxiliary contact of the circuit breaker to obtain its status. The output node of the I / O module is connected to and controls the circuit breaker and the contactor. The switching method includes the following steps: Control the closure of multiple circuit breakers; press the mode button to select the control mode. If the grid connection button is pressed, it is assumed that the power supply from the grid is normal. The energy manager controls the main contactor and the branch contactor to close sequentially through the IO module. Based on the load, the power generation of the photovoltaic array, and the status of the battery pack, the power of the photovoltaic array, the power of the battery pack, and the power of the grid are scheduled to supply power to the load in real time. If the off-grid button is pressed, it is determined that no grid power supply is needed. The energy manager controls the closing of the sub-contaminant through the IO module, and schedules the power of the photovoltaic array and the power of the battery pack to supply power to the load in real time according to the load, the power generation of the photovoltaic array and the status of the battery pack. If the automatic switching button is pressed, it is determined whether the main circuit breaker is closed. If closed, it is assumed that the power grid is supplying power normally. The energy manager controls the main contactor and branch contactor to close sequentially through the IO module. Based on the load, photovoltaic array power generation, and battery pack status, it schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time. If the main circuit breaker trips due to undervoltage, it is assumed that the power grid supply is abnormal. The energy manager controls the branch contactor to close through the IO module and schedules the photovoltaic array power and battery pack power to supply power to the load in real time. When the power grid supply returns to normal, the main circuit breaker automatically recovers from undervoltage tripping. The energy manager controls the main contactor to close through the IO module and schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time.

2. The multi-source grid-connected switching method as described in claim 1, characterized in that, The power distribution assembly also includes multiple electricity meters, which are correspondingly installed at the input terminals of multiple circuit breakers to measure the voltage, current, and power flowing through the corresponding circuit breaker. The multiple electricity meters are respectively connected to the serial port server to send the measured data. Based on the load conditions, photovoltaic array power generation, and battery pack status, the assembly real-time scheduling of photovoltaic array power, battery pack power, and grid power to supply power to the load includes the following steps: Obtain load power and photovoltaic array power generation status, and control photovoltaic inverter and energy storage converter according to load and photovoltaic array power generation status; If the power output of the photovoltaic array is greater than the load power, the power output of the photovoltaic array is converted from DC to AC by the photovoltaic inverter to supply power to the load, and the excess power is converted from AC to DC by the energy storage converter to charge the battery pack. If the photovoltaic array's power output is less than the load power, the photovoltaic array's power output is converted from DC to AC by the photovoltaic inverter to supply power to the load; the energy storage converter switches to VSG mode, and the portion of the load power that is insufficient is supplied by the battery pack through the energy storage converter after DC to AC conversion; if the load power is still insufficient, it is supplied by the grid. If the photovoltaic array is not generating electricity, it is in standby mode. During periods of low electricity demand, the grid charges the battery pack via AC-DC conversion through the energy storage converter, and then supplies power to the load. During periods of high electricity demand, the energy storage converter switches to VSG mode, and the battery pack supplies power to the load via DC-AC conversion through the energy storage converter. If the load power is still insufficient, the grid supplies power again.

3. The multi-source grid-connected switching method as described in claim 2, characterized in that, Based on the load conditions, photovoltaic array power generation, and battery status, the photovoltaic array power and battery power are dispatched to supply power to the load in real time, including the following steps: Obtain load power and photovoltaic array power generation status, and control photovoltaic inverter and energy storage converter according to load and photovoltaic array power generation status; If the power output of the photovoltaic array is greater than the load power, the power output of the photovoltaic array is converted from DC to AC by the photovoltaic inverter to supply power to the load, and the excess power is converted from AC to DC by the energy storage converter to charge the battery pack. If the power output of the photovoltaic array is less than the load power, the power output of the photovoltaic array is supplied to the load after DC-AC conversion by the photovoltaic inverter; the energy storage converter switches to VSG mode, and the part of the load power that is insufficient is supplied to the load by the battery pack after DC-AC conversion by the energy storage converter. If the photovoltaic array is not generating electricity, it is in standby mode; the energy storage converter switches to VSG mode, and the battery pack supplies power to the load after DC-AC conversion through the energy storage converter.

4. The multi-source grid-connected switching method as described in claim 1, characterized in that, It also includes the following steps: When the remaining charge of the battery pack is less than or equal to the set discharge threshold, the energy storage converter is controlled to stop supplying power to the load. When the remaining charge of the battery pack is greater than or equal to the set full charge threshold, the control energy storage converter stops charging the battery pack.

5. A grid-connected cabinet applied to the multi-source grid-connected switching method according to any one of claims 1-4, characterized in that, This includes a cabinet, a power distribution assembly housed within the cabinet, control components, and multiple mode control buttons mounted on the cabinet. The power distribution assembly includes multiple circuit breakers, multiple contactors, and an AC coupling bus. The circuit breakers include main circuit breakers and multiple branch circuit breakers. The contactors include main contactors and branch contactors. The AC coupling bus is connected to the power grid via the main contactors and main circuit breakers. The AC coupling bus is connected to energy storage modules via the branch circuit breakers. The AC coupling bus is connected to parallel loads and photovoltaic modules via the branch circuit breakers and branch contactors. The energy storage module includes an energy storage cabinet and an energy manager, an energy storage converter, and a battery pack installed in the energy storage cabinet; the photovoltaic module includes a photovoltaic array and a photovoltaic inverter; The control components include a switch, a serial server, and an I / O module. The energy manager connects to the serial server and the I / O module through the switch to exchange data. The input node of the I / O module is connected to the mode control button to obtain the status of the mode control button. The input node of the I / O module is connected to the auxiliary contact of the circuit breaker to obtain the status of the circuit breaker. The output node of the I / O module is connected to and controls the circuit breaker and the contactor. The energy manager controls the circuit breaker, the contactor, the photovoltaic inverter, and the energy storage converter to operate based on the status of the mode control button, the load, the photovoltaic array power generation, the battery pack status, and the grid status, and schedules the photovoltaic array power, battery pack power, and grid power to supply power to the load in real time.

6. The grid-connected cabinet as described in claim 5, characterized in that, The power distribution assembly also includes multiple meters, which are correspondingly installed at the input terminals of multiple circuit breakers to measure the voltage, current and power flowing through the corresponding circuit breaker; the multiple meters are respectively connected to the serial port server to send the measured data.

7. The grid-connected cabinet as described in claim 5, characterized in that, The energy storage module includes multiple energy storage cabinets. The energy manager in one of the energy storage cabinets controls the circuit breaker, the contactor, the photovoltaic inverter, and the energy storage converter to operate based on the status of the mode control button, the load status, the photovoltaic array power generation status, the battery pack status, and the grid status.

8. The grid-connected cabinet as described in claim 5, characterized in that, It also includes an industrial router, the switch is connected to the industrial router, and the industrial router is connected to the host computer for data interaction.

9. The grid-connected cabinet as described in claim 5, characterized in that, It also includes a UPS, which provides backup power to the energy manager.

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