Continuous power supply method and system for direct-current power distribution network and storage medium

Abstract

The invention provides a continuous power supply method and system for a direct current power distribution network and a storage medium, the direct current power distribution network and an alternating current power distribution network are interconnected through a converter, and the method comprises the steps: controlling the direct current power distribution network and the alternating current power distribution network to be disconnected if the mains supply voltage loss is detected; monitoring the voltage value of the DC bus in real time, and if the voltage value of the DC bus is greater than a preset voltage threshold, monitoring the charge state of the energy storage system; if the state of charge of the energy storage system is full, the photovoltaic system is controlled to exit MPPT, and power-limited operation is carried out; if the charge state of the energy storage system is under-charge, the energy storage system is controlled to be charged, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and limited power operation; if the voltage value of the direct current bus is smaller than the preset voltage threshold value, the energy storage system is controlled to discharge rapidly, and MPPT operation of the photovoltaic system is maintained; and after discharging is finished, the direct-current transformer is adjusted until the direct-current voltage reaches a preset stable range. The invention aims to realize source-load matching and maintain the stability of direct-current voltage.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a continuous power supply method, system and storage medium for a direct current distribution network. Background Art

[0002] In modern power systems, the stability and reliability of power supply are crucial to maintaining the normal operation of the power system. However, with the widespread application of renewable energy and the complexity of the power system, faults, short circuits and other unstable factors in the power grid may lead to a loss of power supply. In the event of a loss of power supply, the power supply interruption of the power system may have a serious impact on users and equipment.

[0003] To solve this problem, many power systems use energy storage systems and renewable energy (such as photovoltaics) to maintain power supply. However, large-scale access to energy storage systems and renewable energy will increase the pressure on grid system management, especially when the DC distribution network enters an isolated state. How to ensure the stability and reliability of the DC distribution network power supply and achieve smooth switching and continuous power supply of the DC distribution network when the mains voltage is lost is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The main purpose of the present application is to provide a continuous power supply method, system and storage medium for a DC distribution network, aiming to ensure the stability and reliability of the DC distribution network and achieve smooth switching and continuous power supply of the DC distribution network when the mains voltage fails.

[0005] In order to solve the above problems, the embodiments of the present invention mainly provide the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a continuous power supply method for a DC distribution network, wherein the DC distribution network includes: an energy storage system, a photovoltaic system, a DC transformer, and a load; the energy storage system and the photovoltaic system are both connected to a DC bus; the DC distribution network is interconnected with an AC distribution network through a converter via the DC bus, and the photovoltaic system is operated in maximum power tracking; the energy storage system operates according to preset SOC upper and lower limits; the method includes:

[0007] If the mains voltage is lost, the DC distribution network and the AC distribution network are disconnected;

[0008] Monitor the voltage value of the DC bus in real time. If the voltage value of the DC bus is greater than the preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power.

[0009] If the voltage value of the DC bus is less than the preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system;

[0010] After the energy storage system is discharged, the DC transformer is adjusted until the DC voltage reaches a preset stable range.

[0011] In one embodiment, if a mains voltage loss is detected, controlling the DC distribution network and the AC distribution network to be disconnected includes:

[0012] Real-time monitoring of the voltage, frequency and DC side voltage on the AC side. When the voltage on the AC side is overvoltage or undervoltage, or the voltage on the DC side is overvoltage or undervoltage, or the frequency on the AC side is overfrequency or underfrequency, it is judged as isolated grid operation, and the converter is controlled to close the switch tube. At the same time, a command is issued to disconnect the AC side incoming line switch to control the disconnection of the DC distribution network and the AC distribution network.

[0013] In one embodiment, if the voltage value of the DC bus is greater than a preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power, including:

[0014] If the voltage value of the DC bus is greater than a preset voltage threshold, the charge state of the energy storage system is monitored;

[0015] If the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate at limited power;

[0016] If the energy storage system is undercharged, the energy storage system is controlled to charge, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power.

[0017] In one embodiment, if the state of charge of the energy storage system is undercharged, controlling the energy storage system to charge includes:

[0018] If the state of charge of the energy storage system is undercharged, the energy storage system is controlled to operate according to the preset SOC upper and lower limits;

[0019] The positive voltage deviation of the DC bus triggers the charging of the energy storage system.

[0020] In one embodiment, controlling the photovoltaic system to exit MPPT and operate with limited power includes:

[0021] The positive voltage deviation of the DC bus triggers the photovoltaic system to exit the MPPT and enter the power-limited operation mode.

[0022] In one embodiment, after the energy storage system is discharged, adjusting the DC transformer includes:

[0023] After the energy storage system is discharged, the DC transformer is adjusted according to the power consumption of each load and the importance level of each load until the DC voltage reaches the preset stable range.

[0024] In one embodiment, according to the power consumption of each load and the importance level of each load, adjusting the DC transformer until the DC voltage reaches a preset stable range includes:

[0025] Monitor the operating power of each load in real time. When the operating power of a load is less than the adjustable upper limit, control the duty cycle of the DC transformer to quickly adjust the load to the upper limit according to the preset maximum load increase rate, and adjust each load to the upper limit according to the preset maximum load increase rate according to the preset load importance level, until the DC voltage of the DC transformer reaches the preset stable range.

[0026] In one embodiment, if the voltage value of the DC bus is less than a preset voltage threshold, the energy storage system is controlled to discharge rapidly to maintain the MPPT operation of the photovoltaic system, including:

[0027] The positive voltage deviation of the DC bus triggers the rapid discharge of the energy storage system to maintain the MPPT operation of the photovoltaic system.

[0028] A second aspect of the present application provides a continuous power supply system for a DC distribution network, comprising: a DC distribution network and a coordination control device; the coordination control device comprises: a memory and a processor;

[0029] The memory is used to store computer programs;

[0030] The processor is used to execute a computer program and implement the steps of the method for continuous power supply of a DC distribution network provided in the first aspect above when executing the computer program.

[0031] A third aspect of the present application provides a computer-readable storage medium storing a computer program; when the computer program is executed by one or more processors, the one or more processors execute the steps of the continuous power supply method for a DC distribution network provided in the first aspect above.

[0032] The present application provides a method, system and storage medium for continuous power supply of a DC distribution network. The method for continuous power supply of a DC distribution network provided in the embodiment of the present application controls the disconnection of the DC distribution network and the AC distribution network if the loss of mains voltage is detected; monitors the voltage value of the DC bus in real time, and monitors the state of charge of the energy storage system if the voltage value of the DC bus is greater than a preset voltage threshold; if the state of charge of the energy storage system is fully charged, controls the photovoltaic system to exit MPPT and operate with limited power; if the state of charge of the energy storage system is undercharged, controls the energy storage system to charge, and after the energy storage system is fully charged, controls the photovoltaic system to exit MPPT and operate with limited power; if the voltage value of the DC bus is less than a preset voltage threshold, controls the energy storage system to discharge quickly and maintains the MPPT operation of the photovoltaic system; after the discharge is completed, adjusts the DC transformer until the DC voltage reaches a preset stable range. The purpose is to achieve source-load matching and maintain DC voltage stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of a process flow for implementing a continuous power supply method for a DC distribution network provided in an embodiment of the present application;

[0035] Figure 2 A schematic diagram of the structure of a DC distribution network provided in one embodiment of the present application;

[0036] Figure 3 A schematic diagram of a coordinated control device provided in one embodiment of the present application.

[0037] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0040] See also Figure 1 , Figure 1 A schematic diagram of the implementation flow of a continuous power supply method for a DC distribution network provided in one embodiment of the present application.

[0041] The continuous power supply method of the DC distribution network is implemented by a continuous power supply system of the DC distribution network. For example, the continuous power supply system of the DC distribution network provided in the embodiment of the present application includes: a DC distribution network and a coordination control device. Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a DC distribution network provided in an embodiment of the present application. Figure 2 The DC distribution network 200 provided in this embodiment includes: an energy storage system 201, a photovoltaic system 202, a DC transformer 203, and a load 204 powered by the DC transformer 203; wherein the energy storage system 201 and the photovoltaic system 202 are both connected to a DC bus 207; the DC distribution network 200 is interconnected with the AC distribution network through the DC bus through a converter ( Figure 2 ), the photovoltaic system 202 operates in Maximum Power Tracking (MPPT); the batteries in the energy storage system 201 operate according to preset upper and lower limits of the State of Charge (SOC).

[0042] The coordination control device is connected to the DC distribution network in communication, and a control program for the continuous power supply method of the DC distribution network is run on the coordination control device. Figure 1 As shown, the continuous power supply method of the DC distribution network includes steps S101 to S105, which are described in detail as follows:

[0043] S101: If a mains voltage loss is detected, the DC distribution network and the AC distribution network are controlled to be disconnected.

[0044] In one embodiment, the coordination control device detects that the mains voltage is lost, and controls the DC distribution network and the AC distribution network to be disconnected. Specifically, it includes: the coordination control device receives the AC side voltage, frequency and DC side voltage monitored in real time by the AC / DC converter, and when the AC side voltage is overvoltage or undervoltage, or the DC side voltage is overvoltage or undervoltage, or the AC side frequency is overfrequency or underfrequency, it is judged as an isolated network, and the converter is controlled to be turned off, and an instruction is issued to disconnect the AC side incoming line switch, so as to control the DC distribution network and the AC distribution network to be disconnected.

[0045] S102: monitor the voltage value of the DC bus in real time. If the voltage value of the DC bus is greater than a preset voltage threshold, control the photovoltaic system to exit MPPT and operate with limited power.

[0046] In one embodiment, if the voltage value of the DC bus is greater than a preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power, including: if the voltage value of the DC bus is monitored to be greater than the preset voltage threshold, the charge state of the energy storage system is monitored; if the charge state of the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power; if the charge state of the energy storage system is undercharged, the energy storage system is controlled to charge, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power.

[0047] Specifically, if the state of charge of the energy storage system is undercharged, the energy storage system is controlled to charge, including: if the state of charge of the energy storage system is undercharged, the energy storage system is controlled to operate according to preset SOC upper and lower limits; and the energy storage system is triggered to charge based on the positive voltage deviation of the DC bus.

[0048] In some optional implementations, the hardware topology of the energy storage system adopts a current reversible two-quadrant DC-DC converter, and adopts proportional differential dual-loop control and droop control of the power outer loop and the voltage inner loop of the current reversible two-quadrant DC-DC converter to achieve voltage deviation response and power demand response. The two response control methods do not require mode switching and automatically adapt to external responses.

[0049] In one embodiment, controlling the photovoltaic system to exit MPPT and operate with limited power includes: triggering the photovoltaic system to exit MPPT and enter a limited power operation mode based on a positive voltage deviation of a DC bus.

[0050] S103: If the voltage value of the DC bus is less than the preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system.

[0051] In one embodiment, if the voltage value of the DC bus is less than a preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system, including: triggering the energy storage system to discharge quickly based on the positive voltage deviation of the DC bus to maintain the MPPT operation of the photovoltaic system.

[0052] If the voltage value of the DC bus is monitored to be lower than the preset voltage value, the energy storage system is controlled to discharge quickly until it is fully discharged to maintain the MPPT operation of the photovoltaic system. At the same time, according to the power consumption of each load and the importance level of each load, the DC transformer of the load is controlled and adjusted to reduce the load, achieve source-load matching, and maintain DC voltage stability.

[0053] S104: After the energy storage system is discharged, the DC transformer is adjusted until the DC voltage reaches a preset stable range.

[0054] In one embodiment, after the energy storage system is discharged, the DC transformer is adjusted, including: after the energy storage system is discharged, according to the power consumption of each load and the importance level of each load, the DC transformer is adjusted until the DC voltage reaches a preset stable range.

[0055] Specifically, according to the power consumption of each load and the importance level of each load, the DC transformer is adjusted until the DC voltage reaches a preset stable range, including: real-time monitoring of the operating power of each load, when the operating power of a load is less than an adjustable upper limit, controlling the duty cycle of the DC transformer to quickly adjust the load to the upper limit according to a preset maximum load increase rate, and according to the preset load importance level, adjusting each load to the upper limit according to a preset maximum load increase rate, until the DC voltage of the DC transformer reaches a preset stable range.

[0056] Through the above analysis, it can be known that the continuous power supply method of the DC distribution network provided in the embodiment of the present application, if the mains voltage loss is detected, the DC distribution network and the AC distribution network are controlled to be disconnected; the voltage value of the DC bus is monitored in real time, and if the voltage value of the DC bus is greater than the preset voltage threshold, the charge state of the energy storage system is monitored; if the charge state of the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power; if the charge state of the energy storage system is undercharged, the energy storage system is controlled to charge, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power; if the voltage value of the DC bus is less than the preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system; after the discharge is completed, the DC transformer is adjusted until the DC voltage reaches the preset stable range. It aims to achieve source-load matching and maintain DC voltage stability.

[0057] See also Figure 3 As shown, Figure 3 A schematic diagram of a coordinated control device provided in one embodiment of the present application.

[0058] Depend on Figure 3 It can be known that the coordination control device 30 provided in the embodiment of the present application includes: a processor 301, a memory 302, and a computer program 303 stored in the memory 302 and executable on the processor 301, such as a continuous power supply program for a DC distribution network. When the processor 301 executes the computer program 303, the steps of the continuous power supply method for the DC distribution network are implemented. In a specific implementation, the process of implementing the steps of the continuous power supply method for the DC distribution network when the processor 301 executes the computer program 303 can be implemented by hardware or software modules with the same function. Exemplarily, the computer program 303 can be divided into one or more modules, one or more modules are stored in the memory 302, and executed by the processor 303 to complete the present application. One or more units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 303 in the coordination control device 30.

[0059] It should be understood that the coordination control device 30 includes but is not limited to a processor 301 and a memory 302. Those skilled in the art can understand that Figure 3 It is only an example of the coordination and control device 30 and does not constitute a limitation of the coordination and control device 30. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the coordination and control device 30 may also include input and output devices, network access devices, buses, etc.

[0060] The processor 301 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0061] The memory 302 may be an internal storage unit of the coordination control device 30, such as a hard disk or memory of the coordination control device 30. The memory 302 may also be an external storage device of the coordination control device 30, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the coordination control device 30. Furthermore, the memory 302 may also include both an internal storage unit and an external storage device of the coordination control device 30. The memory 302 is used to store computer programs and other programs and data required by the coordination control device 30. The memory 302 can also be used to temporarily store data that has been output or is to be output, etc. Specifically, the present application will not go into detail on the various components included in the coordination control device 30.

[0062] In addition, an embodiment of the present application further provides a computer-readable storage medium, which stores a computer program; when the computer program is executed by one or more processors, the one or more processors execute the following steps:

[0063] If the mains voltage is lost, the DC distribution network and the AC distribution network are disconnected;

[0064] Monitor the voltage value of the DC bus in real time. If the voltage value of the DC bus is greater than the preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power.

[0065] If the voltage value of the DC bus is less than the preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system;

[0066] After the energy storage system is discharged, the DC transformer is adjusted until the DC voltage reaches a preset stable range.

[0067] In one embodiment, if a mains voltage loss is detected, controlling the DC distribution network and the AC distribution network to be disconnected includes:

[0068] Real-time monitoring of the voltage, frequency and DC side voltage on the AC side. When the voltage on the AC side is overvoltage or undervoltage, or the voltage on the DC side is overvoltage or undervoltage, or the frequency on the AC side is overfrequency or underfrequency, it is judged as isolated grid operation, and the converter is controlled to close the switch tube. At the same time, a command is issued to disconnect the AC side incoming line switch to control the disconnection of the DC distribution network and the AC distribution network.

[0069] In one embodiment, if the voltage value of the DC bus is greater than a preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power, including:

[0070] If the voltage value of the DC bus is greater than a preset voltage threshold, the charge state of the energy storage system is monitored;

[0071] If the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate at limited power;

[0072] If the energy storage system is undercharged, the energy storage system is controlled to charge, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power.

[0073] In one embodiment, if the state of charge of the energy storage system is undercharged, controlling the energy storage system to charge includes:

[0074] If the state of charge of the energy storage system is undercharged, the energy storage system is controlled to operate according to the preset SOC upper and lower limits;

[0075] The positive voltage deviation of the DC bus triggers the charging of the energy storage system.

[0076] In one embodiment, controlling the photovoltaic system to exit MPPT and operate with limited power includes:

[0077] The positive voltage deviation of the DC bus triggers the photovoltaic system to exit the MPPT and enter the power-limited operation mode.

[0078] In one embodiment, after the energy storage system is discharged, adjusting the DC transformer includes:

[0079] After the energy storage system is discharged, the DC transformer is adjusted according to the power consumption of each load and the importance level of each load until the DC voltage reaches the preset stable range.

[0080] In one embodiment, according to the power consumption of each load and the importance level of each load, adjusting the DC transformer until the DC voltage reaches a preset stable range includes:

[0081] Monitor the operating power of each load in real time. When the operating power of a load is less than the adjustable upper limit, control the duty cycle of the DC transformer to quickly adjust the load to the upper limit according to the preset maximum load increase rate, and adjust each load to the upper limit according to the preset maximum load increase rate according to the preset load importance level, until the DC voltage of the DC transformer reaches the preset stable range.

[0082] In one embodiment, if the voltage value of the DC bus is less than a preset voltage threshold, the energy storage system is controlled to discharge rapidly to maintain the MPPT operation of the photovoltaic system, including:

[0083] The positive voltage deviation of the DC bus triggers the rapid discharge of the energy storage system to maintain the MPPT operation of the photovoltaic system.

[0084] It should be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0085] It should also be understood that the term "and / or" used in the specification of this application and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations. It should be noted that, in this article, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "including a..." does not exclude the presence of other identical elements in the process, method, article or system including the element.

[0086] The serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments. The above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A continuous power supply method for a DC distribution network, characterized in that: The DC distribution network includes: an energy storage system, a photovoltaic system, a DC transformer and a load; the energy storage system and the photovoltaic system are both connected to a DC bus; the DC distribution network is interconnected with an AC distribution network through a converter via the DC bus, and the photovoltaic system operates in maximum power tracking; the energy storage system operates according to preset SOC upper and lower limits; The method comprises: If a loss of mains voltage is detected, the DC distribution network and the AC distribution network are controlled to be disconnected; Real-time monitoring of the voltage value of the DC bus, if the voltage value of the DC bus is greater than a preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power; If the voltage value of the DC bus is less than a preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system; After the energy storage system is discharged, the DC transformer is adjusted until the DC voltage reaches a preset stable range.

2. The continuous power supply method of a DC distribution network according to claim 1, characterized in that: If the mains voltage loss is detected, controlling the DC distribution network and the AC distribution network to be disconnected includes: Monitor the voltage, frequency and DC side voltage on the AC side in real time. When the voltage on the AC side is overvoltage or undervoltage, or the voltage on the DC side is overvoltage or undervoltage, or the frequency on the AC side is overfrequency or underfrequency, it is judged as isolated grid operation, and the converter is controlled to close the switch tube. At the same time, an instruction is issued to disconnect the incoming line switch on the AC side, so as to control the disconnection of the DC distribution network and the AC distribution network.

3. The continuous power supply method of a DC distribution network according to claim 1, characterized in that: If the voltage value of the DC bus is greater than a preset voltage threshold, the photovoltaic system is controlled to exit MPPT and operate with limited power, including: If the voltage value of the DC bus is greater than a preset voltage threshold, monitoring the charge state of the energy storage system; If the state of charge of the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power; If the state of charge of the energy storage system is undercharged, the energy storage system is controlled to charge, and after the energy storage system is fully charged, the photovoltaic system is controlled to exit MPPT and operate with limited power.

4. The continuous power supply method of a DC distribution network according to claim 3, characterized in that: If the state of charge of the energy storage system is undercharged, controlling the energy storage system to charge includes: If the state of charge of the energy storage system is undercharged, controlling the energy storage system to operate according to preset SOC upper and lower limits; The charging of the energy storage system is triggered based on the positive voltage deviation of the DC bus.

5. The continuous power supply method of a DC distribution network according to claim 4, characterized in that: The controlling the photovoltaic system to exit MPPT and operate with limited power includes: The photovoltaic system is triggered to exit the MPPT and enter a power-limited operation mode based on the positive voltage deviation of the DC bus.

6. The continuous power supply method of a DC distribution network according to claim 1, characterized in that: After the energy storage system is discharged, the DC transformer is adjusted, including: After the energy storage system is discharged, the DC transformer is adjusted according to the power consumption of each load and the importance level of each load until the DC voltage reaches a preset stable range.

7. The continuous power supply method of a DC distribution network according to claim 6, characterized in that: According to the power consumption of each load and the importance level of each load, adjusting the DC transformer until the DC voltage reaches a preset stable range includes: Monitor the operating power of each load in real time. When the operating power of a load is less than the adjustable upper limit, control the duty cycle of the DC transformer to quickly adjust the load to the upper limit according to the preset maximum load increase rate, and adjust each load to the upper limit according to the preset maximum load increase rate according to the preset load importance level, until the DC voltage of the DC transformer reaches the preset stable range.

8. The continuous power supply method of a DC distribution network according to claim 3, characterized in that: If the voltage value of the DC bus is less than the preset voltage threshold, the energy storage system is controlled to discharge quickly to maintain the MPPT operation of the photovoltaic system, including: The positive voltage deviation of the DC bus triggers the rapid discharge of the energy storage system to maintain the MPPT operation of the photovoltaic system.

9. A continuous power supply system for a DC distribution network, comprising: DC distribution network and coordinated control equipment; The coordination control device includes: a memory and a processor; The memory is used to store computer programs; The processor is used to execute the computer program and implement the steps of the method for continuous power supply of a DC distribution network according to any one of claims 1 to 8 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer readable storage medium stores a computer program; When the computer program is executed by one or more processors, the one or more processors are caused to execute the steps of the method for continuous power supply of a DC distribution network as claimed in any one of claims 1 to 8.

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