Loss reduction method, system, medium and equipment for direct-current micro-grid system

Abstract

The invention discloses a loss reduction method and system of a direct current micro-grid system, a medium and equipment, and relates to the technical field of direct current micro-grid optimization control. According to the invention, a loss reduction target corresponding to line loss is converted into a loss reduction control target of the sum of the difference between the voltage of each distributed energy grid-connected point and the output voltage of each distributed energy and the difference between the voltage of each distributed energy grid-connected point by removing line resistance, and disturbance is injected into the output voltage of each distributed energy; the direct current bus can be equivalent to a large capacitor, so that the grid-connected point voltage change of the distributed energy sources can be ignored, and the self-identification of the line resistance from each distributed energy source to the grid-connected point can be realized through the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source; self-identification of the voltage of each distributed energy grid-connected point can be realized according to the output voltage and the output current of each distributed energy; and finally, rapid loss reduction can be realized through PI control based on a loss reduction control target.

Description

Technical Field

[0001] The present invention relates to the technical field of DC microgrid optimization control, and in particular to a loss reduction method, system, medium and equipment for a DC microgrid system. Background Art

[0002] Generally, network losses are a key indicator of the economic benefits of microgrid systems. Line losses, representing the energy loss during microgrid transmission, are a significant component of network losses. Excessive line losses can reduce voltage quality in the microgrid system, waste energy, and compromise the system's economic viability. More seriously, they can lead to line overheating and insulation damage. Therefore, reducing line losses to improve power quality in DC microgrids is essential for building economical, safe, and high-quality DC microgrids.

[0003] The control objectives of a DC microgrid system include precise regulation of busbar voltage and precise power distribution to each unit. Achieving the former helps maintain microgrid system stability, while achieving the latter is closely linked to the system's economic viability. Specifically, to achieve various economic objectives of a DC microgrid system, such as minimizing energy consumption, system costs, and line losses, it is necessary to control the power distribution of each distributed energy source within the DC microgrid.

[0004] In the existing technology, when minimizing the line loss of a DC microgrid system is the economic goal, the focus is often on solving a single optimization problem regarding the line loss of the microgrid system. The optimization problem of a microgrid system regarding line loss is usually a relatively complex non-convex optimization problem, so intelligent algorithms such as ant colonies and particle swarms are generally used to solve it.

[0005] However, the existing methods of solving microgrid system optimization problems through intelligent algorithms are complex and have a slow loss reduction response speed. Summary of the Invention

[0006] Based on this, it is necessary to provide a loss reduction method, system, medium and equipment for a DC microgrid system to address the above technical problems.

[0007] The present invention adopts the following technical solutions: The present invention provides a loss reduction method for a DC microgrid system, which includes a DC bus and multiple distributed energy sources connected to the DC bus. The present invention takes minimizing the difference between the grid connection point voltage of each distributed energy source and the output voltage of each distributed energy source and the sum of the differences between the grid connection point voltages of each distributed energy source as a loss reduction control target. Then, based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of a disturbance voltage, the line resistance from each distributed energy source to the grid connection point is determined. Thus, based on the output voltage of each distributed energy source, the output current of each distributed energy source and the line resistance from each distributed energy source to the grid connection point, the grid connection point voltage of each distributed energy source is determined. Finally, based on the loss reduction control target, the grid connection point voltage of each distributed energy source and the output voltage of each distributed energy source, the loss reduction correction amount corresponding to each distributed energy source is determined through PI control to control the output of each distributed energy source.

[0008] The present invention provides a loss reduction system for a DC microgrid system, wherein the DC microgrid system includes a DC bus and multiple distributed energy sources connected to the DC bus; the system includes: A target building module is used to minimize the sum of the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy source and the difference between the voltages at each distributed energy grid connection point as a loss reduction control target; a resistance identification module for determining the line resistance from each distributed energy source to the grid connection point based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage; A voltage identification module is used to determine the grid connection point voltage of each distributed energy source based on the output voltage and output current of each distributed energy source and the line resistance from each distributed energy source to the grid connection point; The control module is used to determine the control quantity corresponding to each distributed energy through PI control to control the output of each distributed energy according to the loss reduction control target, the grid connection point voltage of each distributed energy and the output voltage of each distributed energy.

[0009] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the loss reduction method of the DC microgrid system is implemented.

[0010] The present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the loss reduction method for the DC microgrid system is implemented.

[0011] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects: The loss reduction target corresponding to line loss of the application is converted into the loss reduction control target of the difference between the voltage of each distributed energy grid-connected point and the output voltage of each distributed energy and the sum of the difference between the voltage of each distributed energy grid-connected point, wherein only the voltage of each distributed energy grid-connected point is an unknown term, for this, the application injects disturbance to the output voltage of each distributed energy, since the DC bus of the DC micro-grid system can be equivalent to a large capacitor, the grid-connected point voltage change of the distributed energy can be ignored, so the self-identification of the line resistance from the grid-connected point of each distributed energy to the grid-connected point can be realized through the ratio of the output voltage change of each distributed energy to the output current change of each distributed energy, and then the self-identification of the grid-connected point voltage of each distributed energy can be realized according to the output voltage and output current of each distributed energy, and finally the loss reduction can be realized quickly through PI control based on the loss reduction control target, which reduces the loss reduction complexity and improves the loss reduction response speed. BRIEF DESCRIPTION OF DRAWINGS

[0012] The drawings described herein are used to provide further understanding of the application, and form a part of the application. The illustrative embodiments of the application and their descriptions serve to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0013] Figure 1 A loss reduction method flow chart of a DC micro-grid system provided by the application; Figure 2 A DC micro-grid system schematic diagram provided by the application; Figure 3 A DC micro-grid system collaborative loss reduction method control block diagram provided by the application; Figure 4 A loss reduction system schematic diagram of a DC micro-grid system provided by the application. DETAILED DESCRIPTION

[0014] To make the purpose, technical scheme and advantages of the application clearer, the technical scheme of the application will be described clearly and completely below in combination with specific embodiments of the application and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0015] At present, the existing DC micro-grid loss reduction technology mainly has the following two problems: (1) The existing loss reduction technology has slow response speed. The system optimization problem of line loss is usually a relatively complex non-convex optimization problem, which is generally solved by intelligent algorithms such as ant colony and particle swarm, which is complex and slow in loss reduction.

[0016] (2) Existing loss reduction technologies lack synergy. Most of them focus on solving a single optimization problem about system line loss, and it is difficult to take into account the precise regulation of bus voltage. Therefore, the control quality of existing methods is poor, and it is difficult to achieve system coordinated multi-objective optimization.

[0017] To solve the above problems, the present invention is based on a distributed collaborative control architecture for DC microgrids, which mainly includes a voltage PI controller (voltage controller) and a power PI controller (loss reduction controller). The former is used to adjust the bus voltage, and the latter is used to regulate the power to minimize the network loss (mainly line loss) of the DC microgrid system.

[0018] This invention proposes a method for reducing losses in a DC microgrid, which can simply and quickly reduce system line losses and improve the system's economic efficiency. Furthermore, the invention can coordinately regulate system voltage, power, and line losses based on a distributed collaborative control architecture. This synergy lies in the fact that the invention can simultaneously achieve loss reduction while precisely regulating bus voltage, maintaining system resilience and improving operational quality. In other words, the invention can quickly and effectively achieve coordinated microgrid loss reduction while also ensuring precise bus voltage regulation.

[0019] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] Figure 1 The present invention is a flow chart of a method for reducing losses in a DC microgrid system. The DC microgrid system includes a DC bus and multiple distributed energy sources connected to the DC bus. The method specifically includes the following steps: S101: The loss reduction control target is to minimize the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy and the sum of the differences between the voltages at each distributed energy grid connection point.

[0021] S102: determining line resistances from each distributed energy source to a grid connection point based on a ratio of a change in the output voltage of each distributed energy source to a change in the output current of each distributed energy source under the disturbance of the disturbance voltage.

[0022] S103: Determine the grid connection point voltage of each distributed energy source according to the output voltage of each distributed energy source, the output current of each distributed energy source, and the line resistance from each distributed energy source to the grid connection point.

[0023] S104: According to the loss reduction control target, the grid connection point voltage of each distributed energy source and the output voltage of each distributed energy source, the loss reduction correction amount corresponding to each distributed energy source is determined through PI control to control the output of each distributed energy source.

[0024] The present invention is mainly aimed at a DC microgrid system with a ring architecture. Figure 2 This is a schematic diagram of a DC microgrid system in the present invention. Figure 2 middle R i Distributed Energy i Line resistance to the grid connection point, R ii-1 Distributed Energy i- 1Grid connection points and distributed energy i Extensive research has demonstrated the widespread applicability of ring-architecture DC microgrids to real-world physical systems. In this structure, distributed energy resources are all controllable, with two-layer control directing their output to achieve economical operation. In summary, the control target in this invention is the grid-connected converter of the distributed energy resource.

[0025] The control objectives of the DC microgrid system first include loss reduction control, and in one or more embodiments of the present invention, may also include bus voltage control, which correspond to a loss reduction controller and a bus voltage controller respectively.

[0026] First, for loss reduction control, such as Figure 2 As shown, Indicates the The busbar access point voltage (or grid connection point voltage) of each distributed energy source can be determined by the following formula based on the energy transmission in the DC microgrid system: .

[0027] in, is the line loss in the DC microgrid system, is the number of distributed energy resources, Distributed Energy i The grid connection point voltage, Distributed Energy i The output voltage, Distributed Energy i Line resistance to the grid connection point, Distributed Energy j The grid connection point voltage, Distributed Energy i Grid connection points and distributed energy j Line resistance between grid connection points.

[0028] Based on this line loss expression, the loss reduction target of minimizing line loss can be determined: .

[0029] In order to minimize the line loss of the DC microgrid system, the line loss expression can be observed: and are all constants. Therefore, in one or more embodiments of the present invention, the line resistance constant in the line loss expression in the loss reduction target can be discarded, and the loss reduction control target can be converted into minimizing the sum of the difference between the grid connection point voltage of each distributed energy resource and the output voltage of each distributed energy resource and the difference between the grid connection point voltages of each distributed energy resource through the following formula: .

[0030] Ideally, for any distributed energy i , the loss reduction control target can be expressed as: .

[0031] However, in fact, the energy transmission in the DC microgrid system depends on the voltage difference. The current flowing through the cable will inevitably cause a certain degree of voltage difference, which means that , It is physically impossible to achieve this. There is no absolute steady state for the loss reduction controller, but the loss reduction component of its output can help reduce network losses.

[0032] For distributed energy resources, the grid connection point voltage is difficult to obtain, especially for microgrid systems with multiple distributed energy resources. If each distributed energy resource has its grid connection point voltage measured, the system construction cost will increase. To address this issue, the present invention adopts a grid connection point voltage self-identification method, which is as follows:

[0033] based on Figure 2 The DC microgrid system structure shown in the figure is for distributed energy exist The moments have the following relationship: .

[0034] in, Distributed Energy exist The output current at the moment, Distributed Energy i The line resistance to the grid connection point is only is an unknown quantity.

[0035] Distributed Energy The output voltage of the injection disturbance is , the disturbance duration is ,go through After that, the disturbance size returns to zero. The moments have the following relationship:

[0036] .

[0037] Combining the above two equations, we have the following relationship: .

[0038] According to research, the DC bus of the DC microgrid system can be equivalent to a large capacitor. disturbance can be ignored, so distributed energy The voltage change at the grid connection point can be ignored. Therefore, the line resistance from each distributed energy source to the grid connection point can be determined by the following formula based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance voltage:

[0039] ; in, Distributed Energy i exist t The output voltage at the moment, Distributed Energy i exist The output voltage at the moment, Distributed Energy i exist Output current at any moment.

[0040] The above formula only contains local voltage and current information, so it is relatively simple to identify the line resistance of each distributed energy source to the grid connection point. It can realize self-identification of the grid connection point voltage of each distributed energy source.

[0041] Therefore, the loss reduction correction amount corresponding to each distributed energy can be determined based on PI control using the following formula according to the loss reduction control target, the grid connection point voltage of each distributed energy, and the output voltage of each distributed energy: .

[0042] in, Distributed Energy i The corresponding loss reduction correction amount is used to achieve line loss reduction. is the proportional coefficient in the loss reduction controller, is the integral coefficient in the loss reduction controller.

[0043] Based on this, the control law corresponding to each distributed energy source can be determined according to the loss reduction correction amount to correct the control instructions of each distributed energy source, control the output of each distributed energy source, and reduce line losses.

[0044] Furthermore, in one or more embodiments of the present invention, while reducing losses, bus voltage control can also be considered. For each distributed energy resource in a DC microgrid, the bus voltage at its grid connection point cannot be completely regulated to be consistent. If the voltage at each distributed energy resource's grid connection point were identical, energy flow would be impossible between distributed energy resources in the microgrid. To address this issue, analogous to the concept of a voltage central point in traditional power systems, the concept of a bus voltage observer has been proposed in DC microgrids.

[0045] Specifically, for each distributed energy resource, the bus voltage observation value of the neighboring distributed energy resources of the distributed energy resource can be obtained first, and the output voltage of the distributed energy resource is used as the initial bus voltage observation value of the distributed energy resource. The error between the bus voltage observation value of the distributed energy resource and the bus voltage observation value of the neighboring distributed energy resource is determined, and then the compensation for the output voltage of the distributed energy resource is determined by integration based on the error to determine the bus voltage observation value of the distributed energy resource. The formula is as follows:

[0046] .

[0047] Where, Indicates Moment The bus voltage observation value of distributed energy, Indicates Moment The bus voltage observation value of distributed energy, distributed energy Representation and Distributed Energy Neighboring distributed energy resources (i.e., neighboring nodes) for communication, Indicates Distributed Energy at All Times The output voltage, Distributed Energy Distributed Energy The communication coefficient between .

[0048] When Distributed Energy and When the observed values ​​of the bus voltages of the distributed energy resources are consistent, the above formula converges and it can be considered that the observation of the bus voltage is achieved. The meaning is: in The bus voltage observation value observed by the distributed energy, It can be considered as the central point voltage.

[0049] Therefore, the goal of bus voltage control is to keep the voltage at each hub point, i.e., the observed bus voltage of each distributed energy source, close to the rated value, as shown in the following formula: .

[0050] Where, Indicates the rated value of the bus voltage.

[0051] Based on this, the difference between the observed value and the rated value of the bus voltage of the distributed energy can be minimized as the bus voltage control target. The voltage correction amount corresponding to each distributed energy is determined by PI control according to the bus voltage control target using the following formula: .

[0052] Where, It is the voltage correction value output by the voltage controller, used to realize bus voltage control. is the proportional coefficient in the voltage controller, is the integral coefficient in the voltage controller.

[0053] Therefore, in one or more embodiments of the present invention, when controlling the output of each distributed energy source, a PI controller may be used to achieve coordinated loss reduction control through the following formula: .

[0054] Where, Distributed Energy i The amount of control. It will eventually be superimposed on the distributed energy voltage control instructions to guide the distributed energy output. Figure 3 The figure shows a control block diagram of a collaborative loss reduction method for a DC microgrid system in the present invention.

[0055] At this point, the coordinated loss reduction control of the DC microgrid, namely bus voltage control and loss reduction control, has been completed. It should be noted that the coordinated loss reduction control of the DC microgrid proposed in the present invention is distributed control. For bus voltage control, only the bus voltage observation value information of the neighboring nodes is required; for loss reduction control, only the grid connection point voltage information of the neighboring nodes is required. There is no need to obtain the global information of the DC microgrid system, and the system construction cost is relatively low.

[0056] based on Figure 1The loss reduction method of the DC microgrid system shown in the figure converts the loss reduction target corresponding to the line loss into a loss reduction control target of the sum of the difference between the voltage of each distributed energy grid connection point and the output voltage of each distributed energy, and the difference between the voltages of each distributed energy grid connection point, where only the voltage of each distributed energy grid connection point is an unknown term. To address this, the present invention injects disturbances into the output voltage of each distributed energy. Since the DC bus of the DC microgrid system can be equivalent to a large capacitor, the voltage change of the distributed energy grid connection point can be ignored. Therefore, the line resistance from each distributed energy to the grid connection point can be self-identified by the ratio of the output voltage change of each distributed energy to the output current change of each distributed energy. Furthermore, the voltage of each distributed energy grid connection point can be self-identified based on the output voltage and output current of each distributed energy. Finally, based on the loss reduction control target, rapid loss reduction can be achieved through PI control, thereby reducing the complexity of loss reduction and improving the loss reduction response speed.

[0057] This invention uses a PI control method, eliminating the need to solve any complex non-convex optimization problems and enabling rapid loss reduction. It can improve the coordination of DC microgrid loss reduction, adopt a low-cost distributed collaborative control strategy, and simultaneously manage system bus voltage regulation, ensuring system control quality.

[0058] When applying the loss reduction method of the DC microgrid system provided by the present invention, it is not necessary to Figure 1 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0059] The above is a loss reduction method for a DC microgrid system provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding loss reduction system for a DC microgrid system, such as Figure 4 shown.

[0060] Figure 4 This is a schematic diagram of a loss reduction system for a DC microgrid system provided by the present invention. The DC microgrid system includes a DC bus and multiple distributed energy sources connected to the DC bus; the system includes: A target construction module 201 is configured to minimize the sum of the difference between the grid connection point voltage of each distributed energy resource and the output voltage of each distributed energy resource and the difference between the grid connection point voltages of each distributed energy resource as a loss reduction control target; The resistance identification module 202 is used to determine the line resistance from each distributed energy source to the grid connection point based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage; The voltage identification module 203 is used to determine the grid connection point voltage of each distributed energy source based on the output voltage and output current of each distributed energy source and the line resistance from each distributed energy source to the grid connection point; The control module 204 is used to determine the control quantity corresponding to each distributed energy through PI control to control the output of each distributed energy according to the loss reduction control target, the grid connection point voltage of each distributed energy and the output voltage of each distributed energy.

[0061] The specific definition of the loss reduction system for a DC microgrid system can be found in the definition of the loss reduction method for a DC microgrid system described above and will not be repeated here. Each module in the aforementioned loss reduction system for a DC microgrid system can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the aforementioned modules can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in a computer device in software form, so that the processor can call and execute the corresponding operations of each of the aforementioned modules.

[0062] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A loss reduction method for a DC microgrid system is provided.

[0063] The present invention also provides a structural diagram. At the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 A loss reduction method for a DC microgrid system is provided.

[0064] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware using a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes in the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0065] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A method for reducing losses in a DC microgrid system, characterized in that: The DC microgrid system includes a DC bus and multiple distributed energy sources connected to the DC bus; the method includes: The loss reduction control goal is to minimize the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy source, and the sum of the differences between the voltages at each distributed energy grid connection point. Determine the line resistance from each distributed energy source to the grid connection point based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage; Determine the grid connection point voltage of each distributed energy source based on the output voltage and current of each distributed energy source and the line resistance from each distributed energy source to the grid connection point; According to the loss reduction control target, the grid connection point voltage of each distributed energy source and the output voltage of each distributed energy source, the loss reduction correction amount corresponding to each distributed energy source is determined through PI control to control the output of each distributed energy source.

2. The loss reduction method of a DC microgrid system according to claim 1, wherein: The loss reduction control objective is to minimize the sum of the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy source, and the difference between the voltages at each distributed energy grid connection point. Specifically, the objective includes: The loss reduction control target is to minimize the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy source, and the sum of the differences between the voltages at each distributed energy grid connection point, using the following formula: ； in, is the number of distributed energy resources, Distributed Energy i The grid connection point voltage, Distributed Energy i The output voltage, Distributed Energy j The grid connection point voltage.

3. The loss reduction method of a DC microgrid system according to claim 1, wherein: The determining of the line resistance from each distributed energy source to the grid connection point based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage specifically includes: A disturbance is injected into the output voltage of each distributed energy source. The line resistance from each distributed energy source to the grid connection point is determined by the following formula based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage: ； in, Distributed Energy i Line resistance to the grid connection point, Distributed Energy i exist t The output voltage at the moment, Distributed Energy i exist The output voltage at the moment, Distributed Energy i exist t The output current at the moment, Distributed Energy i exist The output current at the moment, is the disturbance duration.

4. The loss reduction method of a DC microgrid system according to claim 1, wherein: The method of determining the loss reduction correction amount corresponding to each distributed energy source through PI control specifically includes: The loss reduction correction amount corresponding to each distributed energy source is determined based on PI control using the following formula: ； in, Distributed Energy i The corresponding damage reduction correction amount, is the number of distributed energy resources, is the proportional coefficient in the loss reduction controller, is the integral coefficient in the loss reduction controller, Distributed Energy i The grid connection point voltage, Distributed Energy j The grid connection point voltage, Distributed Energy i output voltage.

5. The loss reduction method of a DC microgrid system according to claim 1, wherein: The method further comprises: For each distributed energy resource, obtain the bus voltage observation value of the neighboring distributed energy resources of the distributed energy resource; Using the output voltage of the distributed energy as the initial bus voltage observation value of the distributed energy, and determining the error between the bus voltage observation value of the distributed energy and the bus voltage observation value of the neighboring distributed energy; Determining compensation for the output voltage of the distributed energy by integration according to the error to determine an observed value of the bus voltage of the distributed energy; The bus voltage control target is to minimize the difference between the observed value and the rated value of the bus voltage of the distributed energy. The voltage correction amount corresponding to each distributed energy is determined through PI control according to the bus voltage control target. The controlling of the output of each distributed energy source specifically includes: According to the sum of the voltage correction amount and the loss reduction correction amount, the control amount corresponding to each distributed energy is determined, and the control amount of each distributed energy is superimposed on the voltage control instruction of each distributed energy to control the output of each distributed energy.

6. A loss reduction system for a DC microgrid system, characterized in that: The DC microgrid system includes a DC bus and multiple distributed energy sources connected to the DC bus; the system includes: A target building module is used to minimize the sum of the difference between the voltage at each distributed energy grid connection point and the output voltage of each distributed energy source and the difference between the voltages at each distributed energy grid connection point as a loss reduction control target; a resistance identification module for determining the line resistance from each distributed energy source to the grid connection point based on the ratio of the output voltage change of each distributed energy source to the output current change of each distributed energy source under the disturbance of the disturbance voltage; A voltage identification module is used to determine the grid connection point voltage of each distributed energy source based on the output voltage and output current of each distributed energy source and the line resistance from each distributed energy source to the grid connection point; The control module is used to determine the control quantity corresponding to each distributed energy through PI control to control the output of each distributed energy according to the loss reduction control target, the grid connection point voltage of each distributed energy and the output voltage of each distributed energy.

7. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

8. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 5 when executing the program.

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