Control method and terminal for shared direct-current bus, and shared direct-current bus system

Abstract

Disclosed are a control method and terminal for a shared direct-current bus, and a shared direct-current bus system. The control method comprises: acquiring state information of a PCS and a battery SOC of each energy storage cabinet, wherein the PCS is used for connecting a shared direct-current bus and a power grid, and each energy storage cabinet among at least two energy storage cabinets is connected to the shared direct-current bus by means of a DCDC and a relay; on the basis of the state information, determining whether the PCS operates normally, and if the PCS operates normally, the PCS outputting a voltage at constant power to establish a bus voltage of the shared direct-current bus; otherwise, controlling the relays to close, and establishing the bus voltage of the shared direct-current bus by the energy storage cabinets; and on the basis of the battery SOC of each energy storage cabinet, performing energy mobilization control. In the present invention, the shared direct-current bus is connected to the power grid and multiple energy storage cabinets, so that multi-form establishment of the bus voltage is implemented; in addition, the battery capacity can be optimized, so that compatible use of large-capacity cabinets and small-capacity cabinets is implemented, and costs can be reduced by means of efficient resource utilization and cost-saving measures.

Description

A shared DC bus control method, terminal and shared DC bus system Technical Field

[0001] The present invention relates to the technical field of shared DC bus control, and in particular to a shared DC bus control method, a terminal, and a shared DC bus system. Background Art

[0002] With the widespread adoption of electric vehicles, charging stations have become a key focus of industrial development. The development of photovoltaic, storage, charging, and inspection systems can address EV charging issues. They integrate photovoltaic clean energy utilization and energy management systems, achieving energy conservation, emission reduction, and a low-carbon, environmentally friendly approach. The architecture of a shared DC bus photovoltaic, storage, charging, and inspection system improves maintainability, optimizes efficiency, and enhances energy utilization.

[0003] The current design scheme is to establish a bus voltage in the energy storage system by combining the energy storage cabinet and DC / DC (or DCDC) into a subsystem. The bus voltage established by this design scheme is relatively simple. If the cabinet cannot be used, there is no way to make the system operate normally. Technical issues

[0004] The technical problem to be solved by the present invention is to provide a control method, terminal and shared DC bus system for a shared DC bus, so as to solve the problem in the existing system that the bus voltage is established by the energy storage cabinet and the DC / DC converter, resulting in unstable system operation. Technical Solutions

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A control method for a shared DC bus, comprising the steps of:

[0007] S1. Collecting PCS status information and battery SOC of each energy storage cabinet. The PCS is used to connect a shared DC bus and a power grid. Each of at least two energy storage cabinets is connected to the shared DC bus via a DC-DC converter and a relay.

[0008] S2. Determine whether the PCS is operating normally based on the status information. If the PCS is operating normally, the PCS outputs a voltage at a constant power to establish a bus voltage of a shared DC bus.

[0009] Otherwise, the control relay is closed, and the energy storage cabinet establishes the bus voltage of the shared DC bus;

[0010] S3. Perform energy mobilization control according to the battery SOC of each energy storage cabinet.

[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0012] A control terminal for a shared DC bus includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for controlling a shared DC bus are implemented.

[0013] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0014] A shared DC bus system includes a power grid, a PCS, a shared DC bus, and at least two power supply subsystems;

[0015] The power supply subsystem includes a DC-DC and an energy storage cabinet, and the energy storage cabinet is connected to the shared DC bus through the DC-DC;

[0016] The shared DC bus is connected to the power grid via the PCS;

[0017] The shared DC bus system implements the steps in the above-mentioned method for controlling a shared DC bus. Beneficial effects

[0018] The beneficial effects of the present invention are as follows: a control method, terminal and shared DC bus system of the present invention are connected to the power grid and the energy storage cabinet, and the bus voltage of the shared DC bus can be established by the power grid or the cabinet, thereby realizing multi-form establishment of the bus voltage; at the same time, the number of connected energy storage cabinets is expanded, the battery capacity can be optimized, and the combined use of large-capacity cabinets and small-capacity cabinets can be realized, and through energy scheduling, it can increase revenue and reduce expenditure and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a flow chart of a control method for a shared DC bus according to an embodiment of the present invention;

[0020] FIG2 is a structural diagram of a control terminal for sharing a DC bus according to an embodiment of the present invention;

[0021] FIG3 is an exemplary diagram of the architecture of a shared DC bus system according to an embodiment of the present invention;

[0022] Description of labels:

[0023] 1. A control terminal for sharing a DC bus; 2. A processor; 3. A memory. Modes for Carrying Out the Invention

[0024] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0025] Referring to FIG. 1 and FIG. 2 , a control method for a shared DC bus includes the following steps:

[0026] S1. Collecting PCS status information and battery SOC of each energy storage cabinet. The PCS is used to connect a shared DC bus and a power grid. Each of at least two energy storage cabinets is connected to the shared DC bus via a DC-DC converter and a relay.

[0027] S2. Determine whether the PCS is operating normally based on the status information. If the PCS is operating normally, the PCS outputs a voltage at a constant power to establish a bus voltage of a shared DC bus.

[0028] Otherwise, the control relay is closed, and the energy storage cabinet establishes the bus voltage of the shared DC bus;

[0029] S3. Perform energy mobilization control according to the battery SOC of each energy storage cabinet.

[0030] As can be seen from the above description, the beneficial effects of the present invention are: a control method, terminal and shared DC bus system of the present invention are connected to the power grid and energy storage cabinets, and the bus voltage of the shared DC bus can be established by the power grid or the cabinet, thereby realizing multi-form establishment of the bus voltage; at the same time, the number of connected energy storage cabinets is expanded, the battery capacity can be optimized, and the combined use of large-capacity cabinets and small-capacity cabinets can be realized, and through energy scheduling, it can increase revenue and reduce expenditure and save costs.

[0031] Furthermore, step S2 is specifically as follows:

[0032] Determine whether the PCS is operating normally according to the status information. If the PCS is operating normally, the PCS outputs a constant power voltage to establish the bus voltage of the shared DC bus, or controls the relay to close so that the energy storage cabinet establishes the bus voltage of the shared DC bus;

[0033] Otherwise, the control relay is closed and the energy storage cabinet establishes the bus voltage of the shared DC bus.

[0034] From the above description, it can be seen that when the external power grid is normal, the PCS operates normally and can also control the maintenance relay in front of the BMS subsystem to be energized, so that the subsystem establishes a common DC bus, and the PCS is then connected to the common DC bus.

[0035] Furthermore, the shared DC bus is also connected to a photovoltaic power generation system;

[0036] Step S3 includes the steps of:

[0037] Detect in real time whether there is a first energy storage cabinet whose battery SOC is lower than a preset low power threshold. If so, determine whether there is a first energy storage cabinet whose battery SOC is higher than a preset high power threshold. If so, execute step A1; otherwise, execute step A2.

[0038] A1. Select the energy storage cabinets whose battery SOC is higher than a preset high power threshold, and then select the second energy storage cabinet with the highest battery SOC to charge the first energy storage cabinet until the battery SOC of the first energy storage cabinet is replenished to a preset stable threshold, or the battery SOC of the second energy storage cabinet is discharged to the stable threshold;

[0039] A2. Control the photovoltaic system to charge the first energy storage cabinet.

[0040] As can be seen from the above description, through energy scheduling and photovoltaic supplementation of the energy storage cabinets, the battery SOC of each energy storage cabinet is maintained above the preset stability threshold as much as possible, ensuring that the battery SOC of each energy storage cabinet can support the critical load. This prevents the situation where a high-capacity energy storage cabinet fails and only a low-capacity energy storage cabinet is left operational, resulting in the energy storage cabinet's power being insufficient to support the critical load. Loads include general loads and critical loads, which are pre-defined by the user.

[0041] Furthermore, the shared DC bus is also connected to the charging pile via DCDC;

[0042] Step A2 includes the steps of:

[0043] A21. Obtain photovoltaic power generation information and determine whether the photovoltaic power generation power is greater than a preset power threshold. If so, control the photovoltaic system to charge the first energy storage cabinet; otherwise, proceed to step A22.

[0044] A22. The battery of the vehicle with the V2G function enabled is controlled to discharge through the charging pile, and the battery is used to supply electricity to the load together with the energy storage cabinet.

[0045] As can be seen from the above description, loads include general loads and critical loads, which are predefined by the user. If the PV system is unable to provide power due to weather conditions, the battery of a vehicle with V2G enabled can be discharged to share the power consumption of general loads with the energy storage cabinet, allowing the energy storage cabinet to support critical loads for a longer period of time.

[0046] Furthermore, the shared DC bus is also connected to the photovoltaic power generation system and connected to the charging pile via DCDC;

[0047] Step S3 further includes the steps of:

[0048] Get the peak and valley electricity time period information of the region. If it is currently in the peak electricity time period, then:

[0049] The energy storage cabinet whose battery SOC is higher than a preset high power threshold is preferentially used to supply power to vehicles with charging needs, and the energy storage cabinet enters the charging state only when the battery SOC of the energy storage cabinet is consumed to a preset low power threshold;

[0050] The battery of the vehicle with V2G function enabled is controlled by the charging pile to first supply power to the vehicle with charging demand, and secondly to charge the energy storage cabinet;

[0051] Controlling the photovoltaic system to first supply power to vehicles that require charging, and secondly to charge the energy storage cabinet;

[0052] Only when the photovoltaic power generation is lower than the preset power threshold, no vehicle is powered by the V2G function, and the battery SOC of each energy storage cabinet is lower than the low power threshold, the grid will supply power to the vehicles with charging needs;

[0053] If it is the off-peak period, then:

[0054] Power is directly drawn from the power grid to supply power to vehicles with charging needs. The photovoltaic system and the batteries of vehicles with V2G function enabled will first charge the energy storage cabinets, and after each energy storage cabinet is fully charged, it will supply power to vehicles with charging needs.

[0055] From the above description, it can be seen that energy scheduling is carried out by combining regional peak and valley electricity period information, photovoltaics, and vehicle V2G functions to minimize costs.

[0056] Please refer to Figure 2, a control terminal for a shared DC bus includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method for controlling a shared DC bus are implemented.

[0057] As can be seen from the above description, the beneficial effects of the present invention are: a control method, terminal and shared DC bus system of the present invention are connected to the power grid and energy storage cabinets, and the bus voltage of the shared DC bus can be established by the power grid or the cabinet, thereby realizing multi-form establishment of the bus voltage; at the same time, the number of connected energy storage cabinets is expanded, the battery capacity can be optimized, and the combined use of large-capacity cabinets and small-capacity cabinets can be realized, and through energy scheduling, it can increase revenue and reduce expenditure and save costs.

[0058] Referring to FIG3 , a shared DC bus system includes a power grid, a PCS, a shared DC bus, and at least two power supply subsystems;

[0059] The power supply subsystem includes a DC-DC and an energy storage cabinet, and the energy storage cabinet is connected to the shared DC bus through the DC-DC;

[0060] The shared DC bus is connected to the power grid via the PCS;

[0061] The shared DC bus system implements the steps in the above-mentioned method for controlling a shared DC bus.

[0062] As can be seen from the above description, the beneficial effects of the present invention are: a control method, terminal and shared DC bus system of the present invention are connected to the power grid and energy storage cabinets, and the bus voltage of the shared DC bus can be established by the power grid or the cabinet, thereby realizing multi-form establishment of the bus voltage; at the same time, the number of connected energy storage cabinets is expanded, the battery capacity can be optimized, and the combined use of large-capacity cabinets and small-capacity cabinets can be realized, and through energy scheduling, it can increase revenue and reduce expenditure and save costs.

[0063] Furthermore, the shared DC bus is connected to the photovoltaic system and is connected to the charging pile through DCDC.

[0064] From the above description, it can be seen that the photovoltaic system and the charging pile vehicle V2G are combined to optimize energy scheduling.

[0065] A shared DC bus control method, terminal, and shared DC bus system of the present invention are suitable for establishing and dispatching the DC bus of a photovoltaic storage charging and testing station.

[0066] Referring to Figures 1 and 3, the first embodiment of the present invention is:

[0067] A control method for a shared DC bus, comprising the steps of:

[0068] S1. Collect PCS status information and battery SOC of each energy storage cabinet. The PCS is used to connect a shared DC bus and a power grid. Each of at least two energy storage cabinets is connected to the shared DC bus through a DC-DC converter and a relay.

[0069] In this embodiment, the EMS patrols the entire system data to collect PCS status and battery SOC.

[0070] S2. Determine whether the PCS is operating normally based on the status information. If the PCS is operating normally, the PCS outputs a voltage at a constant power to establish a bus voltage of a shared DC bus.

[0071] Otherwise, the control relay is closed, and the energy storage cabinet establishes the bus voltage of the shared DC bus;

[0072] Step S2 is specifically as follows:

[0073] Determine whether the PCS is operating normally according to the status information. If the PCS is operating normally, the PCS outputs a constant power voltage to establish the bus voltage of the shared DC bus, or controls the relay to close so that the energy storage cabinet establishes the bus voltage of the shared DC bus;

[0074] Otherwise, the control relay is closed and the energy storage cabinet establishes the bus voltage of the shared DC bus.

[0075] In this embodiment, when the external power grid is normal and the PCS is fault-free, the PCS maintains a constant power output voltage to establish the bus voltage. The maintenance relay in front of the BMS subsystem (DCDC + energy storage cabinet) is energized, and the subsystems are connected to the common DC bus. When the external power grid is normal and the PCS is operating normally, the maintenance relay in front of the BMS subsystem can also be controlled to energize, allowing the subsystems to establish a common DC bus, and the PCS can then connect to the common DC bus. However, if the external power grid is abnormal and the PCS detects a fault, the BMS subsystem must establish the bus voltage. In the event of an external power abnormality and PCS failure, the system monitors the SOC of all batteries. If the BMS subsystem is fully operational, the maintenance relay is energized to establish the bus voltage.

[0076] In this embodiment, after the bus voltage is established, if a subsystem BMS needs to be repaired, the maintenance relay of this subsystem can be disconnected separately, and the system can still operate normally.

[0077] S3. Perform energy mobilization control according to the battery SOC of each energy storage cabinet.

[0078] Referring to Figures 1 and 3, the second embodiment of the present invention is as follows:

[0079] A control method for a shared DC bus, which differs from the first embodiment in that the shared DC bus is also connected to a photovoltaic power generation system and is connected to a charging pile via a DC-DC converter.

[0080] Step S3 includes the steps of:

[0081] Detect in real time whether there is a first energy storage cabinet whose battery SOC is lower than a preset low power threshold. If so, determine whether there is a first energy storage cabinet whose battery SOC is higher than a preset high power threshold. If so, execute step A1; otherwise, execute step A2.

[0082] A1. Among the energy storage cabinets whose battery SOC is higher than a preset high power threshold, the second energy storage cabinet with the highest battery SOC is selected to charge the first energy storage cabinet until the battery SOC of the first energy storage cabinet is replenished to a preset stable threshold, or the battery SOC of the second energy storage cabinet is discharged to the stable threshold.

[0083] In this embodiment, after the bus voltage is established, the system is in the backup operation mode, at which time the subsystem gives priority to supplying power to important loads (load power <100kW, the backup operation only supplies power to important loads).

[0084] In this embodiment, loads include general loads and critical loads, which are predefined by the user. Generally speaking, critical loads include fire power supplies, emergency power supplies, and precision equipment power supplies, while other common electrical devices, or those not significantly impacted by power outages, are defined as general loads. The present invention provides power supply interfaces for both critical and general loads, employing different control strategies for these interfaces based on the system's power status.

[0085] In this embodiment, the subsystem SOC low battery threshold is set to 30%, the high battery threshold is set to 60%, and the stable threshold is set to 50%. In other equivalent embodiments, the low battery threshold, high battery threshold, and stable threshold can be adjusted as needed. Low battery threshold < stable threshold < high battery threshold.

[0086] In this embodiment, if the SOC of a battery in the BMS subsystem is lower than 30%, the first backup echelon process is performed: the SOC of other BMS subsystems is inspected. If the SOC is higher than 60%, the system is allowed to control the discharge of this BMS subsystem, and the remaining power is controlled to charge the low-power subsystem (charging current 3.2A) at a maximum. Discharge stops when the remaining power reaches 50%, and the remaining subsystems supply power to important loads.

[0087] Through the continuous execution of the first backup echelon process, the SOC of the subsystems that can be charged reaches 50% (ensuring that the subsystem has sufficient power to support important loads). If the SOC of the low-power subsystem has not reached 50% at this time, the second backup echelon process will be carried out.

[0088] A2. Control the photovoltaic system to charge the first energy storage cabinet;

[0089] Step A2 includes the steps of:

[0090] A21. Obtain photovoltaic power generation information and determine whether the photovoltaic power generation power is greater than a preset power threshold. If so, control the photovoltaic system to charge the first energy storage cabinet; otherwise, proceed to step A22.

[0091] A22. The battery of the vehicle with the V2G function enabled is controlled to discharge through the charging pile, and the battery is used to supply electricity to the load together with the energy storage cabinet.

[0092] In this embodiment, the second backup echelon process: photovoltaic power generation supplements the remaining power of the subsystem.

[0093] If PV power generation is less than 5kW (PV power generation has an operational mode that shuts down PV power generation during rainy or extreme weather conditions to ensure system insulation), and a subsystem's SOC is still below 50%, the system initiates the third backup process: utilizing the V2G function to control vehicle battery discharge to power loads (both general and critical) through a bidirectional charging station, while also regulating the subsystem discharge current (reducing discharge current to extend subsystem life). If V2G discharge is terminated, the system uses the remaining subsystem power to power critical loads and disconnects other connections.

[0094] In this embodiment, the preset power threshold is 5 kW, and in other equivalent embodiments, it can be adjusted according to actual needs.

[0095] Referring to Figures 1 and 3, the third embodiment of the present invention is:

[0096] A control method for a shared DC bus, which differs from the first or second embodiment in that the shared DC bus is also connected to a photovoltaic power generation system and is connected to a charging pile via a DC-DC converter.

[0097] Step S3 further includes the steps of:

[0098] Get the peak and valley electricity time period information of the region. If it is currently in the peak electricity time period, then:

[0099] The energy storage cabinet whose battery SOC is higher than a preset high power threshold is preferentially used to supply power to vehicles with charging needs, and the energy storage cabinet enters the charging state only when the battery SOC of the energy storage cabinet is consumed to a preset low power threshold;

[0100] The battery of the vehicle with V2G function enabled is controlled by the charging pile to first supply power to the vehicle with charging demand, and secondly to charge the energy storage cabinet;

[0101] Controlling the photovoltaic system to first supply power to vehicles that require charging, and secondly to charge the energy storage cabinet;

[0102] Only when the photovoltaic power generation is lower than the preset power threshold, no vehicle is powered by the V2G function and the battery SOC of each energy storage cabinet is lower than the low power threshold, the power grid will supply power to vehicles with charging needs.

[0103] In this embodiment, after the bus voltage is established, the system operates normally in energy optimization mode, with the grid supplying normal power to the loads. Simultaneously, the system controls energy mobilization based on regional peak and off-peak periods. During peak power periods, the system prioritizes charging vehicles. The BMS subsystem's SOC is inspected. If it exceeds 60%, the system controls the BMS subsystem to discharge power to charge the vehicle. If the SOC falls below 30%, discharging is stopped and charging is resumed. If V2G discharge is detected, the discharged power is prioritized for charging other vehicles, followed by the subsystem. PV power is used to charge vehicles; if no vehicles require charging, the subsystem is charged. Level 2: PV power generation is less than 5kW (PV power generation has an operating mode that shuts down PV power generation during rainy and extreme weather conditions to ensure system insulation), there is no V2G discharge, and the subsystem's power level is below 30%. The grid charges the vehicle.

[0104] If it is the off-peak period, then:

[0105] Power is directly drawn from the power grid to supply power to vehicles with charging needs. The photovoltaic system and the batteries of vehicles with V2G function enabled will first charge the energy storage cabinets, and after each energy storage cabinet is fully charged, it will supply power to vehicles with charging needs.

[0106] In this embodiment, during peak or off-peak hours, the grid directly powers the vehicle. Photovoltaic power generation prioritizes replenishing the subsystems, and the vehicle is then charged when the battery is fully charged. The same applies to vehicle V2G discharge.

[0107] Please refer to FIG2 , the fourth embodiment of the present invention is:

[0108] A control terminal 1 for a shared DC bus includes a processor 2, a memory 3, and a computer program stored in the memory 3 and executable on the processor 2. When the processor 2 executes the computer program, the steps of the control method for a shared DC bus described in the first to third embodiments above are implemented.

[0109] Referring to FIG. 1 and FIG. 3 , the fifth embodiment of the present invention is as follows:

[0110] A shared DC bus system includes a power grid, a PCS, a shared DC bus, and at least two power supply subsystems;

[0111] The power supply subsystem includes a DC-DC and an energy storage cabinet, and the energy storage cabinet is connected to the shared DC bus through the DC-DC;

[0112] The shared DC bus is connected to the power grid via the PCS;

[0113] In addition, the shared DC bus is also connected to the photovoltaic system and connected to the charging pile through DCDC.

[0114] The shared DC bus system implements the steps in the shared DC bus control method described in the first to third embodiments above.

[0115] In summary, the present invention provides a control method, terminal, and shared DC bus system for a shared DC bus. These are connected to a power grid and an energy storage cabinet. The bus voltage of the shared DC bus can be established by the power grid or the cabinet, thus enabling multiple forms of bus voltage establishment. Furthermore, the number of connected energy storage cabinets is expanded, thereby optimizing battery capacity and enabling the combined use of large-capacity and small-capacity cabinets. This enables cost savings through energy scheduling.

[0116] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control method for a shared DC bus, characterized in that: Includes steps: S1, collecting the status information of the PCS and the battery SOC of each energy storage cabinet, wherein the PCS is used to connect the shared DC bus and the power grid, and each of the at least two energy storage cabinets is connected to the shared DC bus through a DCDC and a relay; S2. judging whether the PCS is working normally according to the status information; if the PCS is working normally, the PCS outputs a voltage at a constant power to establish a bus voltage of a shared DC bus; Otherwise, the control relay is closed, and the energy storage cabinet establishes the bus voltage of the shared DC bus; S3. Perform energy mobilization control according to the battery SOC of each energy storage cabinet.

2. A control method for a shared DC bus according to claim 1, characterized in that: Step S2 is specifically as follows: Determine whether the PCS is working normally according to the status information. If the PCS is working normally, the PCS outputs a constant power voltage to establish the bus voltage of the shared DC bus, or controls the relay to close so that the energy storage cabinet establishes the bus voltage of the shared DC bus; Otherwise, the control relay is closed, and the energy storage cabinet establishes the bus voltage of the shared DC bus.

3. The control method for a shared DC bus according to claim 1, characterized in that: The shared DC bus is also connected to a photovoltaic power generation system; Step S3 includes the steps of: Detect in real time whether there is a first energy storage cabinet whose battery SOC is lower than a preset low power threshold. If the first energy storage cabinet exists, determine whether there is the energy storage cabinet whose battery SOC is higher than a preset high power threshold. If so, execute step A1, otherwise execute step A2; A1. Among the energy storage cabinets whose battery SOC is higher than a preset high power threshold, the second energy storage cabinet with the highest battery SOC is selected to charge the first energy storage cabinet until the battery SOC of the first energy storage cabinet is replenished to a preset stable threshold, or the battery SOC of the second energy storage cabinet is discharged to the stable threshold; A2. Control the photovoltaic system to charge the first energy storage cabinet.

4. A control method for a shared DC bus according to claim 3, characterized in that: The shared DC bus is also connected to the charging pile via DCDC; Step A2 comprises the steps of: A21, obtaining photovoltaic power generation information, determining whether the photovoltaic power generation power is greater than a preset power threshold, if so, controlling the photovoltaic system to charge the first energy storage cabinet, otherwise proceeding to step A22; A22. The battery discharge of the vehicle with the V2G function enabled is controlled by the charging pile, and the battery and the energy storage cabinet are used to supply electricity to the load.

5. The control method for a shared DC bus according to claim 1, characterized in that: The shared DC bus is also connected to the photovoltaic power generation system and connected to the charging pile via DCDC; Step S3 also includes the steps of: Get the information of the peak and valley electricity periods in the region. If the current period is the peak electricity period, then: The energy storage cabinet whose battery SOC is higher than a preset high power threshold is preferentially used to supply power to vehicles with charging needs, and the energy storage cabinet enters the charging state only when the battery SOC of the energy storage cabinet is consumed to a preset low power threshold; The battery of the vehicle with V2G function enabled is controlled by the charging pile to first supply power to the vehicle with charging demand, and secondly to charge the energy storage cabinet; Controlling the photovoltaic system to first supply power to vehicles with charging needs, and secondly to charge the energy storage cabinet; Only when the photovoltaic power generation is lower than the preset power threshold, no vehicle is powered by the V2G function, and the battery SOC of each of the energy storage cabinets is lower than the low power threshold, the power grid will supply power to the vehicles with charging needs; If it is the off-peak period, then: Electricity is directly drawn from the power grid to supply power to vehicles with charging needs. The photovoltaic system and the batteries of vehicles with V2G function turned on give priority to charging each of the energy storage cabinets, and after each energy storage cabinet is fully charged, it supplies power to vehicles with charging needs.

6. A control terminal for sharing a DC bus, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps in the control method for a shared DC bus described in any one of claims 1 to 5 are implemented.

7. A shared DC bus system, characterized in that: It includes a power grid, a PCS, a shared DC bus and at least two power supply subsystems; The power supply subsystem includes a DCDC and an energy storage cabinet, and the energy storage cabinet is connected to the shared DC bus through the DCDC; The shared DC bus is connected to the power grid via the PCS; The shared DC bus system implements the steps in a shared DC bus control method as described in any one of claims 1 to 5 above.

8. A shared DC bus system according to claim 7, characterized in that: The shared DC bus is connected to the photovoltaic system and connected to the charging pile through DCDC.

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