A method and device for determining short-circuit capacity requirements of a new energy station

Abstract

The specification provides a method and device for determining short-circuit capacity demand of a new energy station. The method comprises: obtaining new energy station power grid data; wherein the new energy station power grid data comprises: reactive power compensation capacity of a bus node corresponding to a sub-node, equivalent impedance of the bus node corresponding to a power grid, and a preset voltage value; performing equivalent transformation on the bus node according to the reactive power compensation capacity of the bus node corresponding to the sub-node and the equivalent impedance of the bus node corresponding to the power grid, determining a target voltage equation of the bus node after equivalent transformation; determining a value range of short-circuit capacity of the bus node according to the target voltage equation and the preset voltage value; and determining short-circuit capacity demand of the bus node according to the value range of short-circuit capacity of the bus node. Based on the above method, the short-circuit capacity demand can be efficiently determined according to the new energy station power grid data, thereby ensuring the safe operation of the power grid.

Description

Technical Field

[0001] This manual belongs to the field of new energy power generation technology, and in particular relates to a method and apparatus for determining the short-circuit capacity requirement of a new energy power station. Background Technology

[0002] To ensure the safe and stable operation of the power grid, sufficient short-circuit capacity is required. Short-circuit capacity is equal to the product of the three-phase short-circuit current at the short-circuit point and the rated voltage at the short-circuit point; it is an indicator of the grid's voltage strength. If the short-circuit capacity of the power grid comprised of renewable energy power plants (including wind farms and photovoltaic power plants) is insufficient, excessive transient overvoltages will occur. Once these transient overvoltages exceed the preset voltage value, they will trigger grid disconnection accidents, impacting grid safety. Therefore, accurately calculating the grid's short-circuit capacity requirements is crucial for ensuring the safe operation of the power grid.

[0003] In existing technologies, time-domain simulation is typically used. A simulation model is established based on actual power grid data, and then the simulation model is iterated and simulated multiple times in simulation software to obtain the peak value of transient overvoltage. Finally, the minimum short-circuit capacity is obtained based on the peak value of transient overvoltage. This method has a large workload and low computational efficiency.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] This specification provides a method and apparatus for determining the short-circuit capacity demand of new energy power stations, which can efficiently determine the short-circuit capacity demand.

[0006] The purpose of the embodiments in this specification is to provide a method for determining the short-circuit capacity demand of a new energy power station. This method is applied to the power grid of the new energy power station, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes, including:

[0007] Acquire power grid data for new energy power plants; wherein, the power grid data for new energy power plants includes: reactive power compensation capacity under the sub-nodes corresponding to the bus node, the equivalent impedance of the power grid corresponding to the bus node, and preset voltage values;

[0008] Based on the reactive power compensation capacity of the sub-nodes corresponding to the bus node and the equivalent impedance of the power grid corresponding to the bus node, the bus node is transformed into an equivalent form to determine the target voltage equation after the equivalent transformation of the bus node.

[0009] Based on the target voltage equation and the preset voltage value, determine the range of values ​​for the short-circuit capacity of the bus node;

[0010] The short-circuit capacity requirement of the bus node is determined based on the range of values ​​for the short-circuit capacity of the bus node.

[0011] Furthermore, in another embodiment of the method, the step of performing an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding child node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, and determining the target voltage equation of the bus node after the equivalent transformation, includes:

[0012] The peak voltage of the bus node is calculated based on the reactive power compensation capacity of the corresponding sub-node of the bus node; wherein, the reactive power compensation capacity includes: capacity data corresponding to the static var compensator and capacity data corresponding to the static var generator;

[0013] The per-unit value of the forward voltage of the bus node is determined based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node.

[0014] Based on the per-unit value of the forward voltage of the bus node, determine the power equivalent impedance corresponding to the bus node;

[0015] The bus node is equivalently transformed based on the power equivalent impedance and the voltage peak value to construct the voltage equivalent impedance corresponding to the bus node; the voltage value of the voltage equivalent impedance is equal to the voltage value of the bus node; the voltage value of the voltage equivalent impedance is the target voltage.

[0016] Based on the voltage equivalent impedance, the voltage peak value, and the grid equivalent impedance, the target voltage equation after the equivalent transformation of the bus node is obtained.

[0017] Furthermore, in another embodiment of the method, calculating the peak voltage of the bus node based on the reactive power compensation capacity of the corresponding child node of the bus node includes:

[0018] The injected power of the bus node is determined based on the capacity data corresponding to the static var compensator and the capacity data corresponding to the static var generator.

[0019] The injected power of the reactive power compensator is determined based on the corresponding capacity data of the static var compensator and the corresponding capacity data of the static var generator.

[0020] The peak voltage of the bus node is calculated based on the injected power of the bus node and the injected power of the reactive power compensator.

[0021] Furthermore, in another embodiment of the method, determining the per-unit value of the forward voltage of the bus node based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node includes:

[0022] The per-unit value of the forward voltage at the bus node is determined according to the following formula:

[0023]

[0024] Where i represents the bus node number, V i This represents the per-unit value of the forward voltage at bus node i, in V. i max Q represents the peak voltage at bus node i. w,i SB represents the reactive power of bus node i, SB represents the baseline capacity of the renewable energy power station, and X represents the reactive power of the bus node i. s It represents the imaginary part of the equivalent impedance of the power grid corresponding to the bus node.

[0025] Furthermore, in another embodiment of the method, determining the power equivalent impedance corresponding to the bus node based on the per-unit value of the forward voltage of the bus node includes:

[0026] The power equivalent impedance corresponding to the bus node is determined according to the following formula:

[0027]

[0028] Where i represents the number of the bus node, Z w,i V represents the power equivalent impedance corresponding to bus node i. i P represents the per-unit value of the forward voltage at bus node i. w,i Q represents the active power of bus node i. w,i S represents the reactive power of bus node i, j represents the imaginary unit, and S B This indicates the baseline capacity of the new energy power station.

[0029] Furthermore, in another embodiment of the method, obtaining the target voltage equation after the equivalent transformation of the bus node based on the voltage equivalent impedance, the voltage peak value, and the grid equivalent impedance includes:

[0030] The target voltage equation after the equivalent transformation of the bus node is constructed in the following form:

[0031]

[0032] Where i represents the number of the bus node, V′ i This represents the target voltage after the equivalent transformation of bus node i. Z′ represents the voltage equivalent impedance corresponding to bus node i. eq,i The voltage value, V i max Z represents the peak voltage at bus node i. eq,i Q represents the equivalent impedance of the power grid corresponding to bus node i. w,i V represents the reactive power of bus node i.i S represents the per-unit value of the forward voltage at bus node i. B This indicates the baseline capacity of the new energy power station.

[0033] Furthermore, in another embodiment of the method, determining the range of short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value includes:

[0034] Based on the target voltage equation and the preset voltage value, determine the range of values ​​for the target voltage;

[0035] Based on the range of the target voltage, determine the range of the voltage equivalent impedance.

[0036] Based on the correspondence between the short-circuit capacity of the bus node and the voltage equivalent impedance, and the range of values ​​for the voltage equivalent impedance, the range of values ​​for the short-circuit capacity of the bus node is determined.

[0037] Furthermore, in another embodiment of the method, determining the range of values ​​for the short-circuit capacity of the bus node based on the correspondence between the short-circuit capacity of the bus node and the voltage equivalent impedance, and the range of values ​​for the voltage equivalent impedance, includes:

[0038] The range of values ​​for the short-circuit capacity of the bus node is determined according to the following formula:

[0039]

[0040] Where i represents the number of the bus node, S sc,i S represents the short-circuit capacity of bus node i. B V represents the baseline capacity of a new energy power station. i max Z represents the peak voltage at bus node i. eq,i Q represents the equivalent impedance of the power grid corresponding to bus node i. w,i V represents the reactive power of bus node i. i U represents the per-unit value of the forward voltage at bus node i. max This indicates the preset voltage value.

[0041] On the other hand, embodiments of this specification also provide a device for determining the short-circuit capacity demand of a new energy power station. This device is applied to the power grid of the new energy power station, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes, comprising:

[0042] The acquisition module is used to acquire power grid data of new energy power plants; wherein, the power grid data of new energy power plants includes: reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the power grid corresponding to the bus node, and the preset voltage value;

[0043] The first calculation module is used to perform an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding sub-node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, and to determine the target voltage equation of the bus node after the equivalent transformation.

[0044] The second calculation module is used to determine the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value.

[0045] The value retrieval module is used to determine the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node.

[0046] Furthermore, embodiments of this specification also provide a computer-readable storage medium storing computer instructions thereon, wherein the computer-readable storage medium executes the instructions to realize the above-mentioned method for determining the short-circuit capacity requirement of new energy power stations.

[0047] This specification provides an embodiment of a method for determining the short-circuit capacity requirement of a new energy power station. The method involves acquiring grid data for the new energy power station. This grid data includes: the reactive power compensation capacity of the sub-nodes corresponding to the bus node, the equivalent impedance of the grid corresponding to the bus node, and a preset voltage value. Based on the reactive power compensation capacity of the sub-nodes corresponding to the bus node and the equivalent impedance of the grid corresponding to the bus node, an equivalent transformation is performed on the bus node to determine the target voltage equation after the equivalent transformation. Based on the target voltage equation and the preset voltage value, the range of values ​​for the short-circuit capacity of the bus node is determined. Finally, based on the range of values ​​for the short-circuit capacity of the bus node, the short-circuit capacity requirement of the bus node is determined.

[0048] Furthermore, after acquiring the power grid data of the new energy power station, the target voltage equation is determined as follows: The peak voltage of the bus node is calculated based on the reactive power compensation capacity of the corresponding sub-nodes of the bus node; wherein, the reactive power compensation capacity includes: capacity data corresponding to the static var compensator and capacity data corresponding to the static var generator; the per-unit forward voltage value of the bus node is determined based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node; the power equivalent impedance corresponding to the bus node is determined based on the per-unit forward voltage value of the bus node; the equivalent voltage transformation of the bus node is performed based on the power equivalent impedance and the peak voltage to construct the equivalent voltage impedance corresponding to the bus node; the voltage value of the equivalent voltage impedance is equal to the voltage value of the bus node; the voltage value of the equivalent voltage impedance is the target voltage; the target voltage equation after the equivalent transformation of the bus node is obtained based on the equivalent voltage impedance, the peak voltage, and the equivalent impedance of the power grid. Attached Figure Description

[0049] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating an embodiment of a method for determining the short-circuit capacity requirement of a new energy power station provided in this specification.

[0051] Figure 2 This is a schematic diagram of a power grid structure for a new energy power station provided in this manual;

[0052] Figure 3(a) shows a schematic diagram of a Thevenin equivalent circuit provided in the instruction manual;

[0053] Figure 3(b) shows a schematic diagram of a first intermediate circuit provided in the instruction manual;

[0054] Figure 3(c) shows a schematic diagram of a second intermediate circuit provided in the instruction manual;

[0055] Figure 3(d) shows a schematic diagram of a Norton equivalent circuit provided in the instruction manual;

[0056] Figure 4 This manual provides a flowchart illustrating the process for determining short-circuit capacity requirements in a specific scenario example.

[0057] Figure 5 This manual provides a diagram illustrating the short-circuit capacity requirement in a specific scenario example.

[0058] Figure 6This is a schematic diagram of the module structure of an embodiment of the device for determining the short-circuit capacity requirement of a new energy power station provided in this specification;

[0059] Figure 7 This is a schematic diagram of the structural composition of a server provided in this manual. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0061] To ensure the safe and stable operation of the power grid, sufficient short-circuit capacity is required. Short-circuit capacity is equal to the product of the three-phase short-circuit current at the short-circuit point and the rated voltage at the short-circuit point; it is an indicator of the grid's voltage strength. If the short-circuit capacity of the power grid comprised of renewable energy power plants (including wind farms and photovoltaic power plants) is insufficient, excessive transient overvoltages will occur. Once these transient overvoltages exceed the preset voltage value, they will trigger grid disconnection accidents, impacting grid safety. Therefore, accurately calculating the grid's short-circuit capacity requirements is crucial for ensuring the safe operation of the power grid.

[0062] In existing technologies, time-domain simulation is typically used. A simulation model is established based on actual power grid data, and then the simulation model is iterated and simulated multiple times in simulation software to obtain the peak value of transient overvoltage. Finally, the minimum short-circuit capacity is obtained based on the peak value of transient overvoltage. This method has a large workload and low computational efficiency.

[0063] To address the aforementioned problems with existing methods and the specific reasons for these problems, this application introduces a method for determining the short-circuit capacity requirement of new energy power plants based on equivalent transformation. The short-circuit capacity requirement refers to the minimum short-circuit capacity required to support the normal operation of the system, thereby simplifying the calculation steps, improving calculation efficiency, and efficiently determining the short-circuit capacity requirement.

[0064] Based on the above approach, this specification proposes a method for determining the short-circuit capacity requirement of a new energy power station. First, the power grid data of the new energy power station is acquired; wherein, the power grid data includes: the reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the power grid corresponding to the bus node, and a preset voltage value; then, based on the reactive power compensation capacity under the corresponding sub-node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, an equivalent transformation is performed on the bus node to determine the target voltage equation after the equivalent transformation; based on the target voltage equation and the preset voltage value, the range of values ​​for the short-circuit capacity of the bus node is determined; finally, based on the range of values ​​for the short-circuit capacity of the bus node, the short-circuit capacity requirement of the bus node is determined.

[0065] See Figure 1 As shown in the embodiments of this specification, a method for determining the short-circuit capacity demand of a new energy power station is provided. The method is applied to the power grid of the new energy power station, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes. The method includes the following contents.

[0066] S101: Obtain power grid data for new energy power plants; wherein, the power grid data for new energy power plants includes: reactive power compensation capacity under the sub-nodes corresponding to the bus node, the equivalent impedance of the power grid corresponding to the bus node, and the preset voltage value.

[0067] In some embodiments, see Figure 2 As shown, the power grid of a renewable energy power station includes multiple 230 kV buses. Each 230 kV bus is connected to multiple 37 kV buses via transformers. The 37 kV buses are the renewable energy power station buses, and they are connected to multiple wind turbines via transformers. Each 230 kV bus is mapped to a bus node i, and each 37 kV bus is mapped to a renewable energy power station (also called a renewable energy power station node). The wind turbines and reactive power compensators connected to the 37 kV bus are mapped to a sub-node k. One bus node i is connected to multiple renewable energy power stations, and one renewable energy power station bus is simultaneously connected to multiple wind turbines and reactive power compensators. The power of a renewable energy power station node is equal to the sum of the power of the wind turbines connected to that 37 kV bus, while the power of a bus node is equal to the sum of the power of the renewable energy power station nodes connected to it. Each renewable energy power station is connected in parallel with a reactive power compensator, which provides reactive power. Multiple 230 kV busbars are connected to the new energy collection station, which is connected to the outside to form a complete power grid.

[0068] In some embodiments, reactive power compensators include static var compensators (SVCs) and static var generators (SVGs). Reactive power compensators are used in circuits for reactive power compensation. When the reactive power demand in the power grid increases, if reactive power compensators are not installed in the grid, power plants must increase reactive power output through phase adjustment. Since the capacity of generators is limited, the output of active power must be reduced, i.e., the output capacity of generators must be lowered. To meet the electricity demand, the capacity of generators, power lines, and transformers needs to be increased, which not only increases power supply investment and reduces equipment utilization but also increases line losses. To solve the above problems, corresponding capacitors are connected at points in the power grid with high inductive load consumption to provide reactive power to the inductive loads, i.e., reactive power compensators are connected. This can alleviate the reactive power supply pressure on power plants and meet electricity demand. Static var compensators use passive devices for reactive power compensation; the reactive power they generate is generated by the inherent properties of the capacitor itself. Static var generators use power electronics technology to achieve reactive power compensation. The reactive power they generate and the harmonics they filter out are generated by the frequent operation of their internal electronic switches to produce reactive current and current opposite to the harmonic current.

[0069] In some embodiments, the equivalent impedance of the power grid corresponding to a bus node can be obtained as follows: The connecting branches between the bus and the renewable energy collection station are sequentially disconnected. Based on the power flow model of the renewable energy station's power grid, the grid connection relationships, branch parameters, reactive power compensator parameters connected to each node, and generator parameters, the equivalent impedance of the external power grid for each bus node i and the renewable energy collection station is calculated using the Thevenin equivalent method. The equivalent impedance of the power grid corresponding to bus node i is denoted as Z. eq,i .

[0070] In some embodiments, the preset voltage value is a per-unit value (pu), which refers to the percentage obtained by dividing the actual voltage by the nominal voltage, representing the maximum voltage that the bus node can bear. Typically, the preset voltage value is set to 1.3pu. When the preset voltage value is 1.3pu, the actual voltage of bus node i divided by the nominal voltage must be less than or equal to 1.3; if it exceeds 1.3, a grid disconnection accident will occur.

[0071] S102: Based on the reactive power compensation capacity of the sub-nodes corresponding to the bus node and the equivalent impedance of the power grid corresponding to the bus node, perform an equivalent transformation on the bus node to determine the target voltage equation after the equivalent transformation of the bus node.

[0072] In some embodiments, based on the reactive power compensation capacity under the corresponding child node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, an equivalent transformation is performed on the bus node to determine the target voltage equation after the equivalent transformation of the bus node, specifically including:

[0073] S1021: Calculate the peak voltage of the bus node based on the reactive power compensation capacity of the corresponding sub-node of the bus node; wherein, the reactive power compensation capacity includes: capacity data corresponding to the static var compensator and capacity data corresponding to the static var generator;

[0074] S1022: Determine the per-unit value of the forward voltage of the bus node based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node;

[0075] S1023: Determine the power equivalent impedance corresponding to the bus node based on the per-unit value of the forward voltage of the bus node;

[0076] S1024: Perform an equivalent transformation on the bus node based on the power equivalent impedance and the voltage peak value to construct the voltage equivalent impedance corresponding to the bus node; the voltage value of the voltage equivalent impedance is equal to the voltage value of the bus node; the voltage value of the voltage equivalent impedance is the target voltage.

[0077] S1025: Based on the voltage equivalent impedance, the voltage peak value, and the grid equivalent impedance, obtain the target voltage equation after the equivalent transformation of the bus node.

[0078] In some embodiments, the peak voltage of the bus node is calculated based on the reactive power compensation capacity of the corresponding child node, specifically including:

[0079] S10211: Determine the injected power of the bus node based on the capacity data corresponding to the static var compensator and the capacity data corresponding to the static var generator;

[0080] S10212: Determine the injected power of the reactive power compensator based on the corresponding capacity data of the static var compensator and the corresponding capacity data of the static var generator;

[0081] S10213: Calculate the peak voltage of the bus node based on the injected power of the bus node and the injected power of the reactive power compensator.

[0082] In some embodiments, the injected power of the bus node includes: the active power of the bus node and the reactive power of the bus node. After the fault is cleared, if the wind turbine is still in a low-voltage ride-through state (defined as when a system fault causes a drop in the voltage at the wind turbine's grid connection point, the wind turbine can operate without disconnecting from the grid and provide necessary reactive power support to the system, allowing the system voltage to quickly recover to normal values, thus "riding through" this low-voltage state and continuing to operate), the active power of the bus node is equal to 0, and all reactive power compensators are engaged, the injected power of the bus node can be calculated according to the following formula:

[0083]

[0084] Where i represents the number of the bus node, P w,i Q represents the active power of bus node i. w,i Q represents the reactive power of bus node i, k represents the child node number connected to bus node i, and Q represents the reactive power of bus node i. c,k This represents the capacity data of the static var compensator (SVC) in the child node k connected to bus node i, Q. rt,k Qsvg,k represents the reactive power of the wind turbine connected to sub-node k in low-pass condition, and Qsvg,k represents the capacity data of the static var generator in sub-node k connected to bus node i.

[0085] In some embodiments, the injected power of the reactive power compensator includes: the active power of the reactive power compensator and the reactive power of the reactive power compensator. The injected power of the reactive power compensator can be calculated according to the following formula:

[0086]

[0087] Among them, P s,i Q represents the active power of the reactive power compensator. s,i This indicates the reactive power of the reactive power compensator.

[0088] In some embodiments, the peak voltage of the bus node is calculated based on the injected power of the bus node and the injected power of the reactive power compensator, specifically including the following steps: Using the injected power of the bus node and the injected power of the reactive power compensator, a set of power flow equations is constructed for each bus node. The power flow equations are a set of nonlinear equations describing the steady-state characteristics of the power grid; the power flow equations are solved to obtain the peak voltage of multiple bus nodes; the peak voltage of bus node i is denoted as V. i max .

[0089] In some embodiments, the power flow equations for the bus node are as follows:

[0090]

[0091]

[0092] Where n represents the total number of bus nodes i, V i max V represents the peak voltage at bus node i. m This represents the effective voltage value of node m, where node m refers to all nodes connected to bus node i (node ​​m includes child node k, as well as other nodes connected to bus node i except k), G im θ represents the conductance between bus node i and node m. imB represents the phase difference between bus node i and node m. im This represents the susceptance between bus node i and node k.

[0093] In some embodiments, the per-unit value of the forward voltage of the bus node is determined based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node, specifically including:

[0094] S10221: Construct a single-machine infinite bus system for the bus node using the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node; the single-machine infinite bus system consists of the bus node i to be studied connected to an ideal voltage source (infinite power source) through series branches; construct a single-machine infinite bus system for each bus node and determine the power flow equation of the single-machine infinite bus system.

[0095] S10222: Solve the power flow equations of a single-machine infinite bus system to obtain the per-unit voltage values ​​at the bus nodes; the per-unit voltage values ​​at the bus nodes include: positive voltage per-unit value and negative voltage per-unit value.

[0096] S10223: Select the per-unit value of the forward voltage of the bus node.

[0097] In some embodiments, the per-unit voltage value of a bus node can be determined according to the following formula:

[0098]

[0099] Where i represents the bus node number, V i ± represents the per-unit voltage value of bus node i, V eq,i S represents the per-unit value of the infinite system voltage at bus node i. B R represents the baseline capacity of a new energy power station. s Z represents eq,i The real part, X s Z represents eq,i The imaginary part.

[0100] In some embodiments, V eq,i Numerically equal to V i max Therefore, V is used. i max Replace V in Formula 5 eq,i We can obtain:

[0101]

[0102] In some embodiments, P can be determined according to Formula 1. w,i =0; to simplify the calculation, let R = 0; s =0; and Z e2 q,i =R S 2 +X S 2 Therefore, Formula 6 can be further simplified to:

[0103]

[0104] In some embodiments, when Formula 7 is "+", it represents the positive voltage per unit value; when Formula 7 is "-", it represents the negative voltage per unit value. The positive voltage per unit value indicates that the power grid is in a steady state, corresponding to the upper half of the PV curve. Therefore, according to the formula...

[0105] Equation 7 can determine the per-unit value of the forward voltage at the bus node:

[0106]

[0107] Where i represents the number of the bus node, V i This represents the per-unit value of the forward voltage at bus node i, in V. i max Q represents the peak voltage at bus node i. w,i S represents the reactive power of bus node i. B X represents the baseline capacity of a new energy power station. s It represents the imaginary part of the equivalent impedance of the power grid corresponding to the bus node.

[0108] In some embodiments, referring to FIG3(a), FIG3(a) shows the construction of a Thevenin equivalent circuit for bus node i. The Thevenin equivalent circuit consists of a voltage source (V eq,i ) and impedance (Z) w,i Z eq,i The structure consists of a bus node whose power equivalent impedance can be determined based on the per-unit value of the forward voltage of the bus node, according to the following formula:

[0109]

[0110] Where i represents the number of the bus node, Z w,i V represents the power equivalent impedance corresponding to bus node i. i P represents the per-unit value of the forward voltage at bus node i. w,i Q represents the active power of bus node i. w,i S represents the reactive power of bus node i, j represents the imaginary unit, and S B This indicates the baseline capacity of the new energy power station.

[0111] Using Figure 3(a) and Equation 9, the injected power at bus node i is converted into power equivalent impedance.

[0112] In some embodiments, based on the equivalent impedance method, an equivalent transformation is performed to convert the Thevenin equivalent circuit in Figure 3(a) into the first intermediate circuit in Figure 3(b), that is, V eq,i Series Z eq,i Transform into I eq,i Parallel Z eq,i That is, the voltage source V eq,i Transformed into an equivalent current source I eq,i Then, the equivalent transformation of Figure 3(b) is converted into the second intermediate circuit of Figure 3(c), that is, Z w,i Converted into equivalent current source I w0,i I w0,i Satisfy the following formula: Substitute formula 9 into get:

[0113]

[0114] In some embodiments, so that V i If the voltage is less than or equal to the preset value, Z needs to be changed. eq,i And find Z eq,i The critical value will change the Z value. eq,i As Z′ eq,i The equivalent transformation of Figure 3(c) is converted into the Norton equivalent circuit shown in Figure 3(d). The Norton equivalent circuit only contains current sources and impedances. The voltage equivalent impedance corresponding to the bus node is constructed in the Norton equivalent circuit, denoted as Z′. eq,i Z′ eq,i The voltage value is equal to V′ i It is also equal to V′ i The expression is called the target voltage equation after the equivalent transformation of the bus node.

[0115] In some embodiments, the target voltage equation after equivalent transformation of the bus node is obtained based on the voltage equivalent impedance, the voltage peak value, and the grid equivalent impedance. Specifically, this includes:

[0116] The target voltage equation after the equivalent transformation of the bus node is constructed in the following form:

[0117]

[0118] Where i represents the number of the bus node, V′ i This represents the target voltage after the equivalent transformation of bus node i. Z′ represents the voltage equivalent impedance corresponding to bus node i. eq,i The voltage value, V i max Z represents the peak voltage at bus node i.eq,i Q represents the equivalent impedance of the power grid corresponding to bus node i. w,i V represents the reactive power of bus node i. i S represents the per-unit value of the forward voltage at bus node i. B I represents the baseline capacity of a new energy power station. eq,i V represents eq,i The current source of the conversion, I w0,i Z represents w,i The source of the converted current.

[0119] In some embodiments, Formula 11 is abbreviated as:

[0120]

[0121] Where i represents the number of the bus node, V′ i This represents the target voltage after the equivalent transformation of bus node i. Z′ represents the voltage equivalent impedance corresponding to bus node i. eq,i The voltage value, V i max Z represents the peak voltage at bus node i. eq,i Q represents the equivalent impedance of the power grid corresponding to bus node i. w,i V represents the reactive power of bus node i. i S represents the per-unit value of the forward voltage at bus node i. B This indicates the baseline capacity of the new energy power station.

[0122] In some embodiments, V′ i The meaning can also be understood as an estimate of the peak value of transient overvoltage.

[0123] S103: Determine the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value.

[0124] In some embodiments, determining the range of short-circuit capacity values ​​for the bus node based on the target voltage equation and the preset voltage value includes:

[0125] S1031: Determine the range of values ​​for the target voltage based on the target voltage equation and the preset voltage value;

[0126] S1032: Determine the range of values ​​for the voltage equivalent impedance based on the range of values ​​for the target voltage;

[0127] S1033: Determine the range of values ​​for the short-circuit capacity of the bus node based on the correspondence between the short-circuit capacity of the bus node and the voltage equivalent impedance, and the range of values ​​for the voltage equivalent impedance.

[0128] In some embodiments, the target voltage needs to be less than or equal to a preset voltage value: V′ i ≤U max U max This indicates the preset voltage value.

[0129] In some embodiments, substitute Formula 12 into V′ i ≤U max The range of values ​​for the voltage equivalent impedance is obtained as follows:

[0130]

[0131] In some embodiments, the short-circuit capacity of a bus node and its voltage equivalent impedance have the following correspondence:

[0132]

[0133] Among them, S sc,i This represents the short-circuit capacity of bus node i.

[0134] In some embodiments, determining the range of values ​​for the short-circuit capacity of the bus node based on the correspondence between the short-circuit capacity and the equivalent voltage impedance, and the range of values ​​for the equivalent voltage impedance, includes:

[0135] The range of values ​​for the short-circuit capacity of the bus node is determined according to the following formula:

[0136]

[0137] Where i represents the number of the bus node, S sc,i S represents the short-circuit capacity of bus node i. B V represents the baseline capacity of a new energy power station. i max Zeq represents the peak voltage at bus node i. ,i Q represents the equivalent impedance of the power grid corresponding to bus node i. w , i V represents the reactive power of bus node i. i U represents the per-unit value of the forward voltage at bus node i. max This indicates the preset voltage value.

[0138] S104: Determine the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node.

[0139] In some embodiments, the smaller endpoint (minimum value) of the short-circuit capacity range of the bus node is taken as the short-circuit capacity requirement of the bus node:

[0140]

[0141] Among them, S sc,i,min This represents the short-circuit capacity requirement of bus node i.

[0142] In some embodiments, the short-circuit capacity requirement is the minimum short-circuit capacity. The physical meaning of the short-circuit capacity requirement is to prevent V′ from occurring at bus node i after a severe fault. i Minimum short-circuit capacity exceeding the preset voltage value.

[0143] In a specific scenario example, see Figure 4 As shown, this explanation uses a wind farm as an example in the context of new energy power plants. It should be noted that the methods provided in this manual can also be applied to photovoltaic power plants, and can be followed accordingly. Figure 4 Methods for calculating short-circuit capacity requirements:

[0144] Step 1: Read in the grid data of the wind farm station; Based on the severe fault scenario, calculate the injected power of the bus node and the injected power of the reactive power compensator. Assume that after the fault is cleared, the wind turbine is still in a low ride-through state with zero active power and all reactive power compensators of the wind farm station are in operation; Construct the power flow equation of the bus node and solve the power flow equation to obtain the voltage peak of the bus node.

[0145] Step 2: Calculate the equivalent impedance of the power grid (also known as the Thevenin equivalent impedance); construct a single-machine infinite bus system for the bus node based on the equivalent impedance of the power grid and the peak voltage.

[0146] Step 3: Solve the power flow equations of the single-machine infinite bus system to obtain the per-unit value of the forward voltage at the bus node; use the equivalent impedance method to obtain the voltage equivalent impedance, and take the reciprocal of the inequality satisfied by the voltage equivalent impedance to obtain the short-circuit capacity requirement.

[0147] In a specific scenario example, see Figure 5 As shown, taking a wind farm in the new energy power station sector as an example, the method of this embodiment is used to calculate the different transmission capacity requirements (i.e., different simultaneous rates η). k The corresponding short-circuit capacity requirement. Figure 5 The dashed line represents the current short-circuit capacity of this node. It can be seen that when the simultaneity rate (power transmission capacity demand) of this node increases from 0 to 0.6, the current short-circuit capacity (dashed line) provided by the power grid system can meet the short-circuit capacity demand of this node. If the simultaneity rate continues to increase, the current short-circuit capacity can no longer meet the short-circuit capacity demand to avoid transient overvoltages after a fault. Certain measures need to be taken to increase the short-circuit capacity of this node; otherwise, power output restriction (wind and solar curtailment) must be adopted to ensure the safe and stable operation of the power grid system.

[0148] Based on the aforementioned method for determining the short-circuit capacity demand of renewable energy power plants, this specification also proposes an embodiment of a device for determining the short-circuit capacity demand of renewable energy power plants. The device is applied to the power grid of a renewable energy power plant, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes. (See reference...) Figure 6 As shown, the device for determining the short-circuit capacity requirement of the new energy power station specifically includes the following modules:

[0149] The acquisition module 601 is used to acquire power grid data of new energy power plants; wherein, the power grid data of new energy power plants includes: reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the power grid corresponding to the bus node, and the preset voltage value;

[0150] The first calculation module 602 is used to perform an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding sub-node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, and to determine the target voltage equation of the bus node after the equivalent transformation.

[0151] The second calculation module 603 is used to determine the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value.

[0152] The value retrieval module 604 is used to determine the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node.

[0153] In some embodiments, the first calculation module 602 is specifically implemented to calculate the peak voltage of the bus node based on the reactive power compensation capacity of the corresponding sub-node of the bus node; wherein, the reactive power compensation capacity includes: capacity data corresponding to the static var compensator and capacity data corresponding to the static var generator; determine the per-unit value of the forward voltage of the bus node based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node; determine the power equivalent impedance corresponding to the bus node based on the per-unit value of the forward voltage of the bus node; perform an equivalent transformation on the bus node based on the power equivalent impedance and the peak voltage to construct the voltage equivalent impedance corresponding to the bus node; the voltage value of the voltage equivalent impedance is equal to the voltage value of the bus node; the voltage value of the voltage equivalent impedance is the target voltage; and obtain the target voltage equation after the equivalent transformation of the bus node based on the voltage equivalent impedance, the peak voltage, and the equivalent impedance of the power grid.

[0154] In some embodiments, the second calculation module 603 is specifically implemented to determine the range of the target voltage based on the target voltage equation and the preset voltage value; determine the range of the voltage equivalent impedance based on the range of the target voltage; and determine the range of the short-circuit capacity of the bus node based on the correspondence between the short-circuit capacity of the bus node and the voltage equivalent impedance, and the range of the voltage equivalent impedance.

[0155] It should be noted that the units, devices, or modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described by dividing them into various modules according to their functions. Of course, in implementing this specification, the functions of each module can be implemented in one or more software and / or hardware, or the module that implements the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection between the devices or units shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0156] This specification also provides a computer storage medium for a method of determining the short-circuit capacity requirement of a new energy power station. The computer storage medium stores computer program instructions, which, when executed, perform the following: acquiring grid data of the new energy power station; wherein the grid data includes: reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the grid corresponding to the bus node, and a preset voltage value; performing an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding sub-node and the equivalent impedance of the grid corresponding to the bus node, and determining the target voltage equation after the equivalent transformation; determining the range of short-circuit capacity values ​​for the bus node based on the target voltage equation and the preset voltage value; and determining the short-circuit capacity requirement for the bus node based on the range of short-circuit capacity values.

[0157] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0158] In this embodiment, the specific functions and effects implemented by the program instructions stored in the computer storage medium can be explained in comparison with other implementation methods, and will not be repeated here.

[0159] This specification also provides a server, including a processor and a memory for storing processor-executable instructions. In specific implementations, the processor can perform the following steps according to the instructions: acquiring power grid data from a new energy power station; wherein the power grid data from the new energy power station includes: reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the power grid corresponding to the bus node, and a preset voltage value; performing an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding sub-node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, and determining the target voltage equation after the equivalent transformation of the bus node; determining the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value; and determining the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node.

[0160] To execute the above instructions more accurately, please refer to... Figure 7 As shown in the embodiments of this specification, another specific server is also provided, wherein the server includes a network communication port 701, a processor 702, and a memory 703. The above structures are connected by internal cables so that the various structures can perform specific data interaction.

[0161] Specifically, the network communication port 701 can be used to acquire power grid data of new energy power plants; wherein, the power grid data of new energy power plants includes: reactive power compensation capacity under the sub-nodes corresponding to the bus node, the equivalent impedance of the power grid corresponding to the bus node, and the preset voltage value.

[0162] The processor 702 can be specifically used to perform an equivalent transformation on the bus node based on the reactive power compensation capacity of the corresponding sub-node and the equivalent impedance of the power grid corresponding to the bus node, to determine the target voltage equation of the bus node after the equivalent transformation; to determine the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value; and to determine the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node.

[0163] The memory 703 can be used to store the corresponding instruction program.

[0164] In this embodiment, the network communication port 701 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0165] In this embodiment, the processor 702 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0166] In this embodiment, the memory 703 may include multiple layers. In a digital system, anything that can store binary data can be a memory. In an integrated circuit, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc. In a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0167] While this specification provides the steps of operation for the methods described in the embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible order of execution among many steps and does not represent the only possible order. In actual device or client product execution, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

[0168] Those skilled in the art will also know that, besides implementing the controller using purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller function as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0169] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0170] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions of this specification can essentially be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of this specification.

[0171] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. This specification can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0172] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations and modifications are possible without departing from the spirit of this specification, and it is intended that the appended claims cover such variations and modifications without departing from the spirit of this specification.

Claims

1. A method for determining the short-circuit capacity demand of a new energy power station, characterized in that, The method is applied to the power grid of a new energy power station, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes. The method includes: Acquire power grid data for new energy power plants; wherein, the power grid data for new energy power plants includes: reactive power compensation capacity under the sub-nodes corresponding to the bus node, the equivalent impedance of the power grid corresponding to the bus node, and preset voltage values; Based on the reactive power compensation capacity of the sub-nodes corresponding to the bus node and the equivalent impedance of the power grid corresponding to the bus node, the bus node is transformed into an equivalent form to determine the target voltage equation after the equivalent transformation of the bus node. Based on the target voltage equation and the preset voltage value, determine the range of values ​​for the short-circuit capacity of the bus node; The short-circuit capacity requirement of the bus node is determined based on the range of values ​​for the short-circuit capacity of the bus node. The process involves: performing an equivalent transformation on the bus node based on the reactive power compensation capacity of its corresponding sub-nodes and the equivalent grid impedance of the bus node, to determine the target voltage equation after the equivalent transformation. This includes: calculating the peak voltage of the bus node based on the reactive power compensation capacity of its corresponding sub-nodes; wherein the reactive power compensation capacity includes capacity data corresponding to static var compensators (SVCs) and static var generators (SVAs); determining the per-unit forward voltage of the bus node based on the peak voltage and the equivalent grid impedance of the bus node; determining the equivalent power impedance of the bus node based on the per-unit forward voltage; performing an equivalent transformation on the bus node based on the equivalent power impedance and the peak voltage to construct the equivalent voltage impedance of the bus node; the voltage value of the equivalent voltage impedance is equal to the voltage value of the bus node; the voltage value of the equivalent voltage impedance is the target voltage; and obtaining the target voltage equation after the equivalent transformation of the bus node based on the equivalent voltage impedance, the peak voltage, and the equivalent grid impedance. The method further includes: constructing the target voltage equation after the equivalent transformation of the bus node in the following form: Where i represents the number of the bus node, This represents the target voltage after the equivalent transformation of bus node i. Represents the voltage equivalent impedance corresponding to bus node i voltage value, This represents the peak voltage at bus node i. This represents the equivalent impedance of the power grid corresponding to bus node i. This represents the reactive power of bus node i. This represents the per-unit value of the forward voltage at bus node i. This indicates the baseline capacity of the new energy power station.

2. The method according to claim 1, characterized in that, Based on the reactive power compensation capacity of the corresponding child node of the bus node, calculate the peak voltage of the bus node, including: The injected power of the bus node is determined based on the capacity data corresponding to the static var compensator and the capacity data corresponding to the static var generator. The injected power of the reactive power compensator is determined based on the corresponding capacity data of the static var compensator and the corresponding capacity data of the static var generator. The peak voltage of the bus node is calculated based on the injected power of the bus node and the injected power of the reactive power compensator.

3. The method according to claim 1, characterized in that, The per-unit value of the forward voltage of the bus node is determined based on the peak voltage of the bus node and the equivalent impedance of the power grid corresponding to the bus node, including: The per-unit value of the forward voltage at the bus node is determined according to the following formula: Where i represents the number of the bus node, This represents the per-unit value of the forward voltage at bus node i. This represents the peak voltage at bus node i. This represents the reactive power of bus node i. This indicates the baseline capacity of the new energy power station. It represents the imaginary part of the equivalent impedance of the power grid corresponding to the bus node.

4. The method according to claim 1, characterized in that, Based on the per-unit value of the forward voltage of the bus node, determine the power equivalent impedance corresponding to the bus node, including: The power equivalent impedance corresponding to the bus node is determined according to the following formula: Where i represents the number of the bus node, This represents the power equivalent impedance corresponding to bus node i. This represents the per-unit value of the forward voltage at bus node i. This represents the active power of bus node i. This represents the reactive power of bus node i, where j represents the imaginary unit. This indicates the baseline capacity of the new energy power station.

5. The method according to claim 1, characterized in that, Based on the target voltage equation and the preset voltage value, the range of values ​​for the short-circuit capacity of the bus node is determined, including: Based on the target voltage equation and the preset voltage value, determine the range of values ​​for the target voltage; Based on the range of the target voltage, determine the range of the voltage equivalent impedance. Based on the correspondence between the short-circuit capacity of the bus node and the voltage equivalent impedance, and the range of values ​​for the voltage equivalent impedance, the range of values ​​for the short-circuit capacity of the bus node is determined.

6. The method according to claim 5, characterized in that, Based on the correspondence between the short-circuit capacity of the bus node and the equivalent voltage impedance, and the range of values ​​for the equivalent voltage impedance, the range of values ​​for the short-circuit capacity of the bus node is determined, including: The range of values ​​for the short-circuit capacity of the bus node is determined according to the following formula: Where i represents the number of the bus node, This represents the short-circuit capacity of bus node i. This indicates the baseline capacity of the new energy power station. This represents the peak voltage at bus node i. This represents the equivalent impedance of the power grid corresponding to bus node i. This represents the reactive power of bus node i. This represents the per-unit value of the forward voltage at bus node i. This indicates the preset voltage value.

7. A device for determining the short-circuit capacity demand of a new energy power station, characterized in that, The device is applied to the power grid of a new energy power station, which includes multiple bus nodes, multiple reactive power compensators, and multiple sub-nodes. The device includes: The acquisition module is used to acquire power grid data of new energy power plants; wherein, the power grid data of new energy power plants includes: reactive power compensation capacity under the corresponding sub-node of the bus node, the equivalent impedance of the power grid corresponding to the bus node, and the preset voltage value; The first calculation module is used to perform an equivalent transformation on the bus node based on the reactive power compensation capacity under the corresponding sub-node of the bus node and the equivalent impedance of the power grid corresponding to the bus node, and to determine the target voltage equation of the bus node after the equivalent transformation. The second calculation module is used to determine the range of values ​​for the short-circuit capacity of the bus node based on the target voltage equation and the preset voltage value. The value retrieval module is used to determine the short-circuit capacity requirement of the bus node based on the range of values ​​for the short-circuit capacity of the bus node. Specifically, the first calculation module is used to calculate the peak voltage of the bus node based on the reactive power compensation capacity of the corresponding sub-nodes of the bus node; wherein the reactive power compensation capacity includes: capacity data corresponding to the static var compensator and capacity data corresponding to the static var generator; determine the per-unit value of the forward voltage of the bus node based on the peak voltage of the bus node and the equivalent impedance of the grid corresponding to the bus node; determine the power equivalent impedance corresponding to the bus node based on the per-unit value of the forward voltage of the bus node; perform an equivalent transformation on the bus node based on the power equivalent impedance and the peak voltage to construct the voltage equivalent impedance corresponding to the bus node; the voltage value of the voltage equivalent impedance is equal to the voltage value of the bus node; the voltage value of the voltage equivalent impedance is the target voltage; and obtain the target voltage equation of the bus node after the equivalent transformation based on the voltage equivalent impedance, the peak voltage, and the equivalent impedance of the grid. The device is also used to: construct the target voltage equation after the equivalent transformation of the bus node in the following form: Where i represents the number of the bus node, This represents the target voltage after the equivalent transformation of bus node i. Represents the voltage equivalent impedance corresponding to bus node i voltage value, This represents the peak voltage at bus node i. This represents the equivalent impedance of the power grid corresponding to bus node i. This represents the reactive power of bus node i. This represents the per-unit value of the forward voltage at bus node i. This indicates the baseline capacity of the new energy power station.

8. A computer-readable storage medium, characterized in that, It stores computer instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 6.

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