A distributed cooperative control dual switching system for microgrid cluster system

Abstract

The present invention relates to the field of microgrid cluster control technology, and specifically discloses a distributed collaborative control dual switching system for a microgrid cluster system, including: a task allocation decision layer, a time-varying communication topology layer, and a distributed secondary controller; the task allocation decision layer is used to: generate a first switching signal for switching the scheduling task of the microgrid cluster system at a target time; the time-varying communication topology layer is used to: generate a second switching signal for switching the communication topology of the microgrid cluster system at a target time; the distributed secondary controller is used to: perform collaborative control on all individual objects to be controlled in the target microgrid cluster system according to the first switching signal and the second switching signal. The present invention forms a "dual switching" of scheduling task switching changes and communication topology switching changes, and can realize distributed collaborative control of microgrid clusters.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrid cluster control, and in particular to a distributed collaborative control dual switching system for a microgrid cluster system. Background Art

[0002] Microgrids (MGs) composed of distributed energy resources (DERs) are an emerging technology trend in urban buildings. The MGs applied to urban buildings naturally form a microgrid cluster system (MGCs). The stability of the microgrid cluster is the primary issue. Photovoltaics, wind turbines, gas turbines and energy storage in the building microgrid cluster constitute a collection of distributed generators (DGs), which have poor stability. The heterogeneous diversity of DGs makes it difficult for the building multi-energy microgrid to operate stably.

[0003] The multi-energy AC microgrid cluster system (Microgrid Cluster, MGC, referred to as microgrid group) in the context of building energy-saving applications considers the system under source / load disturbance, fault, maintenance and off / on-grid operation conditions, as well as changes in the communication structure, which generates corresponding scheduling tasks and structural topology changes. Most of the existing collaborative control methods of MGC systems are voltage and frequency consistency collaborative control methods under a single instruction mode. In the application of MGC systems, power or output scheduling includes multiple tasks. For example, off-grid / on-grid, heavy load switching, faults, maintenance, etc. will generate different task instructions. In addition to power system relay protection control, output scheduling sometimes needs to achieve the desired approximate power curve. This is especially true for MGC systems in the context of multi-energy buildings. Obviously, traditional voltage and frequency secondary control methods cannot adapt to this situation.

[0004] Therefore, it is urgent to provide a technical solution to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a distributed collaborative control dual switching system for a microgrid cluster system.

[0006] In a first aspect, the present invention provides a distributed cooperative control dual switching system for a microgrid cluster system, and the technical solution of the system is as follows:

[0007] It includes: task allocation decision layer, time-varying communication topology layer and distributed secondary controller;

[0008] The task allocation decision layer is used to: generate a first switching signal for switching the scheduling task of the target microgrid cluster system at a target time, and send the signal to the distributed secondary controller;

[0009] The time-varying communication topology layer is used to: generate a second switching signal for switching the communication topology of the target microgrid cluster system at the target time, and send the second switching signal to the distributed secondary controller;

[0010] The distributed secondary controller is used to: coordinately control all individual objects to be controlled in the target microgrid cluster system according to the first switching signal and the second switching signal.

[0011] The beneficial effects of the distributed cooperative control dual switching system of a microgrid cluster system of the present invention are as follows:

[0012] The system of the present invention forms a "double switch" of scheduling task switching changes and communication topology switching changes, which can realize distributed collaborative control of microgrid clusters.

[0013] On the basis of the above scheme, the distributed cooperative control dual switching system of a microgrid cluster system of the present invention can also be improved as follows.

[0014] In an optional manner, the distributed secondary controller is specifically used for:

[0015] Based on the distributed control protocol, a target control signal for controlling each individual object to be controlled at the target time is generated according to the first switching signal and the second switching signal.

[0016] In an optional manner, the target control signal includes: a voltage frequency control signal and a power micro-increment control.

[0017] In an optional manner, the distributed control protocol is:

[0018] Among them, u i is the voltage-frequency control signal of the ith individual plant, is the power micro-increment control signal of the i-th individual object, is the voltage-frequency local control signal of the ith individual plant, is the power micro-increment local control signal of the i-th individual object, is the voltage-frequency coordinated control signal of the ith individual object, is the power micro-increment cooperative control signal of the i-th individual object,

[0019]

[0020] N is the total number of individual objects, is the connection weight coefficient between the i-th individual object and the j-th individual object, q i is the voltage frequency state signal of the ith individual object, q j is the voltage-frequency state signal of the jth individual object, k is the number of individual objects with the leader role in the system, r(t) is the first switching signal, σ(t) is the second switching signal, is the first uncertainty change of the neighbor information of the i-th individual object, is the second uncertainty change of the neighbor information of the i-th individual object, The third uncertainty change of the neighbor information of the i-th individual object, is the voltage frequency change rate state signal of the ith individual object, is the power scheduling signal of the i-th individual object, is the power scheduling signal of the jth individual object, is the power micro-increment state signal of the i-th individual object, is the power micro-increment state signal of the jth individual object, c1 is the first parameter to be designed, c2 is the second parameter to be designed, c3 is the third parameter to be designed, K1 is the fourth parameter to be designed, K2 is the fifth parameter to be designed, K3 is the sixth parameter to be designed, c1, c2, c3>0.

[0021] In an optional manner, it also includes: a feedback interaction layer;

[0022] The feedback interaction layer is used to output status feedback information of all individual objects of the target microgrid cluster system at a target time.

[0023] In an optional manner, any individual object of the target microgrid cluster system is a distributed power source composed of at least one of photovoltaic, wind turbine, gas turbine and energy storage.

[0024] In an optional manner, the scheduling task switching includes: at least one of a tripping action, a switching action, a closing action and a switching action.

[0025] In an optional manner, the target microgrid cluster system is: a building multi-energy AC microgrid cluster system.

[0026] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0028] Figure 1 A first structural schematic diagram of an embodiment of a distributed cooperative control dual switching system of a microgrid cluster system of the present invention;

[0029] Figure 2 It is a second structural schematic diagram of an embodiment of a distributed collaborative control dual switching system of a microgrid cluster system of the present invention. DETAILED DESCRIPTION

[0030] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0031] Figure 1 FIG. 1 is a schematic diagram showing a structure of an embodiment of a distributed cooperative control dual switching system 100 of a microgrid cluster system provided by the present invention. Figure 1 As shown, the system 100 includes: a task allocation decision layer 110, a time-varying communication topology layer 120 and a distributed secondary controller 130;

[0032] The task allocation decision layer 110 is used to generate a first switching signal for switching the scheduling task of the target microgrid cluster system at the target time, and send the signal to the distributed secondary controller 130.

[0033] 1) The task allocation decision layer 110 is equivalent to the monitoring center. The task allocation decision layer 110 is mainly responsible for energy optimization management, realizing economic dispatch, operation dispatch and power flow between the microgrid and the external power grid. Adopting effective energy management optimization strategy for microgrid and microgrid cluster system is the top-level key technology to achieve stable operation and improve efficiency of microgrid group.

[0034] 2) The target time is the time when control is required. Usually, the time when the switching signal is input into the distributed secondary controller 130 is the previous time of the target time, so that the distributed secondary controller 130 outputs the corresponding control signal at the target time.

[0035] 3) The dispatching task switching includes at least one of tripping action, switching action, closing action and switching action.

[0036] 4) The first switching signal is a signal indicating the change of tripping, closing, switching, etc. caused by off-grid / grid connection, heavy load switching, fault, maintenance, etc. It is defined as r(t):[0,+∞)→{1,2,…γ}, represents a positive integer, r(t) represents the first switching signal at the tth moment, and γ is the maximum number of task instruction switching changes.

[0037] 5) The target microgrid cluster system defaults to a building multi-energy AC microgrid cluster system, which contains multiple individual objects (photovoltaics, wind turbines, gas turbines and energy storage in the building microgrid cluster constitute distributed power sources, DG).

[0038] The time-varying communication topology layer 120 is used to generate a second switching signal for switching the communication topology of the target microgrid cluster system at the target time, and send the second switching signal to the distributed secondary controller 130.

[0039] 1) The time-varying communication topology layer 120 is used to generate a switching change signal of the communication topology of the target microgrid cluster system, that is, a second switching signal.

[0040] 2) The second switching signal is represented by σ(t):[0,+∞)→{1,2,…λ}, λ>1, λ represents the maximum number of communication topology switching changes.

[0041] 3) The time-varying communication topology layer 120 can represent the communication connection between each sub-microgrid of the target microgrid cluster system. The structure and topology of the target microgrid cluster system will be designed accordingly. With the continuous deepening of swarm intelligence research, the impact of non-ideal communication conditions such as communication failures, variable communication topology, delays, and communication bandwidth limitations on distributed control has gradually attracted attention. Generally speaking, as long as the communication topology remains connected, the distributed collaborative control protocol algorithm can remain stable. If the connectivity of the communication topology is destroyed, the distributed collaborative control protocol algorithm cannot achieve global stability. In short, in any case, the time-varying communication topology is a must-have content for a good model organization architecture.

[0042] The distributed secondary controller 130 is used to coordinately control all individual objects to be controlled in the target microgrid cluster system according to the first switching signal and the second switching signal.

[0043] in:

[0044] 1) Any individual object of the target microgrid cluster system is a distributed power source composed of at least one of photovoltaic, wind turbine, gas turbine and energy storage.

[0045] 2) The purpose of collaborative control is to adjust the voltage frequency and power micro-increments of the individual objects to be controlled so that the voltage frequency and power of all individual objects in the target microgrid cluster system are balanced.

[0046] Preferably, the distributed secondary controller is specifically used for:

[0047] Based on the distributed control protocol, a target control signal for controlling each individual object to be controlled at the target time is generated according to the first switching signal and the second switching signal.

[0048] 1) Each individual object to be controlled in the target microgrid cluster system corresponds to a target control signal. The target control signal includes: voltage frequency control signal and power micro-increment control signal.

[0049] 2) The distributed secondary controller 130 sends the target control signal corresponding to each individual object to be controlled to the corresponding individual object to be controlled. For example, when there are three individual objects to be controlled (individual object A to be controlled, individual object B to be controlled, and individual object C to be controlled), there are three target control signals (individual object A to be controlled corresponds to target control signal A, individual object B to be controlled corresponds to target control signal B, and individual object C to be controlled corresponds to target control signal C).

[0050] 3) The distributed control protocol is: Among them, u i is the voltage-frequency control signal of the ith individual plant, is the power micro-increment control signal of the i-th individual object, is the voltage-frequency local control signal of the ith individual plant, is the power micro-increment local control signal of the i-th individual object, is the voltage-frequency coordinated control signal of the ith individual object, is the power micro-increment cooperative control signal of the i-th individual object, N is the total number of individual objects, is the connection weight coefficient between the i-th individual object and the j-th individual object, q i is the voltage frequency state signal of the ith individual object, q jis the voltage-frequency state signal of the jth individual object, k is the number of individual objects with the leader role in the system, r(t) is the first switching signal, σ(t) is the second switching signal, is the first uncertainty change of the neighbor information of the i-th individual object, is the second uncertainty change of the neighbor information of the i-th individual object, The third uncertainty change of the neighbor information of the i-th individual object, is the voltage frequency change rate state signal of the ith individual object, is the power scheduling signal of the i-th individual object, is the power scheduling signal of the jth individual object, is the power micro-increment state signal of the i-th individual object, is the power micro-increment state signal of the jth individual object, c1 is the first parameter to be designed, c2 is the second parameter to be designed, c3 is the third parameter to be designed, K1 is the fourth parameter to be designed, K2 is the fifth parameter to be designed, K3 is the sixth parameter to be designed, c1, c2, c3>0.

[0051] It should be noted that based on Figure 1 The model architecture of the distributed cooperative control dual switching system of the microgrid cluster system shown in the figure sequentially carries out the voltage frequency equation, power micro-increment equation and graph theory description to mathematically describe the global model of the multi-energy AC microgrid MGC system. Figure 2 As shown, specifically:

[0052] Based on small signal analysis, each individual object to be controlled (DG individual) in the target microgrid cluster system can be described by the voltage frequency equation and power incremental differential equation based on the droop control principle. The heterogeneous DG individual model is expressed as: is the voltage-frequency state change of the i-th individual object to be controlled, is the power micro-increment state change of the i-th individual object to be controlled, f i is the known dynamics of the voltage frequency of the i-th individual object to be controlled, is the known dynamic power of the i-th individual object to be controlled, α i is the first model gain parameter of the i-th individual object to be controlled, β i is the second model gain parameter of the i-th individual object to be controlled, d i are all the unmodeled dynamics corresponding to the i-th individual object to be controlled, are the various disturbances corresponding to the i-th individual object to be controlled, u i is the voltage-frequency control signal of the i-th individual object to be controlled, is the power micro-increment control signal of the i-th individual object to be controlled.

[0053] 2) Assume that each individual object to be controlled (DG individual) is in only one sub-microgrid at any time and is connected to at most one leader. That is, the Laplacian submatrix of the sub-microgrid cluster (containing p DG individuals) that is the leader has the following characteristics: is the Laplacian submatrix,

[0054] 3) The distributed control protocol is: Among them, u i is the voltage-frequency control signal of the ith individual plant, is the power micro-increment control signal of the i-th individual object, is the voltage-frequency local control signal of the ith individual plant, is the power micro-increment local control signal of the i-th individual object, is the voltage-frequency coordinated control signal of the ith individual object, is the power micro-increment cooperative control signal of the i-th individual object, N is the total number of individual objects, is the connection weight coefficient between the i-th individual object and the j-th individual object, q i is the voltage frequency state signal of the ith individual object, q j is the voltage-frequency state signal of the jth individual object, k is the number of individual objects with the leader role in the system, r(t) is the first switching signal, σ(t) is the second switching signal, is the first uncertainty change of the neighbor information of the i-th individual object, is the second uncertainty change of the neighbor information of the i-th individual object, The third uncertainty change of the neighbor information of the i-th individual object, is the voltage frequency change rate state signal of the ith individual object, is the power scheduling signal of the i-th individual object, is the power scheduling signal of the jth individual object, is the power micro-increment state signal of the i-th individual object, is the power micro-increment state signal of the jth individual object, c1 is the first parameter to be designed, c2 is the second parameter to be designed, c3 is the third parameter to be designed, K1 is the fourth parameter to be designed, K2 is the fifth parameter to be designed, K3 is the sixth parameter to be designed, c1, c2, c3>0.

[0055] 4) Settings represents the consistent tracking error of each sub-microgrid, then according to the above description, we can get:

[0056]

[0057]

[0058] 5) According to the Laplacian matrix of the communication topology and the formula in 4), the global consistent tracking error has the following form:

[0059]

[0060]

[0061]

[0062] Where, e(t)=[e1(t),e2(t),…,e p (t)] T , is the quadratic control global consistency tracking error of the microgrid cluster; the matrix Interference Vector Function matrix and vector F r(t) (t), G(t), M(t), Both can be derived from the formulas in 3) and 4). Represents the Kronecker product of matrices A and B.

[0063] Preferably, it further includes: a feedback interaction layer 140;

[0064] The feedback interaction layer 140 is used to output status feedback information of all individual objects of the target microgrid cluster system at a target time.

[0065] Among them, feedback interaction refers to the information interaction between the distributed control protocol and the sub-microgrids under the changing communication topology between the sub-microgrids of the target microgrid cluster system. There are various types of status information feedback and interaction between individual objects and sub-microgrids, which provide support for the distributed control protocol and the stability of the entire cluster. Network communication noise, connection weight fluctuations, and transmission delays will make the neighbor information obtained by individual objects uncertain, resulting in poor cluster stability. Therefore, the problem of information interaction fluctuations also requires a better model organization architecture.

[0066] The technical solution of this embodiment proposes a dual switching system model under scheduling task switching and structural topology switching, and a new method of task-driven dual switching secondary control to realize task-driven microgrid cluster control. This is an innovative exploration of methods for new problems of secondary control of microgrid clusters, and has original research significance for the application of MGC systems. The dual switching system (model) architecture can meet the personalized needs of output scheduling. The isolated microgrid group needs to coordinate the output of each microgrid while maintaining the stability of the voltage and frequency of each microgrid. When there is a source / load disturbance or personalized demand for economic operation, under the dual switching model structure proposed in the present invention, the distributed secondary controller of the MGC system can meet the new scheduling instruction change requirements proposed by the microgrid group for system operation regulation.

[0067] The technical solution of this embodiment forms a "double switching" of scheduling task switching changes and communication topology switching changes, which can realize distributed collaborative control of microgrid clusters.

[0068] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0069] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A distributed cooperative control dual switching system for a microgrid cluster system, characterized in that: include: Task allocation decision layer, time-varying communication topology layer and distributed secondary controller; The task allocation decision layer is used to: generate a first switching signal for switching the scheduling task of the target microgrid cluster system at a target time, and send the signal to the distributed secondary controller; The time-varying communication topology layer is used to: generate a second switching signal for switching the communication topology of the target microgrid cluster system at the target time, and send the second switching signal to the distributed secondary controller; The distributed secondary controller is used to: coordinately control all individual objects to be controlled of the target microgrid cluster system according to the first switching signal and the second switching signal; The distributed secondary controller is specifically used for: Based on the distributed control protocol, according to the first switching signal and the second switching signal, a target control signal for controlling each individual object to be controlled at the target time is generated; the target control signal includes: a voltage frequency control signal and a power micro-increment control signal; The distributed control protocol is: Among them, u i is the voltage-frequency control signal of the ith individual plant, is the power micro-increment control signal of the i-th individual object, is the voltage-frequency local control signal of the ith individual plant, is the power micro-increment local control signal of the i-th individual object, is the voltage-frequency coordinated control signal of the ith individual object, is the power micro-increment cooperative control signal of the i-th individual object, N is the total number of individual objects, is the connection weight coefficient between the i-th individual object and the j-th individual object, q i is the voltage frequency state signal of the ith individual object, q j is the voltage-frequency state signal of the jth individual object, k is the number of individual objects with the leader role in the system, r(t) is the first switching signal, σ(t) is the second switching signal, is the first uncertainty change of the neighbor information of the i-th individual object, is the second uncertainty change of the neighbor information of the i-th individual object, The third uncertainty change of the neighbor information of the i-th individual object, is the voltage frequency change rate state signal of the ith individual object, is the power scheduling signal of the i-th individual object, is the power scheduling signal of the jth individual object, is the power micro-increment state signal of the i-th individual object, is the power micro-increment state signal of the jth individual object, c1 is the first parameter to be designed, c2 is the second parameter to be designed, c3 is the third parameter to be designed, K1 is the fourth parameter to be designed, K2 is the fifth parameter to be designed, K3 is the sixth parameter to be designed, c1, c2, c3>

0.

2. The microgrid cluster system distributed collaborative control dual switching system according to claim 1 is characterized in that: Also includes: Feedback interaction layer; The feedback interaction layer is used to output status feedback information of all individual objects of the target microgrid cluster system at a target time.

3. The microgrid cluster system distributed collaborative control dual switching system according to claim 1 is characterized in that: Any individual object of the target microgrid cluster system is a distributed power source composed of at least one of photovoltaic, wind turbine, gas turbine and energy storage.

4. The microgrid cluster system distributed collaborative control dual switching system according to claim 1, characterized in that: The scheduling task switching includes: at least one of a tripping action, a switching action, a closing action and a switching action.

5. The microgrid cluster system distributed cooperative control dual switching system according to any one of claims 1 to 4, characterized in that: The target microgrid cluster system is: a building multi-energy AC microgrid cluster system.

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