New energy storage cluster power optimization method and system considering power grid strength constraint

Abstract

The invention provides a new energy storage cluster power optimization method and system considering power grid strength constraint, and is applied to the technical field of new energy power generation. The method comprises the following steps: calculating the short-circuit ratio of each new energy node and each energy storage node based on a node impedance matrix and the current power of each new energy node and each energy storage node in a new energy storage cluster; based on the short-circuit ratio calculation result, judging the power grid strength of the new energy storage station, and further determining whether the new energy storage cluster needs to be subjected to power optimization or not; if power optimization needs to be carried out, taking the maximum output total power of each new energy node in the new energy storage cluster as a target, and considering the power grid strength constraint to construct a power optimization model for each new energy node and each energy storage node; and solving the power optimization model to obtain an optimization result. The problem that when new energy and stored energy are jointly connected into the power grid, the power grid operation stability is poor possibly due to the fact that the strength of the power grid connected into the area is weak is solved.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy power generation technology, and in particular to a method and system for optimizing power of a renewable energy storage cluster taking into account grid strength constraints. Background Art

[0002] Vigorously developing new energy has become the mainstream of energy development. China's western and northern regions are rich in wind and solar resources. At present, many large-scale clean energy bases have been built. The installed capacity of new energy is large, but the local power grid structure is weak, and there is even no conventional power support. Therefore, the strength of the power grid in the area where the new energy cluster is connected is weak, and stability problems such as transient voltage instability and wide-band oscillation are prominent, which restricts the ability to absorb and send new energy. With the further expansion of new energy installed capacity, the weak strength of the power grid in the area where the new energy cluster is connected will become a common problem faced by new energy development in the "Three Norths" region of my country. In order to alleviate the pressure of new energy transmission, the establishment of an operating mode of "new energy + energy storage" has been promoted. The electrochemical energy storage system uses the energy storage converter as the grid-connected interface and is also a power electronic device. It is connected to the new energy power generation base and can be coupled with the new energy power generation to jointly affect the operating characteristics of the power grid.

[0003] However, when new energy and energy storage are connected to the power grid together, the weak strength of the power grid in the access area may lead to poor grid operation stability. Summary of the invention

[0004] In order to overcome the problem of poor grid operation stability caused by weak grid strength in the access area when the above-mentioned new energy and energy storage are connected to the grid together, the present invention provides a new energy storage cluster power optimization method and system considering grid strength constraints.

[0005] On the one hand, the present invention provides a method for optimizing power of a new energy storage cluster considering grid strength constraints, comprising:

[0006] Calculate the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster;

[0007] Determine the strength of the power grid based on the short-circuit ratio of each new energy node and each energy storage node, and determine whether the new energy storage cluster needs to be power optimized based on the power grid strength;

[0008] If the new energy storage cluster needs to be power optimized, the total output power of each new energy node in the new energy storage cluster is maximized, and a power optimization model for each new energy node and each energy storage node is constructed by considering the grid strength constraint;

[0009] Solve the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

[0010] Optionally, before calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster, the method further includes:

[0011] Obtaining the operating data of the power grid connected to the new energy storage cluster;

[0012] Calculate the power grid flow based on the operation data to obtain the voltage of each new energy node and each energy storage node;

[0013] By setting a three-phase short-circuit fault at each new energy node and each energy storage node, the short-circuit current and short-circuit capacity of each new energy node and each energy storage node are obtained;

[0014] The method of calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster includes:

[0015] Based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated.

[0016] Optionally, the calculation formula of the short-circuit ratio of each new energy node is:

[0017]

[0018] In the formula, is the short-circuit ratio of the new energy node i, i and j are the new energy node indexes, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; is the short-circuit capacity of the new energy node; is the output apparent power of new energy node i, is the output power of new energy node j, is the interaction factor between new energy node i and new energy node j, And j≠i, is the self-impedance of the new energy node i, is the mutual impedance between new energy node j and new energy node i; is the output power of energy storage node k, is the interaction factor between energy storage node k and new energy node i, is the self-impedance of the energy storage node k, is the mutual impedance between the energy storage node k and the new energy node i;

[0019] The calculation formula of the short-circuit ratio of each energy storage node is:

[0020]

[0021] In the formula, is the short-circuit ratio of the energy storage node k, is the short-circuit capacity of the energy storage node k; is the output apparent power of energy storage node k, P i re is the output power of new energy node i, l is the energy storage node index, P l es is the output power of energy storage node l, is the interaction factor between energy storage node l and energy storage node k, And l≠k, is the mutual impedance between the energy storage node l and the energy storage node k.

[0022] Optionally, determining the grid strength based on the short-circuit ratio of each new energy node and each energy storage node includes:

[0023] If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid;

[0024] If the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid;

[0025] The determining whether the new energy storage cluster needs to perform power optimization based on the power grid strength includes:

[0026] If the current power grid is a weak power grid, it is determined that the new energy storage cluster needs to be power optimized;

[0027] If the current power grid is a strong power grid, it is determined that the new energy storage cluster does not need to perform power optimization.

[0028] Optionally, taking the maximum total output power of each new energy node in the new energy storage cluster as the goal and considering the grid strength constraint to construct a power optimization model for each new energy node and each energy storage node, includes:

[0029] Taking the maximum total output power of each new energy node in the new energy storage cluster as the objective function;

[0030] Determine the grid strength constraint based on the short-circuit ratio of each new energy node and each energy storage node;

[0031] Considering the operational safety of each new energy node and each energy storage node, the power constraints of each new energy node and each energy storage node are determined;

[0032] Consider the output balance of each new energy node and each energy storage node before and after optimization, and determine the balance constraint;

[0033] The power optimization model is constructed by taking the power grid strength constraint, the power constraint and the balance constraint as model constraints and combining them with the objective function.

[0034] Optionally, the grid strength constraint includes a minimum short circuit ratio constraint of each new energy node and each energy storage node and an equivalent short circuit ratio constraint of the new energy energy storage cluster;

[0035] The balance constraints include the optimized power increment constraints of each new energy node and each energy storage node, the output mean constraint of each new energy node and the optimized power deviation constraint of each energy storage node;

[0036] Among them, the equivalent short-circuit ratio of the new energy energy storage cluster is obtained by weighted processing of the short-circuit ratios of each new energy node and each energy storage node based on the proportion of the current power of each new energy node and each energy storage node in the total output power of the new energy energy storage cluster.

[0037] Optionally, the expression of the minimum short circuit ratio constraint is:

[0038]

[0039] In the formula, is the short-circuit ratio of new energy node i, is the grid-connected operation limit short-circuit ratio of the new energy node, is the short-circuit ratio of the energy storage node k, is the grid-connected operation limit short-circuit ratio of the energy storage node;

[0040] The expression of the equivalent short-circuit ratio constraint of the new energy storage cluster is:

[0041] WESCR ≥ WESCR min ,

[0042]

[0043] Where, WESCR represents the equivalent short-circuit ratio of the new energy storage cluster, WESCR min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster; P i re is the output power of new energy node i, is the output power of energy storage node k; i is the new energy node index, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster;

[0044] The power constraint expression of each new energy node and each energy storage node is:

[0045]

[0046] In the formula, They are the minimum and maximum output of the new energy node respectively; are the maximum and minimum output values ​​of the energy storage node respectively;

[0047] The expression of the optimized power increment constraint of each new energy node and each energy storage node is:

[0048]

[0049] In the formula, are the current powers of new energy node i and energy storage node k respectively; The maximum deviation between the optimized power data of the new energy node and the current power. The maximum deviation between the optimized power data of the energy storage node and the current power;

[0050] The expression of the output mean constraint of each new energy node is:

[0051]

[0052] In the formula, is the rated power of new energy node i, is the average value of power data after optimization of new energy nodes, is the average value of the rated power of the new energy nodes, is the maximum value of the deviation of the power mean of the new energy node;

[0053] The expression of the optimized power deviation constraint of each energy storage node is:

[0054]

[0055] Where f is the total power deviation before and after the energy storage node is optimized. is the rated power of energy storage node k, is the current power of the energy storage node, f max It is the maximum value of the sum of power deviations before and after energy storage node optimization.

[0056] Optionally, solving the power optimization model to obtain optimized power data of each new energy node and each energy storage node includes:

[0057] The short-circuit ratio of each new energy node and each energy storage node is iteratively optimized based on the node impedance matrix to solve the objective function, thereby obtaining optimized power data of each new energy node and each energy storage node.

[0058] On the other hand, the present invention also provides a new energy storage cluster power optimization system considering grid strength constraints, the system comprising:

[0059] A short circuit ratio calculation module, used to calculate the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster;

[0060] An optimization judgment module is used to determine the strength of the power grid based on the short-circuit ratio of each new energy node and each energy storage node, and determine whether the new energy storage cluster needs to be power optimized based on the power grid strength;

[0061] An optimization model building module is used to build a power optimization model for each new energy node and each energy storage node by taking the power grid strength constraint into consideration, if the new energy storage cluster needs to be power optimized, with the goal of maximizing the total output power of each new energy node in the new energy storage cluster;

[0062] The model solving module is used to solve the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

[0063] Optionally, the short circuit ratio calculation module is specifically used for:

[0064] Obtaining the operating data of the power grid connected to the new energy storage cluster;

[0065] Calculate the power grid flow based on the operation data to obtain the voltage of each new energy node and each energy storage node;

[0066] By setting a three-phase short-circuit fault at each new energy node and each energy storage node, the short-circuit current and short-circuit capacity of each new energy node and each energy storage node are obtained;

[0067] Based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated.

[0068] Optionally, the calculation formula of the short-circuit ratio of each new energy node is:

[0069]

[0070] In the formula, is the short-circuit ratio of the new energy node i, i and j are the new energy node indexes, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; is the short-circuit capacity of the new energy node; is the output apparent power of new energy node i, is the output power of new energy node j, is the interaction factor between new energy node i and new energy node j, And j≠i, is the self-impedance of the new energy node i, is the mutual impedance between new energy node j and new energy node i; is the output power of energy storage node k, is the interaction factor between energy storage node k and new energy node i, is the self-impedance of the energy storage node k, is the mutual impedance between the energy storage node k and the new energy node i;

[0071] The calculation formula of the short-circuit ratio of each energy storage node is:

[0072]

[0073] In the formula, is the short-circuit ratio of the energy storage node k, is the short-circuit capacity of the energy storage node k; is the output apparent power of energy storage node k, P i re is the output power of new energy node i, l is the energy storage node index, P l es is the output power of energy storage node l, is the interaction factor between energy storage node l and energy storage node k, And l≠k, is the mutual impedance between the energy storage node l and the energy storage node k.

[0074] Optionally, the optimization judgment module includes: a power grid strength determination submodule and an optimization determination submodule, and the power grid strength determination submodule is used to:

[0075] If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid;

[0076] If the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid;

[0077] The optimization determines the submodules used to:

[0078] If the current power grid is a weak power grid, it is determined that the new energy storage cluster needs to be power optimized;

[0079] If the current power grid is a strong power grid, it is determined that the new energy storage cluster does not need to perform power optimization.

[0080] Optionally, the optimization model building module is specifically used for:

[0081] Taking the maximum total output power of each new energy node in the new energy storage cluster as the objective function;

[0082] Determine the grid strength constraint based on the short-circuit ratio of each new energy node and each energy storage node;

[0083] Considering the operational safety of each new energy node and each energy storage node, the power constraints of each new energy node and each energy storage node are determined;

[0084] Consider the output balance of each new energy node and each energy storage node before and after optimization, and determine the balance constraint;

[0085] The power grid strength constraint, the power constraint and the balance constraint are used as model constraints, and the power optimization model is constructed in combination with the objective function.

[0086] Optionally, the grid strength constraint includes a minimum short circuit ratio constraint of each new energy node and each energy storage node and an equivalent short circuit ratio constraint of the new energy energy storage cluster;

[0087] The balance constraints include the optimized power increment constraints of each new energy node and each energy storage node, the output mean constraint of each new energy node and the optimized power deviation constraint of each energy storage node;

[0088] Among them, the equivalent short-circuit ratio of the new energy energy storage cluster is obtained by weighted processing of the short-circuit ratios of each new energy node and each energy storage node based on the proportion of the current power of each new energy node and each energy storage node in the total output power of the new energy energy storage cluster.

[0089] Optionally, the expression of the minimum short circuit ratio constraint is:

[0090]

[0091] In the formula, is the short-circuit ratio of new energy node i, is the grid-connected operation limit short-circuit ratio of the new energy node, is the short-circuit ratio of the energy storage node k, is the grid-connected operation limit short-circuit ratio of the energy storage node;

[0092] The expression of the equivalent short-circuit ratio constraint of the new energy storage cluster is:

[0093] WESCR ≥ WESCR min ,

[0094]

[0095] Where, WESCR represents the equivalent short-circuit ratio of the new energy storage cluster, WESCR min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster; P i re is the output power of new energy node i, is the output power of energy storage node k; i is the new energy node index, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster;

[0096] The power constraint expression of each new energy node and each energy storage node is:

[0097]

[0098] In the formula, They are the minimum and maximum output of the new energy node respectively; are the maximum and minimum output values ​​of the energy storage node respectively;

[0099] The expression of the optimized power increment constraint of each new energy node and each energy storage node is:

[0100]

[0101] In the formula, are the current powers of new energy node i and energy storage node k respectively; The maximum deviation between the optimized power data of the new energy node and the current power. The maximum deviation between the optimized power data of the energy storage node and the current power;

[0102] The expression of the output mean constraint of each new energy node is:

[0103]

[0104] In the formula, is the rated power of new energy node i, is the average value of power data after optimization of new energy nodes, is the average value of the rated power of the new energy nodes, is the maximum value of the deviation of the power mean of the new energy node;

[0105] The expression of the optimized power deviation constraint of each energy storage node is:

[0106]

[0107] Where f is the total power deviation before and after the energy storage node is optimized. is the rated power of energy storage node k, is the current power of the energy storage node, f max It is the maximum value of the sum of power deviations before and after energy storage node optimization.

[0108] Optionally, the model solving module is specifically used for:

[0109] The short-circuit ratio of each new energy node and each energy storage node is iteratively optimized based on the node impedance matrix to solve the objective function, thereby obtaining optimized power data of each new energy node and each energy storage node.

[0110] On the other hand, the present invention also provides an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0111] The memory is used to store one or more programs;

[0112] When the one or more programs are executed by the at least one processor, any one of the above-mentioned methods for optimizing the power of a new energy storage cluster taking into account grid strength constraints is implemented.

[0113] On the other hand, the present invention also provides a readable storage medium having an execution program stored thereon, which, when executed, implements any one of the above-mentioned methods for optimizing the power of a new energy storage cluster taking into account grid strength constraints.

[0114] Compared with the prior art, the present invention has the following beneficial effects:

[0115] The present invention provides a power optimization method and system for a new energy storage cluster considering the constraints of power grid strength. On the one hand, the power grid strength is determined by calculating the short-circuit ratio of each new energy node and each energy storage node, and whether the new energy storage cluster needs to be power optimized is judged based on the power grid strength. Corresponding power optimization can be performed specifically for weak power grids, thereby improving the operational stability of weak power grids. On the other hand, for weak power grids that need to be power optimized, the total output power of each new energy node in the new energy storage cluster is maximized, and a power optimization model for each new energy node and each energy storage node is constructed considering the constraints of power grid strength; the power optimization of each new energy node and each energy storage node is performed through the power optimization model, and the maximum output of new energy can be achieved on the basis of ensuring the strength of the power grid, and the stable operation of the power grid under the maximum output of new energy can be achieved, further improving the operational stability of the weak power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0116] Figure 1 One of the flow charts of a method for optimizing power of a new energy storage cluster taking into account grid strength constraints of the present invention;

[0117] Figure 2 The second flowchart of a method for optimizing power of a new energy storage cluster taking into account grid strength constraints of the present invention;

[0118] Figure 3 A comparison result diagram of the short-circuit ratio of a new energy station before and after the output optimization of a new energy storage cluster of the present invention;

[0119] Figure 4 A comparison result diagram of the new energy output before and after the output optimization of a new energy storage cluster of the present invention;

[0120] Figure 5 This is a comparison result diagram of the short-circuit ratio of the energy storage power station before and after the output optimization of the new energy storage cluster of the present invention;

[0121] Figure 6 This is a comparison result diagram of the energy storage power station output before and after the output optimization of the new energy storage cluster of the present invention;

[0122] Figure 7 It is a schematic structural diagram of the electronic device of the present invention. DETAILED DESCRIPTION

[0123] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0124] Embodiment 1:

[0125] The present invention provides a method for optimizing the power of a new energy storage cluster considering the power grid strength constraint, as shown in the schematic diagram Figure 1 As shown, including:

[0126] Step S110, calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster;

[0127] Step S120, determining the strength of the power grid based on the short-circuit ratios of each new energy node and each energy storage node, and determining whether the new energy storage cluster needs to be power optimized based on the power grid strength;

[0128] Step S130, if the new energy storage cluster needs to be power optimized, taking the maximum total output power of each new energy node in the new energy storage cluster as the goal, and considering the grid strength constraint, constructing a power optimization model for each new energy node and each energy storage node;

[0129] Step S140, solving the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

[0130] In this example implementation, the short circuit ratio (SCR) refers to the short circuit capacity of the system divided by the equipment capacity. This indicator is often used to analyze the power grid strength and the dynamic stability of the system after the power electronic equipment is fed into the AC system. The new energy storage cluster includes one or more new energy nodes and one or more energy storage nodes. The new energy node can be various new energy sites, such as wind turbines and / or photovoltaic sites; the energy storage node can be a battery energy storage system, which can store excess energy by charging the battery when the power generation of the new energy node is greater than the load, and supply power to the grid by discharging the battery when the power generation of the new energy node is less than the load. This example judges the strength of the power grid based on the short circuit ratio of each energy node and each energy storage node. For example, when the minimum value of the short circuit ratio of each new energy node is less than the first threshold, the power grid is judged to be a weak power grid; the equivalent short circuit ratio of the new energy storage cluster can also be determined based on the short circuit ratio of each new energy node and the energy storage node, and the power grid strength is judged based on the comparison result of the equivalent short circuit ratio of the new energy storage cluster and the second threshold. Among them, the first threshold and the second threshold can be set according to experience. The current operating power of new energy and energy storage is optimized in real time for the power grid judged as a weak power grid. The present invention aims at the situation where new energy and energy storage are connected to the power grid at the same time, takes into account the grid strength constraints of the new energy station connected to the energy storage, and establishes an output optimization model of the "new energy + energy storage" cluster for the weak power grid scenario. By optimizing the output of the new energy storage cluster, the operating stability of the weak power grid is improved.

[0131] In an example implementation, before calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster in step S110, the method further includes the following process:

[0132] Obtaining the operating data of the power grid connected to the new energy storage cluster;

[0133] Calculate the power grid flow based on the operation data to obtain the voltage of each new energy node and each energy storage node;

[0134] By setting a three-phase short-circuit fault at each new energy node and each energy storage node, the short-circuit current and short-circuit capacity of each new energy node and each energy storage node are obtained;

[0135] The step S110 of calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster includes:

[0136] Based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated.

[0137] In this example implementation, the operation data of the power grid may include the main equipment parameters of the power grid, the topological relationship and measurement data of the equipment during operation, such as the current operating power, installed capacity, node name, node identification and other information of each network node. The voltage of each new energy node and each energy storage node can be obtained through power grid flow calculation based on the operation data of the power grid, and the short-circuit current and short-circuit capacity of each new energy node and each energy storage node can be obtained by setting a three-phase short-circuit fault at each new energy node and each energy storage node. Finally, based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated. In this example, according to the power grid operation data, the name, node name, installed capacity, short-circuit capacity, current power, current station short-circuit ratio and node impedance matrix of the new energy storage cluster of the new energy station and energy storage system in the area where the short-circuit ratio calculation of the new energy cluster needs to be carried out are clearly defined.

[0138] Exemplarily, the short-circuit ratio calculation method of multiple renewable energy stations can be extended to the short-circuit ratio calculation of multiple renewable energy storage clusters. Specifically, taking a renewable energy cluster containing n renewable energy nodes and m energy storage nodes as an example, the short-circuit ratio calculation formula of renewable energy node i is as follows:

[0139]

[0140] In the formula, is the short-circuit ratio of the new energy node i, i and j are the new energy node indexes, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; is the short-circuit capacity of the new energy node; is the output apparent power of new energy node i, is the output power of new energy node j, is the interaction factor between new energy node i and new energy node j, And j≠i, is the self-impedance of the new energy node i, is the mutual impedance between new energy node j and new energy node i; is the output power of energy storage node k, is the interaction factor between energy storage node k and new energy node i, is the self-impedance of the energy storage node k, is the mutual impedance between the energy storage node k and the new energy node i.

[0141] Similarly, the calculation formula for the short-circuit ratio of each energy storage node of new energy is:

[0142]

[0143] In the formula, is the short-circuit ratio of the energy storage node k, is the short-circuit capacity of the energy storage node k; is the output apparent power of energy storage node k, P i re is the output power of new energy node i, l is the energy storage node index, P l es is the output power of energy storage node l, is the interaction factor between energy storage node l and energy storage node k, And l≠k, is the mutual impedance between the energy storage node l and the energy storage node k.

[0144] In formula (1), j≠i in formula (2), According to the above calculation formula, when the new energy station is connected to the energy storage system in the vicinity, the denominator of the short-circuit ratio of multiple stations will increase by one term. When the energy storage is transmitting power to output active power, The short-circuit ratio of new energy stations is reduced; when the energy storage absorbs active power, The short-circuit ratio of new energy stations is improved. It can be seen that in order to improve the strength of new energy access to the grid, the power transmission power needs to be reduced as much as possible when energy storage is transmitting electricity, and the power reception power needs to be increased as much as possible when energy storage is receiving electricity. This example considers the impact of energy storage access on the strength of the new energy storage cluster grid, and improves the calculation accuracy of the strength of the new energy storage cluster grid.

[0145] In an example implementation, the determining of the grid strength based on the short-circuit ratio of each new energy node and each energy storage node in step S120 includes:

[0146] If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid;

[0147] If the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid;

[0148] The determining whether the new energy storage cluster needs to perform power optimization based on the power grid strength includes:

[0149] If the current power grid is a weak power grid, it is determined that the new energy storage cluster needs to be power optimized;

[0150] If the current power grid is a strong power grid, it is determined that the new energy storage cluster does not need to perform power optimization.

[0151] In this example implementation, the grid strength constraint value can be set based on experience or based on historical data of the regional grid. For example, the grid strength constraint value can be 1.5. If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid; if the current grid is a weak grid, it is determined that the new energy storage cluster needs to be power optimized; if the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid; if the current grid is a strong grid, it is determined that the new energy storage cluster does not need to be power optimized. This example can evaluate the current grid strength based on the short-circuit ratio calculation results of the new energy storage cluster. When the minimum value of the short-circuit ratio of multiple stations is less than the grid strength constraint value, the grid strength is judged to be a weak grid, and the output optimization of the new energy storage cluster needs to be carried out; otherwise, the grid strength is judged to be a strong grid, and cluster output optimization does not need to be carried out.

[0152] In some example implementations, the step S130 takes the maximum total output power of each new energy node in the new energy storage cluster as the goal, and constructs a power optimization model for each new energy node and each energy storage node in consideration of the grid strength constraint, including:

[0153] Taking the maximum total output power of each new energy node in the new energy storage cluster as the objective function;

[0154] Determine the grid strength constraint based on the short-circuit ratio of each new energy node and each energy storage node;

[0155] Considering the operational safety of each new energy node and each energy storage node, the power constraints of each new energy node and each energy storage node are determined;

[0156] Consider the output balance of each new energy node and each energy storage node before and after optimization, and determine the balance constraint;

[0157] The power grid strength constraint, the power constraint and the balance constraint are used as model constraints, and the power optimization model is constructed in combination with the objective function.

[0158] In this example implementation, the equivalent short circuit ratio of the new energy storage cluster can be calculated based on the short circuit ratio of the new energy node and the short circuit ratio of the energy storage node, and the grid strength constraint can be set based on the equivalent short circuit ratio. Specifically, the short circuit ratios of each new energy node and each energy storage node can be weighted based on the proportion of the current power of each new energy node and each energy storage node in the total output power of the new energy storage cluster to obtain the equivalent short circuit ratio of the new energy storage cluster. For example, the equivalent short circuit ratio WESCR of the new energy storage cluster can be expressed as follows:

[0159]

[0160] Where, WESCR represents the equivalent short-circuit ratio of the new energy storage cluster, is the short-circuit ratio of new energy node i, is the short circuit ratio WESCR of energy storage node k min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster; P i re is the output power of new energy node i, is the output power of the energy storage node k; i is the new energy node index, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster.

[0161] Exemplarily, the grid strength constraint determined based on the equivalent short-circuit ratio of the above-mentioned new energy energy storage cluster includes the minimum short-circuit ratio constraint of each new energy node and each energy storage node and the equivalent short-circuit ratio constraint of the new energy energy storage cluster; the balance constraint determined considering the balance and rationality of the actual operation of the power grid includes the optimized power increment constraint of each new energy node and each energy storage node, the output mean constraint of each new energy node and the optimized power deviation constraint of each energy storage node; the power constraint of each new energy node and each energy storage node can also be determined considering the operation safety of each new energy node and each energy storage node. The above-mentioned constraints are used as model constraints, and a power optimization model is constructed in combination with the objective function to ensure the strength of the power grid after power optimization, the safety of power grid operation, and the output balance between each new energy node, avoid large-scale power fluctuations and excessive output differences in the same area, ensure that the optimization results are consistent with the actual situation, and ensure the rationality of the optimization results.

[0162] Specifically, the objective function of the power optimization model is to maximize the total power output of the new energy station, that is, the objective function is The optimization variable of the power optimization model is the new energy node power P i re , the power of the energy storage node The constraints are as follows:

[0163] The expression of the minimum short-circuit ratio constraint is:

[0164]

[0165] In the formula, is the short-circuit ratio of new energy node i, is the grid-connected operation limit short-circuit ratio of the new energy node, is the short-circuit ratio of the energy storage node k, is the grid-connected operation limit short-circuit ratio of the energy storage node; Determined by the performance of the device itself.

[0166] The expression of the equivalent short-circuit ratio constraint of the new energy storage cluster is:

[0167] WESCR ≥ WESCR min (5)

[0168] Where WESCR min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster.

[0169] The power constraint expression of each new energy node and each energy storage node is:

[0170]

[0171] In the formula, in the formula, They are the minimum and maximum output of the new energy node respectively; are the maximum and minimum output values ​​of the energy storage node respectively. Since the power of the energy storage node is positive and negative, the maximum and minimum output values ​​of the energy storage node are set according to the positive and negative current operating power of the energy storage node. When the current power of the energy storage node is positive, set Generally, the rated power is taken; when the current power of the energy storage node is negative, Generally, the opposite of the rated power is taken.

[0172] The expression of the optimized power increment constraint of each new energy node and each energy storage node is:

[0173]

[0174] In the formula, are the current powers of new energy node i and energy storage node k respectively; The maximum deviation between the optimized power data of the new energy node and the current power. The maximum deviation between the optimized power data of the energy storage node and the current power;

[0175] The expression of the output mean constraint of each new energy node is:

[0176]

[0177] In the formula, is the rated power of new energy node i, is the average value of power data after optimization of new energy nodes, is the average value of the rated power of the new energy nodes, It is the maximum value of the deviation of the power mean of the new energy node.

[0178] The expression of the optimized power deviation constraint of each energy storage node is:

[0179]

[0180] Where f is the total power deviation before and after the energy storage node is optimized. is the rated power of energy storage node k, is the current power of the energy storage node, f max It is the maximum value of the sum of power deviations before and after energy storage node optimization.

[0181] The power optimization model is constructed by using the objective function and the constraints of formulas (3) to (11).

[0182] In some implementations, solving the power optimization model in step S140 to obtain optimized power data of each new energy node and each energy storage node includes:

[0183] The short-circuit ratio of each new energy node and each energy storage node is iteratively optimized based on the node impedance matrix to solve the objective function, thereby obtaining optimized power data of each new energy node and each energy storage node.

[0184] In this example implementation, the model can be solved based on the node impedance matrix of the new energy storage cluster through CPLEX solver, or genetic algorithm, particle swarm algorithm and other programs, and the short-circuit ratio of the new energy storage cluster can be optimized by continuous iteration to solve the objective function and obtain the optimal output. When optimizing the output of the new energy storage cluster, it is necessary to input the parameters of the new energy storage cluster output optimization model. The parameters that need to be input in the power optimization model include WESCR min , f max Etc. Among them, WESCR min , It is related to the performance and operating status of the equipment in the new energy station and energy storage system. f max Related to the requirements of power grid operation mode, corresponding parameters can be adjusted according to actual needs to ensure that the optimization results are reasonable and reliable.

[0185] In some embodiments, the power optimization results of the new energy and energy storage power station can be evaluated based on the short-circuit ratio and output difference before and after the output optimization of the new energy storage cluster.

[0186] For example, Figure 2 As shown, the specific process of the power optimization method of the new energy storage cluster considering the grid strength constraint of the present invention is: obtain the operating data of the power grid connected to the new energy storage cluster, and obtain the short-circuit capacity and node impedance matrix of each node through the grid flow calculation; calculate the short-circuit ratio of each node based on the short-circuit capacity and the node impedance matrix. If the minimum value of the short-circuit ratio of the new energy node is less than 1.5, the power grid is judged to be a weak power grid, otherwise the power grid is judged to be a strong power grid. For the weak power grid, a power optimization model of the new energy storage cluster is constructed and the model is solved to obtain the optimized output of each node, and each node is controlled based on the optimized output; for the strong power grid, power optimization is not performed, that is, each node can operate according to the current power.

[0187] Although the power system safety and stability guidelines clearly require that the access scale of new energy and direct current must take into account the strength of the power grid, that is, to ensure that the system short-circuit ratio meets the requirements of the guidelines. However, there is no mature technical support for how to evaluate the strength of the power grid and its stable operation capability of the mixed access of energy storage systems and new energy power generation. In order to cope with the large-scale "new energy + energy storage" development model, it is necessary to evaluate the strength of the power grid of the energy storage system access to the new energy station and optimize the output of the energy storage and new energy clusters of the weak power grid, which has become a relevant research that needs to be carried out urgently. The present invention provides a new energy storage cluster output optimization method that considers the constraints of the power grid strength for the "new energy + energy storage" cluster. From the perspective of the constraints of the power grid strength of the new energy station, the method considers the influence of the energy storage output on the short-circuit ratio and the optimal output of the new energy station, and determines the optimal output of the new energy and energy storage cluster by establishing a power optimization model of the new energy storage cluster. The method considers the influence of energy storage access on the power grid strength of the new energy storage cluster, improves the power grid strength of the new energy storage cluster, and improves the optimal output level of new energy under the constraints of the power grid strength.

[0188] Experimental verification

[0189] Taking the "new energy + energy storage" cluster power grid in a certain region as an example, the total output of new energy is 11947MW, 8 energy storage power stations are configured, the total installed capacity is 1640MW, and the energy storage power supply is 830MW. According to the initial data, the short-circuit ratio of the "new energy + energy storage" cluster is calculated. There are 245 new energy sites, of which 59 new energy sites have a short-circuit ratio lower than 1.5. It is necessary to optimize the output of the "new energy + energy storage" cluster, and conduct an evaluation and analysis on the optimization results. The results are shown in Table 1.

[0190] Table 1

[0191] Physical quantity compared Before optimization After optimization Total output of renewable energy (MW) 11947 10147 Total energy storage power (MW) -830 -1322 Equivalent short circuit ratio 2.588 3.000

[0192] As can be seen from Table 1, after the output of the new energy storage cluster is optimized, the total output of new energy is reduced by 1800MW; after the output of the new energy storage cluster is optimized, the energy storage receiving power is increased, and the total receiving power is increased by 492MW. The equivalent short-circuit ratio after the output of the new energy storage cluster is optimized is increased by 0.412, indicating that the stability of the power grid is improved after optimization, which verifies the effectiveness of the present invention. Figure 3-Figure 6 shown. Figure 3 This is a comparison of the short-circuit ratio (ESCR) of new energy stations before and after the output optimization of new energy storage clusters. Figure 3 It can be seen that in order to ensure the maximum output of renewable energy and the balanced output layout, the short-circuit ratio of each renewable energy station can be increased or decreased, and all are above the limit short-circuit ratio. Figure 4 This is a comparison chart of the new energy output (Pg) before and after the optimization of the new energy storage cluster output. Figure 4It can be seen that in order to meet the short-circuit ratio limit constraints of each renewable energy station, renewable energy stations with low short-circuit ratios suffer more output losses. Figure 5 This is a comparison of the short-circuit ratio (ESCR) of the energy storage power station before and after the output optimization of the new energy storage cluster. Figure 5 It can be seen that the short-circuit ratio of energy storage power stations is generally high, significantly higher than 1.5, and the difference in short-circuit ratio before and after cluster output optimization is quite obvious. Figure 6 This is a comparison chart of the output of the energy storage power station (Pg) before and after the optimization of the output of the new energy storage cluster. Figure 6 It can be seen that when optimizing the energy storage power receiving mode, the energy storage power receiving power should be as high as possible. Considering the constraints of installed capacity and output deviation, the optimized energy storage output distribution is relatively uniform and generally maintained at the maximum power receiving power level.

[0193] Embodiment 2:

[0194] Based on the same inventive concept, the present invention also provides a new energy storage cluster power optimization system considering grid strength constraints, the system comprising:

[0195] A short circuit ratio calculation module, used to calculate the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster;

[0196] An optimization judgment module is used to determine the strength of the power grid based on the short-circuit ratio of each new energy node and each energy storage node, and determine whether the new energy storage cluster needs to be power optimized based on the power grid strength;

[0197] An optimization model building module is used to build a power optimization model for each new energy node and each energy storage node by taking the power grid strength constraint into consideration, if the new energy storage cluster needs to be power optimized, with the goal of maximizing the total output power of each new energy node in the new energy storage cluster;

[0198] The model solving module is used to solve the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

[0199] In a possible implementation manner, the short circuit ratio calculation module is specifically used for:

[0200] Obtaining the operating data of the power grid connected to the new energy storage cluster;

[0201] Calculate the power grid flow based on the operation data to obtain the voltage of each new energy node and each energy storage node;

[0202] By setting a three-phase short-circuit fault at each new energy node and each energy storage node, the short-circuit current and short-circuit capacity of each new energy node and each energy storage node are obtained;

[0203] Based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated.

[0204] In a possible implementation, the calculation formula of the short-circuit ratio of each new energy node is:

[0205]

[0206] In the formula, is the short-circuit ratio of the new energy node i, i and j are the new energy node indexes, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; is the short-circuit capacity of the new energy node; is the output apparent power of new energy node i, is the output power of new energy node j, is the interaction factor between new energy node i and new energy node j, And j≠i, is the self-impedance of the new energy node i, is the mutual impedance between new energy node j and new energy node i; is the output power of energy storage node k, is the interaction factor between energy storage node k and new energy node i, is the self-impedance of the energy storage node k, is the mutual impedance between the energy storage node k and the new energy node i;

[0207] The calculation formula of the short-circuit ratio of each energy storage node is:

[0208]

[0209] In the formula, is the short-circuit ratio of the energy storage node k, is the short-circuit capacity of the energy storage node k; is the output apparent power of energy storage node k, P i re is the output power of new energy node i, l is the energy storage node index, P l es is the output power of energy storage node l, is the interaction factor between energy storage node l and energy storage node k, And l≠k, is the mutual impedance between the energy storage node l and the energy storage node k.

[0210] In a possible implementation manner, the optimization judgment module includes: a power grid strength determination submodule and an optimization determination submodule, and the power grid strength determination submodule is used to:

[0211] If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid;

[0212] If the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid;

[0213] The optimization determines the submodules used to:

[0214] If the current power grid is a weak power grid, it is determined that the new energy storage cluster needs to be power optimized;

[0215] If the current power grid is a strong power grid, it is determined that the new energy storage cluster does not need to perform power optimization.

[0216] In a possible implementation manner, the optimization model building module is specifically used to:

[0217] Taking the maximum total output power of each new energy node in the new energy storage cluster as the objective function;

[0218] Determine the grid strength constraint based on the short-circuit ratio of each new energy node and each energy storage node;

[0219] Considering the operational safety of each new energy node and each energy storage node, the power constraints of each new energy node and each energy storage node are determined;

[0220] Consider the output balance of each new energy node and each energy storage node before and after optimization, and determine the balance constraints;

[0221] The power grid strength constraint, the power constraint and the balance constraint are used as model constraints, and the power optimization model is constructed in combination with the objective function.

[0222] In a possible implementation manner, the grid strength constraint includes a minimum short circuit ratio constraint of each new energy node and each energy storage node and an equivalent short circuit ratio constraint of the new energy storage cluster;

[0223] The balance constraints include the optimized power increment constraints of each new energy node and each energy storage node, the output mean constraint of each new energy node and the optimized power deviation constraint of each energy storage node;

[0224] Among them, the equivalent short-circuit ratio of the new energy energy storage cluster is obtained by weighted processing of the short-circuit ratios of each new energy node and each energy storage node based on the proportion of the current power of each new energy node and each energy storage node in the total output power of the new energy energy storage cluster.

[0225] In a possible implementation manner, the expression of the minimum short circuit ratio constraint is:

[0226]

[0227] In the formula, is the short-circuit ratio of new energy node i, is the grid-connected operation limit short-circuit ratio of the new energy node, is the short-circuit ratio of the energy storage node k, is the grid-connected operation limit short-circuit ratio of the energy storage node;

[0228] The expression of the equivalent short-circuit ratio constraint of the new energy storage cluster is:

[0229] WESCR ≥ WESCR min ,

[0230]

[0231] Where, WESCR represents the equivalent short-circuit ratio of the new energy storage cluster, WESCR min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster; P i re is the output power of new energy node i, is the output power of energy storage node k; i is the new energy node index, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster;

[0232] The power constraint expression of each new energy node and each energy storage node is:

[0233]

[0234] In the formula, They are the minimum and maximum output of the new energy node respectively; are the maximum and minimum output values ​​of the energy storage node respectively;

[0235] The expression of the optimized power increment constraint of each new energy node and each energy storage node is:

[0236]

[0237] In the formula, are the current powers of new energy node i and energy storage node k respectively; The maximum deviation between the optimized power data of the new energy node and the current power. The maximum deviation between the optimized power data of the energy storage node and the current power;

[0238] The expression of the output mean constraint of each new energy node is:

[0239]

[0240] In the formula, is the rated power of new energy node i, is the average value of power data after optimization of new energy nodes, is the average value of the rated power of the new energy nodes, is the maximum value of the deviation of the power mean of the new energy node;

[0241] The expression of the optimized power deviation constraint of each energy storage node is:

[0242]

[0243] Where f is the total power deviation before and after the energy storage node is optimized. is the rated power of energy storage node k, is the current power of the energy storage node, f max It is the maximum value of the sum of power deviations before and after energy storage node optimization.

[0244] In a possible implementation, the model solving module is specifically used for:

[0245] The short-circuit ratio of each new energy node and each energy storage node is iteratively optimized based on the node impedance matrix to solve the objective function, thereby obtaining optimized power data of each new energy node and each energy storage node.

[0246] Embodiment 3:

[0247] like Figure 7 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0248] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of a new energy storage cluster power optimization method considering the grid strength constraint in the above embodiment.

[0249] Example 4

[0250] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in an electronic device for storing programs and data. It can be understood that the storage medium here can include both built-in storage media in electronic devices and, of course, extended storage media supported by electronic devices. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of a new energy storage cluster power optimization method considering grid strength constraints in the above embodiment.

[0251] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0252] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 processes in the flowchart and / or block diagram. 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.

[0253] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate 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 A function specified in one or more boxes.

[0254] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0255] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims to be approved.

Claims

1. A method for optimizing the power of a new energy storage cluster considering grid strength constraints, characterized in that: include: Calculate the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster; Determine the strength of the power grid based on the short-circuit ratio of each new energy node and each energy storage node, and determine whether the new energy storage cluster needs to be power optimized based on the power grid strength; If the new energy storage cluster needs to be power optimized, the total output power of each new energy node in the new energy storage cluster is maximized, and a power optimization model for each new energy node and each energy storage node is constructed by considering the grid strength constraint; Solve the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

2. The method according to claim 1, characterized in that Before calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster, the method further includes: Obtaining the operating data of the power grid connected to the new energy storage cluster; Calculate the power grid flow based on the operation data to obtain the voltage of each new energy node and each energy storage node; By setting a three-phase short-circuit fault at each new energy node and each energy storage node, the short-circuit current and short-circuit capacity of each new energy node and each energy storage node are obtained; The method of calculating the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster includes: Based on the short-circuit capacity of each new energy node and each energy storage node, the node impedance matrix and the current power of each new energy node and each energy storage node, the short-circuit ratio of each new energy node and each energy storage node is calculated.

3. The method according to claim 2, characterized in that The calculation formula of the short-circuit ratio of each new energy node is: In the formula, is the short-circuit ratio of the new energy node i, i and j are the new energy node indexes, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; is the short-circuit capacity of the new energy node; is the output apparent power of new energy node i, is the output power of new energy node j, is the interaction factor between new energy node i and new energy node j, And j≠i, is the self-impedance of the new energy node i, is the mutual impedance between new energy node j and new energy node i; is the output power of energy storage node k, is the interaction factor between energy storage node k and new energy node i, is the self-impedance of the energy storage node k, is the mutual impedance between the energy storage node k and the new energy node i; The calculation formula of the short-circuit ratio of each energy storage node is: In the formula, is the short-circuit ratio of the energy storage node k, is the short-circuit capacity of the energy storage node k; is the output apparent power of energy storage node k, P i re is the output power of new energy node i, l is the energy storage node index, P l es is the output power of energy storage node l, is the interaction factor between energy storage node l and energy storage node k, And l≠k, is the mutual impedance between the energy storage node l and the energy storage node k.

4. The method according to claim 1, characterized in that: The determining of the grid strength based on the short-circuit ratio of each new energy node and each energy storage node includes: If the minimum value of the short-circuit ratio of each new energy node is less than the preset grid strength constraint value, the current grid is determined to be a weak grid; If the minimum value of the short-circuit ratio of each new energy node is greater than or equal to the preset grid strength constraint value, the current grid is determined to be a strong grid; The determining whether the new energy storage cluster needs to perform power optimization based on the power grid strength includes: If the current power grid is a weak power grid, it is determined that the new energy storage cluster needs to be power optimized; If the current power grid is a strong power grid, it is determined that the new energy storage cluster does not need to perform power optimization.

5. The method according to claim 4, characterized in that The goal is to maximize the total output power of each new energy node in the new energy storage cluster, and consider the grid strength constraint to construct a power optimization model for each new energy node and each energy storage node, including: Taking the maximum total output power of each new energy node in the new energy storage cluster as the objective function; Determine the grid strength constraint based on the short-circuit ratio of each new energy node and each energy storage node; Considering the operational safety of each new energy node and each energy storage node, the power constraints of each new energy node and each energy storage node are determined; Consider the output balance of each new energy node and each energy storage node before and after optimization, and determine the balance constraint; The power grid strength constraint, the power constraint and the balance constraint are used as model constraints, and the power optimization model is constructed in combination with the objective function.

6. The method according to claim 5, characterized in that The grid strength constraints include the minimum short-circuit ratio constraints of each new energy node and each energy storage node and the equivalent short-circuit ratio constraints of the new energy storage cluster; The balance constraints include the optimized power increment constraints of each new energy node and each energy storage node, the output mean constraint of each new energy node and the optimized power deviation constraint of each energy storage node; Among them, the equivalent short-circuit ratio of the new energy energy storage cluster is obtained by weighted processing of the short-circuit ratios of each new energy node and each energy storage node based on the proportion of the current power of each new energy node and each energy storage node in the total output power of the new energy energy storage cluster.

7. The method according to claim 6, characterized in that The expression of the minimum short-circuit ratio constraint is: In the formula, is the short-circuit ratio of new energy node i, is the grid-connected operation limit short-circuit ratio of the new energy node, is the short-circuit ratio of the energy storage node k, is the grid-connected operation limit short-circuit ratio of the energy storage node; The expression of the equivalent short-circuit ratio constraint of the new energy storage cluster is: WESCR≥WESCR min , Where, WESCR represents the equivalent short-circuit ratio of the new energy storage cluster, WESCR min is the minimum value of the equivalent short-circuit ratio of the new energy storage cluster; P i re is the output power of new energy node i, is the output power of energy storage node k; i is the new energy node index, k is the energy storage node index, n is the number of new energy nodes in the new energy cluster, and m is the number of energy storage nodes in the new energy cluster; The power constraint expression of each new energy node and each energy storage node is: In the formula, They are the minimum and maximum output of the new energy node respectively; are the maximum and minimum output values ​​of the energy storage node respectively; The expression of the optimized power increment constraint of each new energy node and each energy storage node is: In the formula, are the current powers of new energy node i and energy storage node k respectively; The maximum deviation between the optimized power data of the new energy node and the current power. The maximum deviation between the optimized power data of the energy storage node and the current power; The expression of the output mean constraint of each new energy node is: In the formula, is the rated power of new energy node i, is the average value of power data after optimization of new energy nodes, is the average value of the rated power of the new energy nodes, is the maximum value of the deviation of the power mean of the new energy node; The expression of the optimized power deviation constraint of each energy storage node is: Where f is the total power deviation before and after the energy storage node is optimized. is the rated power of energy storage node k, is the current power of the energy storage node, f max It is the maximum value of the sum of power deviations before and after energy storage node optimization.

8. The method according to any one of claims 1 to 7, characterized in that: The solving of the power optimization model to obtain optimized power data of each new energy node and each energy storage node includes: The short-circuit ratio of each new energy node and each energy storage node is iteratively optimized based on the node impedance matrix to solve the objective function, thereby obtaining optimized power data of each new energy node and each energy storage node.

9. A new energy storage cluster power optimization system considering grid strength constraints, characterized in that: include: A short circuit ratio calculation module, used to calculate the short circuit ratio of each new energy node and each energy storage node based on the node impedance matrix of the power grid connected to the new energy energy storage cluster and the current power of each new energy node and each energy storage node in the new energy energy storage cluster; An optimization judgment module is used to determine the strength of the power grid based on the short-circuit ratio of each new energy node and each energy storage node, and determine whether the new energy storage cluster needs to be power optimized based on the power grid strength; An optimization model building module is used to build a power optimization model for each new energy node and each energy storage node by taking the power grid strength constraint into consideration, if the new energy storage cluster needs to be power optimized, with the goal of maximizing the total output power of each new energy node in the new energy storage cluster; The model solving module is used to solve the power optimization model to obtain optimized power data of each new energy node and each energy storage node.

10. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the power optimization method of the new energy storage cluster considering the grid strength constraint as described in any one of claims 1 to 8 is implemented.

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