Method and system for setting calculation conditions of short-circuit current of power grid containing high-proportion new energy

Abstract

The invention discloses a calculation condition setting method and system for short-circuit current of a power grid containing high-proportion new energy, and relates to the technical field of short-circuit current of a power system. A topological structure of the power grid is obtained, and node information and equipment attributes of each node when the power grid breaks down are obtained according to the topological structure of the power grid; performing short-circuit impedance analysis on the information of each node to obtain an impedance parameter of each node, performing condition classification on each node according to the attribute of each device to obtain a setting condition category of each node, and determining a short-circuit current corresponding to each node according to the information of each node and each impedance parameter based on the setting condition category of each node. The technical problems that due to the fact that new energy units such as a photovoltaic unit and a draught fan are used for supporting the power grid voltage, traditional short-circuit current calculation cannot consider the short-circuit characteristics of the new energy units, the calculation precision of short-circuit current cannot meet the requirements of actual production operation, and the reliability of power grid operation is reduced are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of short-circuit current of power systems, and in particular to a method and system for setting calculation conditions for short-circuit current of a power grid containing a high proportion of new energy. Background Art

[0002] Short-circuit calculation is one of the important contents in power grid fault analysis. The results of short-circuit calculation can be used to verify the stability of electrical equipment and provide a basis for power grid design and equipment selection. The traditional short-circuit calculation method is based on the superposition principle, which divides the network state after the fault into a normal state and a fault component state. An electromotive force equal to the voltage of the node before the fault and opposite in direction is added to the short-circuit point. The voltage value of the fault component of each node can be obtained by using the impedance matrix, and then the fault current passing through each branch can be obtained.

[0003] At present, with a large number of new energy power sources connected to the power grid, new energy units such as photovoltaics and wind turbines support the grid voltage, and the traditional short-circuit current calculation cannot take into account the short-circuit characteristics of new energy units. As a result, the calculation accuracy of short-circuit current can no longer meet the needs of actual production and operation, reducing the reliability of power grid operation. Summary of the invention

[0004] The present invention provides a method and system for setting short-circuit current calculation conditions for a power grid containing a high proportion of renewable energy, which solves the technical problem that the calculation accuracy of the short-circuit current cannot meet the needs of actual production and operation, thereby reducing the reliability of the power grid operation, because renewable energy units such as photovoltaics and wind turbines are used to support the power grid voltage, and the traditional short-circuit current calculation cannot take into account the short-circuit characteristics of the renewable energy units.

[0005] A first aspect of the present invention provides a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, comprising:

[0006] Acquire a power grid topology structure, and acquire node information and device attributes of each node when a power grid failure occurs according to the power grid topology structure;

[0007] Performing short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes;

[0008] Conditionally classify each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes;

[0009] Based on the setting condition category of each of the nodes, the short-circuit current corresponding to each of the nodes is determined according to each of the node information and each of the impedance parameters.

[0010] Optionally, the node information includes node admittance, and the step of performing short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes includes:

[0011] Constructing a node admittance matrix using each of the node admittances;

[0012] The node admittance matrix is ​​subjected to matrix conversion processing to obtain a node impedance matrix, and impedance parameters corresponding to each of the nodes are determined according to the node impedance matrix.

[0013] Optionally, the step of conditionally classifying each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes includes:

[0014] Determine respectively whether each of the equipment attributes is a new energy station;

[0015] If the device attribute is the new energy station, determining the setting condition category of the device attribute associated node as the first setting condition category;

[0016] If the device attribute is not a new energy station, determining whether the device attribute is a compensator or a flexible direct current converter station;

[0017] If the device attribute is a compensator or a flexible DC converter station, the setting condition category of the device attribute associated node is determined to be a second setting condition category;

[0018] If the device attribute is not a compensator or a flexible DC converter station, determining whether the device attribute is a converter;

[0019] If the device attribute is a converter, determining the setting condition category of the device attribute associated node as a third setting condition category;

[0020] If the device attribute is not a converter, the setting condition category of the device attribute associated node is determined to be a fourth setting condition category.

[0021] Optionally, the node information further includes a node voltage amplitude and an initial voltage, and the step of determining the short-circuit current corresponding to each of the nodes based on the setting condition category of each of the nodes and according to each of the node information and each of the impedance parameters includes:

[0022] Multiplying the initial voltage of each node by a preset voltage coefficient to obtain a first multiplication value corresponding to each node;

[0023] When the setting condition category of the node is the first setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the first node;

[0024] When the setting condition category of the node is the second setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the second node;

[0025] When the setting condition category of the node is the third setting condition category, obtaining a first contribution current between the node and each of the first nodes and each of the second nodes;

[0026] Determining the short-circuit current corresponding to the node according to each of the first contribution currents, the impedance parameter of the node and the first multiplication value;

[0027] When the setting condition category of the node is the fourth setting condition category, obtaining a second contribution current between the node and each of the first nodes;

[0028] The short-circuit current corresponding to the node is determined according to each of the second contribution currents, the impedance parameter of the node and the first multiplication value.

[0029] Optionally, the step of determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node includes:

[0030] Performing difference processing on a preset trigger voltage threshold and a node voltage amplitude of the node to obtain a first difference;

[0031] The first difference is multiplied by a preset gain coefficient to obtain a short-circuit current corresponding to the node.

[0032] Optionally, the step of determining the short-circuit current corresponding to the node according to each of the first contribution currents, the impedance parameter of the node and the first product value includes:

[0033] Extracting mutual impedances associated with each of the first nodes and each of the second nodes from the impedance parameters of the nodes as first mutual impedances;

[0034] respectively multiplying the first mutual impedance and the first contribution current associated with the node to obtain a plurality of second multiplication values;

[0035] Adding each of the second multiplication values ​​to the first multiplication value corresponding to the node to obtain a first sum value;

[0036] The first sum value is ratio-processed with the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

[0037] Optionally, the step of determining the short-circuit current corresponding to the node according to each of the second contribution currents, the impedance parameter of the node and the first product value includes:

[0038] Extracting the mutual impedance associated with each of the first nodes from the impedance parameters of the nodes as the second mutual impedance;

[0039] Multiplying the second mutual impedance and the second contribution current associated with the node respectively to obtain a plurality of third multiplication values;

[0040] Adding each of the third multiplication values ​​and the first multiplication value corresponding to the node to obtain a second sum value;

[0041] The second sum is ratio-processed with the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

[0042] A second aspect of the present invention provides a system for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, comprising:

[0043] The acquisition module is used to obtain the topology of the power grid, and obtain the node information and device attributes of each node when a fault occurs in the power grid according to the topology of the power grid;

[0044] A first analysis module is used to perform short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes;

[0045] A classification module, used for conditionally classifying each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes;

[0046] The second analysis module is used to determine the short-circuit current corresponding to each of the nodes based on the setting condition category of each of the nodes and according to each of the node information and each of the impedance parameters.

[0047] A third aspect of the present invention provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for setting the short-circuit current calculation conditions for a power grid containing a high proportion of new energy as described in any one of the above items.

[0048] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method for setting the short-circuit current calculation conditions for a power grid containing a high proportion of new energy as described in any one of the above items.

[0049] It can be seen from the above technical solutions that the present invention has the following advantages:

[0050] The present invention classifies each node by each device attribute to obtain the setting condition category corresponding to each node, and determines the short-circuit current corresponding to each node according to the setting condition category of each node, the node information and each impedance parameter. Compared with the traditional short-circuit current calculation method, the present invention overcomes the technical problem that the traditional short-circuit current calculation cannot take into account the short-circuit characteristics of the new energy unit, so that the calculation accuracy of the short-circuit current can no longer meet the needs of actual production and operation, and reduces the reliability of the power grid operation. The short-circuit current corresponding to the node is calculated by the setting condition category of each node and combined with the node information and impedance parameters, and the short-circuit characteristics of the new energy unit are fully considered, so that the calculated short-circuit current is slightly larger than the actual short-circuit current, so as to ensure that the fault adjustment measures have sufficient margin, thereby improving the reliability of the power grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0052] Figure 1 A flowchart of the steps of a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy provided in Embodiment 1 of the present invention;

[0053] Figure 2 A flowchart of the steps of a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy provided in Embodiment 2 of the present invention;

[0054] Figure 3 A motor load equivalent circuit diagram provided in the second embodiment of the present invention;

[0055] Figure 4 A structural block diagram of a system for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy provided in Embodiment 3 of the present invention;

[0056] Figure 5 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0057] The embodiment of the present invention provides a method and system for setting short-circuit current calculation conditions for a power grid containing a high proportion of renewable energy, which is used to solve the technical problem that the calculation accuracy of the short-circuit current can no longer meet the needs of actual production and operation, thereby reducing the reliability of the power grid operation, because renewable energy units such as photovoltaics and wind turbines are used to support the power grid voltage, and traditional short-circuit current calculation cannot take into account the short-circuit characteristics of the renewable energy units.

[0058] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] See also Figure 1 , Figure 1 A flowchart of the steps of a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of renewable energy provided in Embodiment 1 of the present invention.

[0060] The present invention provides a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, comprising:

[0061] Step 101: Obtain a power grid topology structure, and obtain node information and device attributes of each node when a power grid failure occurs according to the power grid topology structure;

[0062] The grid topology refers to the connection relationship between various components (such as generators, transformers, transmission lines, loads, etc.) and the operating parameters of the components in a grid containing a high proportion of renewable energy.

[0063] Node information refers to the node admittance, node voltage amplitude and initial voltage of the nodes in the power grid.

[0064] Equipment attributes refer to the component type of nodes in the power grid.

[0065] In an embodiment of the present invention, a power grid topology structure containing a high proportion of new energy power grid is obtained, and node information and device attributes of each node when a fault occurs in the power grid are extracted from the power grid topology structure.

[0066] Step 102: Perform short-circuit impedance analysis on each node information to obtain impedance parameters of each node;

[0067] Impedance parameters refer to the self-impedance of a node and the mutual impedance between the node and other nodes.

[0068] In the embodiment of the present invention, the node admittance of each node information is used to construct a node admittance matrix, the node admittance matrix is ​​inverted to obtain a node impedance matrix, and the impedance parameters of each node are extracted from the node impedance matrix.

[0069] Step 103: Conditionally classify each node according to each device attribute to obtain a setting condition category of each node;

[0070] In the embodiment of the present invention, when the device attribute of the node is a new energy station, the setting condition category of the node is determined to be the first setting condition category, when the device attribute of the node is a flexible direct current converter station or a STATCOM device, the setting condition category of the node is determined to be the second setting condition category, and when the device attribute of the node is a converter, the setting condition category of the node is determined to be the third setting condition category. When the device attribute of the node is not a new energy station, a flexible direct current converter station, a STATCOM device or a converter, the setting condition category of the node is determined to be the fourth setting condition category.

[0071] Step 104: Based on the setting condition category of each node, the short-circuit current corresponding to each node is determined according to each node information and each impedance parameter.

[0072] In an embodiment of the present invention, when the setting condition category of the node is the first setting condition category or the second setting condition category, the node information of the node is input into the preset first short-circuit current function to obtain the short-circuit current corresponding to the node. When the setting condition category of the node is the third type of node, the contribution current of the node and each first target node (i.e., the node whose setting condition category is the first setting condition category or the second setting condition category) is obtained, and the node information, impedance parameters and each contribution current associated with the node are input into the preset second short-circuit current function to obtain the short-circuit current corresponding to the node. When the setting condition category of the node is the fourth node, the contribution current of the node and each second target node (i.e., the node whose setting condition category is the first setting condition category) is obtained, and the node information, impedance parameters and each contribution current associated with the node are input into the preset third short-circuit current function to obtain the short-circuit current corresponding to the node.

[0073] It should be noted that the first short-circuit current function is specifically:

[0074]

[0075] in, is the short-circuit current, is the gain coefficient, is the trigger voltage threshold, is the node voltage amplitude.

[0076] It should be noted that the second short-circuit current function is specifically:

[0077]

[0078] in, is the short-circuit current at node f, is the voltage coefficient, is the initial voltage, is the self-impedance of node f, is the number of flexible DC converter stations, is the number of new energy stations, is the number of STATCOM devices, Number the flexible DC converter station. Number the new energy station. is the STATCOM device number, Flexible DC converter station The mutual impedance between node f, Flexible DC converter station Contribution current, For new energy stations The mutual impedance between node f, is the contribution current, For STATCOM equipment The mutual impedance between node f, To contribute current.

[0079] It should be noted that the second short-circuit current function is specifically:

[0080]

[0081] in, is the mutual impedance between the flexible DC converter station 1 and the node f, is the mutual impedance between the flexible DC converter station 2 and the node f, is the mutual impedance between the flexible DC converter station 3 and the node f, is the mutual impedance between the flexible DC converter station n and the node f, is the contribution current of flexible DC converter station 1, is the contribution current of flexible DC converter station 2, is the contribution current of flexible DC converter station 3, is the contribution current of the flexible DC converter station n.

[0082] In an embodiment of the present invention, each node is classified by each device attribute to obtain the setting condition category corresponding to each node, and the short-circuit current corresponding to each node is determined according to the setting condition category of each node and the information of each node and each impedance parameter. Compared with the traditional short-circuit current calculation method, the present invention overcomes the technical problem that the traditional short-circuit current calculation cannot take into account the short-circuit characteristics of the new energy unit, so that the calculation accuracy of the short-circuit current can no longer meet the needs of actual production operation, and the reliability of the power grid operation is reduced. The short-circuit current corresponding to the node is calculated by the setting condition category of each node and combined with the node information and impedance parameters, and the short-circuit characteristics of the new energy unit are fully considered, so that the calculated short-circuit current is slightly larger than the actual short-circuit current, so as to ensure that the fault adjustment measures have sufficient margin, thereby improving the reliability of the power grid operation.

[0083] See also Figure 2 , Figure 2 A flowchart of the steps of a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of renewable energy provided in Embodiment 2 of the present invention.

[0084] The present invention provides a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, comprising:

[0085] Step 201: Obtain a power grid topology structure, and obtain node information and device attributes of each node when a power grid failure occurs according to the power grid topology structure;

[0086] In the embodiment of the present invention, a power grid topology structure is obtained, and node information and device attributes of each node when a power grid failure occurs are obtained from the power grid topology structure.

[0087] It should be noted that the node information includes the node admittance, node voltage amplitude and initial voltage of the node. When the device attribute of the node is an induction motor, the motor load is considered. Figure 3 As shown in the figure, Rs, Xs are the stator resistance and reactance of the induction motor; Xm is the magnetizing reactance of the induction motor; Rr, Xr are the rated value of the rotor resistance and the rotor reactance of the induction motor; s is the slip rate of the induction motor; R = Rr / s is the corrected value of the motor rotor resistance after considering the slip rate. Therefore, the node equivalent impedance Z 1 for:

[0088]

[0089] Then the node admittance of the node is:

[0090]

[0091] When the device attribute of the node is a parallel reactive compensation device, the capacitance value C of the node is obtained from the grid topology structure, so that the node admittance of the node is obtained as:

[0092]

[0093] Where, f is the system frequency, which is 50 Hz, and w is the system electrical angular velocity.

[0094] When the device attribute of the node is a line, the node's conductance G and susceptance B to ground are obtained, so that the node admittance of the node is: G+jB. When the device attribute of the node is a transformer reactance, the node's reactance X is obtained, so that the node admittance of the node is: 1 / X.

[0095] Step 202: Perform short-circuit impedance analysis on each node information to obtain impedance parameters of each node;

[0096] Further, the node information includes node admittance, and step 202 includes the following sub-steps:

[0097] S11, constructing a node admittance matrix using the admittance of each node;

[0098] In the embodiment of the present invention, the node admittance matrix of the power grid is constructed using the admittance of each node.

[0099] It should be noted that the node admittance matrix is ​​specifically:

[0100]

[0101] in, is the node admittance matrix, is the self-admittance of node n, is the admittance between node i and node j.

[0102] S12, performing matrix conversion processing on the node admittance matrix to obtain a node impedance matrix, and determining the impedance parameters corresponding to each node according to the node impedance matrix.

[0103] In the embodiment of the present invention, an inverse operation is performed on the node admittance matrix to obtain a node impedance matrix, and impedance parameters corresponding to each node are determined according to the node impedance matrix.

[0104] It should be noted that the node impedance matrix is ​​specifically:

[0105]

[0106] in, is the node impedance matrix, is the self-impedance of node n, is the impedance between node i and node j.

[0107] Step 203: Determine whether each device attribute is a new energy station;

[0108] In the embodiment of the present invention, it is determined whether the device attribute of each node is a new energy station.

[0109] Step 204: If the device attribute is a new energy station, the setting condition category of the device attribute associated node is determined to be a first setting condition category;

[0110] In the embodiment of the present invention, when the device attribute of the node is a new energy station, the category of the node is determined to be the first setting condition category.

[0111] Step 205: If the device attribute is not a new energy station, determine whether the device attribute is a compensator or a flexible direct current converter station;

[0112] In the embodiment of the present invention, when the device attribute is not a new energy station, it is determined whether the device attribute is a STATCOM device or a flexible direct current converter station.

[0113] Step 206: If the device attribute is a compensator or a flexible DC converter station, the setting condition category of the device attribute associated node is determined to be a second setting condition category;

[0114] In the embodiment of the present invention, when the device attribute is a STATCOM device or a flexible DC converter station, the setting condition category of the device attribute associated node is determined to be the second setting condition category.

[0115] Step 207: If the device attribute is not a compensator or a flexible DC converter station, determine whether the device attribute is a converter;

[0116] In the embodiment of the present invention, when the device attribute is not a STATCOM device or a flexible DC converter station, it is determined whether the device attribute is a VSC converter.

[0117] Step 208: If the device attribute is a converter, the setting condition category of the device attribute associated node is determined to be a third setting condition category;

[0118] In the embodiment of the present invention, when the device attribute is a VSC converter, the setting condition category of the device attribute associated node is determined to be the third setting condition category.

[0119] Step 209: If the device attribute is not a converter, the setting condition category of the device attribute associated node is determined to be a fourth setting condition category.

[0120] In the embodiment of the present invention, when the device attribute is not a VSC converter, the setting condition category of the device attribute associated node is determined to be the fourth setting condition category.

[0121] Step 210: Based on the setting condition category of each node, determine the short-circuit current corresponding to each node according to each node information and each impedance parameter.

[0122] Furthermore, the node information also includes the node voltage amplitude and the initial voltage. Step 210 includes the following sub-steps:

[0123] S21, respectively multiplying the initial voltage of each node by a preset voltage coefficient to obtain a first multiplication value corresponding to each node;

[0124] In the embodiment of the present invention, the initial voltage of each node is calculated and multiplied by a preset voltage coefficient to obtain a first multiplication value corresponding to each node.

[0125] S22, when the setting condition category of the node is the first setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the first node;

[0126] Further, S22 includes the following sub-steps:

[0127] S221, performing difference processing on a preset trigger voltage threshold and a node voltage amplitude of a node to obtain a first difference;

[0128] In an embodiment of the present invention, when the setting condition category of the node is the first setting condition category (ie, a new energy station node), a difference processing is performed between the preset trigger voltage threshold and the node voltage amplitude of the node to obtain a first difference.

[0129] It should be noted that the trigger voltage threshold refers to the voltage threshold value that triggers the device to provide reactive current, which is generally around 0.9 pu.

[0130] S222: Multiply the first difference by a preset gain coefficient to obtain a short-circuit current corresponding to the node.

[0131] In the embodiment of the present invention, the multiplication value between the first difference and the preset gain coefficient is calculated to obtain the short-circuit current corresponding to the node.

[0132] It should be noted that the gain coefficient is generally around 1.5.

[0133] S23, when the setting condition category of the node is the second setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the second node;

[0134] In an embodiment of the present invention, when the setting condition category of the node is the second setting condition category (i.e., a STATCOM device node or a flexible DC converter station node), the short-circuit current of the node is calculated according to steps S221-S222, and the node is determined as the second node.

[0135] S24, when the setting condition category of the node is the third setting condition category, obtaining a first contribution current between the node and each first node and each second node;

[0136] In the embodiment of the present invention, when the setting condition category of the node is the third setting condition category (ie, a VSC converter node), the first contribution current between the node and each first node and each second node is obtained.

[0137] It should be noted that the first contribution current is the short-circuit current injected into the power grid by the flexible DC converter station node, STATCOM device node or flexible DC converter station node during a node fault.

[0138] S25, determining the short-circuit current corresponding to the node according to each first contribution current, the impedance parameter of the node and the first multiplication value;

[0139] Further, S25 includes the following sub-steps:

[0140] S251, extracting mutual impedances associated with each first node and each second node from the impedance parameters of the nodes as first mutual impedances;

[0141] In the embodiment of the present invention, the mutual impedance associated with each first node and each second node is obtained from the impedance parameter of the node as the first mutual impedance.

[0142] It should be noted that the first mutual impedance refers to the mutual impedance between a flexible DC converter station node, a STATCOM device node, or a flexible DC converter station node and a node.

[0143] S252, respectively multiplying the first mutual impedance and the first contribution current associated with the node to obtain a plurality of second multiplication values;

[0144] In the embodiment of the present invention, the multiplication values ​​between the first mutual impedance associated with the node and the first contribution current are calculated respectively to obtain a plurality of second multiplication values.

[0145] S253, summing up each second multiplication value and the first multiplication value corresponding to the node to obtain a first sum value;

[0146] In the embodiment of the present invention, the sum of each second multiplication value and the first multiplication value corresponding to the node is calculated to obtain the first sum.

[0147] S254 , performing ratio processing on the first sum and the self-impedance of the impedance parameter of the node to obtain a short-circuit current corresponding to the node.

[0148] In the embodiment of the present invention, the ratio between the first sum and the self-impedance of the node is calculated to obtain the short-circuit current corresponding to the node.

[0149] S26, when the setting condition category of the node is the fourth setting condition category, obtaining a second contribution current between the node and each first node;

[0150] In the embodiment of the present invention, when the setting condition category of the node is the fourth setting condition category, the second contribution current between the node and each first node is acquired.

[0151] It should be noted that the second contribution current refers to the short-circuit current provided by each new energy station node to the node.

[0152] S27. Determine the short-circuit current corresponding to the node according to each second contribution current, the impedance parameter of the node and the first product value.

[0153] Further, S27 includes the following sub-steps:

[0154] S271, extracting mutual impedance associated with each first node from the impedance parameter of the node as a second mutual impedance;

[0155] In the embodiment of the present invention, the mutual impedance associated with each first node is acquired from the impedance parameter of the node as the second mutual impedance.

[0156] S272, respectively multiplying the second mutual impedance and the second contribution current associated with the node to obtain a plurality of third multiplication values;

[0157] In the embodiment of the present invention, the multiplication values ​​between the second mutual impedance associated with the node and the second contribution current are calculated respectively to obtain a plurality of third multiplication values.

[0158] S273, summing each third multiplication value and the first multiplication value corresponding to the node to obtain a second sum value;

[0159] In the embodiment of the present invention, the sum of each third multiplication value and the first multiplication value corresponding to the node is calculated to obtain the second sum.

[0160] S274. Perform ratio processing on the second sum and the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

[0161] In the embodiment of the present invention, the ratio between the second sum and the self-impedance of the node is calculated to obtain the short-circuit current corresponding to the node.

[0162] In an embodiment of the present invention, each node is classified by each device attribute to obtain the setting condition category corresponding to each node, and the short-circuit current corresponding to each node is determined according to the setting condition category of each node and the information of each node and each impedance parameter. Compared with the traditional short-circuit current calculation method, the present invention overcomes the technical problem that the traditional short-circuit current calculation cannot take into account the short-circuit characteristics of the new energy unit, so that the calculation accuracy of the short-circuit current can no longer meet the needs of actual production operation, and the reliability of the power grid operation is reduced. The short-circuit current corresponding to the node is calculated by the setting condition category of each node and combined with the node information and impedance parameters, and the short-circuit characteristics of the new energy unit are fully considered, so that the calculated short-circuit current is slightly larger than the actual short-circuit current, so as to ensure that the fault adjustment measures have sufficient margin, thereby improving the reliability of the power grid operation.

[0163] See also Figure 4 , Figure 4 This is a structural block diagram of a system for setting short-circuit current calculation conditions for a power grid containing a high proportion of renewable energy, provided in Embodiment 3 of the present invention.

[0164] The present invention provides a system for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, comprising:

[0165] The acquisition module 301 is used to obtain the topology of the power grid, and obtain the node information and device attributes of each node when a fault occurs in the power grid according to the topology of the power grid;

[0166] The first analysis module 302 is used to perform short-circuit impedance analysis on each node information to obtain impedance parameters of each node;

[0167] The classification module 303 is used to classify each node according to each device attribute to obtain the setting condition category of each node;

[0168] The second analysis module 304 is used to determine the short-circuit current corresponding to each node based on the setting condition category of each node, according to each node information and each impedance parameter.

[0169] Furthermore, the first analysis module 302 includes:

[0170] A construction submodule is used to construct a node admittance matrix using each node admittance;

[0171] The conversion submodule is used to perform matrix conversion processing on the node admittance matrix to obtain the node impedance matrix, and determine the impedance parameters corresponding to each node according to the node impedance matrix.

[0172] Furthermore, the classification module 303 includes:

[0173] The first classification submodule is used to determine whether each device attribute is a new energy station;

[0174] If the device attribute is a new energy station, the setting condition category of the device attribute associated node is determined to be the first setting condition category;

[0175] The second classification submodule is used to determine whether the device attribute is a compensator or a flexible direct current converter station if the device attribute is not a new energy station;

[0176] If the device attribute is a compensator or a flexible DC converter station, the setting condition category of the device attribute associated node is determined to be a second setting condition category;

[0177] The third classification submodule is used to determine whether the device attribute is a converter if the device attribute is not a compensator or a flexible direct current converter station;

[0178] If the device attribute is a converter, the setting condition category of the device attribute associated node is determined to be a third setting condition category;

[0179] If the device attribute is not a converter, the setting condition category of the device attribute associated node is determined to be a fourth setting condition category.

[0180] Furthermore, the node information also includes the node voltage amplitude and initial voltage. The second analysis module 304 includes:

[0181] A first processing submodule, used for multiplying the initial voltage of each node by a preset voltage coefficient to obtain a first multiplication value corresponding to each node;

[0182] A second processing submodule, for determining a short-circuit current corresponding to the node according to a node voltage amplitude of the node when the setting condition category of the node is a first setting condition category, and determining the node as a first node;

[0183] A third processing submodule, for determining a short-circuit current corresponding to the node according to a node voltage amplitude of the node when the setting condition category of the node is a second setting condition category, and determining the node as a second node;

[0184] A fourth processing submodule, configured to obtain a first contribution current between the node and each first node and each second node when the setting condition category of the node is a third setting condition category;

[0185] A fifth processing submodule, configured to determine a short-circuit current corresponding to a node according to each first contribution current, an impedance parameter of the node and a first multiplication value;

[0186] a sixth processing submodule, configured to obtain a second contribution current between the node and each first node when the setting condition category of the node is a fourth setting condition category;

[0187] The seventh processing submodule is used to determine the short-circuit current corresponding to the node according to each second contribution current, the impedance parameter of the node and the first product value.

[0188] Furthermore, the second processing submodule includes:

[0189] A first processing unit, configured to perform difference processing on a preset trigger voltage threshold and a node voltage amplitude of a node to obtain a first difference;

[0190] The second processing unit is used to multiply the first difference by a preset gain coefficient to obtain a short-circuit current corresponding to the node.

[0191] Furthermore, the fifth processing submodule includes:

[0192] A third processing unit, configured to extract mutual impedances associated with each first node and each second node from the impedance parameters of the nodes as first mutual impedances;

[0193] a fourth processing unit, configured to perform multiplication processing on the first mutual impedance and the first contribution current associated with the node respectively to obtain a plurality of second multiplication values;

[0194] A fifth processing unit, configured to add each second multiplication value and the first multiplication value corresponding to the node to obtain a first sum value;

[0195] The sixth processing unit is used to perform ratio processing on the first sum and the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

[0196] Furthermore, the seventh processing submodule includes:

[0197] a seventh processing unit, configured to extract, from the impedance parameters of the nodes, the mutual impedance associated with each first node as the second mutual impedance;

[0198] An eighth processing unit, configured to perform multiplication processing on the second mutual impedance and the second contribution current associated with the node respectively to obtain a plurality of third multiplication values;

[0199] a ninth processing unit, configured to sum each third multiplication value and the first multiplication value corresponding to the node to obtain a second sum value;

[0200] The tenth processing unit is used to perform ratio processing on the second sum and the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

[0201] See also Figure 5 , Figure 5 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention.

[0202] An electronic device according to an embodiment of the present invention includes: a memory 401 and a processor 402, wherein the memory 402 stores a computer program; when the computer program is executed by the processor 402, the processor 402 executes a method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy as described in any of the above embodiments.

[0203] The memory 401 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 401 has a storage space 403 for a program code 413 for executing any method step in the above method. For example, the storage space 403 for the program code may include individual program codes 413 for implementing the various steps in the above method, respectively. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disk (CD), a memory card or a floppy disk. The program code may be compressed, for example, in an appropriate form. When these codes are run by a computing and processing device, the computing and processing device is caused to execute the various steps in the above-described method.

[0204] Embodiment 5 of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for setting the calculation conditions for the short-circuit current of a power grid containing a high proportion of new energy as described in any of the above embodiments is implemented.

[0205] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0206] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. 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. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0207] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0208] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0209] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0210] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, characterized in that: include: Acquire a power grid topology structure, and acquire node information and device attributes of each node when a power grid failure occurs according to the power grid topology structure; Performing short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes; Conditionally classify each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes; Based on the setting condition category of each of the nodes, the short-circuit current corresponding to each of the nodes is determined according to each of the node information and each of the impedance parameters.

2. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 1, characterized in that: The node information includes node admittance, and the step of performing short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes includes: Constructing a node admittance matrix using each of the node admittances; The node admittance matrix is ​​subjected to matrix conversion processing to obtain a node impedance matrix, and impedance parameters corresponding to each of the nodes are determined according to the node impedance matrix.

3. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 1, characterized in that: The step of conditionally classifying each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes includes: Determine respectively whether each of the equipment attributes is a new energy station; If the device attribute is the new energy station, determining the setting condition category of the device attribute associated node as the first setting condition category; If the device attribute is not a new energy station, determining whether the device attribute is a compensator or a flexible direct current converter station; If the device attribute is a compensator or a flexible DC converter station, the setting condition category of the device attribute associated node is determined to be a second setting condition category; If the device attribute is not a compensator or a flexible DC converter station, determining whether the device attribute is a converter; If the device attribute is a converter, determining the setting condition category of the device attribute associated node as a third setting condition category; If the device attribute is not a converter, the setting condition category of the device attribute associated node is determined to be a fourth setting condition category.

4. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 3, characterized in that: The node information also includes a node voltage amplitude and an initial voltage. The step of determining the short-circuit current corresponding to each of the nodes based on the setting condition category of each of the nodes and according to each of the node information and each of the impedance parameters includes: Multiplying the initial voltage of each node by a preset voltage coefficient to obtain a first multiplication value corresponding to each node; When the setting condition category of the node is the first setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the first node; When the setting condition category of the node is the second setting condition category, determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node, and determining the node as the second node; When the setting condition category of the node is the third setting condition category, obtaining a first contribution current between the node and each of the first nodes and each of the second nodes; Determining the short-circuit current corresponding to the node according to each of the first contribution currents, the impedance parameter of the node and the first multiplication value; When the setting condition category of the node is the fourth setting condition category, obtaining a second contribution current between the node and each of the first nodes; The short-circuit current corresponding to the node is determined according to each of the second contribution currents, the impedance parameter of the node and the first multiplication value.

5. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 4, characterized in that: The step of determining the short-circuit current corresponding to the node according to the node voltage amplitude of the node comprises: Performing difference processing on a preset trigger voltage threshold and a node voltage amplitude of the node to obtain a first difference; The first difference is multiplied by a preset gain coefficient to obtain a short-circuit current corresponding to the node.

6. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 4, characterized in that: The step of determining the short-circuit current corresponding to the node according to each of the first contribution currents, the impedance parameter of the node and the first multiplication value comprises: Extracting mutual impedances associated with each of the first nodes and each of the second nodes from the impedance parameters of the nodes as first mutual impedances; respectively multiplying the first mutual impedance and the first contribution current associated with the node to obtain a plurality of second multiplication values; Adding each of the second multiplication values ​​and the first multiplication value corresponding to the node to obtain a first sum value; The first sum value is ratio-processed with the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

7. The method for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy according to claim 4, characterized in that: The step of determining the short-circuit current corresponding to the node according to each of the second contribution currents, the impedance parameter of the node and the first multiplication value comprises: Extracting the mutual impedance associated with each of the first nodes from the impedance parameters of the nodes as the second mutual impedance; Multiplying the second mutual impedance and the second contribution current associated with the node respectively to obtain a plurality of third multiplication values; Adding each of the third multiplication values ​​and the first multiplication value corresponding to the node to obtain a second sum value; The second sum is ratio-processed with the self-impedance of the impedance parameter of the node to obtain the short-circuit current corresponding to the node.

8. A system for setting short-circuit current calculation conditions for a power grid containing a high proportion of new energy, characterized in that: include: The acquisition module is used to obtain the topology of the power grid, and obtain the node information and device attributes of each node when a fault occurs in the power grid according to the topology of the power grid; A first analysis module is used to perform short-circuit impedance analysis on each of the node information to obtain impedance parameters of each of the nodes; A classification module, used for conditionally classifying each of the nodes according to each of the device attributes to obtain a setting condition category of each of the nodes; The second analysis module is used to determine the short-circuit current corresponding to each of the nodes based on the setting condition category of each of the nodes and according to each of the node information and each of the impedance parameters.

9. An electronic device, characterized in that: It includes a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method for setting the short-circuit current calculation conditions of a power grid containing a high proportion of new energy as described in any one of claims 1-6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method for setting the short-circuit current calculation conditions of a power grid containing a high proportion of new energy sources as described in any one of claims 1 to 6 is implemented.

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