A co-directional progressive convergence energy storage state-of-charge consistency allocation cooperative control method and related device

Abstract

The application provides a same-direction gradual convergence energy storage state of charge consistency distribution cooperative control method and related device, the method comprises the following steps: for the energy storage network control strategy in the micro-grid, a unified generalized droop characteristic equation of the energy storage device is established; according to the equivalent SOC discharge model of the energy storage, in combination with considering the energy storage charge and discharge comfort interval, the state variable of the secondary control under the SOC consistency target in the expected time is designed when the energy storage participates in power-frequency regulation; in combination with the unified generalized droop characteristic equation of the energy storage device and the second-order consistency control equation, an SOC gradual consistency control scheme taking the state variable of the secondary control under the designed SOC consistency target as the target is established. The application can improve the reliable stability of networked distributed energy storage cooperative operation in the remote rural micro-grid scene.

Description

Technical Field

[0001] The present invention relates to the field of distributed energy storage control, and in particular to a method and related device for co-ordinated control of energy storage state of charge consistency distribution with progressive convergence in the same direction. Background Art

[0002] With the large-scale integration of photovoltaic resources into weak, remote rural power grids, concerns have been raised about the undesirable characteristics of grid-connected power generation, such as volatility and intermittent uncertainty, as well as the challenges of local energy consumption. Energy storage devices, with their bidirectional regulation and rapid response capabilities, can effectively smooth out fluctuations in the output power of photovoltaic power sources and enable the coordinated construction of renewable energy networks. Consequently, they are widely deployed in remote rural power grids with high penetrations of photovoltaic power, becoming an indispensable component of these systems.

[0003] In rural microgrids with a high proportion of photovoltaic power, energy storage plays a vital role in ensuring the stable operation of the microgrid and maintaining system power balance and power supply quality. Through grid-based control, energy storage provides effective frequency and voltage support for distributed photovoltaics, enabling local photovoltaic consumption, improving photovoltaic resource utilization, and ensuring the stable operation of the microgrid. In this scenario, system frequency and voltage are jointly maintained by networked energy storage in the rural microgrid. Energy storage should be considered a grid-based voltage source device, with a particular focus on its coordinated control, which falls under the category of secondary control.

[0004] Centralized secondary control achieves coordinated control of multiple objectives by collecting and processing global information through a central controller. However, this control approach is prone to single-point failures, has poor plug-and-play scalability, and poor control robustness. Furthermore, its global communication implementation is costly in large-scale networked energy storage control, making it unsuitable for rural networked energy storage microgrid control structures. Distributed secondary control, on the other hand, achieves global control of networked energy storage coordination through local information exchange between energy storage systems. Furthermore, in the coordinated secondary control of networked distributed energy storage, since the dynamic characteristics of energy storage are closely related to its state of charge (SOC), the SOC of the energy storage should be controlled to operate within an appropriate range to ensure good dynamic response capabilities. Furthermore, due to differences in the characteristics of energy storage systems, the SOC of each energy storage system can vary during actual operation. Ignoring the consistency of energy storage SOC in considering coordination issues will lead to increasing differences in SOC, resulting in overcharging and discharging of some energy storage systems, causing SOC violations and shutdown, coordinated power redistribution, and system frequency fluctuations, which seriously affect microgrid stability.

[0005] To address the above issues, a secondary control scheme based on a consistency algorithm is an effective means to solve the SOC consistency of distributed networked energy storage and improve the operational reliability of weak rural power grids. Existing secondary control schemes rarely consider the impact of SOC during energy storage coordination, and directly use SOC as the control variable to force balancing in energy storage SOC balancing control, resulting in unnecessary mutual charging and discharging between energy storages. Further consideration is needed for its coordinated control problem. Summary of the Invention

[0006] In order to improve the reliability and stability of the coordinated operation of networked distributed energy storage in remote rural microgrid scenarios, the present invention provides a method and related devices for coordinated control of energy storage state of charge consistency distribution with uniform and progressive convergence.

[0007] In a first aspect, the present invention provides a method for coordinated control of energy storage state of charge consistency distribution with progressive convergence in the same direction, comprising the following steps:

[0008] Step 1: Based on the energy storage network control strategy in the microgrid, a unified generalized droop characteristic equation of energy storage equipment is established;

[0009] Step 2: Based on the energy storage equivalent SOC discharge model and taking into account the energy storage charging and discharging comfort zone, design the state variables for secondary control when the energy storage participates in power-frequency regulation to achieve the SOC consistency target within the expected time.

[0010] Step 3: Combine the unified generalized droop characteristic equation of the energy storage device in step 1 with the second-order consistency control equation to establish an SOC progressive consistency control scheme with the state variables of the secondary control under the SOC consistency target designed in step 2 as the target.

[0011] Furthermore, step 1 specifically includes: listing the active-frequency swing equations of the two control methods when the energy storage device adopts the VSG control mode and the droop control mode to form a network, and then calculating and rewriting the swing equation to obtain the expression equation of the angular frequency to the power difference under the two control methods. Finally, through comparison, it is concluded that the droop control is actually a special form of VSG control. When J=0 and D=0, the two control methods are equivalent. For the equivalent synchronous machine droop frequency modulation external characteristics, the following normalization processing is performed, and the generalized frequency droop coefficient is set to be k D , then for energy storage device i, we have:

[0012]

[0013] The unified generalized droop characteristic equation of the energy storage device is expressed as:

[0014]

[0015] Subscript i represents the energy storage number, ωmi is the virtual rotor angular frequency, ω0 is the system rated angular frequency, P ei is the actual output power measured, k Di is the generalized frequency droop coefficient.

[0016] Furthermore, step 2 specifically includes: listing the energy storage SOC calculation formula, designing the energy storage progressive control implementation plan based on the energy storage SOC calculation formula, and then determining the consistency target point S during the discharge process based on the performance indicator relationship between the energy storage SOC and the battery output voltage. e Should satisfy S e ≥0.2, the energy storage outputs constant power according to the preset power distribution ratio during the process of gradual consistency, then:

[0017]

[0018] Therefore, the energy storage output power distribution ratio is reversed to obtain:

[0019]

[0020] The above formula shows that the energy storage power distribution should be distributed according to its pre-used energy ratio within the SOC limit. In order to meet the above control objectives, the state variable x of the consistency control is defined as i , specifically:

[0021]

[0022] Where C exi is the pre-used energy size of energy storage i, which is specifically defined as follows:

[0023]

[0024] In the above pre-used energy expression, the consistency target point S e Should be kept between 0.2 and 0.9, P tui The discharge direction is positive, that is, when discharging, P tui >0, when charging P tui ≤0.

[0025] Furthermore, step 3 specifically includes: introducing the power command compensation input u into the unified generalized droop characteristic equation of the energy storage device established in step 1 i , let y in the second-order consistent control equation i (t) = u i , energy storage output power P tui With the energy storage inverter power output P ei Consistent, state variables controlled by consistency The SOC asymptotic consistency control algorithm to achieve the SOC asymptotic consistency goal is expressed as:

[0026]

[0027] Where N i represents the set of nodes communicating with i. To simplify the control scheme, the global communication weight is set to the same value, k a 、k b 、k ε are the corresponding control coefficients.

[0028] A coordinated control device for consistent allocation of energy storage state of charge with progressive convergence in the same direction, comprising:

[0029] The first module is used to establish a unified generalized droop characteristic equation for energy storage devices based on the energy storage network control strategy within the microgrid;

[0030] The second module is used to design the state variables of secondary control when the energy storage participates in power-frequency regulation, based on the energy storage equivalent SOC discharge model and taking into account the energy storage charging and discharging comfort range, so as to achieve the SOC consistency target within the expected time.

[0031] The third module is used to combine the unified generalized droop characteristic equation of energy storage equipment with the second-order consistency control equation to establish an SOC progressive consistency control scheme with the state variables of the secondary control under the designed SOC consistency target as the target.

[0032] Furthermore, the first module is specifically used to: respectively list the active-frequency swing equations of the two control methods when the energy storage device adopts the VSG control mode and the droop control mode to form a network, and then calculate and rewrite the swing equation to obtain the expression equation of the angular frequency to the power difference under the two control methods. Finally, through comparison, it is concluded that the droop control is actually a special form of VSG control. When J=0 and D=0, the two control methods are equivalent. For the equivalent synchronous machine droop frequency modulation external characteristics, the following normalization processing is performed, and the generalized frequency droop coefficient is set to be k D , then for energy storage device i, we have:

[0033]

[0034] The unified generalized droop characteristic equation of the energy storage device is expressed as:

[0035]

[0036] Subscript i represents the energy storage number, ω mi is the virtual rotor angular frequency, ω0 is the system rated angular frequency, P ei is the actual output power measured, k Di is the generalized frequency droop coefficient.

[0037] Furthermore, the second module is specifically used to: list the energy storage SOC calculation formula, design the energy storage progressive control implementation plan based on the energy storage SOC calculation formula, and then determine the consistency target point S during the discharge process based on the performance indicator relationship between the energy storage SOC and the battery output voltage. e Should satisfy S e ≥0.2, the energy storage outputs constant power according to the preset power distribution ratio during the process of gradual consistency, then:

[0038]

[0039] Therefore, the energy storage output power distribution ratio is reversed to obtain:

[0040]

[0041] The above formula shows that the energy storage power distribution should be distributed according to its pre-used energy ratio within the SOC limit. In order to meet the above control objectives, the state variable x of the consistency control is defined as i , specifically:

[0042]

[0043] Where C exi is the pre-used energy size of energy storage i, which is specifically defined as follows:

[0044]

[0045] In the above pre-used energy expression, the consistency target point S e Should be kept between 0.2 and 0.9, P tui The discharge direction is positive, that is, when discharging, P tui >0, when charging P tui ≤0.

[0046] Furthermore, the third module is specifically used to: introduce the power command compensation input u into the established unified generalized droop characteristic equation of the energy storage device i , let y in the second-order consistent control equation i (t) = u i , energy storage output power P tui With the energy storage inverter power output P ei Consistent, state variables controlled by consistency The SOC asymptotic consistency control algorithm to achieve the SOC asymptotic consistency goal is expressed as:

[0047]

[0048] Where N irepresents the set of nodes communicating with i. To simplify the control scheme, the global communication weight is set to the same value, k a 、k b 、k ε are the corresponding control coefficients.

[0049] A coordinated control system for energy storage state of charge consistency distribution with uniform and progressive convergence, comprising: a computer-readable storage medium and a processor;

[0050] The computer-readable storage medium is used to store executable instructions;

[0051] The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the energy storage charge state consistency distribution collaborative control method with the same-direction progressive convergence.

[0052] A non-transitory computer-readable storage medium stores a computer program, which, when executed by a processor, implements the energy storage state of charge consistency distribution collaborative control method with uniform and progressive convergence.

[0053] Compared with the existing methods, the present invention has the following advantages:

[0054] The method proposed in the present invention is aimed at traditional networked energy storage control that only contains primary control. It can give full play to the networking role of energy storage, maintain the power balance of the microgrid system and provide frequency support. At the same time, the secondary control scheme in the present invention adopts distributed consistency control, which is more in line with the operating scenarios of distributed networked energy storage than existing secondary control schemes. In addition, the present invention performs equivalent processing on the synchronization external characteristics of the networking control, so that the secondary control distribution scheme is applicable to all networking energy storage in the system. Finally, the scheme of the present invention effectively solves the stability problem caused by the uneven SOC in energy storage collaboration, and the progressive consistency scheme avoids unnecessary power circulation between energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a performance indicator diagram of energy storage SOC and battery output voltage according to an embodiment of the present invention;

[0056] Figure 2 This is a diagram of the consistent communication topology structure of the photovoltaic storage microgrid scenario according to an embodiment of the present invention;

[0057] Figure 3 This is a control structure diagram of the SOC progressive consistency controller according to an embodiment of the present invention;

[0058] Figure 4 This is a diagram showing the progressive effect of energy storage according to an embodiment of the present invention. DETAILED DESCRIPTION

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0060] A first aspect of the present invention provides a method for coordinated control of energy storage state of charge consistency distribution with uniform and progressive convergence, comprising the following steps:

[0061] Step 1: For energy storage grid control strategies within microgrids, regardless of whether they possess inertia support or damping capabilities, a unified equivalent synchronous machine external characteristic, namely a unified generalized droop characteristic equation for energy storage devices, is first established to simplify the expression for subsequent processes. Energy storage devices collaborate with photovoltaics to provide effective frequency and voltage support, maintaining microgrid power balance and reliability, and acting as a voltage source within the microgrid system. Currently, commonly used grid control methods include droop control and VSG control. To ensure consistency control is applicable to both grid control methods and to ensure consistent coordination of energy storage under different grid control systems in microgrids, a generalized unification of the synchronous machine frequency regulation external characteristics exhibited by energy storage grid control strategies is required.

[0062] When the energy storage device adopts the VSG control mode to form a grid, its active power-frequency swing equation is expressed as:

[0063]

[0064] Where, P m is the input mechanical power determined by the VSG virtual speed regulator, P e is the measured actual output power of the VSG, J is the virtual inertia of the VSG, and D * is the virtual damping coefficient of VSG, ω m is the virtual rotor angular frequency in the VSG rotor equation, ω g is the phase-locked loop measurement frequency. The speed control equation of the VSG virtual speed regulator is expressed as:

[0065] P m =P0-k p (ω m -ω0)

[0066] Where, P0 is the VSG active power setting instruction, k p is the VSG speed regulation droop coefficient, and ω0 is the system rated angular frequency.

[0067] During actual operation, the change in the rotor angular velocity of the VSG is extremely small, and the steady-state measurement frequency of the system is basically consistent with the rated value. To simplify the equation, some frequency parameters can be replaced with a constant value ω0. Therefore, the swing equation of the VSG can be further expressed as:

[0068]

[0069] Where D is the equivalent virtual damping coefficient of VSG, satisfying D = D * ω0≈D * ω m .

[0070] Therefore, the approximate expression of angular frequency versus power difference is:

[0071]

[0072] Where, In the equation, Represents an equivalent delay link, in steady state The system frequency adjustment is only determined by The value of is determined.

[0073] When the energy storage device adopts droop control to form a grid, its active power-frequency equation is expressed as:

[0074] P0-P e =k pd (ω m -ω0)

[0075] Where k pd is the droop adjustment coefficient of droop control.

[0076] The expression of the angular frequency of droop control to the power difference is:

[0077]

[0078] By comparison, it can be seen that droop control is actually a special form of VSG control. When J = 0 and D = 0, the two control modes are equivalent. For the equivalent synchronous machine droop frequency modulation external characteristics, the following normalization processing can be performed. Let the generalized frequency droop coefficient be k D , then for energy storage device i, we have:

[0079]

[0080] The unified generalized droop characteristic equation of energy storage equipment is expressed as:

[0081]

[0082] Subscript i represents the energy storage number, ω miis the virtual rotor angular frequency, ω0 is the system rated angular frequency, P ei is the actual output power measured, k Di is the generalized frequency droop coefficient.

[0083] Step 2: Based on the energy storage equivalent SOC discharge model and taking into account the energy storage charging and discharging comfort zone, the state variables of secondary control are designed when the energy storage participates in power-frequency regulation to achieve the SOC consistency target within the expected time.

[0084] The SOC of the energy storage needs to be monitored and controlled during charging and discharging to keep it within an appropriate operating range. The SOC calculation formula is:

[0085]

[0086] Where S t is the state of charge of the energy storage at time t, S0 is the initial state of charge of the energy storage, k c is the energy conversion efficiency, P tu is the charging and discharging power of the energy storage, and C is the battery capacity of the energy storage.

[0087] According to the energy storage SOC calculation formula, the energy storage progressive control implementation scheme is designed. Assuming that energy storage is needed to generate power in the current microgrid, the energy storage is in a discharging state. The energy storage discharge time is set to 0, and the time when the energy storage is expected to reach a consistent SOC is T e , the target at the energy storage consistency point is S e , subscript i represents the energy storage number, according to Figure 1 The performance index relationship between energy storage SOC and battery output voltage is shown in the figure. When the energy storage SOC is in the range of 20% to 90%, the performance index is better. Therefore, the consistency target point S e Should satisfy S e ≥0.2, the energy storage outputs constant power according to the preset power distribution ratio during the process of gradual consistency, then:

[0088]

[0089] Therefore, the energy storage output power distribution ratio can be obtained by reverse deduction:

[0090]

[0091] The above formula shows that within the SOC limit, the energy storage power distribution should be distributed according to its pre-used energy ratio (the product of the energy storage battery capacity and the estimated SOC). To meet the above control objectives, the state variable x of the consistency control is defined as i , specifically:

[0092]

[0093] Where C exi is the pre-used energy size of energy storage i, which is specifically defined as follows:

[0094]

[0095] In the above pre-used energy expression, the consistency target point S e Should be kept between 0.2 and 0.9, P tui The discharge direction is positive, that is, when discharging, P tui >0, when charging P tui ≤0.

[0096] Step 3: To solve the frequency error generated during the primary control, i.e., generalized droop frequency modulation control, and to achieve secondary control with SOC asymptotic consistency as the goal, the unified generalized droop characteristic equation of the energy storage device in step 1 and the second-order consistency control equation are combined to establish an SOC asymptotic consistency control scheme with the state variables of the secondary control under the SOC consistency goal designed in step 2 as the goal.

[0097] In step 1, the generalized droop characteristics of energy storage devices using a grid-type control strategy are unified. It can be seen that when using a grid-type control strategy, energy storage already has the primary regulation capability of a synchronous machine. However, primary regulation cannot restore the frequency of the microgrid, so secondary control is required to participate in regulation. In addition to restoring the system frequency, secondary control also requires further coordination and distribution of energy storage output to ensure that the energy storage gradually converges with SOC consistency as the goal. Therefore, the secondary control link involved in this invention is second-order consistency control. Figure 2 This is the consistent communication topology diagram of the photovoltaic storage microgrid scenario.

[0098] The general second-order consistent governing equation is described as:

[0099]

[0100] Where x i (t) is the state variable of the control system, z i (t) is the deviation variable introduced by the second-order consistency algorithm, y i (t) is the system input, a ij It is used to represent the communication weight between energy storage i and j. If there is no communication link between energy storage i and j, then a ij =0, otherwise a ij >0,b ij It also shows the communication weight relationship between energy storage i and j, and a ij The purpose of making the distinction is to distinguish the strength of communication transmission between signals. ε is a non-negative control gain, and ε>0.

[0101] According to the above consistency control equation, combined with the generalized droop characteristic equation, the power command compensation input u is introduced into the unified generalized droop characteristic equation of the energy storage device i , let y in the second-order consistent control equation i (t) = u i , energy storage output power P tui With the energy storage inverter power output P ei Consistent, state variables controlled by consistency The SOC asymptotic consistency control algorithm to achieve the SOC asymptotic consistency goal can be expressed as:

[0102]

[0103] Where N i represents the set of nodes communicating with i. To simplify the control scheme, the global communication weight is set to the same value, k a 、k b 、k ε are the corresponding control coefficients.

[0104] The control structure of the above SOC progressive consistency controller is as follows: Figure 3 As shown, the state variable x in quadratic control is i In the process of convergence, we can achieve balance, thereby ensuring reasonable distribution of energy storage power, keeping the energy storage in the same charging or discharging state at the same time, realizing coordinated charging and discharging of energy storage, and avoiding unnecessary power cycles between energy storage; at the same time, when the expected time T is reached e When all energy storages are able to achieve the same SOC target, it avoids the situation that some energy storages are overcharged and discharged, SOC exceeds the limit and exits the operation, energy storage coordinated power redistribution and other situations that affect the stable operation of the system. It is worth mentioning that the deviation variable z introduced above i (t) It enables secondary control to compensate for the inability of the primary frequency regulation of generalized droop control to restore the rated frequency, effectively exerting the grid-building capability of energy storage and improving the operational stability and power supply reliability of the system.

[0105] The present invention provides an embodiment of the progressive effect of energy storage synergy in four ring topology structures. In the embodiment, the four energy storages are in a discharge state. The capacity of energy storage 1 is 50kW·h, the initial SOC is 0.9, the capacity of energy storage 2 is 36kW·h, the initial SOC is 0.8, the capacity of energy storage 3 is 60kW·h, the initial SOC is 0.6, and the capacity of energy storage 4 is 60kW·h, the initial SOC is 0.5. After a time of 3T, the photovoltaic power is disturbed. The SOC of the energy storage before and after the disturbance is progressively consistent with the power distribution situation. Figure 4As shown in the figure, it can be clearly seen that when the expected time 6T is reached, all energy storage units have achieved the same SOC target, avoiding problems such as overcharging and discharging of some energy storage units, SOC exceeding the limit and exiting operation, and energy storage coordinated power redistribution. This effectively leverages the energy storage's networking capabilities and improves the system's operational stability and power supply reliability.

[0106] Another aspect of the present invention provides a coordinated control device for consistent allocation of energy storage state of charge with progressive convergence in the same direction, comprising:

[0107] The first module is used to establish a unified generalized droop characteristic equation for energy storage devices based on the energy storage network control strategy within the microgrid;

[0108] The second module is used to design the state variables of secondary control when the energy storage participates in power-frequency regulation, based on the energy storage equivalent SOC discharge model and taking into account the energy storage charging and discharging comfort range, so as to achieve the SOC consistency target within the expected time.

[0109] The third module is used to combine the unified generalized droop characteristic equation of energy storage equipment with the second-order consistency control equation to establish an SOC progressive consistency control scheme with the state variables of the secondary control under the designed SOC consistency target as the target.

[0110] Another aspect of the present invention provides a coordinated control system for energy storage state of charge consistency distribution with same-direction progressive convergence, comprising: a computer-readable storage medium and a processor;

[0111] The computer-readable storage medium is used to store executable instructions;

[0112] The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the energy storage charge state consistency distribution collaborative control method with same-direction progressive convergence as described in the first aspect.

[0113] On the other hand, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for coordinated control of energy storage state of charge consistency distribution with uniform and progressive convergence described in the first aspect is implemented.

[0114] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0115] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for coordinating and controlling the consistent distribution of energy storage state of charge with progressive convergence in the same direction, characterized in that: The steps include: Step 1: Based on the energy storage network control strategy in the microgrid, a unified generalized droop characteristic equation of energy storage equipment is established; Step 2: Based on the energy storage equivalent SOC discharge model and considering the energy storage charging and discharging comfort range, design the secondary control state variables for power-frequency regulation , so that each energy storage can achieve the SOC consistency target within its time; state variables Defined as the energy storage output power and expected energy The ratio of Dynamic calculation based on the initial SOC and target SOC of energy storage; Step 3: Combine the unified generalized droop characteristic equation of the energy storage device in step 1 with the second-order consistency control equation to establish an SOC progressive consistency control scheme with the state variables of the secondary control under the SOC consistency target designed in step 2 as the target; Step 2 specifically includes: listing the energy storage SOC calculation formula, designing the energy storage progressive control implementation plan based on the energy storage SOC calculation formula, and then determining the consistency target point S during the discharge process based on the performance indicator relationship between the energy storage SOC and the battery output voltage. e Should meet , the energy storage outputs constant power according to the preset power distribution ratio in the process of gradual consistency, then: ； Therefore, the energy storage output power distribution ratio is reversed to obtain: ； The above formula shows that the energy storage power distribution should be distributed according to its pre-used energy ratio within the SOC limit, and the state variables of consistency control are defined as , specifically: ； Where, is the pre-used energy size of energy storage i, which is specifically defined as follows: ； In the above pre-used energy expression, the consistency target point S e Should be kept between 0.2 and 0.

9. The discharge direction is positive, that is, when discharging , when charging .

2. The method for coordinated control of energy storage state of charge consistency distribution with progressive convergence in the same direction according to claim 1, characterized in that: Step 1 specifically includes: listing the active-frequency swing equations of the two control methods when the energy storage equipment adopts VSG control mode and droop control mode respectively, and then calculating and rewriting the swing equations to obtain the expression equations of angular frequency to power difference under the two control methods. Finally, through comparison, it is concluded that droop control is actually a special form of VSG control. 、 When the two control modes are equivalent, the equivalent synchronous machine droop frequency modulation characteristics are normalized as follows: the generalized frequency droop coefficient is , then for energy storage device i, we have: ； The unified generalized droop characteristic equation of the energy storage device is expressed as: ； The subscript i represents the energy storage number, is the virtual rotor angular frequency, is the system rated angular frequency, is the actual output power measured, is the generalized frequency droop coefficient.

3. The method for coordinated control of energy storage state of charge consistency distribution with progressive convergence in the same direction according to claim 1, characterized in that: Step 3 specifically includes: introducing the power command compensation input into the unified generalized droop characteristic equation of the energy storage device established in step 1 , let the second-order consistent control equation , energy storage output power Power output of energy storage inverter Consistent, state variables controlled by consistency The SOC asymptotic consistency control algorithm to achieve the SOC asymptotic consistency goal is expressed as: ； Where, Represents the set of nodes communicating with i. To simplify the control scheme, the global communication weight is set to the same value. 、 、 are the corresponding control coefficients.

4. A coordinated control device for energy storage state of charge consistency distribution with progressive convergence in the same direction, characterized in that: include: The first module is used to establish a unified generalized droop characteristic equation for energy storage devices based on the energy storage network control strategy within the microgrid; The second module is used to design the secondary control state variables for power-frequency regulation based on the energy storage equivalent SOC discharge model and considering the energy storage charge and discharge comfort range. , so that each energy storage can achieve the SOC consistency target within its time; state variables Defined as the energy storage output power and expected energy The ratio of Dynamic calculation based on the initial SOC and target SOC of energy storage; The third module is used to combine the unified generalized droop characteristic equation of energy storage devices with the second-order consistency control equation to establish an SOC progressive consistency control scheme with the state variables of the second-order control under the designed SOC consistency target as the target; The second module is specifically used to: list the energy storage SOC calculation formula, design the energy storage progressive control implementation plan based on the energy storage SOC calculation formula, and then determine the consistency target point S during the discharge process based on the performance indicator relationship between the energy storage SOC and the battery output voltage. e Should meet , the energy storage outputs constant power according to the preset power distribution ratio in the process of gradual consistency, then: ； Therefore, the energy storage output power distribution ratio is reversed to obtain: ； The above formula shows that the energy storage power distribution should be distributed according to its pre-used energy ratio within the SOC limit, and the state variables of consistency control are defined as , specifically: ； Where, is the pre-used energy size of energy storage i, which is specifically defined as follows: ； In the above pre-used energy expression, the consistency target point S e Should be kept between 0.2 and 0.

9. The discharge direction is positive, that is, when discharging , when charging .

5. The energy storage state of charge consistency distribution collaborative control device with same-direction progressive convergence according to claim 4, characterized in that: The first module is specifically used to: respectively list the active-frequency swing equations of the two control methods when the energy storage device adopts VSG control mode and droop control mode to form a network, then calculate and rewrite the swing equations to obtain the expression equations of angular frequency to power difference under the two control methods, and finally conclude through comparison that droop control is actually a special form of VSG control. 、 When the two control modes are equivalent, the equivalent synchronous machine droop frequency modulation characteristics are normalized as follows: the generalized frequency droop coefficient is , then for energy storage device i, we have: ； The unified generalized droop characteristic equation of the energy storage device is expressed as: ； The subscript i represents the energy storage number, is the virtual rotor angular frequency, is the system rated angular frequency, is the actual output power measured, is the generalized frequency droop coefficient.

6. The energy storage state of charge consistency distribution collaborative control device with same-direction progressive convergence according to claim 4, characterized in that: The third module is specifically used to: introduce the power command compensation input into the established unified generalized droop characteristic equation of the energy storage device , let the second-order consistent control equation , energy storage output power Power output of energy storage inverter Consistent, state variables controlled by consistency The SOC asymptotic consistency control algorithm to achieve the SOC asymptotic consistency goal is expressed as: ； Where, Represents the set of nodes communicating with i. To simplify the control scheme, the global communication weight is set to the same value. 、 、 are the corresponding control coefficients.

7. A coordinated control system for energy storage state of charge consistency distribution with progressive convergence in the same direction, comprising: Computer-readable storage medium and processor; The computer-readable storage medium is used to store executable instructions; The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the energy storage charge state consistency distribution collaborative control method with same-direction progressive convergence according to any one of claims 1-3.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the energy storage state of charge consistency distribution collaborative control method with same-direction progressive convergence according to any one of claims 1 to 3.

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