Energy storage collaborative control method and device for power grid primary frequency modulation and secondary frequency modulation

Abstract

The application discloses a kind of energy storage collaborative control method and device for power grid primary frequency modulation and secondary frequency modulation, method includes: the regional equivalent frequency response model of multi-region interconnected power grid is constructed;According to the command of energy storage primary and secondary frequency modulation of regional tie-line exchange power and regional equivalent frequency response model same direction condition is obtained, and based on fuzzy logic and centroid defuzzification obtains energy storage response priority;According to energy storage response priority and command same direction condition distribution primary and secondary frequency modulation power.The method of the application can make full use of the multi-scene output characteristics of energy storage, optimize its output under the premise of meeting the safe operation of power system, and improve the economy.

Description

Technical Field

[0001] This invention relates to the field of frequency regulation control in power systems, and more particularly to a method and apparatus for coordinated control of energy storage for primary and secondary frequency regulation of power grids. Background Technology

[0002] With the large-scale integration of renewable energy sources, such as wind and solar power, into the power system, system frequency fluctuations frequently occur. Furthermore, as the penetration rate of renewable energy continues to rise, the inertia support capacity of the power system will be further weakened. How to ensure safe and stable operation is a pressing issue that the power system needs to address.

[0003] Energy storage, as a rapid-response, stable, and reliable bidirectional auxiliary regulation resource, has been widely used in frequency regulation. Currently, in reports on energy storage's participation in frequency inertia support, its main task is to assist thermal power units in primary frequency regulation. Virtual droop and virtual inertia control are the main frequency regulation methods for energy storage, alleviating the system's instantaneous power deficit. Some scholars have proposed a flywheel energy storage-thermal power unit joint primary frequency regulation method based on adaptive cooperative droop control, which improves the frequency regulation performance of the thermal-storage joint system by adaptively adjusting the droop coefficient. Other scholars have proposed a virtual synchronization control method with an adaptive droop coefficient, which can reduce the energy storage capacity while ensuring frequency control effectiveness. After energy storage meets the system's rapid frequency support requirements, since primary frequency regulation is a differential regulation, it can further provide secondary frequency regulation auxiliary power, keeping the grid frequency within a safe range and thus enhancing grid frequency stability. In reports on energy storage's participation in automatic generation control, deploying energy storage systems for secondary frequency regulation is a highly feasible option. In this regard, some scholars have proposed a complementary cooperation model to enhance the response capability of energy storage systems and conventional units to secondary frequency regulation signals. Other scholars have developed a control model for energy storage systems participating in day-ahead market secondary frequency regulation, aiming to improve the overall economic benefits of energy storage systems in providing grid regulation services. However, the above research methods mainly focus on energy storage participating in single primary or secondary frequency regulation, without considering complex scenarios under multi-command coordination, thus exhibiting functional limitations. Furthermore, factors such as energy storage output limitations and command regulation direction can affect the frequency regulation efficiency of existing strategies, failing to simultaneously address frequency response requirements during regulation conflicts.

[0004] Therefore, a new technical solution is urgently needed to address the technical problem of how to coordinate the primary and secondary frequency regulation of energy storage. Summary of the Invention

[0005] This invention provides a method and device for coordinated control of energy storage for primary and secondary frequency regulation of power grid, in order to solve the technical problem of how to coordinate the primary and secondary frequency regulation of energy storage.

[0006] To achieve the above objectives, the present invention provides a method for coordinated control of energy storage for primary and secondary frequency regulation of power grids, comprising: Construct a regional equivalent frequency response model for a multi-regional interconnected power grid; obtain the command direction of primary and secondary frequency regulation for energy storage based on the exchange power of regional tie lines and the regional equivalent frequency response model, and obtain the energy storage response priority based on fuzzy logic and centroid defuzzification; allocate primary and secondary frequency regulation power according to the energy storage response priority and the command direction.

[0007] Preferably, the regional equivalent frequency response model for constructing a multi-regional interconnected power grid includes: For multi-region interconnected power grids, a primary frequency response model and a secondary frequency response model incorporating energy storage are constructed. Based on the primary and secondary frequency response models and power disturbances, a regional equivalent frequency response model is obtained using the regional equivalent method.

[0008] Preferably, the command alignment for primary and secondary frequency regulation of energy storage, obtained from the regional tie-line switching power and regional equivalent frequency response model, includes: The expression for the total frequency regulation power of energy storage is obtained based on the primary frequency response model and the secondary frequency response model. Based on the expression for the total frequency regulation power of energy storage, the correlation between the regional tie line switching power and the regional equivalent frequency response model is obtained; based on the correlation, the command direction of primary and secondary frequency regulation of energy storage is obtained.

[0009] Preferably, the energy storage response priority obtained based on fuzzy logic and centroid defuzzification includes: The outputs of the regional tie-line switching power and the regional equivalent frequency response model are used as the first and second inputs of the fuzzy controller, respectively. The energy storage response priority is used as the output of the fuzzy controller. Discrete universes of discourse are set for the inputs and outputs of the fuzzy controller. The energy storage response priority is obtained by combining the centroid defuzzification method under the preset control rules of the fuzzy controller.

[0010] Preferably, the preset control rules include a first rule and a second rule: The first rule includes: if the commands for primary and secondary frequency regulation of energy storage are in the same direction, the priority is determined according to the absolute values ​​of the first and second inputs; the larger the first input, the closer the priority is to 1, indicating that the secondary frequency regulation has a higher priority; the larger the second input, the closer the priority is to 0, indicating that the primary frequency regulation has a higher priority. The second rule includes: if the instructions for primary and secondary frequency regulation of energy storage are opposite, the priority of primary frequency regulation of energy storage will be increased within a preset range.

[0011] Preferably, the allocation of primary and secondary frequency regulation power based on energy storage response priority and command alignment includes: Based on the energy storage response priority and command alignment, and considering the energy storage rated power constraint, an adaptive allocation of primary and secondary frequency regulation power is performed for the first, second, third, and fourth operating conditions. The first operating condition includes the primary and secondary frequency regulation commands of the energy storage being in the same direction and not exceeding the rated power of the energy storage; The second operating condition includes priority for secondary frequency modulation commands; The third operating condition requires a smooth transition in allocation to avoid power jumps caused by priority switching; The fourth operating condition includes priority for the primary frequency modulation command.

[0012] Preferably, adaptive allocation includes: In the first operating condition, no priority intervention is required; the original frequency modulation command is executed. In the second operating condition, according to the direction and amplitude of the secondary frequency regulation command, the secondary frequency regulation power is allocated first under the constraint of the rated power of energy storage, and the primary frequency regulation operates within the remaining margin after the execution of the secondary frequency regulation. In the third operating condition, the rated power of energy storage is divided into primary frequency regulation and secondary frequency regulation allocation margins according to the energy storage response priority. If the primary and secondary frequency regulation commands of energy storage are in the same direction, the frequency regulation commands are executed within their respective margins. If the primary and secondary frequency regulation commands of energy storage are in opposite directions, the secondary frequency regulation command is weakened according to a preset ratio. In the fourth operating condition, the primary frequency regulation power is allocated according to the direction and amplitude of the primary frequency regulation command, under the constraint of the rated power of the energy storage, and the secondary frequency regulation command is not executed.

[0013] The present invention also provides an energy storage coordinated control device for primary and secondary frequency regulation of the power grid, which is used in the method of the present invention. The device includes a first module, a second module and a third module. The first module is used to construct the regional equivalent frequency response model of the multi-regional interconnected power grid; the second module is used to obtain the command direction of primary and secondary frequency regulation of energy storage based on the power exchanged by the regional tie line and the regional equivalent frequency response model, and to obtain the energy storage response priority based on fuzzy logic and centroid defuzzification; the third module is used to allocate the primary and secondary frequency regulation power according to the energy storage response priority and the command direction.

[0014] The present invention has the following beneficial effects: This invention presents a method for coordinated control of energy storage for primary and secondary frequency regulation of power grids. It constructs a regional equivalent frequency response model for a multi-regional interconnected power grid containing energy storage, and quantifies the causes of conflicts between primary and secondary frequency regulation commands and their impact on system frequency based on this model. This provides a model foundation and data on unidirectional conflicts for subsequent priority determination. By designing a frequency regulation priority determination rule based on fuzzy logic, it adaptively allocates frequency regulation power while meeting the rated power constraints of energy storage, achieving coordinated control of primary and secondary frequency regulation of energy storage. This method can solve the problems of reversed primary and secondary frequency regulation commands and excessive energy storage output, demonstrating good scalability. This invention fully utilizes the multi-scenario output characteristics of energy storage, optimizing its output while ensuring the safe operation of the power system and improving economic efficiency.

[0015] The energy storage coordinated control device for primary and secondary frequency regulation of the power grid of the present invention, when used in the method of the present invention, has the same beneficial effects as the method of the present invention.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the method flow of a preferred embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram illustrating the relationship between fuzzy input and output in a preferred embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the modified 11-node, two-region system structure of a preferred embodiment of the present invention.

[0020] Figure 4 This is a data diagram of the method of the present invention and the method without coordinated control in a preferred embodiment of the present invention; wherein, (a) is the frequency deviation under different methods; (b) is the energy storage output under different methods; (c) is the secondary frequency modulation command component of the method of the present invention; and (d) is the frequency modulation priority of the method of the present invention. Detailed Implementation

[0021] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0022] See Figure 1In a preferred embodiment of the present invention, an energy storage coordinated control method for primary and secondary frequency regulation of the power grid is provided, comprising: A1. Constructing a regional equivalent frequency response model for a multi-regional interconnected power grid. A1 specifically includes: For multi-region interconnected power grids, construct primary and secondary frequency response models including energy storage, including: (1) Construct a primary frequency response model including energy storage: Taking thermal power units as conventional units, their dynamic frequency response characteristics are mainly characterized by the governor and the reheat turbine, and their transfer functions are expressed as follows: ; in, For the response transfer function of a conventional unit; T CH , T RH and T CO These represent the time constants of the turbine, governor, and reheater in a conventional unit, respectively. F HP , F IP and F LP These represent the percentages of total turbine power allocated to the high, medium, and low-power turbine stages, respectively. s For the Laplace operator; For the speed controller transfer function; For the transfer function of the reheat turbine; is the response time constant of the thermal power unit.

[0023] When a frequency deviation occurs in the system, conventional units participate in primary frequency regulation through droop control, and their response power can be expressed as: ; in, This is the primary frequency regulation power command for a conventional generating unit; This is the power grid frequency signal; This refers to the unit frequency regulation power of a conventional unit.

[0024] Compared to conventional generating units, energy storage offers significant advantages in ramp-up speed and response time. It can output power by simulating the power-frequency characteristics of conventional frequency-regulating units and provide rapid inertial support by responding to frequency change rate signals. Participating in frequency regulation by tracking grid frequency signal changes through a phase-locked loop (PLL) relies heavily on the frequency signal for its performance. Furthermore, the frequency response process involves response delays and inherent signal measurement delays. Considering delays, inertia, and droop control elements to simulate actual frequency regulation characteristics, its frequency response process is expressed as follows: ; in, The primary frequency regulation power command for energy storage; The first-order frequency response transfer function for energy storage; The delay caused by the phase-locked loop; The delay time constant; is the response time constant of energy storage; , These represent the virtual droop and inertia coefficient of energy storage, respectively.

[0025] (2) Construct a quadratic frequency response model including energy storage: In a preferred embodiment of the present invention, a secondary frequency response model based on regional deviation signal control is adopted. This model calculates the secondary frequency power command and allocates it to energy storage and conventional generating units. The model is as follows: ; ; ; in, This is a regional deviation signal; This is the frequency deviation coefficient; This is the power allocation factor for the energy storage system, with a value range of [0, 1]. and These are the regional deviation power commands for energy storage systems and conventional generating units, respectively. The switching power of the tie lines in this area can be calculated using the following formula: ; in, Indicates the number of regions connected to this region; For the region Frequency deviation; This area and region The connecting line coefficient between them.

[0026] In regional deviation signal control, conventional units use traditional proportional-integral control for secondary frequency regulation, while energy storage directly receives secondary frequency regulation power commands. The frequency regulation power of both can be expressed as: ; in, This is the secondary frequency regulation power command for conventional generating units. This is the secondary frequency regulation power command for the energy storage system. and These are the proportional and integral control parameters, respectively.

[0027] After constructing the primary and secondary frequency response models including energy storage, and combining these models with power perturbations, a regional equivalent frequency response model is obtained based on the regional equivalent method: When power disturbance When this occurs, the resulting power difference is jointly compensated by the energy storage system and conventional generating units. Combining the primary and secondary frequency response models, the regional equivalent frequency response model is expressed as: ; in, , These are the equivalent inertial time constant and damping coefficient of the regional power system, respectively; the regional equivalent frequency response model consists of the grid frequency signal and the frequency deviation of the regional power system.

[0028] A2. Based on the regional tie line exchange power and the regional equivalent frequency response model, the command direction of primary and secondary frequency regulation of energy storage is obtained, and the energy storage response priority is obtained based on fuzzy logic and centroid defuzzification.

[0029] In a preferred embodiment of the present invention, obtaining the unidirectional command situation for primary and secondary frequency regulation of energy storage based on the regional tie-line switching power and the regional equivalent frequency response model includes: Based on the primary and secondary frequency response models, the expression for the total frequency regulation power of energy storage is obtained: From the expressions for the primary and secondary frequency regulation power of energy storage, it can be seen that the total frequency regulation power of energy storage... It can be written as: ; Based on the expression for the total frequency regulation power of energy storage, the correlation between the regional tie-line switching power and the regional equivalent frequency response model is obtained; based on the correlation, the command direction of primary and secondary frequency regulation of energy storage is determined: Total frequency regulation power of energy storage It can be seen that the direction of the primary frequency regulation power command for energy storage is entirely determined by... The decision is made, and the secondary frequency modulation power command is... as well as Joint decision, that is, when and Reverse and absolute value greater than At that time, the secondary frequency regulation power command for energy storage is opposite in sign to the primary frequency regulation power command, and vice versa. D ir =1 indicates that the two frequency modulation power commands are in the same direction. D ir =0 indicates the inverted direction, which can be represented as: ; In a preferred embodiment of the present invention, obtaining the energy storage response priority based on fuzzy logic and centroid defuzzification includes: The outputs of the regional tie-line exchange power and the regional equivalent frequency response model are used as the first and second inputs of the fuzzy controller, respectively. The energy storage response priority is used as the output of the fuzzy controller. Discrete universes of discourse are set for the inputs and outputs of the fuzzy controller. Under the preset control rules of the fuzzy controller, the energy storage response priority is obtained by combining the centroid defuzzification method, specifically including: Normalized and As the first input of the fuzzy controller u 1 and second input u 2, u 1 and u Both are set with 7 discrete universes of discourse, corresponding to fuzzy sets NB, NM, NS, ZO, PS, PM, and PB.

[0030] Set energy storage response priority k c As the output variables of the fuzzy controller, six discrete universes are set, corresponding to the fuzzy sets VS, S, MS, MB, B, and VB.

[0031] The preset control rules include the first rule and the second rule: The first rule includes: if the commands for primary and secondary frequency regulation of energy storage are in the same direction, the priority is determined according to the absolute values ​​of the first and second inputs; the larger the first input, the closer the priority is to 1, indicating that the secondary frequency regulation has a higher priority; the larger the second input, the closer the priority is to 0, indicating that the primary frequency regulation has a higher priority. The second rule includes: if the instructions for primary and secondary frequency regulation of energy storage are opposite, the priority of primary frequency regulation of energy storage will be increased within a preset range in order to quickly reduce the frequency deviation in this area.

[0032] Based on the discrete universes of discourse of the input and output, combined with the above-mentioned preset control rules, the control rule table is obtained, as shown in Table 1: Table 1 Control Rules Table ; The energy storage response priority k is calculated using the centroid defuzzification method. c For its fuzzy input-output relationship, please refer to [link / reference]. Figure 2 , Figure 2 This reflects the quantitative results of energy storage frequency regulation priority under different combinations of local frequency deviation and tie-line power, providing an intuitive control basis for subsequent adaptive power allocation strategies. c The quantization expression is: ; in, A u1and A u2 They are and Membership function.

[0033] A3. Allocate primary and secondary frequency regulation power according to energy storage response priority and command alignment. A3 specifically includes: Based on the energy storage response priority and command alignment, and considering the energy storage rated power constraint, an adaptive allocation of primary and secondary frequency regulation power is performed for the first, second, third, and fourth operating conditions. The first operating condition includes the primary and secondary frequency regulation commands of the energy storage being in the same direction and not exceeding the rated power of the energy storage; The second operating condition includes priority for secondary frequency modulation commands; The third operating condition requires a smooth transition in allocation to avoid power jumps caused by priority switching; The fourth operating condition includes priority for the primary frequency modulation command.

[0034] In a preferred embodiment of the present invention, adaptive allocation includes: In the first operating condition, no priority intervention is required; the original frequency modulation command is executed.

[0035] This operating condition refers to the energy storage receiving both primary and secondary frequency regulation commands simultaneously, with both commands having the same power direction. If the total frequency regulation power at this time does not exceed its rated power, it indicates that the energy storage has sufficient margin and no priority intervention is needed; the original frequency regulation command is executed directly. In this case, the frequency regulation power of the energy storage is: ; in, , These are the actual power of primary and secondary frequency regulation of energy storage, respectively; This is the rated power of the energy storage.

[0036] In the second operating condition, the secondary frequency regulation power is allocated preferentially under the constraint of the rated power of the energy storage according to the direction and amplitude of the secondary frequency regulation command, and the primary frequency regulation operates within the remaining margin after the execution of the secondary frequency regulation.

[0037] Under this working condition k c < k c,low , k c,low The preset secondary frequency regulation priority threshold is used; the core objective is to ensure secondary frequency regulation, which requires prioritizing the allocation of secondary frequency regulation power under the constraint of the energy storage rated power. Primary frequency regulation can only operate within the remaining margin after the execution of secondary frequency regulation. The energy storage frequency regulation power can be expressed as: ; ; Here, sign[] represents the sign determination function.

[0038] In the third operating condition, the rated power of energy storage is divided into primary frequency regulation and secondary frequency regulation allocation margins according to the energy storage response priority. If the primary and secondary frequency regulation commands of energy storage are in the same direction, the frequency regulation commands are executed within their respective margins. If the primary and secondary frequency regulation commands of energy storage are in opposite directions, the secondary frequency regulation command is weakened according to a preset ratio.

[0039] Under this working condition k c,low < k c < k c,high , k c,high The preset primary frequency regulation priority threshold is used; the core objective is to avoid power jumps caused by priority switching. Based on priority, the rated power of energy storage is divided into primary and secondary frequency regulation allocation margins. For commands in the same direction, execution is carried out within their respective margins; for commands in the opposite direction, the secondary frequency regulation command is further weakened proportionally. The energy storage frequency regulation power can be expressed as: ; ; In the fourth operating condition, the primary frequency regulation power is allocated according to the direction and amplitude of the primary frequency regulation command, under the constraint of the rated power of the energy storage, and the secondary frequency regulation command is not executed.

[0040] Under this working condition k c > k c,high In response to emergency frequency regulation conditions in the power grid, the core objective is to prioritize ensuring the safety of the power grid frequency. The primary frequency regulation power must be allocated strictly according to the direction and amplitude of the primary frequency regulation command, within the constraints of the energy storage's rated power. To ensure that all energy storage output is used to reduce frequency deviation in the local area, the secondary frequency regulation command is completely blocked to prevent it from consuming the frequency regulation margin. The energy storage frequency regulation power can be expressed as: ; Based on A2 to A3 above, primary and secondary frequency regulation of energy storage can be coordinated and controlled in each frequency regulation cycle.

[0041] This invention presents a method for coordinated control of energy storage for primary and secondary frequency regulation of power grids. It constructs a regional equivalent frequency response model for a multi-regional interconnected power grid containing energy storage, and quantifies the causes of conflicts between primary and secondary frequency regulation commands and their impact on system frequency based on this model. This provides a model foundation and data on unidirectional conflicts for subsequent priority determination. By designing a frequency regulation priority determination rule based on fuzzy logic, it adaptively allocates frequency regulation power while meeting the rated power constraints of energy storage, achieving coordinated control of primary and secondary frequency regulation of energy storage. This method can solve the problems of reversed primary and secondary frequency regulation commands and excessive energy storage output, demonstrating good scalability. This invention fully utilizes the multi-scenario output characteristics of energy storage, optimizing its output while ensuring the safe operation of the power system and improving economic efficiency.

[0042] In a preferred embodiment of the present invention, an energy storage coordinated control device for primary and secondary frequency regulation of the power grid is also provided for use in the method of the present invention. The device includes a first module, a second module and a third module. The first module is used to construct the regional equivalent frequency response model of the multi-regional interconnected power grid; the second module is used to obtain the command direction of primary and secondary frequency regulation of energy storage based on the power exchanged by the regional tie line and the regional equivalent frequency response model, and to obtain the energy storage response priority based on fuzzy logic and centroid defuzzification; the third module is used to allocate the primary and secondary frequency regulation power according to the energy storage response priority and the command direction.

[0043] The energy storage coordinated control device for primary and secondary frequency regulation of the power grid of the present invention, when used in the method of the present invention, has the same beneficial effects as the method of the present invention.

[0044] Verification section: To demonstrate the feasibility of this method, it was validated in the MATLAB / Simulink environment. The simulation model uses a modified 11-node, two-region system, with the specific structure as follows: Figure 3 As shown. Figure 3 The four conventional generating units G1 to G4 in the case study each have a rated capacity of 250 MW. The power data in the case study has been standardized and is based on a 1000 MW benchmark. An energy storage node 6 with a rated capacity of 0.1 MWh is connected to the system. The energy storage participates in both primary and secondary frequency regulation. The initial state of charge of the energy storage is set to 0.5, and other frequency regulation parameters are shown in Table 2. At 0s, step power disturbances with amplitudes of 0.0022 pu and 0.0048 pu are set for regions 1 and 2, respectively.

[0045] Table 2 Other FM parameters ; The method of this invention is compared with that of non-cooperative control. For the frequency deviation, energy storage output, secondary frequency modulation command components, and frequency modulation priority under different methods, please refer to [reference needed]. Figure 4 .like Figure 4 (a) It can be seen that without the coordination of primary and secondary frequency modulation commands, the rate and magnitude of frequency drop in the system are relatively large, such as Figure 4 (b) and Figure 4 (c) It can be seen that because the two power components in the secondary frequency modulation command have opposite signs, the primary and secondary frequency modulation commands for energy storage also exhibit opposite signs in the 0-30s interval. This cancellation and reduction is detrimental to fully utilizing the rapid response capability of energy storage, and consequently, hinders frequency improvement. Figure 4 (d) Within the 0-30s interval, when two frequency modulation power commands are opposite, the priority of the primary frequency modulation shows a trend of low to high. At this time, the frequency modulation power when the frequency modulation power commands are opposite needs to be constrained based on the rated power of the energy storage. Since the power commands are opposite at this time, according to the power allocation rule, it is only necessary to reduce the secondary frequency modulation power to fully restore the frequency deviation in this region. From the data perspective, compared with no coordination, the minimum frequency deviation of the method of this invention is improved by 5.48%, and the root mean square value of frequency deviation is improved by 2.1%.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for coordinated control of energy storage for primary and secondary frequency regulation of power grids, characterized in that, include: Construct a regional equivalent frequency response model for a multi-regional interconnected power grid; obtain the command alignment status of primary and secondary frequency regulation for energy storage based on the exchange power of regional tie lines and the regional equivalent frequency response model, and obtain the energy storage response priority based on fuzzy logic and centroid defuzzification; allocate primary and secondary frequency regulation power according to the energy storage response priority and the command alignment status.

2. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 1, characterized in that, The construction of regional equivalent frequency response models for multi-regional interconnected power grids includes: For a multi-regional interconnected power grid, a primary frequency response model and a secondary frequency response model incorporating energy storage are constructed. Based on the primary and secondary frequency response models and power disturbances, the regional equivalent frequency response model is obtained using the regional equivalent method.

3. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 2, characterized in that, Based on the regional tie-line switching power and the regional equivalent frequency response model, the command unidirectional conditions for primary and secondary frequency regulation of energy storage include: The expression for the total frequency regulation power of energy storage is obtained based on the first frequency response model and the second frequency response model. The correlation between the regional tie-line switching power and the regional equivalent frequency response model is obtained based on the total frequency regulation power expression of the energy storage; the command direction of primary and secondary frequency regulation of energy storage is obtained based on the correlation.

4. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 3, characterized in that, Based on fuzzy logic and centroid defuzzification, the energy storage response priority includes: The regional tie-line switching power and the output of the regional equivalent frequency response model are used as the first and second inputs of the fuzzy controller, respectively. The energy storage response priority is used as the output of the fuzzy controller. Discrete universes of discourse are set for the input and output of the fuzzy controller, respectively. The energy storage response priority is obtained by combining the centroid defuzzification method under the preset control rules of the fuzzy controller.

5. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 4, characterized in that, The preset control rules include the first rule and the second rule: The first rule includes: if the commands for primary and secondary frequency regulation of energy storage are in the same direction, the priority is determined according to the absolute values ​​of the first input and the second input; the larger the first input, the closer the priority is to 1, indicating that the secondary frequency regulation has a higher priority; the larger the second input, the closer the priority is to 0, indicating that the primary frequency regulation has a higher priority. The second rule includes: if the instructions for primary and secondary frequency regulation of energy storage are opposite, the priority of primary frequency regulation of energy storage will be increased within a preset range.

6. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 5, characterized in that, The allocation of primary and secondary frequency regulation power based on the energy storage response priority and the command unidirectionality includes: Based on the energy storage response priority and the command unidirectional situation, and considering the energy storage rated power constraint, adaptive allocation of primary and secondary frequency regulation power is performed for the first, second, third, and fourth operating conditions. The first operating condition includes the primary and secondary frequency regulation commands of the energy storage being in the same direction and not exceeding the rated power of the energy storage; The second operating condition includes priority for secondary frequency modulation commands; The third operating condition includes the need for a smooth transition in allocation to avoid power jumps caused by priority switching. The fourth operating condition includes priority for the first frequency modulation command.

7. The energy storage coordinated control method for primary and secondary frequency regulation of the power grid according to claim 6, characterized in that, Adaptive allocation includes: In the first operating condition, no priority intervention is required, and the original frequency modulation command is executed; In the second operating condition, according to the direction and amplitude of the secondary frequency regulation command, the secondary frequency regulation power is preferentially allocated under the constraint of the rated power of the energy storage, and the primary frequency regulation operates within the remaining margin after the execution of the secondary frequency regulation. In the third operating condition, the rated power of energy storage is divided into primary frequency regulation and secondary frequency regulation allocation margins according to the energy storage response priority; if the primary and secondary frequency regulation commands of energy storage are in the same direction, the frequency regulation commands are executed within their respective margins; if the primary and secondary frequency regulation commands of energy storage are in opposite directions, the secondary frequency regulation command is weakened according to a preset ratio. In the fourth operating condition, the primary frequency regulation power is allocated according to the direction and amplitude of the primary frequency regulation command under the constraint of the rated power of the energy storage, and the secondary frequency regulation command is not executed.

8. An energy storage coordinated control device for primary and secondary frequency regulation of a power grid, used in the method described in any one of claims 1 to 7, characterized in that, The device includes a first module, a second module, and a third module; The first module is used to construct a regional equivalent frequency response model for a multi-regional interconnected power grid; the second module is used to obtain the command direction of primary and secondary frequency regulation of energy storage based on the power exchanged by the regional tie line and the regional equivalent frequency response model, and to obtain the energy storage response priority based on fuzzy logic and centroid defuzzification; the third module is used to allocate primary and secondary frequency regulation power according to the energy storage response priority and the command direction.

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