Hybrid microgrid group power coordination control method and device

By establishing a topological structure in an AC-DC hybrid microgrid group operating in an island and using adaptive sag control and MFO algorithms, the problem of complexity of coordinated control of multiple subnets is solved, the power supply reliability and quality is improved, and reasonable power management between distributed power supplies and energy storage units is realized.

CN120016559AActive Publication Date: 2025-05-16STATE GRID JIANGSU ELECTRIC POWER CO LTD TAIZHOU POWER SUPPLY BRANCH +1

Patent Information

Application Number
CN202510460737.X
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-04-14
Publication Date
2025-05-16
Estimated Expiration
2045-04-14

AI Technical Summary

Technical Problem

The prior art is difficult to effectively manage AC and DC hybrid microgrid groups operating in silos, especially in the coordination control of multiple subnets, resulting in insufficient power supply reliability and quality.

Method used

By establishing the topological structure of the hybrid microgrid group, adaptive sag control and MFO algorithm are used to calculate the interactive power, and adaptive adjustment coefficients and sag control coefficients are introduced to realize power coordination between the AC subnet, DC subnet and energy storage subnet.

Benefits of technology

It improves the power supply reliability and quality of the isolated AC and DC hybrid microgrid group, realizes reasonable power management between distributed power supplies and energy storage units, and has good robustness, and can still operate effectively especially in the event of communication failure.

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Patent Text Reader

Abstract

The invention discloses a hybrid micro-grid group power coordination control method and device. The method comprises the following steps: establishing a hybrid micro-grid group topological structure; each alternating-current sub-network collects the bus frequency of the corresponding alternating-current bus, and each direct-current sub-network collects the bus voltage of the corresponding direct-current bus; when the bus frequency of the alternating current subnet or the bus voltage of the direct current subnet fluctuates in a first preset range, the alternating current subnet and the direct current subnet adopt adaptive droop control to realize power coordination; when the bus frequency of the alternating-current subnet or the bus voltage of the direct-current subnet fluctuates within a second preset range, the alternating-current subnet and the direct-current subnet achieve power coordination through power exchange; and when the bus frequency of the AC subnet or the bus voltage fluctuation of the DC subnet exceeds a second preset range, controlling the power output of the energy storage subnet to realize power coordination, and the method can improve the robustness of the system.
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Description

Technical Field

[0001] The present invention relates to the field of microgrid control technology, and in particular to a hybrid microgrid group power coordination control method and device. Background Art

[0002] In order to improve the reliability of AC / DC hybrid microgrid power supply, multiple adjacent AC subgrids and DC subgrids are often interconnected to form an AC / DC hybrid microgrid group to supply power to the load. For such isolated hybrid microgrid groups, their stable operation depends entirely on reasonable power interaction management strategies between subgrids and output control methods of distributed power sources. Therefore, it is necessary to conduct in-depth research on the power management strategy of hybrid microgrid groups.

[0003] At present, there have been a lot of research on the power management strategy of hybrid microgrid groups operating in isolated islands. However, the current research results are based on isolated AC microgrid groups, which cannot meet the working conditions of AC and DC hybrid power supply. In addition, in the power management of isolated hybrid microgrid groups, the focus is on achieving the mutual support effect of power between sub-microgrids, ignoring the independent autonomous operation capability of sub-microgrids. The hybrid microgrid groups studied in the existing research only contain a single AC and a single DC subgrid, and the control is relatively simple. When the hybrid microgrid group contains more different subgrids, its coordinated control will become more complicated. For example, the patent text CN111740426B discloses a power collaborative control method for isolated AC / DC hybrid microgrid groups, including: for DC sub-microgrids with constant power loads, Construct a V2-P droop control strategy; construct a SOC dynamic balance consistency control strategy for the energy storage sub-microgrid; construct a sub-microgrid power exchange control strategy for the DC sub-microgrid, AC sub-microgrid and energy storage sub-microgrid; construct a communication trigger control strategy based on the sub-microgrid power exchange control strategy; use the V2-P droop control strategy, SOC dynamic balance consistency control strategy and traditional Pf droop control strategy to control the output power of the DC sub-microgrid, energy storage sub-microgrid and AC sub-microgrid respectively; apply the sub-microgrid power exchange control strategy and communication trigger control strategy to the isolated AC / DC hybrid microgrid group to control the power exchange and interconnection communication between each sub-microgrid. However, the control strategy of this method is complex and the reliability is not high in practical applications. Summary of the invention

[0004] The present invention provides a hybrid microgrid group power coordination control method and device, which can effectively improve the reliability of the hybrid microgrid group power coordination control.

[0005] A hybrid microgrid group power coordination control method, comprising: Establishing a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; Each of the AC subnets collects the bus frequency of the corresponding AC bus, and each of the DC subnets collects the bus voltage of the corresponding DC bus; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range, the AC subnet and the DC subnet adopt adaptive droop control to achieve power coordination; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates beyond a second preset range, an adaptive adjustment coefficient is calculated according to the common bus voltage, a droop control coefficient is calculated according to the state of the energy storage unit, and the power output of the energy storage subnet is controlled according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination.

[0006] Furthermore, the distributed power sources in the AC subnet are connected to the corresponding AC bus through an AC / AC converter, the distributed power sources in the DC subnet are connected to the corresponding DC bus through a DC / DC converter, the AC bus is connected to the common bus through an AC / DC converter, the DC bus is connected to the common bus through a DC / DC converter, and the energy storage unit in the energy storage subnet is connected to the common bus through a DC / DC converter.

[0007] Furthermore, the AC subnet adopts adaptive droop control to achieve power coordination, including: Calculating the frequency change of the AC subnet within a first preset time period according to the bus frequency; Calculating a frequency correction droop coefficient of the AC subnet according to the frequency change, the first preset duration, the rated frequency of the AC subnet and a preset frequency correction parameter; Calculate the droop control coefficient of the AC subnet according to the frequency correction droop coefficient, the upper frequency limit value of the AC subnet, the lower frequency limit value of the AC subnet, and the upper limit value of the output power of the AC subnet; Calculate the target output frequency of the AC subnet based on the droop control coefficient of the AC subnet, the actual output power of the DC subnet and the upper frequency limit of the AC subnet; The frequency output of the AC subnet is controlled according to the calculated target output frequency.

[0008] Furthermore, the DC subnet adopts adaptive droop control to achieve power coordination, including: Calculating a voltage variation of the DC subnet within a second preset time period according to the bus voltage; Calculating a voltage correction droop coefficient of the DC subnet according to the voltage variation, the second preset time length, the rated voltage of the DC subnet and a preset voltage correction parameter; Calculate the droop control coefficient of the DC subnet according to the voltage correction droop coefficient, the voltage upper limit value of the DC subnet, the voltage lower limit value of the DC subnet, and the upper limit value of the output power of the DC subnet; Calculate the target voltage of the DC subnet according to the droop control coefficient of the DC subnet, the actual output power of the DC subnet and the voltage upper limit of the DC subnet; The voltage output of the DC subnet is controlled according to the calculated target voltage.

[0009] Further, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination, including: Establishing objective functions with the lowest bus frequency deviation of the AC subnet and the lowest bus voltage deviation of the DC subnet; Construct power conservation constraints for AC and DC subnets, frequency constraints for AC subnets, and voltage constraints for DC subnets; Based on the MFO algorithm, the AC subgrid interaction power and the DC subgrid interaction power that satisfy the objective function, the AC subgrid and the DC subgrid power conservation constraints, the AC subgrid frequency constraints, and the DC subgrid voltage constraints are calculated; The output power of the corresponding AC subgrid and DC subgrid is controlled according to the calculated AC subgrid interactive power and DC subgrid interactive power.

[0010] Further, an adaptive adjustment coefficient is calculated according to the common bus voltage, a droop control coefficient is calculated according to the state of the energy storage unit, and the power output of the energy storage subnet is controlled according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination, including: Collecting common bus voltage; Calculating the rate of change of the common bus voltage over time according to the common bus voltage; Calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time; Detecting the state of charge and the maximum output power of the energy storage unit, and calculating the droop control coefficient of the power output of the energy storage subnet according to the state of charge and the maximum output power; Calculating the output power of the energy storage subgrid according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subgrid; Collect the bus voltage of the energy storage unit; Perform current calculation according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; Inputting the energy storage unit exchange current into a PI controller for calculation, and outputting a target voltage of the energy storage unit; The target voltage of the energy storage unit is PWM modulated to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

[0011] Further, calculating the adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time includes: The common bus voltage is compared with a preset voltage threshold, and when the common bus voltage is less than or equal to the preset voltage threshold, the adaptive adjustment coefficient is 1; When the common bus voltage is greater than the preset voltage threshold, the adaptive adjustment coefficient is calculated according to the hyperbolic tangent function value of the rate of change of the common bus voltage over time.

[0012] Furthermore, the droop control coefficient of the energy storage subgrid power output is calculated by the following formula: ; Among them, b k represents the droop control coefficient of the energy storage subgrid power output, k O represents the parameter for adjusting the droop coefficient, μ represents the parameter for adjusting the SOC balancing speed of each energy storage unit, and P ds,k Indicates the maximum output power of the kth energy storage unit, SOC k It represents the current state of charge of the kth energy storage unit, and SOC* represents the reference state of charge value given by the battery standard of each energy storage unit.

[0013] A hybrid microgrid group power coordination control device, comprising: A topology building module, used to establish a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; A frequency acquisition module, each of the AC subnets acquires the bus frequency of the corresponding AC bus through the frequency acquisition module; A voltage acquisition module, each of the DC subnets acquires the bus voltage of the corresponding DC bus through the voltage acquisition module; An adaptive droop control module, used to control the AC subnet and the DC subnet to adopt adaptive droop control to achieve power coordination when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range; A power interaction control module, which is used to calculate the AC subnet interaction power and the DC subnet interaction power based on the MFO algorithm when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, and control the AC subnet and the DC subnet to exchange power through the AC subnet interaction power and the DC subnet interaction power to achieve power coordination; The energy storage control module is used to calculate an adaptive adjustment coefficient according to the common bus voltage, calculate a droop control coefficient according to the state of the energy storage unit, and control the power output of the energy storage subnetwork according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination when the bus frequency of the AC subnetwork or the bus voltage of the DC subnetwork fluctuates beyond a second preset range.

[0014] Furthermore, the distributed power sources in the AC subnet are connected to the corresponding AC bus through an AC / AC converter, the distributed power sources in the DC subnet are connected to the corresponding DC bus through a DC / DC converter, the AC bus is connected to the common bus through an AC / DC converter, the DC bus is connected to the common bus through a DC / DC converter, and the energy storage unit in the energy storage subnet is connected to the common bus through a DC / DC converter.

[0015] Furthermore, the AC subnet adopts adaptive droop control to achieve power coordination, including: Calculating the frequency change of the AC subnet within a first preset time period according to the bus frequency; Calculating a frequency correction droop coefficient of the AC subnet according to the frequency change, the first preset duration, the rated frequency of the AC subnet and a preset frequency correction parameter; Calculate the droop control coefficient of the AC subnet according to the frequency correction droop coefficient, the upper frequency limit value of the AC subnet, the lower frequency limit value of the AC subnet, and the upper limit value of the output power of the AC subnet; Calculate the target output frequency of the AC subnet based on the droop control coefficient of the AC subnet, the actual output power of the DC subnet and the upper frequency limit of the AC subnet; The frequency output of the AC subnet is controlled according to the calculated target output frequency.

[0016] Furthermore, the DC subnet adopts adaptive droop control to achieve power coordination, including: Calculating a voltage variation of the DC subnet within a second preset time period according to the bus voltage; Calculating a voltage correction droop coefficient of the DC subnet according to the voltage change, the second preset time length, the DC subnet rated voltage and a preset voltage correction parameter; Calculate the droop control coefficient of the DC subnet according to the voltage correction droop coefficient, the voltage upper limit value of the DC subnet, the voltage lower limit value of the DC subnet, and the upper limit value of the output power of the DC subnet; Calculate the target voltage of the DC subnet according to the droop control coefficient of the DC subnet, the actual output power of the DC subnet and the voltage upper limit of the DC subnet; The voltage output of the DC subnet is controlled according to the calculated target voltage.

[0017] Further, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination, including: Establishing objective functions with the lowest bus frequency deviation of the AC subnet and the lowest bus voltage deviation of the DC subnet; Construct power conservation constraints for AC and DC subnets, frequency constraints for AC subnets, and voltage constraints for DC subnets; Based on the MFO algorithm, the AC subgrid interaction power and the DC subgrid interaction power that satisfy the objective function, the AC subgrid and the DC subgrid power conservation constraints, the AC subgrid frequency constraints, and the DC subgrid voltage constraints are calculated; The output power of the corresponding AC subgrid and DC subgrid is controlled according to the calculated AC subgrid interactive power and DC subgrid interactive power.

[0018] Furthermore, the energy storage control module calculates an adaptive adjustment coefficient according to the common bus voltage, calculates a droop control coefficient according to the state of the energy storage unit, and controls the power output of the energy storage subnet according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination, including: Collecting common bus voltage; Calculating the rate of change of the common bus voltage over time according to the common bus voltage; Calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time; Detecting the state of charge and the maximum output power of the energy storage unit, and calculating the droop control coefficient of the power output of the energy storage subnet according to the state of charge and the maximum output power; Calculating the output power of the energy storage subgrid according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subgrid; Collect the bus voltage of the energy storage unit; Perform current calculation according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; Inputting the energy storage unit exchange current into a PI controller for calculation, and outputting a target voltage of the energy storage unit; The target voltage of the energy storage unit is PWM modulated to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

[0019] Furthermore, the energy storage control module calculates an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time, including: The common bus voltage is compared with a preset voltage threshold, and when the common bus voltage is less than or equal to the preset voltage threshold, the adaptive adjustment coefficient is 1; When the common bus voltage is greater than the preset voltage threshold, the adaptive adjustment coefficient is calculated according to the hyperbolic tangent function value of the rate of change of the common bus voltage over time.

[0020] Furthermore, the droop control coefficient of the energy storage subgrid power output is calculated by the following formula: ; Among them, b k represents the droop control coefficient of the energy storage subgrid power output, k O represents the parameter for adjusting the droop coefficient, μ represents the parameter for adjusting the SOC balancing speed of each energy storage unit, and P ds,k Indicates the maximum output power of the kth energy storage unit, SOC k It represents the current state of charge of the kth energy storage unit, and SOC* represents the reference state of charge value given by the battery standard of each energy storage unit.

[0021] An electronic device comprises a processor and a storage device, wherein the storage device stores a plurality of instructions, and the processor is used to read the instructions and execute the above method.

[0022] The hybrid microgrid group power coordination control method and device provided by the present invention have at least the following beneficial effects: (1) Under different frequency fluctuations and voltage fluctuations, a power management strategy consisting of subgrid power autonomous control, inter-subgrid power interactive support, and energy storage unit power balance is adopted. The power supply reliability and quality of the isolated AC / DC hybrid microgrid group are improved through coordinated control among the three layers. Reasonable power management is achieved among distributed power sources within the hybrid microgrid group, between sub-microgrids with different distributed power sources capacities and power quality requirements, and between energy storage units. This method is still applicable in the event of communication failures and has good robustness. (2) The AC subgrid and the DC subgrid use adaptive droop control to achieve power coordination. The frequency change and voltage change are introduced into the droop control coefficient. Droop control is performed based on the frequency change and voltage change to achieve fast and stable control of frequency and voltage. (3) The MFO algorithm is used to calculate the interaction power between the AC subgrid and the DC subgrid, which can obtain a better global optimal solution and improve the reliability of the coordinated power control between the AC subgrid and the DC subgrid; (4) In the process of controlling the power output of the energy storage subgrid, an adaptive adjustment coefficient is introduced. When the common bus voltage is higher than the preset voltage threshold, the adaptive adjustment parameter takes effect. When the rate of change of the common bus voltage over time increases, the adaptive adjustment coefficient becomes larger, thereby improving the system inertia capacity and suppressing further deterioration of the voltage. When the rate of change of the common bus voltage over time is in a recovery state, the adaptive adjustment coefficient is reduced to reduce the inertia, thereby shortening the time for the voltage to recover and stabilize. By using the hyperbolic tangent function, the adjustment coefficient can be smoothly and quickly selected autonomously according to the degree of voltage deviation, and the whole process is a continuous adjustment without obvious step process, which is more friendly to the inner loop control of the microgrid converter and achieves no obvious voltage distortion in the microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention provides a flow chart of an embodiment of a hybrid microgrid group power coordination control method.

[0024] Figure 2 A schematic diagram of an embodiment of a hybrid microgrid group topology structure in the hybrid microgrid group power coordination control method provided by the present invention.

[0025] Figure 3 The present invention provides a flow chart of an embodiment of a hybrid microgrid group power coordination control method provided by the present invention, in which an AC subnet uses adaptive droop control to achieve power coordination.

[0026] Figure 4 The present invention provides a flow chart of an embodiment of a hybrid microgrid group power coordination control method provided by the present invention, in which a DC subnet uses adaptive droop control to achieve power coordination.

[0027] Figure 5 The present invention provides a flow chart of an embodiment of a hybrid microgrid group power coordination control method provided by the present invention, in which an AC subnet or a DC subnet realizes power coordination by exchanging power.

[0028] Figure 6 The present invention provides a flow chart of an embodiment of realizing power coordination by power output of an energy storage subnet in the power coordination control method of a hybrid microgrid group provided by the present invention.

[0029] Figure 7 A schematic structural diagram of an embodiment of a hybrid microgrid group power coordination control device provided by the present invention. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] refer to Figure 1 In some embodiments, a hybrid microgrid group power coordination control method is provided, comprising: S1. Establish a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; S2. Each of the AC subnets collects the bus frequency of the corresponding AC bus, and each of the DC subnets collects the bus voltage of the corresponding DC bus; S3: When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range, the AC subnet and the DC subnet adopt adaptive droop control to achieve power coordination; S4, when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination; S5. When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates beyond a second preset range, an adaptive adjustment coefficient is calculated according to the common bus voltage, a droop control coefficient is calculated according to the state of the energy storage unit, and the power output of the energy storage subnet is controlled according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination.

[0032] Further, refer to Figure 2 In step S1, the hybrid microgrid group topology structure is established as follows: Figure 2 As shown, the distributed power sources in the AC subnet are connected to the corresponding AC bus through an AC / AC converter, the distributed power sources in the DC subnet are connected to the corresponding DC bus through a DC / DC converter, the AC bus is connected to the common bus through an AC / DC converter, the DC bus is connected to the common bus through a DC / DC converter, and the energy storage unit in the energy storage subnet is connected to the common bus through a DC / DC converter.

[0033] Furthermore, in step S2, each of the AC subnets collects the bus frequency of the corresponding AC bus, and each of the DC subnets collects the bus voltage of the corresponding DC bus, as a judgment basis and calculation basis for subsequent coordinated control.

[0034] Further, in step S3, when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range, the AC subnet and the DC subnet adopt adaptive droop control to achieve power coordination, wherein the first preset range may be less than 10%, that is, when the bus frequency of the AC subnet fluctuates below 10%, or when the bus voltage of the DC subnet fluctuates below 10%, adaptive droop control is adopted to achieve power coordination, and the control timing is in seconds.

[0035] Specifically, refer to Figure 3 In step S3, the AC subnet adopts adaptive droop control to achieve power coordination, including: S31, calculating the frequency change of the AC subnet within a first preset time period according to the bus frequency; S32, calculating the frequency correction droop coefficient of the AC subnet according to the frequency change, the first preset duration, the rated frequency of the AC subnet and the preset frequency correction parameter; S33, calculating the droop control coefficient of the AC subnet according to the frequency correction droop coefficient, the upper frequency limit value of the AC subnet, the lower frequency limit value of the AC subnet, and the upper limit value of the output power of the AC subnet; S34, calculating the target output frequency of the AC subnet according to the droop control coefficient of the AC subnet, the actual output power of the AC subnet and the upper frequency limit of the AC subnet; S35. Control the frequency output of the AC subnet according to the target output frequency obtained by calculation.

[0036] Specifically, in step S31, according to the bus frequency of the AC subnet, the change △ f .

[0037] In step S32, according to the frequency change Δ f , the first preset duration △t1, the rated frequency of the AC subnet f n and the preset frequency correction parameter k f , calculate the frequency correction droop coefficient of the AC subnet u fix , the specific calculation formula is: ; (1) Among them, △ f Indicates the frequency change, △t1 indicates the first preset duration, f N Indicates the rated frequency of the AC subnet, k f Indicates the preset frequency correction parameters, u fix Indicates the frequency correction droop coefficient of the AC subnet.

[0038] Further, in step S33, the droop coefficient is corrected according to the frequency u fix , the upper frequency limit of the AC subnet f max , the lower frequency limit of the AC subnet f min , the upper limit of the AC subnet output power , calculate the droop control coefficient u of the AC subnet, the specific calculation formula is: ; (2) in, u fix represents the frequency correction droop coefficient, f max Indicates the upper frequency limit of the AC subnet. f min Indicates the lower frequency limit of the AC subnet. It represents the upper limit of the output power of the AC sub-network, and u represents the droop control coefficient of the AC sub-network.

[0039] Further, in step S34, according to the droop control coefficient u of the AC subnet and the actual output power P of the AC subnet, ac and the upper frequency limit of the AC subnet f max , calculate the target output frequency of the AC subnet f , the calculation formula is as follows: ; (3) Where u represents the droop control coefficient of the AC subnetwork, P ac Indicates the actual output power of the AC subnet. f max Indicates the upper frequency limit of the AC subnet. f Indicates the target output frequency of the AC subnet.

[0040] Furthermore, in step S35, a corresponding control signal is generated according to the target output frequency obtained by calculation to control the frequency output of the AC subnet.

[0041] Further, refer to Figure 4 In step S3, the DC subnet adopts adaptive droop control to achieve power coordination, including: S3A, calculating a voltage change of the DC subnet within a second preset time period according to the bus voltage; S3B, calculating the voltage correction droop coefficient of the DC subnet according to the voltage change, the second preset time length, the DC subnet rated voltage and the preset voltage correction parameter; S3C, calculating the droop control coefficient of the DC subnet according to the voltage correction droop coefficient, the voltage upper limit value of the DC subnet, the voltage lower limit value of the DC subnet, and the upper limit value of the DC subnet output power; S3D, calculating the target voltage of the DC subnet according to the droop control coefficient of the DC subnet, the actual output power of the DC subnet and the voltage upper limit of the DC subnet; S3E. Control the voltage output of the DC subnet according to the calculated target voltage.

[0042] Specifically, in step S3A, the voltage variation of the DC subnet within the second preset time length Δt2 is ΔV dc .

[0043] Further, in step S3B, according to the voltage change ΔV dc , the second preset time length △t2, the DC subnet rated voltage V dcN and the preset voltage correction parameter k v , calculate the voltage correction droop coefficient w of the DC subnet fix , the calculation formula is as follows: ; (4) Among them, △V dc represents the voltage change, △t2 represents the second preset time, V dcN Indicates the rated voltage of the DC subnet, k v Indicates the preset voltage correction parameter, w fix Indicates the voltage correction droop coefficient of the DC subnetwork.

[0044] Further, in step S3C, the droop coefficient w is corrected according to the voltage fix , the upper voltage limit of the DC subnet , the lower voltage limit of the DC subnet , the upper limit of the DC subnet output power , calculate the droop control coefficient w of the DC subnetwork, the calculation formula is as follows: ; (5) Among them, w fix represents the voltage correction droop coefficient, Indicates the upper voltage limit of the DC subnet. Indicates the lower voltage limit of the DC subnet. It represents the upper limit of the DC sub-grid output power, and w represents the droop control coefficient of the DC sub-grid.

[0045] Further, in step S3D, according to the droop control coefficient w of the DC subnet and the actual output power P of the DC subnet, dc and the upper voltage limit of the DC subnet , calculate the target voltage V of the DC subnet dc , the calculation formula is as follows: ; (6) Where w represents the droop control coefficient of the DC subnetwork, P dc Indicates the actual output power of the DC subnet, Indicates the voltage upper limit of the DC subnet, V dc Indicates the target voltage of the DC subnet.

[0046] Furthermore, in step S3E, a corresponding control signal is generated according to the calculated target voltage to control the voltage output of the DC subnet.

[0047] When the bus frequency of the AC subgrid or the bus voltage of the DC subgrid fluctuates within the first preset range, the distributed power sources in each subgrid realize autonomous power coordination within the subgrid through adaptive correction droop control. The droop coefficient can be adaptively corrected according to the frequency change rate of the AC subgrid and the voltage change rate of the DC subgrid, thereby realizing rapid and stable control of frequency and voltage and maintaining subgrid power autonomy.

[0048] Further, refer to Figure 5 In step S4, when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination, specifically including: S41, establishing an objective function with the bus frequency deviation of the AC subnet being the lowest and the bus voltage deviation of the DC subnet being the lowest; S42, constructing power conservation constraints for the AC subnet and the DC subnet, frequency constraints for the AC subnet, and voltage constraints for the DC subnet; S43, based on the MFO algorithm, calculating the AC subnet interactive power and the DC subnet interactive power that satisfy the objective function, the AC subnet and DC subnet power conservation constraints, the AC subnet frequency constraints, and the DC subnet voltage constraints; S44. Control the output power of the corresponding AC subnet and DC subnet according to the calculated AC subnet interactive power and DC subnet interactive power.

[0049] Specifically, in step S41, an objective function is established to minimize the bus frequency deviation of the AC subnet and minimize the bus voltage deviation of the DC subnet, which specifically includes: ; (7) ; (8) ; (9) in, f i represents the actual output frequency of the ith AC subnet, n represents the number of AC subnets, f N Indicates the rated frequency of the AC subnet. F1 indicates that the bus frequency deviation of the AC subnet is the lowest. represents the actual voltage of the ith DC subnet, V dcN represents the rated voltage of the DC subnet, m represents the number of DC subnets, F2 represents the bus voltage deviation of the DC subnet is the lowest, and F represents the objective function.

[0050] Furthermore, in step S42, the power conservation constraints of the AC subnet and the DC subnet are as follows: ; (10) ; (11) Where n represents the number of AC subnets, m represents the number of DC subnets, represents the interaction power of the ith AC subnetwork, represents the interaction power of the ith DC subnetwork, represents the interactive reactive power of the ith AC subnetwork.

[0051] Furthermore, the AC subnet frequency constraints are as follows: ; (12) in, Respectively represent the frequency difference of each AC subnet, Indicates the maximum frequency deviation threshold of the AC subnet.

[0052] Furthermore, the DC subnet voltage constraints are as follows: ; (13) in, Respectively represent the voltage difference of each DC subnet, Indicates the maximum voltage deviation threshold of the DC subnet.

[0053] Further, in step S43, based on the MFO algorithm, the AC subgrid interaction power and the DC subgrid interaction power that satisfy the objective function, the AC subgrid and the DC subgrid power conservation constraints, the AC subgrid frequency constraints, and the DC subgrid voltage constraints are calculated, including: S431, using the power conservation constraints of the AC subnet and the DC subnet, the frequency constraints of the AC subnet, and the voltage constraints of the DC subnet as boundary conditions to construct a search space; S432, randomly generating initial values ​​of the AC subnet interaction power and the DC subnet interaction power in the search space as moths; S433, calculating the fitness of the moth based on the objective function; S434, sorting the moths in descending order according to their fitness, and selecting a preset number of moths with the highest order as flames; S435. In each iteration, the moth approaches the flame along the spiral flight path and calculates the fitness, updates the flame according to the fitness, and updates the spiral flight path until the stop condition is met and the optimal solution is output.

[0054] Moth-Flame Optimization (MFO) is a nature-inspired optimization algorithm proposed by S. Mirjalili in 2015. The algorithm simulates the behavior of moths flying around a light source at night. This behavior is manifested as a spiral trajectory, similar to the phenomenon of moths "flying into fire". The core idea of ​​the MFO algorithm is to simulate the spiral path of moths flying around a light source (flame), where "moth" represents a possible solution and "flame" represents the current optimal solution. By continuously updating the position of the moth to approach the flame, the algorithm can gradually find the global optimal solution.

[0055] When the bus frequency of the AC subgrid or the bus voltage of the DC subgrid fluctuates within the second preset range, a multi-objective optimization algorithm is used to minimize the frequency deviation of the AC subgrid and the voltage deviation of the DC subgrid, and the power conservation, frequency and voltage operation of the subgrid group are taken as constraints to construct a multi-objective optimization control model of the AC / DC hybrid microgrid, and the moth-to-flame optimization algorithm is used to obtain the interactive power P of each AC / DC microgrid. ea , P ed , where P ea It represents the power exchanged between the AC subnet and the public bus, that is, the interactive support power, P ed It represents the power exchanged between the DC subgrid and the public bus. Here, the interactive support inflow to the subgrid is defined as positive, and outflow to the subgrid is defined as negative. Through the design of this layer of control, the key control parameters of the power electronic converter (AC / DC, DC / DC) of each AC / DC subgrid can be given, thereby realizing the power optimization scheduling between AC / DC microgrids.

[0056] Further, refer to Figure 6 In step S5, an adaptive adjustment coefficient is calculated according to the common bus voltage, a droop control coefficient is calculated according to the state of the energy storage unit, and the power output of the energy storage subnet is controlled according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination, including: S51, collecting common bus voltage; S52, calculating the rate of change of the common bus voltage over time according to the common bus voltage; S53, calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time; S54, detecting the state of charge and the maximum output power of the energy storage unit, and calculating the droop control coefficient of the power output of the energy storage subnet according to the state of charge and the maximum output power; S55, calculating the output power of the energy storage subnetwork according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subnetwork; S56, collecting the bus voltage of the energy storage unit; S57, performing current calculation according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; S58, inputting the energy storage unit exchange current into a PI controller for calculation, and outputting a target voltage of the energy storage unit; S59, performing PWM modulation on the target voltage of the energy storage unit to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

[0057] Specifically, in step S52, the rate of change of the common bus voltage over time is the differential of the common bus voltage with respect to time, that is, , where V cb Indicates the common bus voltage.

[0058] Further, in step S53, the adaptive adjustment coefficient is calculated according to the common bus voltage and the rate of change of the common bus voltage over time, including: The common bus voltage is compared with a preset voltage threshold, and when the common bus voltage is less than or equal to the preset voltage threshold, the adaptive adjustment coefficient is 1; When the common bus voltage is greater than the preset voltage threshold, the adaptive adjustment coefficient is calculated according to the hyperbolic tangent function value of the rate of change of the common bus voltage over time.

[0059] Specifically, when the common bus voltage is greater than the preset voltage threshold and the rate of change of the common bus voltage over time is greater than 0, the adaptive adjustment coefficient is the sum of the hyperbolic tangent function value of the product of the rate of change of the common bus voltage over time and the corresponding adjustment rate and 1; When the common bus voltage is greater than the preset voltage threshold and the rate of change of the common bus voltage over time is less than 0, the adaptive adjustment coefficient is the difference between 1 and the hyperbolic tangent function value of the product of the rate of change of the common bus voltage over time and the corresponding adjustment rate.

[0060] Specifically, the adaptive adjustment coefficient is calculated by the following formula: ; (14) Among them, a k is the adaptive adjustment coefficient, V cb Represents the common bus voltage, m1 and m2 are the adjustment rate setting values, which can be adjusted according to the control requirements, V cbN Indicates the preset voltage threshold.

[0061] When the common bus voltage is lower than the preset voltage threshold, it means that the common bus voltage deviation of the hybrid microgrid is acceptable; when the common bus voltage is higher than the preset voltage threshold, the adaptive adjustment parameter takes effect. When the rate of change of the common bus voltage over time increases, the adaptive adjustment coefficient becomes larger, improving the inertia capacity of the system and inhibiting further deterioration of the voltage; when the rate of change of the common bus voltage over time is in a recovery state, the adaptive adjustment coefficient is reduced to reduce inertia, thereby shortening the time for the voltage to recover and stabilize.

[0062] By using the hyperbolic tangent function, the adjustment coefficient can be smoothly and quickly selected autonomously according to the degree of voltage deviation, and the whole process is continuous adjustment without obvious step process. It is more friendly to the inner loop control of the microgrid converter and achieves no obvious voltage distortion in the microgrid.

[0063] Furthermore, in step S54, the droop control coefficient of the energy storage subgrid power output is calculated by the following formula: ; Among them, b k represents the droop control coefficient of the energy storage subgrid power output, k O represents the parameter for adjusting the droop coefficient, μ represents the parameter for adjusting the SOC balancing speed of each energy storage unit, and P ds,k Indicates the maximum output power of the kth energy storage unit, SOC k It represents the current state of charge of the kth energy storage unit, and SOC* represents the reference state of charge value given by the battery standard of each energy storage unit.

[0064] Furthermore, in step S55, the output power of the energy storage subnet is calculated according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subnet, and the calculation formula is as follows: ; Among them, P ds,k represents the output power of the energy storage subnet, b k represents the droop control coefficient of the energy storage subgrid power output, a k is the adaptive adjustment coefficient, V cb Indicates the common bus voltage.

[0065] Furthermore, after calculating and obtaining the output power of the energy storage subnet, the bus voltage of the energy storage unit is collected, and the current is calculated according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; the energy storage unit exchange current is input into the PI controller for calculation, and the energy storage unit target voltage is output; the energy storage unit target voltage is PWM modulated to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

[0066] refer to Figure 7 In some embodiments, a hybrid microgrid group power coordination control device is provided, comprising: A topology building module 201 is used to establish a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; A frequency acquisition module 202, each of the AC subnets acquires the bus frequency of the corresponding AC bus through the frequency acquisition module; A voltage acquisition module 203, each of the DC subnets acquires the bus voltage of the corresponding DC bus through the voltage acquisition module; The adaptive droop control module 204 is used to control the AC subnet and the DC subnet to adopt adaptive droop control to achieve power coordination when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range; The power interaction control module 205 is used to calculate the AC subnet interaction power and the DC subnet interaction power based on the MFO algorithm when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, and control the AC subnet and the DC subnet to exchange power through the AC subnet interaction power and the DC subnet interaction power to achieve power coordination; The energy storage control module 206 is used to calculate an adaptive adjustment coefficient according to the common bus voltage, calculate a droop control coefficient according to the state of the energy storage unit, and control the power output of the energy storage subnetwork to achieve power coordination according to the adaptive adjustment coefficient and the droop control coefficient when the bus frequency of the AC subnetwork or the bus voltage of the DC subnetwork fluctuates beyond a second preset range.

[0067] Furthermore, the distributed power sources in the AC subnet are connected to the corresponding AC bus through an AC / AC converter, the distributed power sources in the DC subnet are connected to the corresponding DC bus through a DC / DC converter, the AC bus is connected to the common bus through an AC / DC converter, the DC bus is connected to the common bus through a DC / DC converter, and the energy storage unit in the energy storage subnet is connected to the common bus through a DC / DC converter.

[0068] Furthermore, the AC subnet adopts adaptive droop control to achieve power coordination, including: Calculating the frequency change of the AC subnet within a first preset time period according to the bus frequency; Calculating a frequency correction droop coefficient of the AC subnet according to the frequency change, the first preset duration, the rated frequency of the AC subnet and a preset frequency correction parameter; Calculate the droop control coefficient of the AC subnet according to the frequency correction droop coefficient, the upper frequency limit value of the AC subnet, the lower frequency limit value of the AC subnet, and the upper limit value of the output power of the AC subnet; Calculate the target output frequency of the AC subnet based on the droop control coefficient of the AC subnet, the actual output power of the DC subnet and the upper frequency limit of the AC subnet; The frequency output of the AC subnet is controlled according to the calculated target output frequency.

[0069] Furthermore, the DC subnet adopts adaptive droop control to achieve power coordination, including: Calculating a voltage variation of the DC subnet within a second preset time period according to the bus voltage; Calculating a voltage correction droop coefficient of the DC subnet according to the voltage change, the second preset time length, the DC subnet rated voltage and a preset voltage correction parameter; Calculate the droop control coefficient of the DC subnet according to the voltage correction droop coefficient, the voltage upper limit value of the DC subnet, the voltage lower limit value of the DC subnet, and the upper limit value of the output power of the DC subnet; Calculate the target voltage of the DC subnet according to the droop control coefficient of the DC subnet, the actual output power of the DC subnet and the voltage upper limit of the DC subnet; The voltage output of the DC subnet is controlled according to the calculated target voltage.

[0070] Further, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination, including: Establishing objective functions with the lowest bus frequency deviation of the AC subnet and the lowest bus voltage deviation of the DC subnet; Construct power conservation constraints for AC and DC subnets, frequency constraints for AC subnets, and voltage constraints for DC subnets; Based on the MFO algorithm, the AC subgrid interaction power and the DC subgrid interaction power that satisfy the objective function, the AC subgrid and the DC subgrid power conservation constraints, the AC subgrid frequency constraints, and the DC subgrid voltage constraints are calculated; The output power of the corresponding AC subgrid and DC subgrid is controlled according to the calculated AC subgrid interactive power and DC subgrid interactive power.

[0071] Furthermore, the energy storage control module calculates an adaptive adjustment coefficient according to the common bus voltage, calculates a droop control coefficient according to the state of the energy storage unit, and controls the power output of the energy storage subnet according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination, including: Collecting common bus voltage; Calculating the rate of change of the common bus voltage over time according to the common bus voltage; Calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time; Detecting the state of charge and the maximum output power of the energy storage unit, and calculating the droop control coefficient of the power output of the energy storage subnet according to the state of charge and the maximum output power; Calculating the output power of the energy storage subgrid according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subgrid; Collect the bus voltage of the energy storage unit; Perform current calculation according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; Inputting the energy storage unit exchange current into a PI controller for calculation, and outputting a target voltage of the energy storage unit; The target voltage of the energy storage unit is PWM modulated to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

[0072] Furthermore, the energy storage control module calculates an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time, including: The common bus voltage is compared with a preset voltage threshold, and when the common bus voltage is less than or equal to the preset voltage threshold, the adaptive adjustment coefficient is 1; When the common bus voltage is greater than the preset voltage threshold, the adaptive adjustment coefficient is calculated according to the hyperbolic tangent function value of the rate of change of the common bus voltage over time.

[0073] Furthermore, the droop control coefficient of the energy storage subgrid power output is calculated by the following formula: ; Among them, b k represents the droop control coefficient of the energy storage subgrid power output, k O represents the parameter for adjusting the droop coefficient, μ represents the parameter for adjusting the SOC balancing speed of each energy storage unit, and P ds,kIndicates the maximum output power of the kth energy storage unit, SOC k It represents the current state of charge of the kth energy storage unit, and SOC* represents the reference state of charge value given by the battery standard of each energy storage unit.

[0074] In some embodiments, an electronic device is also provided, including a processor and a storage device, wherein the storage device stores a plurality of instructions, and the processor is used to read the instructions and execute the above method.

[0075] The hybrid microgrid group power coordination control method and device provided in the above embodiment have at least the following beneficial effects: (1) Under different frequency fluctuations and voltage fluctuations, a power management strategy consisting of subgrid power autonomous control, inter-subgrid power interactive support, and energy storage unit power balance is adopted. The power supply reliability and quality of the isolated AC / DC hybrid microgrid group are improved through coordinated control among the three layers. Reasonable power management is achieved among distributed power sources within the hybrid microgrid group, between sub-microgrids with different distributed power sources capacities and power quality requirements, and between energy storage units. This method is still applicable in the event of communication failures and has good robustness. (2) The AC subgrid and the DC subgrid use adaptive droop control to achieve power coordination. The frequency change and voltage change are introduced into the droop control coefficient. Droop control is performed based on the frequency change and voltage change to achieve rapid and stable control of frequency and voltage. (3) The MFO algorithm is used to calculate the interaction power between the AC subgrid and the DC subgrid, which can obtain a better global optimal solution and improve the reliability of the coordinated power control between the AC subgrid and the DC subgrid; (4) In the process of controlling the power output of the energy storage subgrid, an adaptive adjustment coefficient is introduced. When the common bus voltage is higher than the preset voltage threshold, the adaptive adjustment parameter takes effect. When the rate of change of the common bus voltage over time increases, the adaptive adjustment coefficient becomes larger, thereby improving the system inertia capacity and suppressing further deterioration of the voltage. When the rate of change of the common bus voltage over time is in a recovery state, the adaptive adjustment coefficient is reduced to reduce the inertia, thereby shortening the time for the voltage to recover and stabilize. By using the hyperbolic tangent function, the adjustment coefficient can be smoothly and quickly selected autonomously according to the degree of voltage deviation, and the whole process is a continuous adjustment without obvious step process, which is more friendly to the inner loop control of the microgrid converter and achieves no obvious voltage distortion in the microgrid.

[0076] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hybrid microgrid group power coordination control method, characterized in that: include: Establishing a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; Each of the AC subnets collects the bus frequency of the corresponding AC bus, and each of the DC subnets collects the bus voltage of the corresponding DC bus; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range, the AC subnet and the DC subnet adopt adaptive droop control to achieve power coordination; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, the AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination; When the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates beyond a second preset range, an adaptive adjustment coefficient is calculated according to the common bus voltage, a droop control coefficient is calculated according to the state of the energy storage unit, and the power output of the energy storage subnet is controlled according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination.

2. The method according to claim 1, characterized in that The distributed power sources in the AC subnet are connected to the corresponding AC bus through an AC / AC converter, the distributed power sources in the DC subnet are connected to the corresponding DC bus through a DC / DC converter, the AC bus is connected to the common bus through an AC / DC converter, the DC bus is connected to the common bus through a DC / DC converter, and the energy storage unit in the energy storage subnet is connected to the common bus through a DC / DC converter.

3. The method according to claim 1, characterized in that The AC subnetwork adopts adaptive droop control to achieve power coordination, including: Calculating the frequency change of the AC subnet within a first preset time period according to the bus frequency; Calculating a frequency correction droop coefficient of the AC subnet according to the frequency change, the first preset duration, the rated frequency of the AC subnet and a preset frequency correction parameter; Calculate the droop control coefficient of the AC subnet according to the frequency correction droop coefficient, the upper frequency limit value of the AC subnet, the lower frequency limit value of the AC subnet, and the upper limit value of the output power of the AC subnet; Calculate the target output frequency of the AC subnet based on the droop control coefficient of the AC subnet, the actual output power of the DC subnet and the upper frequency limit of the AC subnet; The frequency output of the AC subnet is controlled according to the calculated target output frequency.

4. The method according to claim 1, characterized in that: The DC subgrid adopts adaptive droop control to achieve power coordination, including: Calculating a voltage variation of the DC subnet within a second preset time period according to the bus voltage; Calculating a voltage correction droop coefficient of the DC subnet according to the voltage change, the second preset time length, the DC subnet rated voltage and a preset voltage correction parameter; Calculate the droop control coefficient of the DC subnet according to the voltage correction droop coefficient, the voltage upper limit value of the DC subnet, the voltage lower limit value of the DC subnet, and the upper limit value of the output power of the DC subnet; Calculate the target voltage of the DC subnet according to the droop control coefficient of the DC subnet, the actual output power of the DC subnet and the voltage upper limit of the DC subnet; The voltage output of the DC subnet is controlled according to the calculated target voltage.

5. The method according to claim 1, characterized in that: The AC subnet interactive power and the DC subnet interactive power are calculated based on the MFO algorithm, and the AC subnet and the DC subnet exchange power through the AC subnet interactive power and the DC subnet interactive power to achieve power coordination, including: Establishing objective functions with the lowest bus frequency deviation of the AC subnet and the lowest bus voltage deviation of the DC subnet; Construct power conservation constraints for AC and DC subnets, frequency constraints for AC subnets, and voltage constraints for DC subnets; Based on the MFO algorithm, the AC subgrid interaction power and the DC subgrid interaction power that satisfy the objective function, the AC subgrid and the DC subgrid power conservation constraints, the AC subgrid frequency constraints, and the DC subgrid voltage constraints are calculated; The output power of the corresponding AC subgrid and DC subgrid is controlled according to the calculated AC subgrid interactive power and DC subgrid interactive power.

6. The method according to claim 2, characterized in that Calculating an adaptive adjustment coefficient according to the common bus voltage, calculating a droop control coefficient according to the state of the energy storage unit, and controlling the power output of the energy storage subnet according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination, including: Collecting common bus voltage; Calculating the rate of change of the common bus voltage over time according to the common bus voltage; Calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time; Detecting the state of charge and the maximum output power of the energy storage unit, and calculating the droop control coefficient of the power output of the energy storage subnet according to the state of charge and the maximum output power; Calculating the output power of the energy storage subgrid according to the common bus voltage, the adaptive adjustment coefficient and the droop control coefficient of the power output of the energy storage subgrid; Collect the bus voltage of the energy storage unit; Perform current calculation according to the output power of the energy storage subnet and the bus voltage of the energy storage unit to obtain the energy storage unit exchange current; Inputting the energy storage unit exchange current into a PI controller for calculation, and outputting a target voltage of the energy storage unit; The target voltage of the energy storage unit is PWM modulated to generate a power exchange control signal to control the corresponding DC / DC converter to perform power exchange.

7. The method according to claim 6, characterized in that Calculating an adaptive adjustment coefficient according to the common bus voltage and the rate of change of the common bus voltage over time includes: The common bus voltage is compared with a preset voltage threshold, and when the common bus voltage is less than or equal to the preset voltage threshold, the adaptive adjustment coefficient is 1; When the common bus voltage is greater than the preset voltage threshold, the adaptive adjustment coefficient is calculated according to the hyperbolic tangent function value of the rate of change of the common bus voltage over time.

8. The method according to claim 6, characterized in that The droop control coefficient of the energy storage subgrid power output is calculated using the following formula: ; Among them, b k represents the droop control coefficient of the energy storage subgrid power output, k O represents the parameter for adjusting the droop coefficient, μ represents the parameter for adjusting the SOC balancing speed of each energy storage unit, and P ds,k Indicates the maximum output power of the kth energy storage unit, SOC k It represents the current state of charge of the kth energy storage unit, and SOC* represents the reference state of charge value given by the battery standard of each energy storage unit.

9. A hybrid microgrid group power coordination control device, characterized in that: include: A topology building module, used to establish a hybrid microgrid group topology structure, wherein the hybrid microgrid group topology includes multiple AC subgrids, DC subgrids and energy storage subgrids; A frequency acquisition module, each of the AC subnets acquires the bus frequency of the corresponding AC bus through the frequency acquisition module; A voltage acquisition module, each of the DC subnets acquires the bus voltage of the corresponding DC bus through the voltage acquisition module; An adaptive droop control module, used to control the AC subnet and the DC subnet to adopt adaptive droop control to achieve power coordination when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a first preset range; A power interaction control module, which is used to calculate the AC subnet interaction power and the DC subnet interaction power based on the MFO algorithm when the bus frequency of the AC subnet or the bus voltage of the DC subnet fluctuates within a second preset range, and control the AC subnet and the DC subnet to exchange power through the AC subnet interaction power and the DC subnet interaction power to achieve power coordination; The energy storage control module is used to calculate an adaptive adjustment coefficient according to the common bus voltage, calculate a droop control coefficient according to the state of the energy storage unit, and control the power output of the energy storage subnetwork according to the adaptive adjustment coefficient and the droop control coefficient to achieve power coordination when the bus frequency of the AC subnetwork or the bus voltage of the DC subnetwork fluctuates beyond a second preset range.

10. An electronic device, characterized in that: The method comprises a processor and a storage device, wherein the storage device stores a plurality of instructions, and the processor is used to read the instructions and execute the method according to any one of claims 1 to 8.

Citation Information

Patent Citations

  • A Power Cooperative Control Method for Isolated AC / DC Hybrid Microgrid Groups

    CN111740426B

  • Variable regulation factor SOC droop control method of distributed energy storage system

    CN109687490A

  • Island AC-DC hybrid microgrid group power cooperative control method

    CN111740426A

  • Island AC / DC hybrid microgrid control method and system considering power constraint

    CN114447934A

  • Micro-grid energy storage optimal configuration method and terminal

    CN115860235A

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