Power grid energy storage planning and configuration method considering safety and stability domain of novel power system

Abstract

The invention discloses a power grid energy storage planning and configuration method considering a novel power system safety and stability domain, and the method comprises the steps: determining a first objective function corresponding to a voltage safety boundary in a power grid based on the quantitative analysis of a basic loop model, a node voltage and loop current mixed analysis method, and the current load level and network parameters in the power grid; based on the income model of the energy storage system, the power grid safety and the operation stability of the energy storage system, optimizing the charging and discharging strategy of each time period in the day to enable the power system to determine a second objective function corresponding to maximization of the energy storage access income of the power grid; according to the first and second objective functions, constructing a cost minimization model under power grid energy storage access; and based on energy storage, distributed power supply and power grid constraints, optimizing the operation of energy storage, and obtaining an energy storage site selection scheme and a constant volume scheme with the minimum annual operation cost of the power system. According to the method, the problems of large calculation amount and difficulty in realizing online application in related technologies are solved, and consideration factors of power grid energy storage planning are increased.

Description

Technical Field

[0001] The present invention relates to the field of power grid planning, operation and energy storage configuration, and in particular to a power grid energy storage planning and configuration method taking into account a new type of power system safety and stability domain. Background Art

[0002] With the increasing attention paid to renewable energy and the rapid development of technology around the world, the proportion of new energy (such as wind power, solar energy, etc.) in the power system has increased year by year, injecting new vitality into the sustainable development of the power industry. However, the widespread access to new energy has also brought new challenges to the stable operation of the power grid. The intermittent and volatile characteristics of renewable energy generation have brought potential risks to the voltage stability of the power grid. The configuration of energy storage can not only improve the ability of the power grid to absorb new energy, but also improve the system's frequency and voltage support capabilities. It is an indispensable flexibility resource in the power system. Therefore, the research on the power grid energy storage planning and configuration method for voltage stability analysis has always been widely concerned by scholars at home and abroad.

[0003] A distribution network energy storage planning method considering different photovoltaic penetration rates and demand response is disclosed in the Chinese patent application with application number 202310963151.6. The method includes: converting the double-layer model into a single-layer model by using a unified method of upper and lower layer association, and solving the single-layer model by calling the optimization solver to obtain the distribution network energy storage planning scheme and operation scheme. However, this scheme only considers the maximization of energy storage economic optimization. The double-layer model has a large amount of computation. The grid side does not analyze the safety hazards of the grid and the changes in the grid safety boundary before and after the energy storage is connected, while meeting the basic capacity and power constraints.

[0004] A method and system for evaluating the importance of nodes in energy storage planning for a distribution network is disclosed in a Chinese patent application with application number 202111518329.3. The method includes: traversing the N-1 fault scenarios of the system, calculating the total load loss expectation of the system under all N-1 faults, and based on this, comprehensively analyzing the weight information of the loads of the distribution network nodes, generating a set of candidate nodes for energy storage planning of the distribution network, and realizing the importance evaluation of the nodes in energy storage planning of the distribution network. In this system, the importance of the nodes of the distribution network is evaluated, but the evaluation module performs an expectation analysis on all non-substation nodes, does not consider the impact of energy storage nodes, and evaluates the importance of nodes based on the probability of failure. The slow response speed makes it difficult for the distribution network to have efficient evaluation results, and online applications are difficult.

[0005] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a grid energy storage planning and configuration method taking into account the safety and stability domain of the new power system, combines the economic evaluation indicators of the energy storage system and analyzes its cost and benefit composition, establishes a grid energy storage model based on a dual objective function, and optimizes the configuration of energy storage as well as the break-even and sensitivity analysis.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for planning and configuring power grid energy storage taking into account a new power system security and stability domain, the method comprising the following steps:

[0009] 1) Based on the quantitative analysis of the basic loop model, the node voltage and loop current hybrid analysis method, and the current load level and network parameters in the power grid, determine the first objective function corresponding to the voltage safety boundary in the power grid;

[0010] 2) Based on the revenue model of the energy storage system, the safety of the power grid and the operational stability of the energy storage system, the charging and discharging strategies at different time periods during the day are optimized to maximize the power system and determine the second objective function corresponding to the maximum revenue of the grid energy storage access;

[0011] 3) Determining a grid energy storage access cost minimization model based on the first objective function and the second objective function;

[0012] 4) Based on energy storage, distributed power sources and grid constraints, the single-layer multi-objective planning of battery energy storage site selection and sizing is transformed into a double-layer single-objective optimization for solution, and the energy storage site selection and sizing plan with the minimum annual operating cost of the power system is obtained.

[0013] As a further improvement of the present invention, the step 1) is based on the quantitative analysis of the basic loop model, and the node voltage and loop current hybrid analysis method to determine the first objective function corresponding to the voltage safety boundary in the power grid, including: based on the current load level and network parameters in the power grid, determining the node voltage stability boundary in the power grid, constructing the circular voltage stability domain boundary and the voltage instability area in the state space, constructing the power grid network topology relationship, and constructing the voltage stability margin index as the first objective function.

[0014] As a further improvement of the present invention, the step 2) is based on the profit model of the energy storage system. Based on the profit model of the energy storage system, the grid security and the operational stability of the energy storage system, the charging and discharging strategies for each time period during the day are optimized to determine the second objective function corresponding to the maximization of the grid energy storage access revenue, including: determining the direct investment revenue and the comprehensive social revenue of the energy storage system, and determining the "low storage and high release" index of the energy storage system as the second objective function.

[0015] As a further improvement of the present invention, the step 3) determines the grid energy storage access cost minimization model according to the first objective function and the second objective function, including: determining the grid energy storage access objective function, and determining the operating stability constraint conditions under the grid energy storage access.

[0016] As a further improvement of the present invention, the basic loop model is: Fig.10 As shown:

[0017] The loop current equation is:

[0018]

[0019] Node voltage equation:

[0020]

[0021] In the formula is the injected current at node a; is the sum of all admittance branch currents associated with node a;

[0022] S a =p a +jq a , S b =p b +jq b are the injected powers of nodes a and b respectively. Let the voltage phasors of nodes a and b be The current in this circuit is The subscripts a, b = 1, 2, ..., N are node numbers, and the subscript l = 1, 2, ..., L is the loop number.

[0023] As a further improvement of the present invention, the node voltage and loop current hybrid analysis model is:

[0024]

[0025] When the branch-to-ground conductance is neglected, season

[0026] In the formula is the loop current phasor.

[0027] As a further improvement of the present invention, the state space circular voltage stability model is:

[0028]

[0029] The voltage stability margin index is:

[0030]

[0031] As a further improvement of the present invention, the revenue model based on the energy storage system is:

[0032]

[0033] Where: P dg (t) is the reactive power output by the distributed power source at the sampling time; P hv (t) is the reactive power provided by the grid, R dg R(t) is the unit cost of reactive power output by distributed generation at the sampling time, which is 0.03 times the price of R(t) in the same period; hv P(t) is the unit cost of reactive power injected into the grid side, which is 0.06 times the price of R(t) in the same period. ch (t) represents the charging power of the energy storage battery at the sampling time; P dis (t) represents the BESS discharge power; B ch (t) and B dis (t) represent the charge and discharge status of BESS at time t; R(t) represents the time-of-use electricity price, C BESS Represents the investment and construction cost of the energy storage system; C M Represents the energy storage operation and maintenance cost. bess ,x represents the energy storage system x configuration power; E bess , x represents the x configuration capacity of the energy storage system; C P Represents the unit power cost of energy storage; C E represents the unit capacity cost of energy storage; r represents the discount rate; n represents the life of the energy storage system; and h represents the maximum number of energy storage installations. M represents the operation and maintenance cost of the annual power generation of energy storage; Q represents the annual power generation of BESS.

[0034] As a further improvement of the present invention, the “low storage and high release” index of the energy storage system is:

[0035]

[0036] Where: B ch (t) and B dis (t) represent the charging and discharging states of BESS at time t; P ch (t) and P dis (t) represents the charging and discharging power of BESS at time t; Δt represents the system sampling interval; T represents the time when the PV output is greater than the initial load; N day Indicates the annual operating time of BESS.

[0037] As a further improvement of the present invention, the objective function is expressed as:

[0038] minF=C LOSS +C DG +C HV +C PB +C DBSS

[0039] Where: F is the total annual operating cost of the power system; C LOSS is the grid loss cost; C DG and C HV They are the reactive power costs provided by distributed sources and the reactive power costs provided by the grid to ensure stable operation of the grid; C PB C is the energy storage charging and discharging cost; DBSS The cost of energy storage;

[0040] The second constraint conditions include: power system power balance, node voltage amplitude, transmission line active power, generator output, battery energy storage system charging and discharging, and charge state continuity constraints;

[0041] The power balance constraint is used to indicate that: the total power generated in the power system must be equal to the total power consumed plus the transmission loss; the power supply and demand are matched within the power balance range to avoid power outages or over-power supply;

[0042] The node voltage amplitude constraint is used to indicate that the voltage magnitudes of the connection points and substations of the power grid need to be kept within a specified range to ensure the normal operation of equipment and the stable transmission of power;

[0043] The generator output constraint is used to indicate: the amount of electricity generated by the system generator set, including its minimum and maximum output limits; the output of the generator needs to be adjusted according to the grid demand and cannot exceed its operating limit;

[0044] The battery energy storage system charge and discharge constraints are used to indicate that the charging and discharging of the battery energy storage system satisfies that the stored energy is within a set range, including upper and lower limits of the charge and discharge rate and time;

[0045] The state of charge continuity constraint is used to indicate that the state of charge charging level of the energy storage system maintains continuous and smooth changes.

[0046] Beneficial effects: Compared with the prior art, the present invention adopts the above technical solution and has the following advantages:

[0047] (1) Conduct economic analysis and capacity optimization configuration research on energy storage configuration on the photovoltaic side. Establish a two-layer optimization model: the outer layer uses a traversal algorithm to traverse and plan the power and capacity of the energy storage system at a certain step length, and the inner layer uses the CPLEX tool to optimize the charging and discharging power of the energy storage under the given configuration of the outer layer and solve the relevant economic indicators.

[0048] (2) Energy storage selection method considering comprehensive evaluation of multiple economic indicators. Based on the analytic hierarchy process, economic indicators such as initial investment cost, net present value, dynamic investment payback period and internal rate of return were established as decision factors; finally, the optimal energy storage solution was determined through the selection model.

[0049] (3) Optimize the site selection and configuration methods of energy storage systems in microgrids. Avoid the limitations of a single indicator and consider comprehensive evaluation of multiple economic indicators to study energy storage selection planning. At the same time, investors can assign importance to different economic indicators based on their own financial characteristics and return expectations, providing solutions for multi-subject energy storage planning with multiple attributes.

[0050] (4) Considering the complexity and importance of power system voltage stability, the basic loop model analysis and node voltage-loop current hybrid analysis method provide a new solution for the quantitative evaluation of voltage stability. It reveals the voltage stability of the power grid under the current load level and provides a scientific decision-making basis for the planning and site selection of power grid energy storage.

[0051] (5) In the large-scale construction of power grid transmission, the existing power grid supporting facilities are difficult to meet the needs of new energy open development. Smoothing out the fluctuation of photovoltaic power generation output makes its output power smoother, meets the needs of power grid dispatching, and helps to improve the safety of the power system and the reliability of power supply.

[0052] In summary, the present invention is based on a two-layer optimization model of energy storage with constraints such as energy storage, distributed power sources and power grid as inner functions and the minimum annual operating cost of the power system as the outer function, realizing the research on energy storage planning and configuration that takes into account the safety assessment of power grid voltage, optimizing power generation and energy storage configuration, reducing the use of traditional thermal power, reducing carbon emissions, and promoting the use of new energy, which meets the requirements of sustainable development. Through scientific resource optimization and allocation, we can ensure the efficient use of electric energy, improve the economic and environmental benefits of the power system, and achieve sustainable development of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a flow chart of the method of the present invention;

[0054] Figure 2 It is the voltage stability analysis principle diagram of the present invention;

[0055] Figure 3 is a 17-node power grid topology diagram of an embodiment of the present invention;

[0056] Figure 4 It is a voltage safety boundary state diagram of scheme 1 of embodiment 2 of the present invention;

[0057] Figure 5The charging and discharging policy, load curve diagram and energy storage site selection of Solution 1 of Embodiment 2 of the present invention;

[0058] Figure 6 It is a voltage safety boundary state diagram of scheme 2 of embodiment 2 of the present invention;

[0059] Figure 7 The charging and discharging policy, load curve diagram and energy storage site selection of scheme 2 of embodiment 2 of the present invention;

[0060] Figure 8 It is a voltage safety boundary state diagram of scheme 3 of embodiment 2 of the present invention;

[0061] Fig. 9 The charging and discharging policy, load curve diagram and energy storage site selection of scheme 3 of embodiment 2 of the present invention;

[0062] Fig.10 It is the basic circuit model of the present invention. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0064] The method flow chart of the present invention is as follows Figure 1 As shown, the voltage stability analysis principle diagram of the present invention is as follows Figure 2 As shown;

[0065] Example 1

[0066] This paper studies the planning of energy storage to 220kV voltage level, taking the 17-node power grid topology as an example, where the 17-node power grid topology is shown in the figure Figure 3 As shown in the figure, it can be seen in detail that these nodes represent the key substations and power generation facilities in the power grid, with a total of 33 lines, forming the skeleton of the power grid. A typical regional time-of-use electricity price table is selected, and its peak and valley electricity price execution period and specific price, as well as energy storage battery related parameters are selected as follows:

[0067] Table 1 Time-of-use electricity price list

[0068]

[0069] Table 2 Engineering parameters

[0070]

[0071]

[0072] Example results:

[0073] Table 3 Voltage stability results based on 17 nodes

[0074]

[0075] As shown in Figure 3, under the current load level, the stability margins of nodes 3, 7, and 8 are small, close to the stability limit, and the stability is the worst. If the load of these three nodes increases further, voltage instability may occur; nodes 2, 5, 10, 11, 12, 13, and 16 have medium stability margins; while nodes 1, 6, and 15 have large stability margins and good stability. In a physical sense, under the current load level, nodes 3, 7, and 8 are close to the 2B m q m is the center of the circle, The boundary of the circular voltage instability area with a radius of 1 is shown in Figure 1. If the load continues to increase, it will enter the voltage instability area and a voltage instability accident will occur. Nodes 1 and 6 are far away from the voltage instability area and can withstand more loads.

[0076] Example 2

[0077] In order to verify the economy and effectiveness of the energy storage planning model proposed in this embodiment, the energy storage site selection and capacity determination were carried out under the conditions of different photovoltaic nodes connected to the distribution network; in order to better analyze the impact of demand response on the optimal configuration results of energy storage, nodes with different voltage stability conditions and different photovoltaic access points were selected, and the photovoltaic storage node access that conforms to the actual situation was considered. In summary, the following three schemes were set for comparative analysis.

[0078] Solution 1: Consider connecting 1 node to a photovoltaic station and 4 nodes to a pumped storage station. Consider the various costs of the distribution network when the photovoltaic penetration rate is 40%, and the load of each node in the power grid remains unchanged.

[0079] The voltage safety boundary state diagram of Scheme 1 is as follows: Figure 4 As shown in Figure 1, the charging and discharging policy, load curve and energy storage site selection of Scheme 1 are as follows: Figure 5 shown.

[0080] Solution 2: Consider connecting nodes 5 and 11 to a photovoltaic station respectively, and considering the various costs of the distribution network when the photovoltaic penetration rate is 60%. Node 5 is selected as the observation point, and the load of each node in the power grid remains unchanged.

[0081] The voltage safety boundary state diagram of Scheme 2 is as follows: Figure 6 As shown in Figure 2, the charging and discharging policy, load curve and energy storage site selection of Option 2 are as follows: Figure 7 As shown;

[0082] Option 3: Taking energy storage and demand-side response load into consideration, photovoltaic power is connected and equipped with energy storage equipment. Taking nodes 11 and 14 as examples, photovoltaic power and energy storage equipment are connected respectively. The photovoltaic penetration rate is 60%, and the load at the grid cutover point remains unchanged.

[0083] The voltage safety boundary state diagram of scheme 3 is as follows: Figure 8As shown in Figure 2, the charging and discharging policy, load curve and energy storage site selection of Scheme 3 are as follows: Fig. 9 shown.

[0084] Scheme 1 was used to obtain the storage site selection and capacity determination results, and the other 5 nodes were selected to place energy storage devices of the same capacity for cost comparison. It can be seen that the selected nodes can minimize the annual cost of the power system. As can be seen from Table 3, the stability margin of adding energy storage at node 14 is large, indicating good voltage stability under the current load level, and high power supply reliability and flexibility. Compared with the two cases of not adding energy storage and adding energy storage at 10 nodes, Figure 4 It can be found that the voltage instability area is getting larger and larger, and the current point is getting closer to the circle, indicating that the voltage stability domain is getting smaller and smaller. When the energy storage point is not selected well, the margin index becomes negative and the node is unstable. The charge and discharge policy and load curve of the energy storage are solved as follows Figure 5 As shown, after the energy storage configuration, the "low storage and high release" strategy described in the invention is met, and the power compensation under photovoltaic access is adapted to reduce the grid loss. The annual operation volume of the distribution network is reduced compared with other nodes, indicating that the connected energy storage node improves the economy of the grid.

[0085] Table 4 Comparison of the planning scheme of the method of the present invention with no energy storage and other node energy storage schemes

[0086]

[0087] Table 5 Comparison of the total annual operating cost of energy storage site selection by the present invention and other node energy storage

[0088]

[0089]

[0090] Scheme 2 was used to obtain the storage site selection and capacity determination results, and the other 5 nodes were selected to place energy storage devices of the same capacity for cost comparison. It can be seen that the selected nodes can minimize the annual cost of the power system. As can be seen from Table 6, the stability margin of adding energy storage at node 6 is large, indicating good voltage stability under the current load level, and high power supply reliability and flexibility. Compared with the two cases of not adding energy storage and adding energy storage at 10 nodes, Figure 6 It can be found that the voltage instability area is getting larger and larger, and the current point is getting closer to the circle, indicating that the voltage stability domain is getting smaller and smaller. When the energy storage point is not selected well, the margin index becomes negative and the node is unstable. The charge and discharge policy and load curve of the energy storage are solved as follows Figure 7As shown in Table 7, after the energy storage configuration, the "low storage and high release" strategy described in the invention is met, and the power compensation under photovoltaic access is adapted to reduce the grid loss. It can be found from Table 7 that the annual operation volume of the distribution network is reduced compared with other nodes, indicating that the connected energy storage node improves the economy of the grid.

[0091] Table 6 Comparison of the planning scheme of the method of the present invention with the scheme without energy storage and other node energy storage schemes

[0092]

[0093] Table 7 Comparison of the total annual operating cost of energy storage site selection by the present invention and other node energy storage

[0094]

[0095]

[0096] Scheme 3 is used to obtain the voltage safety boundary at the same node of photovoltaic and energy storage, which can be known from the stability analysis. It can be seen that when photovoltaic and energy storage equipment is added at node 11, the stability margin is very small, indicating that the voltage at the current node is critically stable. The current vector is very close to the boundary circle, and node 11 is close to the boundary of the stability domain and is in critical stability. Analyzing the reasons, node 7 is connected to the power plant and has a large transmission power, which may cause it to be under greater power flow pressure and thus approach the stability limit; adding photovoltaic and energy storage equipment at node 14 will increase the radius of the circle, so that the current vector is wrapped in the circle, and node 14 cannot maintain a sufficient voltage level, which will cause voltage instability. Therefore, it is not recommended that the power grid add photovoltaic and energy storage equipment at node 14. For the charging and discharging policy and load curve of the energy storage at node 11, as shown in the figure below: Fig. 9 shown.

[0097] Table 8 Comparison of the planning scheme of the method of the present invention with no energy storage and other node energy storage schemes

[0098]

[0099] In summary, the present invention designs a method for planning and configuring power grid energy storage that takes into account the safety and stability domain of the new power system. The proposed two-layer optimization model can effectively solve the problems of energy storage site selection layout and optimal configuration in distributed photovoltaic systems. At the same time, the algorithm runs stably and has good convergence, which reveals the voltage stability of the power grid under the current load level and provides a scientific decision-making basis for power grid planning and operation. The present invention solves the problems of large amount of calculation and difficulty in realizing online application in related technologies, and increases the considerations for power grid energy storage planning. By obtaining the energy storage site selection and sizing with the lowest annual operating cost of the power system and formulating corresponding safety boundaries, the accuracy and applicability of energy storage planning are improved, providing theoretical support and practical guidance for the stable operation of the power grid.

[0100] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system, characterized by: The method comprises the following steps: 1) Based on the quantitative analysis of the basic loop model, the node voltage and loop current hybrid analysis method, and the current load level and network parameters in the power grid, determine the first objective function corresponding to the voltage safety boundary in the power grid; 2) Based on the revenue model of the energy storage system, the safety of the power grid and the operational stability of the energy storage system, the charging and discharging strategies at different time periods during the day are optimized to maximize the power system and determine the second objective function corresponding to the maximum revenue of the grid energy storage access; 3) Determining a grid energy storage access cost minimization model based on the first objective function and the second objective function; 4) Based on energy storage, distributed power sources and grid constraints, the single-layer multi-objective planning of battery energy storage site selection and sizing is transformed into a double-layer single-objective optimization for solution, and the energy storage site selection and sizing plan with the minimum annual operating cost of the power system is obtained.

2. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 1 is characterized in that: The step 1) is based on the quantitative analysis of the basic loop model and the hybrid analysis method of node voltage and loop current to determine the first objective function corresponding to the voltage safety boundary in the power grid, including: based on the current load level and network parameters in the power grid, determining the node voltage stability boundary in the power grid, constructing the circular voltage stability domain boundary and voltage instability area in the state space, constructing the network topology relationship of the power grid, and constructing a voltage stability margin index as the first objective function.

3. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 1 is characterized in that: The step 2) based on the revenue model of the energy storage system, the grid security and the operational stability of the energy storage system, optimizes the charging and discharging strategies for each period of the day, and determines the second objective function corresponding to the maximization of the grid energy storage access revenue, including: determining the direct investment revenue and social comprehensive revenue of the energy storage system, and determining the "low storage and high discharge" index of the energy storage system as the second objective function.

4. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 1 is characterized in that: The step 3) determining the grid energy storage access cost minimization model according to the first objective function and the second objective function includes: determining the grid energy storage access objective function, and determining the operation stability constraint conditions under the grid energy storage access.

5. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 2, characterized in that: The basic circuit model is: The loop current equation is: Node voltage equation: In the formula is the injected current at node a; is the sum of all admittance branch currents associated with node a; S a =p a +jq a , S b =p b +jq b are the injected powers of nodes a and b respectively. Let the voltage phasors of nodes a and b be The current in this circuit is The subscripts a, b = 1, 2, ..., N are node numbers, and the subscript l = 1, 2, ..., L is the loop number.

6. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 2 is characterized in that: The node voltage and loop current hybrid analysis model is: When the branch-to-ground conductance is neglected, season In the formula is the loop current phasor.

7. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 2 is characterized in that: The state space circular voltage stability model is: The voltage stability margin index is:

8. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 3 is characterized in that: The revenue model based on the energy storage system is: Where: P dg (t) is the reactive power output of the distributed power supply at the sampling time; P hv (t) is the reactive power provided by the grid, R dg R(t) is the unit cost of reactive power output by distributed generation at the sampling time, which is 0.03 times the price of R(t) in the same period; hv P(t) is the unit cost of reactive power injected into the grid side, which is 0.06 times the price of R(t) in the same period. ch (t) represents the charging power of the energy storage battery at the sampling time; P dis (t) represents the BESS discharge power; B ch (t) and B dis (t) represent the charge and discharge status of BESS at time t; R(t) represents the time-of-use electricity price, C BESS Represents the investment and construction cost of the energy storage system; C M Represents the energy storage operation and maintenance cost. bess ,x represents the energy storage system x configuration power; E bess , x represents the x configuration capacity of the energy storage system; C P Represents the unit power cost of energy storage; C E represents the unit capacity cost of energy storage; r represents the discount rate; n represents the life of the energy storage system; and h represents the maximum number of energy storage installations. M represents the operation and maintenance cost of the annual power generation of energy storage; Q represents the annual power generation of BESS.

9. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 3 is characterized in that: The "low storage and high release" indicators of the energy storage system are: Where: B ch (t) and B dis (t) represent the charging and discharging states of BESS at time t; P ch (t) and P dis (t) represents the charging and discharging power of BESS at time t, respectively; Δt represents the system sampling interval; T indicates that the photovoltaic output is greater than the initial load moment; N day Indicates the annual operating time of BESS.

10. The method for planning and configuring power grid energy storage taking into account the safety and stability domain of a new power system according to claim 4, characterized in that: The objective function is expressed as: minF=C LOSS +C DG +C HV +C PB +C DBSS Where: F is the total annual operating cost of the power system; C LOSS is the grid loss cost; C DG and C HV They are the reactive power costs provided by distributed sources and the reactive power costs provided by the grid to ensure stable operation of the grid; C PB The cost of charging and discharging energy storage; C DBSS The cost of energy storage; The second constraint conditions include: power system power balance, node voltage amplitude, transmission line active power, generator output, battery energy storage system charging and discharging, and charge state continuity constraints; The power balance constraint is used to indicate that: the total power generated in the power system must be equal to the total power consumed plus the transmission loss; the power supply and demand are matched within the power balance range to avoid power outages or over-power supply; The node voltage amplitude constraint is used to indicate that the voltage magnitudes of the connection points and substations of the power grid need to be kept within a specified range to ensure the normal operation of equipment and the stable transmission of power; The generator output constraint is used to indicate: the amount of electricity generated by the system generator set, including its minimum and maximum output limits; the output of the generator needs to be adjusted according to the grid demand and cannot exceed its operating limit; The battery energy storage system charge and discharge constraints are used to indicate that the charging and discharging of the battery energy storage system satisfies that the stored energy is within a set range, including upper and lower limits of the charge and discharge rate and time; The state of charge continuity constraint is used to indicate that the state of charge charging level of the energy storage system maintains continuous and smooth changes.

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