Distributed coordination control method for voltage deviation of island-type direct-current micro-grid

Abstract

The invention relates to the technical field of direct-current micro-grids, and provides an island type direct-current micro-grid voltage deviation distributed coordination control method, which comprises the following steps of: accessing each distributed power supply of a plurality of distributed power supplies in an island type direct-current micro-grid to the direct-current micro-grid through a current converter, each distributed power supply is provided with a distributed coordination controller; establishing a full duplex communication network among the distributed coordination controllers of the plurality of distributed power supplies; real-time state information of adjacent distributed coordination controller nodes is interacted through a full duplex communication network, and each distributed coordination controller realizes average voltage regulation and distributed voltage deviation regulation of the DC micro-grid by using a distributed coordination control algorithm according to the state information of neighbor nodes and the state of local distributed power supply nodes. According to the technical scheme of the invention, stable average voltage regulation of the island-type DC micro-grid is realized.

Description

Technical Field

[0001] The present application relates to the technical field of direct current microgrids, and in particular to a voltage deviation distributed coordinated control method for an island-type direct current microgrid. Background Art

[0002] As distributed power sources, new energy power generation devices and energy storage equipment have obvious DC characteristics. The island-type DC microgrid can not only realize the effective integration of new energy power generation devices, energy storage and loads, but also operate independently without relying on the external power grid, realizing efficient and flexible local consumption of green energy. Its related technologies are an important guarantee for building a new power system.

[0003] Voltage deviation is a key power quality indicator for measuring the safe and stable operation of DC microgrids. Distributed power sources in islanded DC microgrids have the characteristics of small capacity and instability. It is impossible to control the voltage deviation of each busbar of the microgrid within a reasonable range by controlling a single power source. Coordinated control must be used to encourage multiple distributed power sources in the microgrid to cooperate and work together to achieve safe and stable operation of the microgrid.

[0004] The voltage deviation distributed coordinated control method controls the coordinated output of distributed power sources in a distributed manner, controls the voltage deviation within a reasonable range, realizes the safe and stable operation of the microgrid, and ensures the flexible expansion capability of the system. Although some of the currently adopted distributed coordinated control methods have certain voltage deviation adjustment capabilities, they cannot achieve refined and high-quality adjustment of voltage deviations, and are difficult to meet occasions with high requirements for power quality, such as data centers, causing safety hazards in system operation. Summary of the invention

[0005] The present application provides a voltage deviation distributed coordinated control method for an island type DC microgrid, which can achieve stable average voltage regulation of the island type DC microgrid.

[0006] The voltage deviation distributed coordinated control method of the island type DC microgrid of the present application includes:

[0007] Connecting each of the multiple distributed power sources in the island type DC microgrid to the DC microgrid through a converter, wherein each distributed power source is configured with a distributed coordination controller;

[0008] Establishing a full-duplex communication network among the plurality of distributed power sources;

[0009] The real-time status information of adjacent distributed coordination controller nodes is exchanged through the full-duplex communication network. Each distributed coordination controller uses a distributed coordination control algorithm to achieve average voltage regulation and distributed voltage deviation regulation of the DC microgrid based on the status information of its neighbor nodes and the status of the local distributed power supply nodes.

[0010] Optionally, the distributed coordinated controller includes an average voltage regulator, a voltage deviation regulator and a reference voltage generator; the average voltage regulator is used to adjust the average voltage of each node in the DC microgrid to the rated voltage of the DC microgrid; the voltage deviation regulator is used to adjust the relative deviation of the bus voltage of each node in the DC microgrid; the reference voltage generator is used to generate a reference voltage of the distributed power supply node to which the reference voltage generator belongs based on the reference voltage correction amount output by the average voltage regulator and the reference current correction amount output by the voltage deviation regulator.

[0011] Optionally, each distributed coordination controller uses a distributed coordination control algorithm to implement average voltage regulation of the DC microgrid according to the state information of neighboring nodes and the state of the local power supply node. Specifically, the average voltage regulation of the DC microgrid is implemented by the following distributed average value tracking algorithm based on initial value robustness:

[0012]

[0013] Among them, the is the reference voltage correction value output by the average voltage regulator of distributed power node i, V rat is the rated voltage of the DC microgrid, are respectively the estimated values ​​of the average voltage of all distributed power supply nodes in the DC microgrid by the distributed power supply nodes i and j, Vi(t) is the measured bus voltage of the distributed power supply node i, and Respectively V i (t) and Differentiation operation, α is a positive real number, a ij represents the communication link weight between node i and node j. When there is data interaction between nodes i and j, a ij > 0, otherwise a ij =0.

[0014] Optionally, the algorithm used to generate the reference voltage of the distributed power supply node to which the reference voltage generator belongs according to the reference voltage correction amount output by the average voltage regulator and the reference current correction amount output by the voltage deviation regulator is as follows:

[0015]

[0016] Among them, the The reference voltage generator is a reference voltage of a distributed power source node i, V rat is the rated voltage of the DC microgrid, is the reference voltage correction value output by the average voltage regulator of distributed power generation node i, It is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i.

[0017] Optionally, each distributed coordination controller uses a distributed coordination control algorithm to implement distributed voltage deviation regulation of the DC microgrid according to the state information of neighboring nodes and the state of the local power supply node, specifically to achieve coordination and consistency of the distributed power sources in the DC microgrid through the following distributed consistency algorithm:

[0018]

[0019] Among them, the is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i, are the per-unit values ​​of the current output by the converter at nodes i and j, I i (t) is the actual output current of the converter at node i obtained by measurement, are the rated load current and the rated capacity of the power supply directly provided by the bus of node i, and θ∈[0,1] is the voltage deviation coefficient.

[0020] Optionally, the method further includes: adjusting a voltage deviation coefficient in the distributed coordinated controller according to a maximum voltage deviation of a bus voltage allowed by the DC microgrid.

[0021] Optionally, the voltage deviation coefficient θ has a value range of θ∈[0, θ d ], the θ d Solve according to the following formula

[0022]

[0023] Among them, the is the maximum bus voltage deviation allowed by the DC microgrid, Ψ = [ψ1, ψ2, ..., ψ N ]T, Y is the admittance matrix corresponding to the DC microgrid main circuit, V rat is the rated voltage of the DC microgrid, Y L is a diagonal matrix, 1 N Represents a unit vector of dimension N.

[0024] Optionally, establishing a full-duplex communication network among the multiple distributed power sources includes: establishing a sparse full-duplex communication network among the multiple distributed power sources based on a proximity principle.

[0025] Optionally, the establishing a sparse full-duplex communication network among the multiple distributed power sources based on the proximity principle includes: establishing a sparse self-organizing full-duplex communication network among the multiple distributed power sources based on the proximity principle.

[0026] Optionally, the full-duplex communication network supports dynamic joining and exiting of nodes, and automatically updates the communication path when the nodes change.

[0027] It can be seen from the above technical scheme that compared with the prior art, the distributed average voltage regulation scheme adopted in the present application has initial value robustness, and can accurately realize average voltage estimation when facing the access or exit of certain distributed power sources during the operation of the microgrid. According to the volatility and intermittency of new energy power sources such as wind power and photovoltaics, the technical scheme of the present application can achieve stable average voltage regulation and high-precision regulation of DC voltage deviation, and even adjust the voltage deviation to 0; on the other hand, the voltage deviation regulation algorithm adopted in the present application can adjust the voltage deviation coefficient according to the actual voltage deviation control requirements, so as to meet the strict voltage deviation regulation requirements in actual occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a flow chart of the implementation of the voltage deviation distributed coordinated control method of the island type DC microgrid of the present application.

[0030] Figure 2 This is a schematic diagram of an electrical network according to an embodiment of the present application.

[0031] Figure 3 A schematic diagram of a communication network between coordination controllers according to an embodiment of the present application.

[0032] Figure 4 This is a schematic diagram of a voltage deviation coordinated control system in one embodiment of the present application.

[0033] Figure 5 A DC microgrid of one embodiment of the present application includes a block diagram of a voltage deviation distributed coordination controller involved in the present application and a schematic diagram of its connection method.

[0034] Figure 6 This is a schematic diagram of the principle of implementing voltage deviation coefficient adjustment in a DC microgrid according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] 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 only 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.

[0036] In this specification, adjectives such as first and second may be used only to distinguish one element or action from another element or action, without necessarily requiring or implying any actual such relationship or order. Where circumstances permit, reference to an element or component or step (etc.) should not be interpreted as being limited to only one of the elements, components, or steps, but may be one or more of the elements, components, or steps, etc.

[0037] In this specification, for the convenience of description, the sizes of various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0038] Voltage deviation is a key power quality indicator for measuring the safe and stable operation of DC microgrids. Distributed power sources in island-type DC microgrids have the characteristics of small capacity and instability. It is impossible to control the voltage deviation of each busbar of the microgrid within a reasonable range by controlling a single power source. It is necessary to use coordinated control methods to promote the cooperation and collaboration of multiple distributed power sources in the microgrid to achieve safe and stable operation of the microgrid. The voltage deviation distributed coordinated control method controls the coordinated output of distributed power sources in a distributed manner, controls the voltage deviation within a reasonable range, achieves safe and stable operation of the microgrid, and ensures the flexible expansion capability of the system. Although some of the currently adopted distributed coordinated control methods have certain voltage deviation regulation capabilities, they cannot achieve the refined and high-quality regulation requirements of voltage deviation, and are difficult to meet occasions with high requirements for power quality, such as data centers, etc., causing safety hazards in system operation.

[0039] The following is a further and clearer description of the embodiments of the present application in conjunction with the accompanying drawings. It should be noted that the control method involved in the present application is not limited to the present embodiment, and the control method involved in the present application is applicable to different island microgrid structures, and the corresponding ones should also be included in the protection scope of the present application.

[0040] like Figure 1As shown, it is a flowchart of the implementation method of the distributed coordinated control of voltage deviation of the island type DC microgrid involved in this application, including steps S101 to S103, which are described in detail as follows:

[0041] Step S101: each of the multiple distributed power sources in the island type DC microgrid is connected to the DC microgrid through a converter, wherein each distributed power source is configured with a distributed coordination controller.

[0042] like Figure 2 As shown, it is an embodiment of an island type DC microgrid applicable to the present application. The microgrid may include multiple DC buses and multiple distributed power sources. There are no special requirements for the network topology, the type of distributed power sources and the type of load. All are applicable to the distributed coordinated control method described in the present application. Figure 2 In the example of an island-type DC microgrid, each distributed power source such as photovoltaic, energy storage, and wind power is equipped with a distributed coordination controller, such as Figure 3 shown. Figure 3 Each photovoltaic unit, wind power unit or energy storage unit and its configured coordinated controller constitute the main unit of each distributed power source. Of course, each distributed power source may also include Figure 3 Other units not shown. As mentioned above, each distributed power source is connected to the DC microgrid through a converter (e.g., AC / DC or DC / DC converter). Each distributed coordination controller can generate coordination control instructions to the converter (including the controller) configured for the distributed power source to which the distributed coordination controller belongs, so that each distributed power source can work together to control the voltage deviation of each node in the microgrid. Each distributed coordination controller includes an average voltage regulator, a voltage deviation regulator and a reference voltage generator, such as Figure 4 As shown, the average voltage regulator is mainly used to adjust the average voltage of each distributed power supply node in the DC microgrid to the rated voltage of the DC microgrid. Specifically, a reference voltage correction is calculated by using the collected local voltage signal (i.e., the voltage of the distributed power supply to which the average voltage regulator belongs) and the average voltage estimate obtained by the neighboring nodes in the full-duplex communication network composed of multiple distributed power supplies. The reference voltage correction will be used to adjust the average voltage of each node in the DC microgrid to the rated voltage of the DC microgrid and can adapt to the hot plug requirements of each node; the voltage deviation regulator is used to adjust the relative deviation of the bus voltage of each node in the DC microgrid; the reference voltage generator is used to generate a reference voltage of the distributed power supply node to which the reference voltage generator belongs according to the reference voltage correction output by the average voltage regulator and the reference current correction output by the voltage deviation regulator.

[0043] Specifically, the reference voltage generator is used to generate the reference voltage of the distributed power supply node to which the reference voltage generator belongs according to the reference voltage correction amount output by the average voltage regulator and the reference current correction amount output by the voltage deviation regulator. The algorithm used is as follows:

[0044]

[0045] in, is the reference voltage of the distributed power source node i to which the reference voltage generator belongs, V rat is the rated voltage of the DC microgrid, is the reference voltage correction value output by the average voltage regulator of distributed power generation node i, It is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i. The reference signal will be sent to the controller of the converter corresponding to the i-th distributed power node, and finally the bus voltage of the i-th distributed power node will be equal to the reference voltage, that is,

[0046] Step S102: Establishing a full-duplex communication network between the distributed coordination controllers of the plurality of distributed power sources.

[0047] As an embodiment of the present application, a full-duplex communication network can be established between the distributed coordination controllers of multiple distributed power sources based on the principle of proximity, and a sparse full-duplex communication network can be established between the distributed coordination controllers of multiple distributed power sources. Figure 3 FIG. 1 is a schematic diagram of a full-duplex communication network between distributed coordination controllers established in accordance with an embodiment of the present application. Figure 3 In the example full-duplex communication network, communication between any two nodes can be done by wired or wireless communication. The entire communication network can be sparse, but it is required to have connectivity, that is, there is a communication path from any node to any other node.

[0048] The so-called proximity principle refers to giving priority to establishing communication connections between distributed power sources and their coordination controllers that are relatively close geographically, so as to reduce communication delays, reduce data transmission load, and improve the overall response speed of the system. The "sparseness" of the full-duplex communication network means that a fully connected network is not established between the distributed coordination controllers of the entire microgrid, but direct communication connections are only established between some adjacent nodes. The sparse communication network can effectively reduce the complexity and communication load of the network while ensuring basic network connectivity. Specifically, based on the proximity principle, a sparse full-duplex communication network can be established between distributed coordination controllers of multiple distributed power sources by: preliminarily calculating or measuring the physical distance or electrical topological distance between distributed power source nodes, and selecting some of the closest nodes to establish communication connections; among all possible node pairs, only some of the nodes are selected to establish communication connections; in the above scheme, the selection of node connections follows the following conditions, namely: 1) node pairs that meet the proximity principle; 2) being able to ensure the connectivity of the network throughout the entire network, that is, each node can communicate with any other node through several hops (through forwarding by other nodes), and the distance assessment can be based on actual geographic coordinates, network topology or electrical distance (such as resistance, induction, etc.).

[0049] In one embodiment of the present application, based on the principle of proximity, a sparse full-duplex communication network is established between the distributed coordination controllers of multiple distributed power sources. Based on the principle of proximity, a sparse self-organizing full-duplex communication network is established between the distributed coordination controllers of multiple distributed power sources. Compared with an ordinary full-duplex communication network, a self-organizing full-duplex communication network has stronger robustness and fault recovery capability, and the establishment of a sparse self-organizing full-duplex communication network can be achieved through the following steps S1021 to S1024:

[0050] Step S1021: Based on the initial detection result, select several nodes that are closest to each other for initial connection.

[0051] Each distributed coordination controller enters the initial state at startup, scans the surrounding environment, detects other nearby distributed coordination controllers, and based on the initial detection results, selects several nearest nodes for initial connection to form a basic self-organizing network structure.

[0052] Step S1022: Dynamically adjust the network topology of the formed full-duplex communication network.

[0053] As the full-duplex communication network operates, each distributed coordination controller continuously measures and evaluates the quality of the connection with the neighboring nodes, including parameters such as signal strength, delay, and bandwidth. If it detects that the quality of a connection has dropped below a threshold, the controller will automatically search for a new alternative connection and readjust its communication path to maintain the robustness of the network. The topology of the full-duplex communication network can be adjusted automatically through a self-organizing protocol without manual intervention.

[0054] Step S1023: Maintain redundant paths for the full-duplex communication network.

[0055] In an embodiment of the present application, a distributed coordination controller in the self-organizing network maintains a set of redundant communication paths based on the path discovery mechanism in the self-organizing protocol. During normal operation, the main path and the backup path are monitored simultaneously. Once the main path fails, it automatically switches to the backup path to ensure the continuity of communication. It should be noted that during the operation of the network, the path discovery mechanism in the self-organizing protocol can be regularly updated.

[0056] Step S1024: When a network failure occurs, the redundant path maintained by the full-duplex communication network is enabled to recover from the failure.

[0057] On the one hand, when a node fails or loses connection, the surrounding distributed coordination controllers will detect the disappearance of the node and enable the path discovery mechanism to automatically start the path reorganization process; on the other hand, it can notify other nodes of the failure event through broadcast or multicast, and quickly adjust its own connection strategy to re-establish connection with the remaining nodes to restore the connectivity of the overall network.

[0058] In another embodiment of the present application, the sparse full-duplex communication network supports dynamic joining and exiting of nodes, and automatically updates the communication path when the node changes.

[0059] Step S103: The real-time status information of adjacent distributed coordination controller nodes is exchanged through the full-duplex communication network. Each distributed coordination controller uses a distributed coordination control algorithm to implement average voltage regulation and distributed voltage deviation regulation of the DC microgrid based on the status information of its neighbor nodes and the status of the local distributed power supply nodes.

[0060] In one embodiment of the present application, each distributed coordination controller uses a distributed coordination control algorithm to implement average voltage regulation of a DC microgrid based on the state information of neighboring nodes and the state of a local power supply node. Specifically, the average voltage regulation of a DC microgrid is implemented by the following distributed average value tracking algorithm based on initial value robustness. The corresponding block diagram of the distributed average value tracking algorithm based on initial value robustness is as follows: Figure 5 As shown:

[0061]

[0062] In the above expression, is the reference voltage correction value output by the average voltage regulator of distributed power node i, V rat is the rated voltage of the DC microgrid, are the estimated values ​​of the average voltage of all distributed power nodes in the DC microgrid by distributed power node i and j, V i (t) is the measured bus voltage of distributed generation node i, and Respectively V i (t) and Differentiation operation, α is a positive real number, a ij represents the communication link weight between node i and node j. When there is data interaction between nodes i and j, a ij >0, otherwise a ij =0. From the above expression, we can see that when means being Adjust to the rated voltage of the DC microgrid, so, The regulation process of the average voltage of the DC microgrid is expressed.

[0063] In one embodiment of the present application, each distributed coordination controller uses a distributed coordination control algorithm to implement distributed voltage deviation regulation of a DC microgrid based on the status information of neighboring nodes and the status of local power supply nodes. Specifically, the following distributed consistency algorithm is used to achieve the coordination and consistency of distributed power sources in the DC microgrid. Specifically, the voltage deviation regulator receives the output current per unit value transmitted by the neighboring node in the full-duplex communication network, combines the output current per unit value of the converter corresponding to the local distributed power supply node, and uses a distributed consistency algorithm to achieve the coordination and consistency of distributed power sources in the microgrid. During this process, a voltage deviation coefficient is designed, and the voltage deviation coefficient is adjusted to achieve effective regulation of the bus voltage deviation. The block diagram of the control algorithm used is as follows: Figure 5 As shown;

[0064]

[0065] In the above expression, is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i, are the per-unit values ​​of the current output by the converter at nodes i and j, I i (t) is the actual output current of the converter at the distributed generation node i obtained by measurement, are the rated load current and rated capacity of the power supply directly provided by the bus of the distributed power node i, respectively, and θ∈[0,1] is the voltage deviation coefficient. When θ=0, the bus voltage deviation of all distributed power nodes is 0, reaching the minimum value. When θ increases from 0, the bus voltage deviation of all distributed power nodes increases accordingly. When θ=1, the bus voltage deviation of all distributed power nodes reaches their respective maximum values. Therefore, the bus voltage deviation of the distributed power node in the DC microgrid can be accurately adjusted through the voltage deviation coefficient.

[0066] In one embodiment of the present application, the voltage deviation coefficient in the distributed coordination controller can also be adjusted according to the maximum voltage deviation of the bus voltage allowed by the DC microgrid. Figure 6 As shown in FIG. 1 , it is a schematic diagram of the principle of realizing voltage deviation coefficient adjustment of a DC microgrid according to an embodiment of the present application. The voltage deviation control algorithm can adjust the voltage deviation coefficient θ in the distributed coordination controller according to the maximum voltage deviation of the bus voltage allowed by the DC microgrid, that is, the maximum allowable value of the bus voltage deviation given by the DC microgrid, ΓV, and the value range of the voltage deviation coefficient θ is θ∈[0, θ d ], where θ d Solve according to the following formula

[0067]

[0068] In the above expression, Γ V is the maximum bus voltage deviation allowed by the DC microgrid, Ψ = [ψ1, ψ2, …, ψ N ] T , Y is the admittance matrix corresponding to the main circuit of the DC microgrid, V rat is the rated voltage of the DC microgrid, Y L is a diagonal matrix, 1 N represents a unit vector of dimension N, Serves 1 N The transpose of .

[0069] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application, and is not used to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A distributed coordinated control method for voltage deviation of an islanded DC microgrid, characterized in that: The method comprises: Connecting each of the multiple distributed power sources in the island type DC microgrid to the DC microgrid through a converter, wherein each distributed power source is configured with a distributed coordination controller; Establishing a full-duplex communication network between the distributed coordination controllers of the plurality of distributed power sources; The real-time status information of adjacent distributed coordination controller nodes is exchanged through the full-duplex communication network. Each distributed coordination controller uses a distributed coordination control algorithm to achieve average voltage regulation and distributed voltage deviation regulation of the DC microgrid based on the status information of its neighbor nodes and the status of the local distributed power supply nodes.

2. The distributed coordinated control method for voltage deviation of an island type DC microgrid according to claim 1, characterized in that: The distributed coordination controller includes an average voltage regulator, a voltage deviation regulator and a reference voltage generator; The average voltage regulator is used to adjust the average voltage of each distributed power supply node in the DC microgrid to the rated voltage of the DC microgrid; The voltage deviation regulator is used to adjust the relative deviation of the bus voltage of each node in the DC microgrid; The reference voltage generator is used to generate a reference voltage of a distributed power supply node to which the reference voltage generator belongs according to a reference voltage correction amount output by the average voltage regulator and a reference current correction amount output by the voltage deviation regulator.

3. The distributed coordinated control method for voltage deviation of an island type DC microgrid as claimed in claim 2, characterized in that: Each of the distributed coordination controllers implements average voltage regulation of the DC microgrid using a distributed coordination control algorithm according to the state information of neighboring nodes and the state of the local power supply node, specifically, implements average voltage regulation of the DC microgrid using the following distributed average value tracking algorithm based on initial value robustness: Among them, the is the reference voltage correction value output by the average voltage regulator of distributed power node i, V rat is the rated voltage of the DC microgrid, are respectively the estimated values ​​of the average voltage of all distributed power supply nodes in the DC microgrid by the distributed power supply nodes i and j, V i (t) is the measured bus voltage of distributed generation node i, and Respectively V i (t) and Differentiation operation, α is a positive real number, a ij represents the communication link weight between node i and node j. When there is data interaction between nodes i and j, a ij > 0, otherwise a ij =0.

4. The distributed coordinated control method for voltage deviation of an islanded DC microgrid as claimed in claim 2, characterized in that: The algorithm used to generate the reference voltage of the distributed power supply node to which the reference voltage generator belongs according to the reference voltage correction amount output by the average voltage regulator and the reference current correction amount output is as follows: Among them, the is the reference voltage of the distributed power source node i to which the reference voltage generator belongs, V rat is the rated voltage of the DC microgrid, is the reference voltage correction value output by the average voltage regulator of distributed power generation node i, It is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i.

5. The distributed coordinated control method for voltage deviation of an islanded DC microgrid as claimed in claim 2, characterized in that: Each of the distributed coordination controllers implements distributed voltage deviation regulation of the DC microgrid using a distributed coordination control algorithm according to the state information of neighboring nodes and the state of the local power supply node, specifically, the coordination and consistency of the distributed power sources in the DC microgrid is achieved through the following distributed consistency algorithm: Among them, the is the reference current correction value output by the voltage deviation regulator of the distributed power generation node i, are the per-unit values ​​of the current output by the converter at nodes i and j, I i (t) is the actual output current of the converter at node i obtained by measurement, are the rated load current and the rated capacity of the power supply directly provided by the bus of node i, and θ∈[0,1] is the voltage deviation coefficient.

6. The distributed coordinated control method for voltage deviation of an islanded DC microgrid as claimed in claim 5, characterized in that: The method further comprises: According to the maximum voltage deviation of the bus voltage allowed by the DC microgrid, the voltage deviation coefficient in the distributed coordination controller is adjusted.

7. The distributed coordinated control method for voltage deviation of an islanded DC microgrid as claimed in claim 6, characterized in that: The voltage deviation coefficient θ has a value range of θ∈[0,θ d ], the θ d Solve according to the following formula Among them, the Γ V is the maximum bus voltage deviation allowed by the DC microgrid, Ψ = [ψ1, ψ2, ..., ψ N ] T , Y is the admittance matrix corresponding to the DC microgrid main circuit, V rat is the rated voltage of the DC microgrid, Y L is a diagonal matrix, 1 N Represents a unit vector of dimension N.

8. The distributed coordinated control method for voltage deviation of an islanded DC microgrid according to any one of claims 1 to 7, characterized in that: The full-duplex communication network is established between the distributed coordination controllers of the plurality of distributed power sources. It includes: Based on the proximity principle, a sparse full-duplex communication network is established between the distributed coordination controllers of the multiple distributed power sources.

9. The distributed coordinated control method for voltage deviation of an island type DC microgrid as claimed in claim 8, characterized in that: The method of establishing a sparse full-duplex communication network among the distributed coordination controllers of the multiple distributed power sources based on the proximity principle includes: establishing a sparse self-organizing full-duplex communication network among the distributed coordination controllers of the multiple distributed power sources based on the proximity principle.

10. The distributed coordinated control method for voltage deviation of an islanded DC microgrid according to claim 8, characterized in that: The full-duplex communication network supports dynamic joining and exiting of nodes, and automatically updates the communication path when the nodes change.

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